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docs: i2c: convert to ReST and add to driver-api bookset
Convert each file at I2C subsystem, renaming them to .rst and adding to the driver-api book. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Mauro Carvalho Chehab
Jonathan Corbet
parent
09f4c750a8
commit
ccf988b66d
@ -42,7 +42,7 @@ Optional properties:
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This means that no unrelated I2C transactions are allowed on the parent I2C
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adapter for the complete multiplexed I2C transaction.
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The properties of mux-locked and parent-locked multiplexers are discussed
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in more detail in Documentation/i2c/i2c-topology.
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in more detail in Documentation/i2c/i2c-topology.rst.
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For each i2c child node, an I2C child bus will be created. They will
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be numbered based on their order in the device tree.
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@ -83,7 +83,7 @@ Instantiate the device
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----------------------
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After loading the driver, you can instantiate the device as
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described in 'Documentation/i2c/instantiating-devices'.
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described in 'Documentation/i2c/instantiating-devices.rst'.
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If you have multiple BMCs, each connected to your Satellite MC via
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a different I2C bus, you can instantiate a device for each of
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those BMCs.
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@ -142,7 +142,7 @@ loading the adm1021 module, then things are good.
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If nothing happens when loading the adm1021 module, and you are certain
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that your specific Xeon processor model includes compatible sensors, you
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will have to explicitly instantiate the sensor chips from user-space. See
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method 4 in Documentation/i2c/instantiating-devices. Possible slave
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method 4 in Documentation/i2c/instantiating-devices.rst. Possible slave
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addresses are 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e. It is likely that
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only temp2 will be correct and temp1 will have to be ignored.
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@ -75,7 +75,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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The ADM1075, unlike many other PMBus devices, does not support internal voltage
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@ -27,7 +27,7 @@ The devices communicate with the I2C protocol. All sensors are set to the same
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I2C address 0x27 by default, so an entry with I2C_BOARD_INFO("hih6130", 0x27)
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can be used in the board setup code.
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Please see Documentation/i2c/instantiating-devices for details on how to
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Please see Documentation/i2c/instantiating-devices.rst for details on how to
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instantiate I2C devices.
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sysfs-Interface
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@ -17,7 +17,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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Sysfs entries
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@ -76,7 +76,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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@ -28,7 +28,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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@ -79,7 +79,7 @@ Usage Notes
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This driver does not probe for devices, since there is no register which
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can be safely used to identify the chip. You will have to instantiate
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the devices explicitly. Please see Documentation/i2c/instantiating-devices for
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the devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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WARNING: Do not access chip registers using the i2cdump command, and do not use
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@ -30,7 +30,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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@ -83,7 +83,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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For MAX34446, the value of the currX_crit attribute determines if current or
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@ -55,7 +55,7 @@ Usage notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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Module parameters
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@ -28,7 +28,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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@ -28,7 +28,7 @@ Usage Notes
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This driver is part of the MFD driver named "menf21bmc" and does
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not auto-detect devices.
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You will have to instantiate the MFD driver explicitly.
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Please see Documentation/i2c/instantiating-devices for
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Please see Documentation/i2c/instantiating-devices.rst for
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details.
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Sysfs entries
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@ -68,7 +68,7 @@ Accessing PCF8591 via /sys interface
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The PCF8591 is plainly impossible to detect! Thus the driver won't even
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try. You have to explicitly instantiate the device at the relevant
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address (in the interval [0x48..0x4f]) either through platform data, or
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using the sysfs interface. See Documentation/i2c/instantiating-devices
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using the sysfs interface. See Documentation/i2c/instantiating-devices.rst
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for details.
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Directories are being created for each instantiated PCF8591:
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@ -26,7 +26,7 @@ scaled by 1000, i.e. the value for 31.5 degrees celsius is 31500.
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The device communicates with the I2C protocol. Sensors can have the I2C
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addresses 0x44 or 0x45, depending on the wiring. See
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Documentation/i2c/instantiating-devices for methods to instantiate the device.
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Documentation/i2c/instantiating-devices.rst for methods to instantiate the device.
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There are two options configurable by means of sht3x_platform_data:
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@ -36,7 +36,7 @@ humidity is expressed as a percentage. Driver can be used as well for SHTW1
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chip, which has the same electrical interface.
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The device communicates with the I2C protocol. All sensors are set to I2C
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address 0x70. See Documentation/i2c/instantiating-devices for methods to
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address 0x70. See Documentation/i2c/instantiating-devices.rst for methods to
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instantiate the device.
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There are two options configurable by means of shtc1_platform_data:
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@ -30,4 +30,4 @@ The driver provides the common sysfs-interface for temperatures (see
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Documentation/hwmon/sysfs-interface.rst under Temperatures).
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Please refer how to instantiate this driver:
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Documentation/i2c/instantiating-devices
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Documentation/i2c/instantiating-devices.rst
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@ -28,7 +28,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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@ -64,7 +64,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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@ -40,7 +40,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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@ -40,7 +40,7 @@ all as a 686A.
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The Via 686a southbridge has integrated hardware monitor functionality.
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It also has an I2C bus, but this driver only supports the hardware monitor.
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For the I2C bus driver, see <file:Documentation/i2c/busses/i2c-viapro>
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For the I2C bus driver, see <file:Documentation/i2c/busses/i2c-viapro.rst>
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The Via 686a implements three temperature sensors, two fan rotation speed
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sensors, five voltage sensors and alarms.
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@ -121,7 +121,7 @@ Usage Notes
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-----------
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This driver does not auto-detect devices. You will have to instantiate the
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devices explicitly. Please see Documentation/i2c/instantiating-devices for
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devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
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details.
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.. warning::
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@ -1,16 +1,19 @@
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=========================
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Kernel driver i2c-ali1535
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=========================
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Supported adapters:
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* Acer Labs, Inc. ALI 1535 (south bridge)
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Datasheet: Now under NDA
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http://www.ali.com.tw/
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Authors:
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Frodo Looijaard <frodol@dds.nl>,
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Philip Edelbrock <phil@netroedge.com>,
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Mark D. Studebaker <mdsxyz123@yahoo.com>,
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Dan Eaton <dan.eaton@rocketlogix.com>,
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Stephen Rousset<stephen.rousset@rocketlogix.com>
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- Frodo Looijaard <frodol@dds.nl>,
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- Philip Edelbrock <phil@netroedge.com>,
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- Mark D. Studebaker <mdsxyz123@yahoo.com>,
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- Dan Eaton <dan.eaton@rocketlogix.com>,
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- Stephen Rousset<stephen.rousset@rocketlogix.com>
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Description
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-----------
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@ -1,7 +1,10 @@
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=========================
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Kernel driver i2c-ali1563
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=========================
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Supported adapters:
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* Acer Labs, Inc. ALI 1563 (south bridge)
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Datasheet: Now under NDA
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http://www.ali.com.tw/
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@ -1,20 +1,23 @@
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=========================
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Kernel driver i2c-ali15x3
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=========================
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Supported adapters:
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* Acer Labs, Inc. ALI 1533 and 1543C (south bridge)
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Datasheet: Now under NDA
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http://www.ali.com.tw/
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Authors:
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Frodo Looijaard <frodol@dds.nl>,
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Philip Edelbrock <phil@netroedge.com>,
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Mark D. Studebaker <mdsxyz123@yahoo.com>
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- Frodo Looijaard <frodol@dds.nl>,
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- Philip Edelbrock <phil@netroedge.com>,
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- Mark D. Studebaker <mdsxyz123@yahoo.com>
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Module Parameters
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-----------------
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* force_addr: int
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Initialize the base address of the i2c controller
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Initialize the base address of the i2c controller
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Notes
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@ -25,7 +28,9 @@ the BIOS. Does not do a PCI force; the device must still be present in
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lspci. Don't use this unless the driver complains that the base address is
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not set.
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Example: 'modprobe i2c-ali15x3 force_addr=0xe800'
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Example::
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modprobe i2c-ali15x3 force_addr=0xe800
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SMBus periodically hangs on ASUS P5A motherboards and can only be cleared
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by a power cycle. Cause unknown (see Issues below).
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@ -38,47 +43,53 @@ This is the driver for the SMB Host controller on Acer Labs Inc. (ALI)
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M1541 and M1543C South Bridges.
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The M1543C is a South bridge for desktop systems.
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The M1541 is a South bridge for portable systems.
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They are part of the following ALI chipsets:
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* "Aladdin Pro 2" includes the M1621 Slot 1 North bridge with AGP and
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100MHz CPU Front Side bus
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100MHz CPU Front Side bus
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* "Aladdin V" includes the M1541 Socket 7 North bridge with AGP and 100MHz
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CPU Front Side bus
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CPU Front Side bus
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Some Aladdin V motherboards:
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Asus P5A
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Atrend ATC-5220
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BCM/GVC VP1541
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Biostar M5ALA
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Gigabyte GA-5AX (** Generally doesn't work because the BIOS doesn't
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enable the 7101 device! **)
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Iwill XA100 Plus
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Micronics C200
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Microstar (MSI) MS-5169
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- Asus P5A
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- Atrend ATC-5220
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- BCM/GVC VP1541
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- Biostar M5ALA
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- Gigabyte GA-5AX (Generally doesn't work because the BIOS doesn't
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enable the 7101 device!)
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- Iwill XA100 Plus
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- Micronics C200
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- Microstar (MSI) MS-5169
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* "Aladdin IV" includes the M1541 Socket 7 North bridge
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with host bus up to 83.3 MHz.
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with host bus up to 83.3 MHz.
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For an overview of these chips see http://www.acerlabs.com. At this time the
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full data sheets on the web site are password protected, however if you
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contact the ALI office in San Jose they may give you the password.
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The M1533/M1543C devices appear as FOUR separate devices on the PCI bus. An
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output of lspci will show something similar to the following:
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output of lspci will show something similar to the following::
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00:02.0 USB Controller: Acer Laboratories Inc. M5237 (rev 03)
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00:03.0 Bridge: Acer Laboratories Inc. M7101 <= THIS IS THE ONE WE NEED
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00:07.0 ISA bridge: Acer Laboratories Inc. M1533 (rev c3)
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00:0f.0 IDE interface: Acer Laboratories Inc. M5229 (rev c1)
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** IMPORTANT **
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** If you have a M1533 or M1543C on the board and you get
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** "ali15x3: Error: Can't detect ali15x3!"
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** then run lspci.
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** If you see the 1533 and 5229 devices but NOT the 7101 device,
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** then you must enable ACPI, the PMU, SMB, or something similar
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** in the BIOS.
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** The driver won't work if it can't find the M7101 device.
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.. important::
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If you have a M1533 or M1543C on the board and you get
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"ali15x3: Error: Can't detect ali15x3!"
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then run lspci.
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If you see the 1533 and 5229 devices but NOT the 7101 device,
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then you must enable ACPI, the PMU, SMB, or something similar
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in the BIOS.
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The driver won't work if it can't find the M7101 device.
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The SMB controller is part of the M7101 device, which is an ACPI-compliant
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Power Management Unit (PMU).
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@ -109,4 +120,3 @@ There may be electrical problems on this board.
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On the P5A, the W83781D sensor chip is on both the ISA and
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SMBus. Therefore the SMBus hangs can generally be avoided
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by accessing the W83781D on the ISA bus only.
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@ -1,23 +0,0 @@
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Kernel driver i2c-amd-mp2
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Supported adapters:
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* AMD MP2 PCIe interface
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Datasheet: not publicly available.
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Authors:
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Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
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Nehal Shah <nehal-bakulchandra.shah@amd.com>
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Elie Morisse <syniurge@gmail.com>
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Description
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-----------
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The MP2 is an ARM processor programmed as an I2C controller and communicating
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with the x86 host through PCI.
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If you see something like this:
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03:00.7 MP2 I2C controller: Advanced Micro Devices, Inc. [AMD] Device 15e6
|
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in your 'lspci -v', then this driver is for your device.
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25
Documentation/i2c/busses/i2c-amd-mp2.rst
Normal file
25
Documentation/i2c/busses/i2c-amd-mp2.rst
Normal file
@ -0,0 +1,25 @@
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=========================
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Kernel driver i2c-amd-mp2
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=========================
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Supported adapters:
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* AMD MP2 PCIe interface
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||||
Datasheet: not publicly available.
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||||
|
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Authors:
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- Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
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- Nehal Shah <nehal-bakulchandra.shah@amd.com>
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- Elie Morisse <syniurge@gmail.com>
|
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|
||||
Description
|
||||
-----------
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||||
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The MP2 is an ARM processor programmed as an I2C controller and communicating
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with the x86 host through PCI.
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|
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If you see something like this::
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03:00.7 MP2 I2C controller: Advanced Micro Devices, Inc. [AMD] Device 15e6
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in your ``lspci -v``, then this driver is for your device.
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@ -1,18 +1,22 @@
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========================
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Kernel driver i2c-amd756
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========================
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Supported adapters:
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* AMD 756
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* AMD 766
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* AMD 768
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* AMD 8111
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||||
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Datasheets: Publicly available on AMD website
|
||||
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* nVidia nForce
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||||
|
||||
Datasheet: Unavailable
|
||||
|
||||
Authors:
|
||||
Frodo Looijaard <frodol@dds.nl>,
|
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Philip Edelbrock <phil@netroedge.com>
|
||||
- Frodo Looijaard <frodol@dds.nl>,
|
||||
- Philip Edelbrock <phil@netroedge.com>
|
||||
|
||||
Description
|
||||
-----------
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||||
@ -1,4 +1,6 @@
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||||
=========================
|
||||
Kernel driver i2c-adm8111
|
||||
=========================
|
||||
|
||||
Supported adapters:
|
||||
* AMD-8111 SMBus 2.0 PCI interface
|
||||
@ -13,14 +15,14 @@ Author: Vojtech Pavlik <vojtech@suse.cz>
|
||||
Description
|
||||
-----------
|
||||
|
||||
If you see something like this:
|
||||
If you see something like this::
|
||||
|
||||
00:07.2 SMBus: Advanced Micro Devices [AMD] AMD-8111 SMBus 2.0 (rev 02)
|
||||
Subsystem: Advanced Micro Devices [AMD] AMD-8111 SMBus 2.0
|
||||
Flags: medium devsel, IRQ 19
|
||||
I/O ports at d400 [size=32]
|
||||
00:07.2 SMBus: Advanced Micro Devices [AMD] AMD-8111 SMBus 2.0 (rev 02)
|
||||
Subsystem: Advanced Micro Devices [AMD] AMD-8111 SMBus 2.0
|
||||
Flags: medium devsel, IRQ 19
|
||||
I/O ports at d400 [size=32]
|
||||
|
||||
in your 'lspci -v', then this driver is for your chipset.
|
||||
in your ``lspci -v``, then this driver is for your chipset.
|
||||
|
||||
Process Call Support
|
||||
--------------------
|
||||
@ -1,7 +1,10 @@
|
||||
============================
|
||||
Kernel driver i2c-diolan-u2c
|
||||
============================
|
||||
|
||||
Supported adapters:
|
||||
* Diolan U2C-12 I2C-USB adapter
|
||||
|
||||
Documentation:
|
||||
http://www.diolan.com/i2c/u2c12.html
|
||||
|
||||
@ -1,4 +1,7 @@
|
||||
======================
|
||||
Kernel driver i2c-i801
|
||||
======================
|
||||
|
||||
|
||||
Supported adapters:
|
||||
* Intel 82801AA and 82801AB (ICH and ICH0 - part of the
|
||||
@ -39,28 +42,33 @@ Supported adapters:
|
||||
* Intel Comet Lake (PCH)
|
||||
* Intel Elkhart Lake (PCH)
|
||||
* Intel Tiger Lake (PCH)
|
||||
|
||||
Datasheets: Publicly available at the Intel website
|
||||
|
||||
On Intel Patsburg and later chipsets, both the normal host SMBus controller
|
||||
and the additional 'Integrated Device Function' controllers are supported.
|
||||
|
||||
Authors:
|
||||
Mark Studebaker <mdsxyz123@yahoo.com>
|
||||
Jean Delvare <jdelvare@suse.de>
|
||||
Authors:
|
||||
- Mark Studebaker <mdsxyz123@yahoo.com>
|
||||
- Jean Delvare <jdelvare@suse.de>
|
||||
|
||||
|
||||
Module Parameters
|
||||
-----------------
|
||||
|
||||
* disable_features (bit vector)
|
||||
|
||||
Disable selected features normally supported by the device. This makes it
|
||||
possible to work around possible driver or hardware bugs if the feature in
|
||||
question doesn't work as intended for whatever reason. Bit values:
|
||||
|
||||
==== =========================================
|
||||
0x01 disable SMBus PEC
|
||||
0x02 disable the block buffer
|
||||
0x08 disable the I2C block read functionality
|
||||
0x10 don't use interrupts
|
||||
0x20 disable SMBus Host Notify
|
||||
==== =========================================
|
||||
|
||||
|
||||
Description
|
||||
@ -73,7 +81,7 @@ Pentium-based PCs, '815E' chipset, and others.
|
||||
|
||||
The ICH chips contain at least SEVEN separate PCI functions in TWO logical
|
||||
PCI devices. An output of lspci will show something similar to the
|
||||
following:
|
||||
following::
|
||||
|
||||
00:1e.0 PCI bridge: Intel Corporation: Unknown device 2418 (rev 01)
|
||||
00:1f.0 ISA bridge: Intel Corporation: Unknown device 2410 (rev 01)
|
||||
@ -139,14 +147,14 @@ and you think there's something interesting on the SMBus (e.g. a
|
||||
hardware monitoring chip), you need to add your board to the list.
|
||||
|
||||
The motherboard is identified using the subvendor and subdevice IDs of the
|
||||
host bridge PCI device. Get yours with "lspci -n -v -s 00:00.0":
|
||||
host bridge PCI device. Get yours with ``lspci -n -v -s 00:00.0``::
|
||||
|
||||
00:00.0 Class 0600: 8086:2570 (rev 02)
|
||||
Subsystem: 1043:80f2
|
||||
Flags: bus master, fast devsel, latency 0
|
||||
Memory at fc000000 (32-bit, prefetchable) [size=32M]
|
||||
Capabilities: [e4] #09 [2106]
|
||||
Capabilities: [a0] AGP version 3.0
|
||||
00:00.0 Class 0600: 8086:2570 (rev 02)
|
||||
Subsystem: 1043:80f2
|
||||
Flags: bus master, fast devsel, latency 0
|
||||
Memory at fc000000 (32-bit, prefetchable) [size=32M]
|
||||
Capabilities: [e4] #09 [2106]
|
||||
Capabilities: [a0] AGP version 3.0
|
||||
|
||||
Here the host bridge ID is 2570 (82865G/PE/P), the subvendor ID is 1043
|
||||
(Asus) and the subdevice ID is 80f2 (P4P800-X). You can find the symbolic
|
||||
@ -165,7 +173,8 @@ kernel. It's very convenient if you just want to check if there's
|
||||
anything interesting on your hidden ICH SMBus.
|
||||
|
||||
|
||||
**********************
|
||||
----------------------------------------------------------------------------
|
||||
|
||||
The lm_sensors project gratefully acknowledges the support of Texas
|
||||
Instruments in the initial development of this driver.
|
||||
|
||||
@ -1,4 +1,7 @@
|
||||
======================
|
||||
Kernel driver i2c-ismt
|
||||
======================
|
||||
|
||||
|
||||
Supported adapters:
|
||||
* Intel S12xx series SOCs
|
||||
@ -11,16 +14,21 @@ Module Parameters
|
||||
-----------------
|
||||
|
||||
* bus_speed (unsigned int)
|
||||
|
||||
Allows changing of the bus speed. Normally, the bus speed is set by the BIOS
|
||||
and never needs to be changed. However, some SMBus analyzers are too slow for
|
||||
monitoring the bus during debug, thus the need for this module parameter.
|
||||
Specify the bus speed in kHz.
|
||||
|
||||
Available bus frequency settings:
|
||||
0 no change
|
||||
80 kHz
|
||||
100 kHz
|
||||
400 kHz
|
||||
1000 kHz
|
||||
|
||||
==== =========
|
||||
0 no change
|
||||
80 kHz
|
||||
100 kHz
|
||||
400 kHz
|
||||
1000 kHz
|
||||
==== =========
|
||||
|
||||
|
||||
Description
|
||||
@ -30,7 +38,7 @@ The S12xx series of SOCs have a pair of integrated SMBus 2.0 controllers
|
||||
targeted primarily at the microserver and storage markets.
|
||||
|
||||
The S12xx series contain a pair of PCI functions. An output of lspci will show
|
||||
something similar to the following:
|
||||
something similar to the following::
|
||||
|
||||
00:13.0 System peripheral: Intel Corporation Centerton SMBus 2.0 Controller 0
|
||||
00:13.1 System peripheral: Intel Corporation Centerton SMBus 2.0 Controller 1
|
||||
@ -1,9 +1,12 @@
|
||||
==================
|
||||
Driver i2c-mlxcpld
|
||||
==================
|
||||
|
||||
Author: Michael Shych <michaelsh@mellanox.com>
|
||||
|
||||
This is the Mellanox I2C controller logic, implemented in Lattice CPLD
|
||||
device.
|
||||
|
||||
Device supports:
|
||||
- Master mode.
|
||||
- One physical bus.
|
||||
@ -20,6 +23,8 @@ The next transaction types are supported:
|
||||
- Write Byte/Block.
|
||||
|
||||
Registers:
|
||||
|
||||
=============== === =======================================================================
|
||||
CPBLTY 0x0 - capability reg.
|
||||
Bits [6:5] - transaction length. b01 - 72B is supported,
|
||||
36B in other case.
|
||||
@ -49,3 +54,4 @@ DATAx 0xa - 0x54 - 68 bytes data buffer regs.
|
||||
For read transactions address is sent in a separate transaction and
|
||||
specified in the four first bytes (DATA0 - DATA3). Data is read
|
||||
starting from DATA0.
|
||||
=============== === =======================================================================
|
||||
@ -1,10 +1,12 @@
|
||||
=========================
|
||||
Kernel driver i2c-nforce2
|
||||
=========================
|
||||
|
||||
Supported adapters:
|
||||
* nForce2 MCP 10de:0064
|
||||
* nForce2 Ultra 400 MCP 10de:0084
|
||||
* nForce3 Pro150 MCP 10de:00D4
|
||||
* nForce3 250Gb MCP 10de:00E4
|
||||
* nForce2 MCP 10de:0064
|
||||
* nForce2 Ultra 400 MCP 10de:0084
|
||||
* nForce3 Pro150 MCP 10de:00D4
|
||||
* nForce3 250Gb MCP 10de:00E4
|
||||
* nForce4 MCP 10de:0052
|
||||
* nForce4 MCP-04 10de:0034
|
||||
* nForce MCP51 10de:0264
|
||||
@ -16,26 +18,27 @@ Supported adapters:
|
||||
* nForce MCP78S 10de:0752
|
||||
* nForce MCP79 10de:0AA2
|
||||
|
||||
Datasheet: not publicly available, but seems to be similar to the
|
||||
Datasheet:
|
||||
not publicly available, but seems to be similar to the
|
||||
AMD-8111 SMBus 2.0 adapter.
|
||||
|
||||
Authors:
|
||||
Hans-Frieder Vogt <hfvogt@gmx.net>,
|
||||
Thomas Leibold <thomas@plx.com>,
|
||||
Patrick Dreker <patrick@dreker.de>
|
||||
|
||||
- Hans-Frieder Vogt <hfvogt@gmx.net>,
|
||||
- Thomas Leibold <thomas@plx.com>,
|
||||
- Patrick Dreker <patrick@dreker.de>
|
||||
|
||||
Description
|
||||
-----------
|
||||
|
||||
i2c-nforce2 is a driver for the SMBuses included in the nVidia nForce2 MCP.
|
||||
|
||||
If your 'lspci -v' listing shows something like the following,
|
||||
If your ``lspci -v`` listing shows something like the following::
|
||||
|
||||
00:01.1 SMBus: nVidia Corporation: Unknown device 0064 (rev a2)
|
||||
Subsystem: Asustek Computer, Inc.: Unknown device 0c11
|
||||
Flags: 66Mhz, fast devsel, IRQ 5
|
||||
I/O ports at c000 [size=32]
|
||||
Capabilities: <available only to root>
|
||||
00:01.1 SMBus: nVidia Corporation: Unknown device 0064 (rev a2)
|
||||
Subsystem: Asustek Computer, Inc.: Unknown device 0c11
|
||||
Flags: 66Mhz, fast devsel, IRQ 5
|
||||
I/O ports at c000 [size=32]
|
||||
Capabilities: <available only to root>
|
||||
|
||||
then this driver should support the SMBuses of your motherboard.
|
||||
|
||||
@ -1,4 +1,6 @@
|
||||
============================
|
||||
Kernel driver i2c-nvidia-gpu
|
||||
============================
|
||||
|
||||
Datasheet: not publicly available.
|
||||
|
||||
@ -11,8 +13,8 @@ Description
|
||||
i2c-nvidia-gpu is a driver for I2C controller included in NVIDIA Turing
|
||||
and later GPUs and it is used to communicate with Type-C controller on GPUs.
|
||||
|
||||
If your 'lspci -v' listing shows something like the following,
|
||||
If your ``lspci -v`` listing shows something like the following::
|
||||
|
||||
01:00.3 Serial bus controller [0c80]: NVIDIA Corporation Device 1ad9 (rev a1)
|
||||
01:00.3 Serial bus controller [0c80]: NVIDIA Corporation Device 1ad9 (rev a1)
|
||||
|
||||
then this driver should support the I2C controller of your GPU.
|
||||
@ -1,4 +1,6 @@
|
||||
========================
|
||||
Kernel driver i2c-ocores
|
||||
========================
|
||||
|
||||
Supported adapters:
|
||||
* OpenCores.org I2C controller by Richard Herveille (see datasheet link)
|
||||
@ -23,9 +25,9 @@ distance between registers and the input clock speed.
|
||||
There is also a possibility to attach a list of i2c_board_info which
|
||||
the i2c-ocores driver will add to the bus upon creation.
|
||||
|
||||
E.G. something like:
|
||||
E.G. something like::
|
||||
|
||||
static struct resource ocores_resources[] = {
|
||||
static struct resource ocores_resources[] = {
|
||||
[0] = {
|
||||
.start = MYI2C_BASEADDR,
|
||||
.end = MYI2C_BASEADDR + 8,
|
||||
@ -36,10 +38,10 @@ static struct resource ocores_resources[] = {
|
||||
.end = MYI2C_IRQ,
|
||||
.flags = IORESOURCE_IRQ,
|
||||
},
|
||||
};
|
||||
};
|
||||
|
||||
/* optional board info */
|
||||
struct i2c_board_info ocores_i2c_board_info[] = {
|
||||
/* optional board info */
|
||||
struct i2c_board_info ocores_i2c_board_info[] = {
|
||||
{
|
||||
I2C_BOARD_INFO("tsc2003", 0x48),
|
||||
.platform_data = &tsc2003_platform_data,
|
||||
@ -49,20 +51,20 @@ struct i2c_board_info ocores_i2c_board_info[] = {
|
||||
I2C_BOARD_INFO("adv7180", 0x42 >> 1),
|
||||
.irq = ADV_IRQ
|
||||
}
|
||||
};
|
||||
};
|
||||
|
||||
static struct ocores_i2c_platform_data myi2c_data = {
|
||||
static struct ocores_i2c_platform_data myi2c_data = {
|
||||
.regstep = 2, /* two bytes between registers */
|
||||
.clock_khz = 50000, /* input clock of 50MHz */
|
||||
.devices = ocores_i2c_board_info, /* optional table of devices */
|
||||
.num_devices = ARRAY_SIZE(ocores_i2c_board_info), /* table size */
|
||||
};
|
||||
};
|
||||
|
||||
static struct platform_device myi2c = {
|
||||
static struct platform_device myi2c = {
|
||||
.name = "ocores-i2c",
|
||||
.dev = {
|
||||
.platform_data = &myi2c_data,
|
||||
},
|
||||
.num_resources = ARRAY_SIZE(ocores_resources),
|
||||
.resource = ocores_resources,
|
||||
};
|
||||
};
|
||||
@ -1,178 +0,0 @@
|
||||
Kernel driver i2c-parport
|
||||
|
||||
Author: Jean Delvare <jdelvare@suse.de>
|
||||
|
||||
This is a unified driver for several i2c-over-parallel-port adapters,
|
||||
such as the ones made by Philips, Velleman or ELV. This driver is
|
||||
meant as a replacement for the older, individual drivers:
|
||||
* i2c-philips-par
|
||||
* i2c-elv
|
||||
* i2c-velleman
|
||||
* video/i2c-parport (NOT the same as this one, dedicated to home brew
|
||||
teletext adapters)
|
||||
|
||||
It currently supports the following devices:
|
||||
* (type=0) Philips adapter
|
||||
* (type=1) home brew teletext adapter
|
||||
* (type=2) Velleman K8000 adapter
|
||||
* (type=3) ELV adapter
|
||||
* (type=4) Analog Devices ADM1032 evaluation board
|
||||
* (type=5) Analog Devices evaluation boards: ADM1025, ADM1030, ADM1031
|
||||
* (type=6) Barco LPT->DVI (K5800236) adapter
|
||||
* (type=7) One For All JP1 parallel port adapter
|
||||
* (type=8) VCT-jig
|
||||
|
||||
These devices use different pinout configurations, so you have to tell
|
||||
the driver what you have, using the type module parameter. There is no
|
||||
way to autodetect the devices. Support for different pinout configurations
|
||||
can be easily added when needed.
|
||||
|
||||
Earlier kernels defaulted to type=0 (Philips). But now, if the type
|
||||
parameter is missing, the driver will simply fail to initialize.
|
||||
|
||||
SMBus alert support is available on adapters which have this line properly
|
||||
connected to the parallel port's interrupt pin.
|
||||
|
||||
|
||||
Building your own adapter
|
||||
-------------------------
|
||||
|
||||
If you want to build you own i2c-over-parallel-port adapter, here is
|
||||
a sample electronics schema (credits go to Sylvain Munaut):
|
||||
|
||||
Device PC
|
||||
Side ___________________Vdd (+) Side
|
||||
| | |
|
||||
--- --- ---
|
||||
| | | | | |
|
||||
|R| |R| |R|
|
||||
| | | | | |
|
||||
--- --- ---
|
||||
| | |
|
||||
| | /| |
|
||||
SCL ----------x--------o |-----------x------------------- pin 2
|
||||
| \| | |
|
||||
| | |
|
||||
| |\ | |
|
||||
SDA ----------x----x---| o---x--------------------------- pin 13
|
||||
| |/ |
|
||||
| |
|
||||
| /| |
|
||||
---------o |----------------x-------------- pin 3
|
||||
\| | |
|
||||
| |
|
||||
--- ---
|
||||
| | | |
|
||||
|R| |R|
|
||||
| | | |
|
||||
--- ---
|
||||
| |
|
||||
### ###
|
||||
GND GND
|
||||
|
||||
Remarks:
|
||||
- This is the exact pinout and electronics used on the Analog Devices
|
||||
evaluation boards.
|
||||
/|
|
||||
- All inverters -o |- must be 74HC05, they must be open collector output.
|
||||
\|
|
||||
- All resitors are 10k.
|
||||
- Pins 18-25 of the parallel port connected to GND.
|
||||
- Pins 4-9 (D2-D7) could be used as VDD is the driver drives them high.
|
||||
The ADM1032 evaluation board uses D4-D7. Beware that the amount of
|
||||
current you can draw from the parallel port is limited. Also note that
|
||||
all connected lines MUST BE driven at the same state, else you'll short
|
||||
circuit the output buffers! So plugging the I2C adapter after loading
|
||||
the i2c-parport module might be a good safety since data line state
|
||||
prior to init may be unknown.
|
||||
- This is 5V!
|
||||
- Obviously you cannot read SCL (so it's not really standard-compliant).
|
||||
Pretty easy to add, just copy the SDA part and use another input pin.
|
||||
That would give (ELV compatible pinout):
|
||||
|
||||
|
||||
Device PC
|
||||
Side ______________________________Vdd (+) Side
|
||||
| | | |
|
||||
--- --- --- ---
|
||||
| | | | | | | |
|
||||
|R| |R| |R| |R|
|
||||
| | | | | | | |
|
||||
--- --- --- ---
|
||||
| | | |
|
||||
| | |\ | |
|
||||
SCL ----------x--------x--| o---x------------------------ pin 15
|
||||
| | |/ |
|
||||
| | |
|
||||
| | /| |
|
||||
| ---o |-------------x-------------- pin 2
|
||||
| \| | |
|
||||
| | |
|
||||
| | |
|
||||
| |\ | |
|
||||
SDA ---------------x---x--| o--------x------------------- pin 10
|
||||
| |/ |
|
||||
| |
|
||||
| /| |
|
||||
---o |------------------x--------- pin 3
|
||||
\| | |
|
||||
| |
|
||||
--- ---
|
||||
| | | |
|
||||
|R| |R|
|
||||
| | | |
|
||||
--- ---
|
||||
| |
|
||||
### ###
|
||||
GND GND
|
||||
|
||||
|
||||
If possible, you should use the same pinout configuration as existing
|
||||
adapters do, so you won't even have to change the code.
|
||||
|
||||
|
||||
Similar (but different) drivers
|
||||
-------------------------------
|
||||
|
||||
This driver is NOT the same as the i2c-pport driver found in the i2c
|
||||
package. The i2c-pport driver makes use of modern parallel port features so
|
||||
that you don't need additional electronics. It has other restrictions
|
||||
however, and was not ported to Linux 2.6 (yet).
|
||||
|
||||
This driver is also NOT the same as the i2c-pcf-epp driver found in the
|
||||
lm_sensors package. The i2c-pcf-epp driver doesn't use the parallel port as
|
||||
an I2C bus directly. Instead, it uses it to control an external I2C bus
|
||||
master. That driver was not ported to Linux 2.6 (yet) either.
|
||||
|
||||
|
||||
Legacy documentation for Velleman adapter
|
||||
-----------------------------------------
|
||||
|
||||
Useful links:
|
||||
Velleman http://www.velleman.be/
|
||||
Velleman K8000 Howto http://howto.htlw16.ac.at/k8000-howto.html
|
||||
|
||||
The project has lead to new libs for the Velleman K8000 and K8005:
|
||||
LIBK8000 v1.99.1 and LIBK8005 v0.21
|
||||
With these libs, you can control the K8000 interface card and the K8005
|
||||
stepper motor card with the simple commands which are in the original
|
||||
Velleman software, like SetIOchannel, ReadADchannel, SendStepCCWFull and
|
||||
many more, using /dev/velleman.
|
||||
http://home.wanadoo.nl/hihihi/libk8000.htm
|
||||
http://home.wanadoo.nl/hihihi/libk8005.htm
|
||||
http://struyve.mine.nu:8080/index.php?block=k8000
|
||||
http://sourceforge.net/projects/libk8005/
|
||||
|
||||
|
||||
One For All JP1 parallel port adapter
|
||||
-------------------------------------
|
||||
|
||||
The JP1 project revolves around a set of remote controls which expose
|
||||
the I2C bus their internal configuration EEPROM lives on via a 6 pin
|
||||
jumper in the battery compartment. More details can be found at:
|
||||
|
||||
http://www.hifi-remote.com/jp1/
|
||||
|
||||
Details of the simple parallel port hardware can be found at:
|
||||
|
||||
http://www.hifi-remote.com/jp1/hardware.shtml
|
||||
@ -1,13 +1,15 @@
|
||||
===============================
|
||||
Kernel driver i2c-parport-light
|
||||
===============================
|
||||
|
||||
Author: Jean Delvare <jdelvare@suse.de>
|
||||
|
||||
This driver is a light version of i2c-parport. It doesn't depend
|
||||
This driver is a light version of i2c-parport. It doesn't depend
|
||||
on the parport driver, and uses direct I/O access instead. This might be
|
||||
preferred on embedded systems where wasting memory for the clean but heavy
|
||||
parport handling is not an option. The drawback is a reduced portability
|
||||
and the impossibility to daisy-chain other parallel port devices.
|
||||
|
||||
and the impossibility to daisy-chain other parallel port devices.
|
||||
|
||||
Please see i2c-parport for documentation.
|
||||
|
||||
Module parameters:
|
||||
190
Documentation/i2c/busses/i2c-parport.rst
Normal file
190
Documentation/i2c/busses/i2c-parport.rst
Normal file
@ -0,0 +1,190 @@
|
||||
=========================
|
||||
Kernel driver i2c-parport
|
||||
=========================
|
||||
|
||||
Author: Jean Delvare <jdelvare@suse.de>
|
||||
|
||||
This is a unified driver for several i2c-over-parallel-port adapters,
|
||||
such as the ones made by Philips, Velleman or ELV. This driver is
|
||||
meant as a replacement for the older, individual drivers:
|
||||
|
||||
* i2c-philips-par
|
||||
* i2c-elv
|
||||
* i2c-velleman
|
||||
* video/i2c-parport
|
||||
(NOT the same as this one, dedicated to home brew teletext adapters)
|
||||
|
||||
It currently supports the following devices:
|
||||
|
||||
* (type=0) Philips adapter
|
||||
* (type=1) home brew teletext adapter
|
||||
* (type=2) Velleman K8000 adapter
|
||||
* (type=3) ELV adapter
|
||||
* (type=4) Analog Devices ADM1032 evaluation board
|
||||
* (type=5) Analog Devices evaluation boards: ADM1025, ADM1030, ADM1031
|
||||
* (type=6) Barco LPT->DVI (K5800236) adapter
|
||||
* (type=7) One For All JP1 parallel port adapter
|
||||
* (type=8) VCT-jig
|
||||
|
||||
These devices use different pinout configurations, so you have to tell
|
||||
the driver what you have, using the type module parameter. There is no
|
||||
way to autodetect the devices. Support for different pinout configurations
|
||||
can be easily added when needed.
|
||||
|
||||
Earlier kernels defaulted to type=0 (Philips). But now, if the type
|
||||
parameter is missing, the driver will simply fail to initialize.
|
||||
|
||||
SMBus alert support is available on adapters which have this line properly
|
||||
connected to the parallel port's interrupt pin.
|
||||
|
||||
|
||||
Building your own adapter
|
||||
-------------------------
|
||||
|
||||
If you want to build you own i2c-over-parallel-port adapter, here is
|
||||
a sample electronics schema (credits go to Sylvain Munaut)::
|
||||
|
||||
Device PC
|
||||
Side ___________________Vdd (+) Side
|
||||
| | |
|
||||
--- --- ---
|
||||
| | | | | |
|
||||
|R| |R| |R|
|
||||
| | | | | |
|
||||
--- --- ---
|
||||
| | |
|
||||
| | /| |
|
||||
SCL ----------x--------o |-----------x------------------- pin 2
|
||||
| \| | |
|
||||
| | |
|
||||
| |\ | |
|
||||
SDA ----------x----x---| o---x--------------------------- pin 13
|
||||
| |/ |
|
||||
| |
|
||||
| /| |
|
||||
---------o |----------------x-------------- pin 3
|
||||
\| | |
|
||||
| |
|
||||
--- ---
|
||||
| | | |
|
||||
|R| |R|
|
||||
| | | |
|
||||
--- ---
|
||||
| |
|
||||
### ###
|
||||
GND GND
|
||||
|
||||
Remarks:
|
||||
- This is the exact pinout and electronics used on the Analog Devices
|
||||
evaluation boards.
|
||||
- All inverters::
|
||||
|
||||
/|
|
||||
-o |-
|
||||
\|
|
||||
|
||||
must be 74HC05, they must be open collector output.
|
||||
- All resitors are 10k.
|
||||
- Pins 18-25 of the parallel port connected to GND.
|
||||
- Pins 4-9 (D2-D7) could be used as VDD is the driver drives them high.
|
||||
The ADM1032 evaluation board uses D4-D7. Beware that the amount of
|
||||
current you can draw from the parallel port is limited. Also note that
|
||||
all connected lines MUST BE driven at the same state, else you'll short
|
||||
circuit the output buffers! So plugging the I2C adapter after loading
|
||||
the i2c-parport module might be a good safety since data line state
|
||||
prior to init may be unknown.
|
||||
- This is 5V!
|
||||
- Obviously you cannot read SCL (so it's not really standard-compliant).
|
||||
Pretty easy to add, just copy the SDA part and use another input pin.
|
||||
That would give (ELV compatible pinout)::
|
||||
|
||||
|
||||
Device PC
|
||||
Side ______________________________Vdd (+) Side
|
||||
| | | |
|
||||
--- --- --- ---
|
||||
| | | | | | | |
|
||||
|R| |R| |R| |R|
|
||||
| | | | | | | |
|
||||
--- --- --- ---
|
||||
| | | |
|
||||
| | |\ | |
|
||||
SCL ----------x--------x--| o---x------------------------ pin 15
|
||||
| | |/ |
|
||||
| | |
|
||||
| | /| |
|
||||
| ---o |-------------x-------------- pin 2
|
||||
| \| | |
|
||||
| | |
|
||||
| | |
|
||||
| |\ | |
|
||||
SDA ---------------x---x--| o--------x------------------- pin 10
|
||||
| |/ |
|
||||
| |
|
||||
| /| |
|
||||
---o |------------------x--------- pin 3
|
||||
\| | |
|
||||
| |
|
||||
--- ---
|
||||
| | | |
|
||||
|R| |R|
|
||||
| | | |
|
||||
--- ---
|
||||
| |
|
||||
### ###
|
||||
GND GND
|
||||
|
||||
|
||||
If possible, you should use the same pinout configuration as existing
|
||||
adapters do, so you won't even have to change the code.
|
||||
|
||||
|
||||
Similar (but different) drivers
|
||||
-------------------------------
|
||||
|
||||
This driver is NOT the same as the i2c-pport driver found in the i2c
|
||||
package. The i2c-pport driver makes use of modern parallel port features so
|
||||
that you don't need additional electronics. It has other restrictions
|
||||
however, and was not ported to Linux 2.6 (yet).
|
||||
|
||||
This driver is also NOT the same as the i2c-pcf-epp driver found in the
|
||||
lm_sensors package. The i2c-pcf-epp driver doesn't use the parallel port as
|
||||
an I2C bus directly. Instead, it uses it to control an external I2C bus
|
||||
master. That driver was not ported to Linux 2.6 (yet) either.
|
||||
|
||||
|
||||
Legacy documentation for Velleman adapter
|
||||
-----------------------------------------
|
||||
|
||||
Useful links:
|
||||
|
||||
- Velleman http://www.velleman.be/
|
||||
- Velleman K8000 Howto http://howto.htlw16.ac.at/k8000-howto.html
|
||||
|
||||
The project has lead to new libs for the Velleman K8000 and K8005:
|
||||
|
||||
LIBK8000 v1.99.1 and LIBK8005 v0.21
|
||||
|
||||
With these libs, you can control the K8000 interface card and the K8005
|
||||
stepper motor card with the simple commands which are in the original
|
||||
Velleman software, like SetIOchannel, ReadADchannel, SendStepCCWFull and
|
||||
many more, using /dev/velleman.
|
||||
|
||||
- http://home.wanadoo.nl/hihihi/libk8000.htm
|
||||
- http://home.wanadoo.nl/hihihi/libk8005.htm
|
||||
- http://struyve.mine.nu:8080/index.php?block=k8000
|
||||
- http://sourceforge.net/projects/libk8005/
|
||||
|
||||
|
||||
One For All JP1 parallel port adapter
|
||||
-------------------------------------
|
||||
|
||||
The JP1 project revolves around a set of remote controls which expose
|
||||
the I2C bus their internal configuration EEPROM lives on via a 6 pin
|
||||
jumper in the battery compartment. More details can be found at:
|
||||
|
||||
http://www.hifi-remote.com/jp1/
|
||||
|
||||
Details of the simple parallel port hardware can be found at:
|
||||
|
||||
http://www.hifi-remote.com/jp1/hardware.shtml
|
||||
@ -1,6 +1,9 @@
|
||||
=========================
|
||||
Kernel driver i2c-pca-isa
|
||||
=========================
|
||||
|
||||
Supported adapters:
|
||||
|
||||
This driver supports ISA boards using the Philips PCA 9564
|
||||
Parallel bus to I2C bus controller
|
||||
|
||||
@ -10,11 +13,11 @@ Module Parameters
|
||||
-----------------
|
||||
|
||||
* base int
|
||||
I/O base address
|
||||
I/O base address
|
||||
* irq int
|
||||
IRQ interrupt
|
||||
IRQ interrupt
|
||||
* clock int
|
||||
Clock rate as described in table 1 of PCA9564 datasheet
|
||||
Clock rate as described in table 1 of PCA9564 datasheet
|
||||
|
||||
Description
|
||||
-----------
|
||||
@ -1,4 +1,6 @@
|
||||
=======================
|
||||
Kernel driver i2c-piix4
|
||||
=======================
|
||||
|
||||
Supported adapters:
|
||||
* Intel 82371AB PIIX4 and PIIX4E
|
||||
@ -20,9 +22,9 @@ Supported adapters:
|
||||
* Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge
|
||||
Datasheet: Publicly available at the SMSC website http://www.smsc.com
|
||||
|
||||
Authors:
|
||||
Frodo Looijaard <frodol@dds.nl>
|
||||
Philip Edelbrock <phil@netroedge.com>
|
||||
Authors:
|
||||
- Frodo Looijaard <frodol@dds.nl>
|
||||
- Philip Edelbrock <phil@netroedge.com>
|
||||
|
||||
|
||||
Module Parameters
|
||||
@ -39,16 +41,16 @@ Description
|
||||
|
||||
The PIIX4 (properly known as the 82371AB) is an Intel chip with a lot of
|
||||
functionality. Among other things, it implements the PCI bus. One of its
|
||||
minor functions is implementing a System Management Bus. This is a true
|
||||
minor functions is implementing a System Management Bus. This is a true
|
||||
SMBus - you can not access it on I2C levels. The good news is that it
|
||||
natively understands SMBus commands and you do not have to worry about
|
||||
timing problems. The bad news is that non-SMBus devices connected to it can
|
||||
confuse it mightily. Yes, this is known to happen...
|
||||
|
||||
Do 'lspci -v' and see whether it contains an entry like this:
|
||||
Do ``lspci -v`` and see whether it contains an entry like this::
|
||||
|
||||
0000:00:02.3 Bridge: Intel Corp. 82371AB/EB/MB PIIX4 ACPI (rev 02)
|
||||
Flags: medium devsel, IRQ 9
|
||||
0000:00:02.3 Bridge: Intel Corp. 82371AB/EB/MB PIIX4 ACPI (rev 02)
|
||||
Flags: medium devsel, IRQ 9
|
||||
|
||||
Bus and device numbers may differ, but the function number must be
|
||||
identical (like many PCI devices, the PIIX4 incorporates a number of
|
||||
@ -91,7 +93,7 @@ the SMI mode.
|
||||
device is located at 00:0f.0.
|
||||
2) Now you just need to change the value in 0xD2 register. Get it first with
|
||||
command: lspci -xxx -s 00:0f.0
|
||||
If the value is 0x3 then you need to change it to 0x1
|
||||
If the value is 0x3 then you need to change it to 0x1:
|
||||
setpci -s 00:0f.0 d2.b=1
|
||||
|
||||
Please note that you don't need to do that in all cases, just when the SMBus is
|
||||
@ -1,9 +1,11 @@
|
||||
=========================
|
||||
Kernel driver i2c-sis5595
|
||||
=========================
|
||||
|
||||
Authors:
|
||||
Frodo Looijaard <frodol@dds.nl>,
|
||||
Mark D. Studebaker <mdsxyz123@yahoo.com>,
|
||||
Philip Edelbrock <phil@netroedge.com>
|
||||
- Frodo Looijaard <frodol@dds.nl>,
|
||||
- Mark D. Studebaker <mdsxyz123@yahoo.com>,
|
||||
- Philip Edelbrock <phil@netroedge.com>
|
||||
|
||||
Supported adapters:
|
||||
* Silicon Integrated Systems Corp. SiS5595 Southbridge
|
||||
@ -11,14 +13,19 @@ Supported adapters:
|
||||
|
||||
Note: all have mfr. ID 0x1039.
|
||||
|
||||
========= ======
|
||||
SUPPORTED PCI ID
|
||||
========= ======
|
||||
5595 0008
|
||||
========= ======
|
||||
|
||||
Note: these chips contain a 0008 device which is incompatible with the
|
||||
5595. We recognize these by the presence of the listed
|
||||
"blacklist" PCI ID and refuse to load.
|
||||
|
||||
============= ====== ================
|
||||
NOT SUPPORTED PCI ID BLACKLIST PCI ID
|
||||
============= ====== ================
|
||||
540 0008 0540
|
||||
550 0008 0550
|
||||
5513 0008 5511
|
||||
@ -36,15 +43,18 @@ Note: all have mfr. ID 0x1039.
|
||||
735 0008 0735
|
||||
745 0008 0745
|
||||
746 0008 0746
|
||||
============= ====== ================
|
||||
|
||||
Module Parameters
|
||||
-----------------
|
||||
|
||||
* force_addr=0xaddr Set the I/O base address. Useful for boards
|
||||
================== =====================================================
|
||||
force_addr=0xaddr Set the I/O base address. Useful for boards
|
||||
that don't set the address in the BIOS. Does not do a
|
||||
PCI force; the device must still be present in lspci.
|
||||
Don't use this unless the driver complains that the
|
||||
base address is not set.
|
||||
================== =====================================================
|
||||
|
||||
Description
|
||||
-----------
|
||||
@ -56,4 +66,3 @@ WARNING: If you are trying to access the integrated sensors on the SiS5595
|
||||
chip, you want the sis5595 driver for those, not this driver. This driver
|
||||
is a BUS driver, not a CHIP driver. A BUS driver is used by other CHIP
|
||||
drivers to access chips on the bus.
|
||||
|
||||
@ -1,58 +0,0 @@
|
||||
Kernel driver i2c-sis630
|
||||
|
||||
Supported adapters:
|
||||
* Silicon Integrated Systems Corp (SiS)
|
||||
630 chipset (Datasheet: available at http://www.sfr-fresh.com/linux)
|
||||
730 chipset
|
||||
964 chipset
|
||||
* Possible other SiS chipsets ?
|
||||
|
||||
Author: Alexander Malysh <amalysh@web.de>
|
||||
Amaury Decrême <amaury.decreme@gmail.com> - SiS964 support
|
||||
|
||||
Module Parameters
|
||||
-----------------
|
||||
|
||||
* force = [1|0] Forcibly enable the SIS630. DANGEROUS!
|
||||
This can be interesting for chipsets not named
|
||||
above to check if it works for you chipset, but DANGEROUS!
|
||||
|
||||
* high_clock = [1|0] Forcibly set Host Master Clock to 56KHz (default,
|
||||
what your BIOS use). DANGEROUS! This should be a bit
|
||||
faster, but freeze some systems (i.e. my Laptop).
|
||||
SIS630/730 chip only.
|
||||
|
||||
|
||||
Description
|
||||
-----------
|
||||
|
||||
This SMBus only driver is known to work on motherboards with the above
|
||||
named chipsets.
|
||||
|
||||
If you see something like this:
|
||||
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS] 630 Host (rev 31)
|
||||
00:01.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513
|
||||
|
||||
or like this:
|
||||
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS] 730 Host (rev 02)
|
||||
00:01.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513
|
||||
|
||||
or like this:
|
||||
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS] 760/M760 Host (rev 02)
|
||||
00:02.0 ISA bridge: Silicon Integrated Systems [SiS] SiS964 [MuTIOL Media IO]
|
||||
LPC Controller (rev 36)
|
||||
|
||||
in your 'lspci' output , then this driver is for your chipset.
|
||||
|
||||
Thank You
|
||||
---------
|
||||
Philip Edelbrock <phil@netroedge.com>
|
||||
- testing SiS730 support
|
||||
Mark M. Hoffman <mhoffman@lightlink.com>
|
||||
- bug fixes
|
||||
|
||||
To anyone else which I forgot here ;), thanks!
|
||||
|
||||
63
Documentation/i2c/busses/i2c-sis630.rst
Normal file
63
Documentation/i2c/busses/i2c-sis630.rst
Normal file
@ -0,0 +1,63 @@
|
||||
========================
|
||||
Kernel driver i2c-sis630
|
||||
========================
|
||||
|
||||
Supported adapters:
|
||||
* Silicon Integrated Systems Corp (SiS)
|
||||
630 chipset (Datasheet: available at http://www.sfr-fresh.com/linux)
|
||||
730 chipset
|
||||
964 chipset
|
||||
* Possible other SiS chipsets ?
|
||||
|
||||
Author:
|
||||
- Alexander Malysh <amalysh@web.de>
|
||||
- Amaury Decrême <amaury.decreme@gmail.com> - SiS964 support
|
||||
|
||||
Module Parameters
|
||||
-----------------
|
||||
|
||||
================== =====================================================
|
||||
force = [1|0] Forcibly enable the SIS630. DANGEROUS!
|
||||
This can be interesting for chipsets not named
|
||||
above to check if it works for you chipset,
|
||||
but DANGEROUS!
|
||||
|
||||
high_clock = [1|0] Forcibly set Host Master Clock to 56KHz (default,
|
||||
what your BIOS use). DANGEROUS! This should be a bit
|
||||
faster, but freeze some systems (i.e. my Laptop).
|
||||
SIS630/730 chip only.
|
||||
================== =====================================================
|
||||
|
||||
|
||||
Description
|
||||
-----------
|
||||
|
||||
This SMBus only driver is known to work on motherboards with the above
|
||||
named chipsets.
|
||||
|
||||
If you see something like this::
|
||||
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS] 630 Host (rev 31)
|
||||
00:01.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513
|
||||
|
||||
or like this::
|
||||
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS] 730 Host (rev 02)
|
||||
00:01.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513
|
||||
|
||||
or like this::
|
||||
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS] 760/M760 Host (rev 02)
|
||||
00:02.0 ISA bridge: Silicon Integrated Systems [SiS] SiS964 [MuTIOL Media IO]
|
||||
LPC Controller (rev 36)
|
||||
|
||||
in your ``lspci`` output , then this driver is for your chipset.
|
||||
|
||||
Thank You
|
||||
---------
|
||||
Philip Edelbrock <phil@netroedge.com>
|
||||
- testing SiS730 support
|
||||
Mark M. Hoffman <mhoffman@lightlink.com>
|
||||
- bug fixes
|
||||
|
||||
To anyone else which I forgot here ;), thanks!
|
||||
@ -1,13 +1,18 @@
|
||||
========================
|
||||
Kernel driver i2c-sis96x
|
||||
========================
|
||||
|
||||
Replaces 2.4.x i2c-sis645
|
||||
|
||||
Supported adapters:
|
||||
|
||||
* Silicon Integrated Systems Corp (SiS)
|
||||
|
||||
Any combination of these host bridges:
|
||||
645, 645DX (aka 646), 648, 650, 651, 655, 735, 745, 746
|
||||
|
||||
and these south bridges:
|
||||
961, 962, 963(L)
|
||||
961, 962, 963(L)
|
||||
|
||||
Author: Mark M. Hoffman <mhoffman@lightlink.com>
|
||||
|
||||
@ -21,17 +26,17 @@ those of the SiS630, although they are located in a completely different
|
||||
place. Thanks to Alexander Malysh <amalysh@web.de> for providing the
|
||||
SiS630 datasheet (and driver).
|
||||
|
||||
The command "lspci" as root should produce something like these lines:
|
||||
The command ``lspci`` as root should produce something like these lines::
|
||||
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS]: Unknown device 0645
|
||||
00:02.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513
|
||||
00:02.1 SMBus: Silicon Integrated Systems [SiS]: Unknown device 0016
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS]: Unknown device 0645
|
||||
00:02.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513
|
||||
00:02.1 SMBus: Silicon Integrated Systems [SiS]: Unknown device 0016
|
||||
|
||||
or perhaps this...
|
||||
or perhaps this::
|
||||
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS]: Unknown device 0645
|
||||
00:02.0 ISA bridge: Silicon Integrated Systems [SiS]: Unknown device 0961
|
||||
00:02.1 SMBus: Silicon Integrated Systems [SiS]: Unknown device 0016
|
||||
00:00.0 Host bridge: Silicon Integrated Systems [SiS]: Unknown device 0645
|
||||
00:02.0 ISA bridge: Silicon Integrated Systems [SiS]: Unknown device 0961
|
||||
00:02.1 SMBus: Silicon Integrated Systems [SiS]: Unknown device 0016
|
||||
|
||||
(kernel versions later than 2.4.18 may fill in the "Unknown"s)
|
||||
|
||||
@ -50,7 +55,7 @@ TO DOs
|
||||
------
|
||||
|
||||
* The driver does not support SMBus block reads/writes; I may add them if a
|
||||
scenario is found where they're needed.
|
||||
scenario is found where they're needed.
|
||||
|
||||
|
||||
Thank You
|
||||
@ -58,16 +63,20 @@ Thank You
|
||||
|
||||
Mark D. Studebaker <mdsxyz123@yahoo.com>
|
||||
- design hints and bug fixes
|
||||
|
||||
Alexander Maylsh <amalysh@web.de>
|
||||
- ditto, plus an important datasheet... almost the one I really wanted
|
||||
|
||||
Hans-Günter Lütke Uphues <hg_lu@t-online.de>
|
||||
- patch for SiS735
|
||||
|
||||
Robert Zwerus <arzie@dds.nl>
|
||||
- testing for SiS645DX
|
||||
|
||||
Kianusch Sayah Karadji <kianusch@sk-tech.net>
|
||||
- patch for SiS645DX/962
|
||||
|
||||
Ken Healy
|
||||
- patch for SiS655
|
||||
|
||||
To anyone else who has written w/ feedback, thanks!
|
||||
|
||||
@ -1,4 +1,6 @@
|
||||
==========================
|
||||
Kernel driver i2c-taos-evm
|
||||
==========================
|
||||
|
||||
Author: Jean Delvare <jdelvare@suse.de>
|
||||
|
||||
@ -23,10 +25,10 @@ Using this driver
|
||||
In order to use this driver, you'll need the serport driver, and the
|
||||
inputattach tool, which is part of the input-utils package. The following
|
||||
commands will tell the kernel that you have a TAOS EVM on the first
|
||||
serial port:
|
||||
serial port::
|
||||
|
||||
# modprobe serport
|
||||
# inputattach --taos-evm /dev/ttyS0
|
||||
# modprobe serport
|
||||
# inputattach --taos-evm /dev/ttyS0
|
||||
|
||||
|
||||
Technical details
|
||||
@ -1,4 +1,6 @@
|
||||
=====================
|
||||
Kernel driver i2c-via
|
||||
=====================
|
||||
|
||||
Supported adapters:
|
||||
* VIA Technologies, InC. VT82C586B
|
||||
@ -12,23 +14,27 @@ Description
|
||||
i2c-via is an i2c bus driver for motherboards with VIA chipset.
|
||||
|
||||
The following VIA pci chipsets are supported:
|
||||
- MVP3, VP3, VP2/97, VPX/97
|
||||
- MVP3, VP3, VP2/97, VPX/97
|
||||
- others with South bridge VT82C586B
|
||||
|
||||
Your lspci listing must show this :
|
||||
Your ``lspci`` listing must show this ::
|
||||
|
||||
Bridge: VIA Technologies, Inc. VT82C586B ACPI (rev 10)
|
||||
|
||||
Problems?
|
||||
|
||||
Q: You have VT82C586B on the motherboard, but not in the listing.
|
||||
|
||||
A: Go to your BIOS setup, section PCI devices or similar.
|
||||
Turn USB support on, and try again.
|
||||
Problems?
|
||||
---------
|
||||
|
||||
Q: No error messages, but still i2c doesn't seem to work.
|
||||
Q:
|
||||
You have VT82C586B on the motherboard, but not in the listing.
|
||||
|
||||
A: This can happen. This driver uses the pins VIA recommends in their
|
||||
A:
|
||||
Go to your BIOS setup, section PCI devices or similar.
|
||||
Turn USB support on, and try again.
|
||||
|
||||
Q:
|
||||
No error messages, but still i2c doesn't seem to work.
|
||||
|
||||
A:
|
||||
This can happen. This driver uses the pins VIA recommends in their
|
||||
datasheets, but there are several ways the motherboard manufacturer
|
||||
can actually wire the lines.
|
||||
|
||||
@ -1,4 +1,6 @@
|
||||
========================
|
||||
Kernel driver i2c-viapro
|
||||
========================
|
||||
|
||||
Supported adapters:
|
||||
* VIA Technologies, Inc. VT82C596A/B
|
||||
@ -26,9 +28,9 @@ Supported adapters:
|
||||
Datasheet: available on http://linux.via.com.tw
|
||||
|
||||
Authors:
|
||||
Kyösti Mälkki <kmalkki@cc.hut.fi>,
|
||||
Mark D. Studebaker <mdsxyz123@yahoo.com>,
|
||||
Jean Delvare <jdelvare@suse.de>
|
||||
- Kyösti Mälkki <kmalkki@cc.hut.fi>,
|
||||
- Mark D. Studebaker <mdsxyz123@yahoo.com>,
|
||||
- Jean Delvare <jdelvare@suse.de>
|
||||
|
||||
Module Parameters
|
||||
-----------------
|
||||
@ -44,8 +46,9 @@ Description
|
||||
i2c-viapro is a true SMBus host driver for motherboards with one of the
|
||||
supported VIA south bridges.
|
||||
|
||||
Your lspci -n listing must show one of these :
|
||||
Your ``lspci -n`` listing must show one of these :
|
||||
|
||||
================ ======================
|
||||
device 1106:3050 (VT82C596A function 3)
|
||||
device 1106:3051 (VT82C596B function 3)
|
||||
device 1106:3057 (VT82C686 function 4)
|
||||
@ -61,6 +64,7 @@ Your lspci -n listing must show one of these :
|
||||
device 1106:8353 (VX800/VX820)
|
||||
device 1106:8409 (VX855/VX875)
|
||||
device 1106:8410 (VX900)
|
||||
================ ======================
|
||||
|
||||
If none of these show up, you should look in the BIOS for settings like
|
||||
enable ACPI / SMBus or even USB.
|
||||
33
Documentation/i2c/busses/index.rst
Normal file
33
Documentation/i2c/busses/index.rst
Normal file
@ -0,0 +1,33 @@
|
||||
. SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
===============
|
||||
I2C Bus Drivers
|
||||
===============
|
||||
|
||||
.. toctree::
|
||||
:maxdepth: 1
|
||||
|
||||
i2c-ali1535
|
||||
i2c-ali1563
|
||||
i2c-ali15x3
|
||||
i2c-amd756
|
||||
i2c-amd8111
|
||||
i2c-amd-mp2
|
||||
i2c-diolan-u2c
|
||||
i2c-i801
|
||||
i2c-ismt
|
||||
i2c-mlxcpld
|
||||
i2c-nforce2
|
||||
i2c-nvidia-gpu
|
||||
i2c-ocores
|
||||
i2c-parport-light
|
||||
i2c-parport
|
||||
i2c-pca-isa
|
||||
i2c-piix4
|
||||
i2c-sis5595
|
||||
i2c-sis630
|
||||
i2c-sis96x
|
||||
i2c-taos-evm
|
||||
i2c-viapro
|
||||
i2c-via
|
||||
scx200_acb
|
||||
@ -1,4 +1,6 @@
|
||||
========================
|
||||
Kernel driver scx200_acb
|
||||
========================
|
||||
|
||||
Author: Christer Weinigel <wingel@nano-system.com>
|
||||
|
||||
@ -25,8 +27,11 @@ Device-specific notes
|
||||
|
||||
The SC1100 WRAP boards are known to use base addresses 0x810 and 0x820.
|
||||
If the scx200_acb driver is built into the kernel, add the following
|
||||
parameter to your boot command line:
|
||||
parameter to your boot command line::
|
||||
|
||||
scx200_acb.base=0x810,0x820
|
||||
|
||||
If the scx200_acb driver is built as a module, add the following line to
|
||||
a configuration file in /etc/modprobe.d/ instead:
|
||||
a configuration file in /etc/modprobe.d/ instead::
|
||||
|
||||
options scx200_acb base=0x810,0x820
|
||||
@ -1,3 +1,7 @@
|
||||
====================
|
||||
I2C Device Interface
|
||||
====================
|
||||
|
||||
Usually, i2c devices are controlled by a kernel driver. But it is also
|
||||
possible to access all devices on an adapter from userspace, through
|
||||
the /dev interface. You need to load module i2c-dev for this.
|
||||
@ -18,7 +22,7 @@ C example
|
||||
=========
|
||||
|
||||
So let's say you want to access an i2c adapter from a C program.
|
||||
First, you need to include these two headers:
|
||||
First, you need to include these two headers::
|
||||
|
||||
#include <linux/i2c-dev.h>
|
||||
#include <i2c/smbus.h>
|
||||
@ -28,7 +32,7 @@ inspect /sys/class/i2c-dev/ or run "i2cdetect -l" to decide this.
|
||||
Adapter numbers are assigned somewhat dynamically, so you can not
|
||||
assume much about them. They can even change from one boot to the next.
|
||||
|
||||
Next thing, open the device file, as follows:
|
||||
Next thing, open the device file, as follows::
|
||||
|
||||
int file;
|
||||
int adapter_nr = 2; /* probably dynamically determined */
|
||||
@ -42,7 +46,7 @@ Next thing, open the device file, as follows:
|
||||
}
|
||||
|
||||
When you have opened the device, you must specify with what device
|
||||
address you want to communicate:
|
||||
address you want to communicate::
|
||||
|
||||
int addr = 0x40; /* The I2C address */
|
||||
|
||||
@ -53,7 +57,7 @@ address you want to communicate:
|
||||
|
||||
Well, you are all set up now. You can now use SMBus commands or plain
|
||||
I2C to communicate with your device. SMBus commands are preferred if
|
||||
the device supports them. Both are illustrated below.
|
||||
the device supports them. Both are illustrated below::
|
||||
|
||||
__u8 reg = 0x10; /* Device register to access */
|
||||
__s32 res;
|
||||
@ -100,35 +104,35 @@ Full interface description
|
||||
|
||||
The following IOCTLs are defined:
|
||||
|
||||
ioctl(file, I2C_SLAVE, long addr)
|
||||
``ioctl(file, I2C_SLAVE, long addr)``
|
||||
Change slave address. The address is passed in the 7 lower bits of the
|
||||
argument (except for 10 bit addresses, passed in the 10 lower bits in this
|
||||
case).
|
||||
|
||||
ioctl(file, I2C_TENBIT, long select)
|
||||
``ioctl(file, I2C_TENBIT, long select)``
|
||||
Selects ten bit addresses if select not equals 0, selects normal 7 bit
|
||||
addresses if select equals 0. Default 0. This request is only valid
|
||||
if the adapter has I2C_FUNC_10BIT_ADDR.
|
||||
|
||||
ioctl(file, I2C_PEC, long select)
|
||||
``ioctl(file, I2C_PEC, long select)``
|
||||
Selects SMBus PEC (packet error checking) generation and verification
|
||||
if select not equals 0, disables if select equals 0. Default 0.
|
||||
Used only for SMBus transactions. This request only has an effect if the
|
||||
the adapter has I2C_FUNC_SMBUS_PEC; it is still safe if not, it just
|
||||
doesn't have any effect.
|
||||
|
||||
ioctl(file, I2C_FUNCS, unsigned long *funcs)
|
||||
Gets the adapter functionality and puts it in *funcs.
|
||||
``ioctl(file, I2C_FUNCS, unsigned long *funcs)``
|
||||
Gets the adapter functionality and puts it in ``*funcs``.
|
||||
|
||||
ioctl(file, I2C_RDWR, struct i2c_rdwr_ioctl_data *msgset)
|
||||
``ioctl(file, I2C_RDWR, struct i2c_rdwr_ioctl_data *msgset)``
|
||||
Do combined read/write transaction without stop in between.
|
||||
Only valid if the adapter has I2C_FUNC_I2C. The argument is
|
||||
a pointer to a
|
||||
a pointer to a::
|
||||
|
||||
struct i2c_rdwr_ioctl_data {
|
||||
struct i2c_rdwr_ioctl_data {
|
||||
struct i2c_msg *msgs; /* ptr to array of simple messages */
|
||||
int nmsgs; /* number of messages to exchange */
|
||||
}
|
||||
}
|
||||
|
||||
The msgs[] themselves contain further pointers into data buffers.
|
||||
The function will write or read data to or from that buffers depending
|
||||
@ -136,8 +140,8 @@ ioctl(file, I2C_RDWR, struct i2c_rdwr_ioctl_data *msgset)
|
||||
The slave address and whether to use ten bit address mode has to be
|
||||
set in each message, overriding the values set with the above ioctl's.
|
||||
|
||||
ioctl(file, I2C_SMBUS, struct i2c_smbus_ioctl_data *args)
|
||||
If possible, use the provided i2c_smbus_* methods described below instead
|
||||
``ioctl(file, I2C_SMBUS, struct i2c_smbus_ioctl_data *args)``
|
||||
If possible, use the provided ``i2c_smbus_*`` methods described below instead
|
||||
of issuing direct ioctls.
|
||||
|
||||
You can do plain i2c transactions by using read(2) and write(2) calls.
|
||||
@ -145,7 +149,8 @@ You do not need to pass the address byte; instead, set it through
|
||||
ioctl I2C_SLAVE before you try to access the device.
|
||||
|
||||
You can do SMBus level transactions (see documentation file smbus-protocol
|
||||
for details) through the following functions:
|
||||
for details) through the following functions::
|
||||
|
||||
__s32 i2c_smbus_write_quick(int file, __u8 value);
|
||||
__s32 i2c_smbus_read_byte(int file);
|
||||
__s32 i2c_smbus_write_byte(int file, __u8 value);
|
||||
@ -157,6 +162,7 @@ for details) through the following functions:
|
||||
__s32 i2c_smbus_read_block_data(int file, __u8 command, __u8 *values);
|
||||
__s32 i2c_smbus_write_block_data(int file, __u8 command, __u8 length,
|
||||
__u8 *values);
|
||||
|
||||
All these transactions return -1 on failure; you can read errno to see
|
||||
what happened. The 'write' transactions return 0 on success; the
|
||||
'read' transactions return the read value, except for read_block, which
|
||||
@ -174,39 +180,39 @@ Implementation details
|
||||
For the interested, here's the code flow which happens inside the kernel
|
||||
when you use the /dev interface to I2C:
|
||||
|
||||
1* Your program opens /dev/i2c-N and calls ioctl() on it, as described in
|
||||
section "C example" above.
|
||||
1) Your program opens /dev/i2c-N and calls ioctl() on it, as described in
|
||||
section "C example" above.
|
||||
|
||||
2* These open() and ioctl() calls are handled by the i2c-dev kernel
|
||||
driver: see i2c-dev.c:i2cdev_open() and i2c-dev.c:i2cdev_ioctl(),
|
||||
respectively. You can think of i2c-dev as a generic I2C chip driver
|
||||
that can be programmed from user-space.
|
||||
2) These open() and ioctl() calls are handled by the i2c-dev kernel
|
||||
driver: see i2c-dev.c:i2cdev_open() and i2c-dev.c:i2cdev_ioctl(),
|
||||
respectively. You can think of i2c-dev as a generic I2C chip driver
|
||||
that can be programmed from user-space.
|
||||
|
||||
3* Some ioctl() calls are for administrative tasks and are handled by
|
||||
i2c-dev directly. Examples include I2C_SLAVE (set the address of the
|
||||
device you want to access) and I2C_PEC (enable or disable SMBus error
|
||||
checking on future transactions.)
|
||||
3) Some ioctl() calls are for administrative tasks and are handled by
|
||||
i2c-dev directly. Examples include I2C_SLAVE (set the address of the
|
||||
device you want to access) and I2C_PEC (enable or disable SMBus error
|
||||
checking on future transactions.)
|
||||
|
||||
4* Other ioctl() calls are converted to in-kernel function calls by
|
||||
i2c-dev. Examples include I2C_FUNCS, which queries the I2C adapter
|
||||
functionality using i2c.h:i2c_get_functionality(), and I2C_SMBUS, which
|
||||
performs an SMBus transaction using i2c-core-smbus.c:i2c_smbus_xfer().
|
||||
4) Other ioctl() calls are converted to in-kernel function calls by
|
||||
i2c-dev. Examples include I2C_FUNCS, which queries the I2C adapter
|
||||
functionality using i2c.h:i2c_get_functionality(), and I2C_SMBUS, which
|
||||
performs an SMBus transaction using i2c-core-smbus.c:i2c_smbus_xfer().
|
||||
|
||||
The i2c-dev driver is responsible for checking all the parameters that
|
||||
come from user-space for validity. After this point, there is no
|
||||
difference between these calls that came from user-space through i2c-dev
|
||||
and calls that would have been performed by kernel I2C chip drivers
|
||||
directly. This means that I2C bus drivers don't need to implement
|
||||
anything special to support access from user-space.
|
||||
The i2c-dev driver is responsible for checking all the parameters that
|
||||
come from user-space for validity. After this point, there is no
|
||||
difference between these calls that came from user-space through i2c-dev
|
||||
and calls that would have been performed by kernel I2C chip drivers
|
||||
directly. This means that I2C bus drivers don't need to implement
|
||||
anything special to support access from user-space.
|
||||
|
||||
5* These i2c.h functions are wrappers to the actual implementation of
|
||||
your I2C bus driver. Each adapter must declare callback functions
|
||||
implementing these standard calls. i2c.h:i2c_get_functionality() calls
|
||||
i2c_adapter.algo->functionality(), while
|
||||
i2c-core-smbus.c:i2c_smbus_xfer() calls either
|
||||
adapter.algo->smbus_xfer() if it is implemented, or if not,
|
||||
i2c-core-smbus.c:i2c_smbus_xfer_emulated() which in turn calls
|
||||
i2c_adapter.algo->master_xfer().
|
||||
5) These i2c.h functions are wrappers to the actual implementation of
|
||||
your I2C bus driver. Each adapter must declare callback functions
|
||||
implementing these standard calls. i2c.h:i2c_get_functionality() calls
|
||||
i2c_adapter.algo->functionality(), while
|
||||
i2c-core-smbus.c:i2c_smbus_xfer() calls either
|
||||
adapter.algo->smbus_xfer() if it is implemented, or if not,
|
||||
i2c-core-smbus.c:i2c_smbus_xfer_emulated() which in turn calls
|
||||
i2c_adapter.algo->master_xfer().
|
||||
|
||||
After your I2C bus driver has processed these requests, execution runs
|
||||
up the call chain, with almost no processing done, except by i2c-dev to
|
||||
@ -1,3 +1,7 @@
|
||||
=====================
|
||||
I2C/SMBUS Fault Codes
|
||||
=====================
|
||||
|
||||
This is a summary of the most important conventions for use of fault
|
||||
codes in the I2C/SMBus stack.
|
||||
|
||||
@ -125,4 +129,3 @@ ETIMEDOUT
|
||||
when a slave stretches clocks too far. I2C has no such
|
||||
timeouts, but it's normal for I2C adapters to impose some
|
||||
arbitrary limits (much longer than SMBus!) too.
|
||||
|
||||
@ -1,11 +1,15 @@
|
||||
=======================
|
||||
I2C/SMBus Functionality
|
||||
=======================
|
||||
|
||||
INTRODUCTION
|
||||
------------
|
||||
|
||||
Because not every I2C or SMBus adapter implements everything in the
|
||||
Because not every I2C or SMBus adapter implements everything in the
|
||||
I2C specifications, a client can not trust that everything it needs
|
||||
is implemented when it is given the option to attach to an adapter:
|
||||
the client needs some way to check whether an adapter has the needed
|
||||
functionality.
|
||||
functionality.
|
||||
|
||||
|
||||
FUNCTIONALITY CONSTANTS
|
||||
@ -14,6 +18,7 @@ FUNCTIONALITY CONSTANTS
|
||||
For the most up-to-date list of functionality constants, please check
|
||||
<uapi/linux/i2c.h>!
|
||||
|
||||
=============================== ==============================================
|
||||
I2C_FUNC_I2C Plain i2c-level commands (Pure SMBus
|
||||
adapters typically can not do these)
|
||||
I2C_FUNC_10BIT_ADDR Handles the 10-bit address extensions
|
||||
@ -33,9 +38,11 @@ For the most up-to-date list of functionality constants, please check
|
||||
I2C_FUNC_SMBUS_WRITE_BLOCK_DATA Handles the SMBus write_block_data command
|
||||
I2C_FUNC_SMBUS_READ_I2C_BLOCK Handles the SMBus read_i2c_block_data command
|
||||
I2C_FUNC_SMBUS_WRITE_I2C_BLOCK Handles the SMBus write_i2c_block_data command
|
||||
=============================== ==============================================
|
||||
|
||||
A few combinations of the above flags are also defined for your convenience:
|
||||
|
||||
========================= ======================================
|
||||
I2C_FUNC_SMBUS_BYTE Handles the SMBus read_byte
|
||||
and write_byte commands
|
||||
I2C_FUNC_SMBUS_BYTE_DATA Handles the SMBus read_byte_data
|
||||
@ -49,6 +56,7 @@ A few combinations of the above flags are also defined for your convenience:
|
||||
I2C_FUNC_SMBUS_EMUL Handles all SMBus commands that can be
|
||||
emulated by a real I2C adapter (using
|
||||
the transparent emulation layer)
|
||||
========================= ======================================
|
||||
|
||||
In kernel versions prior to 3.5 I2C_FUNC_NOSTART was implemented as
|
||||
part of I2C_FUNC_PROTOCOL_MANGLING.
|
||||
@ -58,11 +66,11 @@ ADAPTER IMPLEMENTATION
|
||||
----------------------
|
||||
|
||||
When you write a new adapter driver, you will have to implement a
|
||||
function callback `functionality'. Typical implementations are given
|
||||
function callback ``functionality``. Typical implementations are given
|
||||
below.
|
||||
|
||||
A typical SMBus-only adapter would list all the SMBus transactions it
|
||||
supports. This example comes from the i2c-piix4 driver:
|
||||
supports. This example comes from the i2c-piix4 driver::
|
||||
|
||||
static u32 piix4_func(struct i2c_adapter *adapter)
|
||||
{
|
||||
@ -72,7 +80,7 @@ supports. This example comes from the i2c-piix4 driver:
|
||||
}
|
||||
|
||||
A typical full-I2C adapter would use the following (from the i2c-pxa
|
||||
driver):
|
||||
driver)::
|
||||
|
||||
static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
|
||||
{
|
||||
@ -94,7 +102,7 @@ CLIENT CHECKING
|
||||
Before a client tries to attach to an adapter, or even do tests to check
|
||||
whether one of the devices it supports is present on an adapter, it should
|
||||
check whether the needed functionality is present. The typical way to do
|
||||
this is (from the lm75 driver):
|
||||
this is (from the lm75 driver)::
|
||||
|
||||
static int lm75_detect(...)
|
||||
{
|
||||
@ -129,7 +137,7 @@ If you try to access an adapter from a userspace program, you will have
|
||||
to use the /dev interface. You will still have to check whether the
|
||||
functionality you need is supported, of course. This is done using
|
||||
the I2C_FUNCS ioctl. An example, adapted from the i2cdetect program, is
|
||||
below:
|
||||
below::
|
||||
|
||||
int file;
|
||||
if (file = open("/dev/i2c-0", O_RDWR) < 0) {
|
||||
@ -104,10 +104,10 @@ There doesn't need to be a device at this address because arbitration lost
|
||||
should be detected beforehand. Also note, that SCL going down is monitored
|
||||
using interrupts, so the interrupt latency might cause the first bits to be not
|
||||
corrupted. A good starting point for using this fault injector on an otherwise
|
||||
idle bus is:
|
||||
idle bus is::
|
||||
|
||||
# echo 200 > lose_arbitration &
|
||||
# i2cget -y <bus_to_test> 0x3f
|
||||
# echo 200 > lose_arbitration &
|
||||
# i2cget -y <bus_to_test> 0x3f
|
||||
|
||||
Panic during transfer
|
||||
=====================
|
||||
@ -127,10 +127,10 @@ The calling process will then sleep and wait for the next bus clock. The
|
||||
process is interruptible, though.
|
||||
|
||||
Start of a transfer is detected by waiting for SCL going down by the master
|
||||
under test. A good starting point for using this fault injector is:
|
||||
under test. A good starting point for using this fault injector is::
|
||||
|
||||
# echo 0 > inject_panic &
|
||||
# i2cget -y <bus_to_test> <some_address>
|
||||
# echo 0 > inject_panic &
|
||||
# i2cget -y <bus_to_test> <some_address>
|
||||
|
||||
Note that there doesn't need to be a device listening to the address you are
|
||||
using. Results may vary depending on that, though.
|
||||
@ -1,8 +1,13 @@
|
||||
============
|
||||
I2C Protocol
|
||||
============
|
||||
|
||||
This document describes the i2c protocol. Or will, when it is finished :-)
|
||||
|
||||
Key to symbols
|
||||
==============
|
||||
|
||||
=============== =============================================================
|
||||
S (1 bit) : Start bit
|
||||
P (1 bit) : Stop bit
|
||||
Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0.
|
||||
@ -15,33 +20,35 @@ Data (8 bits): A plain data byte. Sometimes, I write DataLow, DataHigh
|
||||
for 16 bit data.
|
||||
Count (8 bits): A data byte containing the length of a block operation.
|
||||
|
||||
[..]: Data sent by I2C device, as opposed to data sent by the host adapter.
|
||||
[..]: Data sent by I2C device, as opposed to data sent by the
|
||||
host adapter.
|
||||
=============== =============================================================
|
||||
|
||||
|
||||
Simple send transaction
|
||||
======================
|
||||
=======================
|
||||
|
||||
This corresponds to i2c_master_send.
|
||||
This corresponds to i2c_master_send::
|
||||
|
||||
S Addr Wr [A] Data [A] Data [A] ... [A] Data [A] P
|
||||
|
||||
|
||||
Simple receive transaction
|
||||
===========================
|
||||
==========================
|
||||
|
||||
This corresponds to i2c_master_recv
|
||||
This corresponds to i2c_master_recv::
|
||||
|
||||
S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P
|
||||
|
||||
|
||||
Combined transactions
|
||||
====================
|
||||
=====================
|
||||
|
||||
This corresponds to i2c_transfer
|
||||
|
||||
They are just like the above transactions, but instead of a stop bit P
|
||||
a start bit S is sent and the transaction continues. An example of
|
||||
a byte read, followed by a byte write:
|
||||
a byte read, followed by a byte write::
|
||||
|
||||
S Addr Rd [A] [Data] NA S Addr Wr [A] Data [A] P
|
||||
|
||||
@ -65,8 +72,10 @@ I2C_M_NO_RD_ACK:
|
||||
I2C_M_NOSTART:
|
||||
In a combined transaction, no 'S Addr Wr/Rd [A]' is generated at some
|
||||
point. For example, setting I2C_M_NOSTART on the second partial message
|
||||
generates something like:
|
||||
generates something like::
|
||||
|
||||
S Addr Rd [A] [Data] NA Data [A] P
|
||||
|
||||
If you set the I2C_M_NOSTART variable for the first partial message,
|
||||
we do not generate Addr, but we do generate the startbit S. This will
|
||||
probably confuse all other clients on your bus, so don't try this.
|
||||
@ -79,7 +88,8 @@ I2C_M_NOSTART:
|
||||
I2C_M_REV_DIR_ADDR:
|
||||
This toggles the Rd/Wr flag. That is, if you want to do a write, but
|
||||
need to emit an Rd instead of a Wr, or vice versa, you set this
|
||||
flag. For example:
|
||||
flag. For example::
|
||||
|
||||
S Addr Rd [A] Data [A] Data [A] ... [A] Data [A] P
|
||||
|
||||
I2C_M_STOP:
|
||||
@ -1,6 +1,9 @@
|
||||
MODULE: i2c-stub
|
||||
========
|
||||
i2c-stub
|
||||
========
|
||||
|
||||
DESCRIPTION:
|
||||
Description
|
||||
===========
|
||||
|
||||
This module is a very simple fake I2C/SMBus driver. It implements six
|
||||
types of SMBus commands: write quick, (r/w) byte, (r/w) byte data, (r/w)
|
||||
@ -28,6 +31,7 @@ SMBus block operations. Writes can be partial. Block read commands always
|
||||
return the number of bytes selected with the largest write so far.
|
||||
|
||||
The typical use-case is like this:
|
||||
|
||||
1. load this module
|
||||
2. use i2cset (from the i2c-tools project) to pre-load some data
|
||||
3. load the target chip driver module
|
||||
@ -36,7 +40,8 @@ The typical use-case is like this:
|
||||
There's a script named i2c-stub-from-dump in the i2c-tools package which
|
||||
can load register values automatically from a chip dump.
|
||||
|
||||
PARAMETERS:
|
||||
Parameters
|
||||
==========
|
||||
|
||||
int chip_addr[10]:
|
||||
The SMBus addresses to emulate chips at.
|
||||
@ -47,18 +52,15 @@ unsigned long functionality:
|
||||
value 0x1f0000 would only enable the quick, byte and byte data
|
||||
commands.
|
||||
|
||||
u8 bank_reg[10]
|
||||
u8 bank_mask[10]
|
||||
u8 bank_start[10]
|
||||
u8 bank_end[10]:
|
||||
u8 bank_reg[10], u8 bank_mask[10], u8 bank_start[10], u8 bank_end[10]:
|
||||
Optional bank settings. They tell which bits in which register
|
||||
select the active bank, as well as the range of banked registers.
|
||||
|
||||
CAVEATS:
|
||||
Caveats
|
||||
=======
|
||||
|
||||
If your target driver polls some byte or word waiting for it to change, the
|
||||
stub could lock it up. Use i2cset to unlock it.
|
||||
|
||||
If you spam it hard enough, printk can be lossy. This module really wants
|
||||
something like relayfs.
|
||||
|
||||
@ -1,3 +1,4 @@
|
||||
============
|
||||
I2C topology
|
||||
============
|
||||
|
||||
@ -14,6 +15,7 @@ than a straight-forward i2c bus with one adapter and one or more devices.
|
||||
that has to be operated before the device can be accessed.
|
||||
|
||||
Etc
|
||||
===
|
||||
|
||||
These constructs are represented as i2c adapter trees by Linux, where
|
||||
each adapter has a parent adapter (except the root adapter) and zero or
|
||||
@ -37,7 +39,9 @@ mux-locked or parent-locked muxes. As is evident from below, it can be
|
||||
useful to know if a mux is mux-locked or if it is parent-locked. The
|
||||
following list was correct at the time of writing:
|
||||
|
||||
In drivers/i2c/muxes/
|
||||
In drivers/i2c/muxes/:
|
||||
|
||||
====================== =============================================
|
||||
i2c-arb-gpio-challenge Parent-locked
|
||||
i2c-mux-gpio Normally parent-locked, mux-locked iff
|
||||
all involved gpio pins are controlled by the
|
||||
@ -52,18 +56,25 @@ i2c-mux-pinctrl Normally parent-locked, mux-locked iff
|
||||
all involved pinctrl devices are controlled
|
||||
by the same i2c root adapter that they mux.
|
||||
i2c-mux-reg Parent-locked
|
||||
====================== =============================================
|
||||
|
||||
In drivers/iio/
|
||||
In drivers/iio/:
|
||||
|
||||
====================== =============================================
|
||||
gyro/mpu3050 Mux-locked
|
||||
imu/inv_mpu6050/ Mux-locked
|
||||
====================== =============================================
|
||||
|
||||
In drivers/media/
|
||||
In drivers/media/:
|
||||
|
||||
======================= =============================================
|
||||
dvb-frontends/lgdt3306a Mux-locked
|
||||
dvb-frontends/m88ds3103 Parent-locked
|
||||
dvb-frontends/rtl2830 Parent-locked
|
||||
dvb-frontends/rtl2832 Mux-locked
|
||||
dvb-frontends/si2168 Mux-locked
|
||||
usb/cx231xx/ Parent-locked
|
||||
======================= =============================================
|
||||
|
||||
|
||||
Mux-locked muxes
|
||||
@ -78,6 +89,7 @@ full transaction, unrelated i2c transfers may interleave the different
|
||||
stages of the transaction. This has the benefit that the mux driver
|
||||
may be easier and cleaner to implement, but it has some caveats.
|
||||
|
||||
==== =====================================================================
|
||||
ML1. If you build a topology with a mux-locked mux being the parent
|
||||
of a parent-locked mux, this might break the expectation from the
|
||||
parent-locked mux that the root adapter is locked during the
|
||||
@ -105,11 +117,15 @@ ML4. If any non-i2c operation in the mux driver changes the i2c mux state,
|
||||
Otherwise garbage may appear on the bus as seen from devices
|
||||
behind the mux, when an unrelated i2c transfer is in flight during
|
||||
the non-i2c mux-changing operation.
|
||||
==== =====================================================================
|
||||
|
||||
|
||||
Mux-locked Example
|
||||
------------------
|
||||
|
||||
|
||||
::
|
||||
|
||||
.----------. .--------.
|
||||
.--------. | mux- |-----| dev D1 |
|
||||
| root |--+--| locked | '--------'
|
||||
@ -148,6 +164,7 @@ adapter during the transaction are unlocked i2c transfers (using e.g.
|
||||
__i2c_transfer), or a deadlock will follow. There are a couple of
|
||||
caveats.
|
||||
|
||||
==== ====================================================================
|
||||
PL1. If you build a topology with a parent-locked mux being the child
|
||||
of another mux, this might break a possible assumption from the
|
||||
child mux that the root adapter is unused between its select op
|
||||
@ -161,11 +178,14 @@ PL2. If select/deselect calls out to other subsystems such as gpio,
|
||||
caused by these subsystems are unlocked. This can be convoluted to
|
||||
accomplish, maybe even impossible if an acceptably clean solution
|
||||
is sought.
|
||||
==== ====================================================================
|
||||
|
||||
|
||||
Parent-locked Example
|
||||
---------------------
|
||||
|
||||
::
|
||||
|
||||
.----------. .--------.
|
||||
.--------. | parent- |-----| dev D1 |
|
||||
| root |--+--| locked | '--------'
|
||||
@ -177,20 +197,20 @@ Parent-locked Example
|
||||
|
||||
When there is an access to D1, this happens:
|
||||
|
||||
1. Someone issues an i2c-transfer to D1.
|
||||
2. M1 locks muxes on its parent (the root adapter in this case).
|
||||
3. M1 locks its parent adapter.
|
||||
4. M1 calls ->select to ready the mux.
|
||||
5. If M1 does any i2c-transfers (on this root adapter) as part of
|
||||
its select, those transfers must be unlocked i2c-transfers so
|
||||
that they do not deadlock the root adapter.
|
||||
6. M1 feeds the i2c-transfer from step 1 to the root adapter as an
|
||||
unlocked i2c-transfer, so that it does not deadlock the parent
|
||||
adapter.
|
||||
7. M1 calls ->deselect, if it has one.
|
||||
8. Same rules as in step 5, but for ->deselect.
|
||||
9. M1 unlocks its parent adapter.
|
||||
10. M1 unlocks muxes on its parent.
|
||||
1. Someone issues an i2c-transfer to D1.
|
||||
2. M1 locks muxes on its parent (the root adapter in this case).
|
||||
3. M1 locks its parent adapter.
|
||||
4. M1 calls ->select to ready the mux.
|
||||
5. If M1 does any i2c-transfers (on this root adapter) as part of
|
||||
its select, those transfers must be unlocked i2c-transfers so
|
||||
that they do not deadlock the root adapter.
|
||||
6. M1 feeds the i2c-transfer from step 1 to the root adapter as an
|
||||
unlocked i2c-transfer, so that it does not deadlock the parent
|
||||
adapter.
|
||||
7. M1 calls ->deselect, if it has one.
|
||||
8. Same rules as in step 5, but for ->deselect.
|
||||
9. M1 unlocks its parent adapter.
|
||||
10. M1 unlocks muxes on its parent.
|
||||
|
||||
|
||||
This means that accesses to both D2 and D3 are locked out for the full
|
||||
@ -203,7 +223,7 @@ Complex Examples
|
||||
Parent-locked mux as parent of parent-locked mux
|
||||
------------------------------------------------
|
||||
|
||||
This is a useful topology, but it can be bad.
|
||||
This is a useful topology, but it can be bad::
|
||||
|
||||
.----------. .----------. .--------.
|
||||
.--------. | parent- |-----| parent- |-----| dev D1 |
|
||||
@ -227,7 +247,7 @@ through and be seen by the M2 adapter, thus closing M2 prematurely.
|
||||
Mux-locked mux as parent of mux-locked mux
|
||||
------------------------------------------
|
||||
|
||||
This is a good topology.
|
||||
This is a good topology::
|
||||
|
||||
.----------. .----------. .--------.
|
||||
.--------. | mux- |-----| mux- |-----| dev D1 |
|
||||
@ -248,7 +268,7 @@ are still possibly interleaved.
|
||||
Mux-locked mux as parent of parent-locked mux
|
||||
---------------------------------------------
|
||||
|
||||
This is probably a bad topology.
|
||||
This is probably a bad topology::
|
||||
|
||||
.----------. .----------. .--------.
|
||||
.--------. | mux- |-----| parent- |-----| dev D1 |
|
||||
@ -282,7 +302,7 @@ auto-closing, the topology is fine.
|
||||
Parent-locked mux as parent of mux-locked mux
|
||||
---------------------------------------------
|
||||
|
||||
This is a good topology.
|
||||
This is a good topology::
|
||||
|
||||
.----------. .----------. .--------.
|
||||
.--------. | parent- |-----| mux- |-----| dev D1 |
|
||||
@ -306,7 +326,7 @@ adapter is locked directly.
|
||||
Two mux-locked sibling muxes
|
||||
----------------------------
|
||||
|
||||
This is a good topology.
|
||||
This is a good topology::
|
||||
|
||||
.--------.
|
||||
.----------. .--| dev D1 |
|
||||
@ -330,7 +350,7 @@ accesses to D5 may be interleaved at any time.
|
||||
Two parent-locked sibling muxes
|
||||
-------------------------------
|
||||
|
||||
This is a good topology.
|
||||
This is a good topology::
|
||||
|
||||
.--------.
|
||||
.----------. .--| dev D1 |
|
||||
@ -354,7 +374,7 @@ out.
|
||||
Mux-locked and parent-locked sibling muxes
|
||||
------------------------------------------
|
||||
|
||||
This is a good topology.
|
||||
This is a good topology::
|
||||
|
||||
.--------.
|
||||
.----------. .--| dev D1 |
|
||||
37
Documentation/i2c/index.rst
Normal file
37
Documentation/i2c/index.rst
Normal file
@ -0,0 +1,37 @@
|
||||
. SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
===================
|
||||
I2C/SMBus Subsystem
|
||||
===================
|
||||
|
||||
.. toctree::
|
||||
:maxdepth: 1
|
||||
|
||||
dev-interface
|
||||
dma-considerations
|
||||
fault-codes
|
||||
functionality
|
||||
gpio-fault-injection
|
||||
i2c-protocol
|
||||
i2c-stub
|
||||
i2c-topology
|
||||
instantiating-devices
|
||||
old-module-parameters
|
||||
slave-eeprom-backend
|
||||
slave-interface
|
||||
smbus-protocol
|
||||
summary
|
||||
ten-bit-addresses
|
||||
upgrading-clients
|
||||
writing-clients
|
||||
|
||||
muxes/i2c-mux-gpio
|
||||
|
||||
busses/index
|
||||
|
||||
.. only:: subproject and html
|
||||
|
||||
Indices
|
||||
=======
|
||||
|
||||
* :ref:`genindex`
|
||||
@ -1,3 +1,4 @@
|
||||
==============================
|
||||
How to instantiate I2C devices
|
||||
==============================
|
||||
|
||||
@ -17,9 +18,9 @@ which is known in advance. It is thus possible to pre-declare the I2C
|
||||
devices which live on this bus. This is done with an array of struct
|
||||
i2c_board_info which is registered by calling i2c_register_board_info().
|
||||
|
||||
Example (from omap2 h4):
|
||||
Example (from omap2 h4)::
|
||||
|
||||
static struct i2c_board_info h4_i2c_board_info[] __initdata = {
|
||||
static struct i2c_board_info h4_i2c_board_info[] __initdata = {
|
||||
{
|
||||
I2C_BOARD_INFO("isp1301_omap", 0x2d),
|
||||
.irq = OMAP_GPIO_IRQ(125),
|
||||
@ -32,15 +33,15 @@ static struct i2c_board_info h4_i2c_board_info[] __initdata = {
|
||||
I2C_BOARD_INFO("24c01", 0x57),
|
||||
.platform_data = &m24c01,
|
||||
},
|
||||
};
|
||||
};
|
||||
|
||||
static void __init omap_h4_init(void)
|
||||
{
|
||||
static void __init omap_h4_init(void)
|
||||
{
|
||||
(...)
|
||||
i2c_register_board_info(1, h4_i2c_board_info,
|
||||
ARRAY_SIZE(h4_i2c_board_info));
|
||||
(...)
|
||||
}
|
||||
}
|
||||
|
||||
The above code declares 3 devices on I2C bus 1, including their respective
|
||||
addresses and custom data needed by their drivers. When the I2C bus in
|
||||
@ -57,7 +58,7 @@ Method 1b: Declare the I2C devices via devicetree
|
||||
This method has the same implications as method 1a. The declaration of I2C
|
||||
devices is here done via devicetree as subnodes of the master controller.
|
||||
|
||||
Example:
|
||||
Example::
|
||||
|
||||
i2c1: i2c@400a0000 {
|
||||
/* ... master properties skipped ... */
|
||||
@ -99,20 +100,20 @@ bus in advance, so the method 1 described above can't be used. Instead,
|
||||
you can instantiate your I2C devices explicitly. This is done by filling
|
||||
a struct i2c_board_info and calling i2c_new_device().
|
||||
|
||||
Example (from the sfe4001 network driver):
|
||||
Example (from the sfe4001 network driver)::
|
||||
|
||||
static struct i2c_board_info sfe4001_hwmon_info = {
|
||||
static struct i2c_board_info sfe4001_hwmon_info = {
|
||||
I2C_BOARD_INFO("max6647", 0x4e),
|
||||
};
|
||||
};
|
||||
|
||||
int sfe4001_init(struct efx_nic *efx)
|
||||
{
|
||||
int sfe4001_init(struct efx_nic *efx)
|
||||
{
|
||||
(...)
|
||||
efx->board_info.hwmon_client =
|
||||
i2c_new_device(&efx->i2c_adap, &sfe4001_hwmon_info);
|
||||
|
||||
(...)
|
||||
}
|
||||
}
|
||||
|
||||
The above code instantiates 1 I2C device on the I2C bus which is on the
|
||||
network adapter in question.
|
||||
@ -124,12 +125,12 @@ it may have different addresses from one board to the next (manufacturer
|
||||
changing its design without notice). In this case, you can call
|
||||
i2c_new_probed_device() instead of i2c_new_device().
|
||||
|
||||
Example (from the nxp OHCI driver):
|
||||
Example (from the nxp OHCI driver)::
|
||||
|
||||
static const unsigned short normal_i2c[] = { 0x2c, 0x2d, I2C_CLIENT_END };
|
||||
static const unsigned short normal_i2c[] = { 0x2c, 0x2d, I2C_CLIENT_END };
|
||||
|
||||
static int usb_hcd_nxp_probe(struct platform_device *pdev)
|
||||
{
|
||||
static int usb_hcd_nxp_probe(struct platform_device *pdev)
|
||||
{
|
||||
(...)
|
||||
struct i2c_adapter *i2c_adap;
|
||||
struct i2c_board_info i2c_info;
|
||||
@ -142,7 +143,7 @@ static int usb_hcd_nxp_probe(struct platform_device *pdev)
|
||||
normal_i2c, NULL);
|
||||
i2c_put_adapter(i2c_adap);
|
||||
(...)
|
||||
}
|
||||
}
|
||||
|
||||
The above code instantiates up to 1 I2C device on the I2C bus which is on
|
||||
the OHCI adapter in question. It first tries at address 0x2c, if nothing
|
||||
@ -172,6 +173,7 @@ explicitly. Instead, i2c-core will probe for such devices as soon as their
|
||||
drivers are loaded, and if any is found, an I2C device will be
|
||||
instantiated automatically. In order to prevent any misbehavior of this
|
||||
mechanism, the following restrictions apply:
|
||||
|
||||
* The I2C device driver must implement the detect() method, which
|
||||
identifies a supported device by reading from arbitrary registers.
|
||||
* Only buses which are likely to have a supported device and agree to be
|
||||
@ -189,6 +191,7 @@ first.
|
||||
Those of you familiar with the i2c subsystem of 2.4 kernels and early 2.6
|
||||
kernels will find out that this method 3 is essentially similar to what
|
||||
was done there. Two significant differences are:
|
||||
|
||||
* Probing is only one way to instantiate I2C devices now, while it was the
|
||||
only way back then. Where possible, methods 1 and 2 should be preferred.
|
||||
Method 3 should only be used when there is no other way, as it can have
|
||||
@ -224,11 +227,13 @@ device. As no two devices can live at the same address on a given I2C
|
||||
segment, the address is sufficient to uniquely identify the device to be
|
||||
deleted.
|
||||
|
||||
Example:
|
||||
# echo eeprom 0x50 > /sys/bus/i2c/devices/i2c-3/new_device
|
||||
Example::
|
||||
|
||||
# echo eeprom 0x50 > /sys/bus/i2c/devices/i2c-3/new_device
|
||||
|
||||
While this interface should only be used when in-kernel device declaration
|
||||
can't be done, there is a variety of cases where it can be helpful:
|
||||
|
||||
* The I2C driver usually detects devices (method 3 above) but the bus
|
||||
segment your device lives on doesn't have the proper class bit set and
|
||||
thus detection doesn't trigger.
|
||||
@ -1,4 +1,6 @@
|
||||
==========================
|
||||
Kernel driver i2c-mux-gpio
|
||||
==========================
|
||||
|
||||
Author: Peter Korsgaard <peter.korsgaard@barco.com>
|
||||
|
||||
@ -8,7 +10,7 @@ Description
|
||||
i2c-mux-gpio is an i2c mux driver providing access to I2C bus segments
|
||||
from a master I2C bus and a hardware MUX controlled through GPIO pins.
|
||||
|
||||
E.G.:
|
||||
E.G.::
|
||||
|
||||
---------- ---------- Bus segment 1 - - - - -
|
||||
| | SCL/SDA | |-------------- | |
|
||||
@ -33,20 +35,20 @@ bus, the number of bus segments to create and the GPIO pins used
|
||||
to control it. See include/linux/platform_data/i2c-mux-gpio.h for details.
|
||||
|
||||
E.G. something like this for a MUX providing 4 bus segments
|
||||
controlled through 3 GPIO pins:
|
||||
controlled through 3 GPIO pins::
|
||||
|
||||
#include <linux/platform_data/i2c-mux-gpio.h>
|
||||
#include <linux/platform_device.h>
|
||||
#include <linux/platform_data/i2c-mux-gpio.h>
|
||||
#include <linux/platform_device.h>
|
||||
|
||||
static const unsigned myboard_gpiomux_gpios[] = {
|
||||
static const unsigned myboard_gpiomux_gpios[] = {
|
||||
AT91_PIN_PC26, AT91_PIN_PC25, AT91_PIN_PC24
|
||||
};
|
||||
};
|
||||
|
||||
static const unsigned myboard_gpiomux_values[] = {
|
||||
static const unsigned myboard_gpiomux_values[] = {
|
||||
0, 1, 2, 3
|
||||
};
|
||||
};
|
||||
|
||||
static struct i2c_mux_gpio_platform_data myboard_i2cmux_data = {
|
||||
static struct i2c_mux_gpio_platform_data myboard_i2cmux_data = {
|
||||
.parent = 1,
|
||||
.base_nr = 2, /* optional */
|
||||
.values = myboard_gpiomux_values,
|
||||
@ -54,15 +56,15 @@ static struct i2c_mux_gpio_platform_data myboard_i2cmux_data = {
|
||||
.gpios = myboard_gpiomux_gpios,
|
||||
.n_gpios = ARRAY_SIZE(myboard_gpiomux_gpios),
|
||||
.idle = 4, /* optional */
|
||||
};
|
||||
};
|
||||
|
||||
static struct platform_device myboard_i2cmux = {
|
||||
static struct platform_device myboard_i2cmux = {
|
||||
.name = "i2c-mux-gpio",
|
||||
.id = 0,
|
||||
.dev = {
|
||||
.platform_data = &myboard_i2cmux_data,
|
||||
},
|
||||
};
|
||||
};
|
||||
|
||||
If you don't know the absolute GPIO pin numbers at registration time,
|
||||
you can instead provide a chip name (.chip_name) and relative GPIO pin
|
||||
@ -1,3 +1,4 @@
|
||||
=================================================
|
||||
I2C device driver binding control from user-space
|
||||
=================================================
|
||||
|
||||
@ -19,23 +20,27 @@ Below is a mapping from the old module parameters to the new interface.
|
||||
Attaching a driver to an I2C device
|
||||
-----------------------------------
|
||||
|
||||
Old method (module parameters):
|
||||
# modprobe <driver> probe=1,0x2d
|
||||
# modprobe <driver> force=1,0x2d
|
||||
# modprobe <driver> force_<device>=1,0x2d
|
||||
Old method (module parameters)::
|
||||
|
||||
New method (sysfs interface):
|
||||
# echo <device> 0x2d > /sys/bus/i2c/devices/i2c-1/new_device
|
||||
# modprobe <driver> probe=1,0x2d
|
||||
# modprobe <driver> force=1,0x2d
|
||||
# modprobe <driver> force_<device>=1,0x2d
|
||||
|
||||
New method (sysfs interface)::
|
||||
|
||||
# echo <device> 0x2d > /sys/bus/i2c/devices/i2c-1/new_device
|
||||
|
||||
Preventing a driver from attaching to an I2C device
|
||||
---------------------------------------------------
|
||||
|
||||
Old method (module parameters):
|
||||
# modprobe <driver> ignore=1,0x2f
|
||||
Old method (module parameters)::
|
||||
|
||||
New method (sysfs interface):
|
||||
# echo dummy 0x2f > /sys/bus/i2c/devices/i2c-1/new_device
|
||||
# modprobe <driver>
|
||||
# modprobe <driver> ignore=1,0x2f
|
||||
|
||||
New method (sysfs interface)::
|
||||
|
||||
# echo dummy 0x2f > /sys/bus/i2c/devices/i2c-1/new_device
|
||||
# modprobe <driver>
|
||||
|
||||
Of course, it is important to instantiate the "dummy" device before loading
|
||||
the driver. The dummy device will be handled by i2c-core itself, preventing
|
||||
@ -1,3 +1,4 @@
|
||||
==============================
|
||||
Linux I2C slave eeprom backend
|
||||
==============================
|
||||
|
||||
@ -5,10 +6,9 @@ by Wolfram Sang <wsa@sang-engineering.com> in 2014-15
|
||||
|
||||
This is a proof-of-concept backend which acts like an EEPROM on the connected
|
||||
I2C bus. The memory contents can be modified from userspace via this file
|
||||
located in sysfs:
|
||||
located in sysfs::
|
||||
|
||||
/sys/bus/i2c/devices/<device-directory>/slave-eeprom
|
||||
|
||||
As of 2015, Linux doesn't support poll on binary sysfs files, so there is no
|
||||
notification when another master changed the content.
|
||||
|
||||
@ -1,3 +1,4 @@
|
||||
=====================================
|
||||
Linux I2C slave interface description
|
||||
=====================================
|
||||
|
||||
@ -12,7 +13,7 @@ EEPROM, the Linux I2C slave can access the content via sysfs and handle data as
|
||||
needed. The backend driver and the I2C bus driver communicate via events. Here
|
||||
is a small graph visualizing the data flow and the means by which data is
|
||||
transported. The dotted line marks only one example. The backend could also
|
||||
use a character device, be in-kernel only, or something completely different:
|
||||
use a character device, be in-kernel only, or something completely different::
|
||||
|
||||
|
||||
e.g. sysfs I2C slave events I/O registers
|
||||
@ -35,7 +36,7 @@ them as described in the document 'instantiating-devices'. The only difference
|
||||
is that i2c slave backends have their own address space. So, you have to add
|
||||
0x1000 to the address you would originally request. An example for
|
||||
instantiating the slave-eeprom driver from userspace at the 7 bit address 0x64
|
||||
on bus 1:
|
||||
on bus 1::
|
||||
|
||||
# echo slave-24c02 0x1064 > /sys/bus/i2c/devices/i2c-1/new_device
|
||||
|
||||
@ -54,7 +55,7 @@ drivers and writing backends will be given.
|
||||
I2C slave events
|
||||
----------------
|
||||
|
||||
The bus driver sends an event to the backend using the following function:
|
||||
The bus driver sends an event to the backend using the following function::
|
||||
|
||||
ret = i2c_slave_event(client, event, &val)
|
||||
|
||||
@ -69,8 +70,9 @@ Event types:
|
||||
|
||||
* I2C_SLAVE_WRITE_REQUESTED (mandatory)
|
||||
|
||||
'val': unused
|
||||
'ret': always 0
|
||||
'val': unused
|
||||
|
||||
'ret': always 0
|
||||
|
||||
Another I2C master wants to write data to us. This event should be sent once
|
||||
our own address and the write bit was detected. The data did not arrive yet, so
|
||||
@ -79,8 +81,9 @@ to be done, though.
|
||||
|
||||
* I2C_SLAVE_READ_REQUESTED (mandatory)
|
||||
|
||||
'val': backend returns first byte to be sent
|
||||
'ret': always 0
|
||||
'val': backend returns first byte to be sent
|
||||
|
||||
'ret': always 0
|
||||
|
||||
Another I2C master wants to read data from us. This event should be sent once
|
||||
our own address and the read bit was detected. After returning, the bus driver
|
||||
@ -88,8 +91,9 @@ should transmit the first byte.
|
||||
|
||||
* I2C_SLAVE_WRITE_RECEIVED (mandatory)
|
||||
|
||||
'val': bus driver delivers received byte
|
||||
'ret': 0 if the byte should be acked, some errno if the byte should be nacked
|
||||
'val': bus driver delivers received byte
|
||||
|
||||
'ret': 0 if the byte should be acked, some errno if the byte should be nacked
|
||||
|
||||
Another I2C master has sent a byte to us which needs to be set in 'val'. If 'ret'
|
||||
is zero, the bus driver should ack this byte. If 'ret' is an errno, then the byte
|
||||
@ -97,8 +101,9 @@ should be nacked.
|
||||
|
||||
* I2C_SLAVE_READ_PROCESSED (mandatory)
|
||||
|
||||
'val': backend returns next byte to be sent
|
||||
'ret': always 0
|
||||
'val': backend returns next byte to be sent
|
||||
|
||||
'ret': always 0
|
||||
|
||||
The bus driver requests the next byte to be sent to another I2C master in
|
||||
'val'. Important: This does not mean that the previous byte has been acked, it
|
||||
@ -111,8 +116,9 @@ your backend, though.
|
||||
|
||||
* I2C_SLAVE_STOP (mandatory)
|
||||
|
||||
'val': unused
|
||||
'ret': always 0
|
||||
'val': unused
|
||||
|
||||
'ret': always 0
|
||||
|
||||
A stop condition was received. This can happen anytime and the backend should
|
||||
reset its state machine for I2C transfers to be able to receive new requests.
|
||||
@ -190,4 +196,3 @@ this time of writing. Some points to keep in mind when using buffers:
|
||||
* A master can send STOP at any time. For partially transferred buffers, this
|
||||
means additional code to handle this exception. Such code tends to be
|
||||
error-prone.
|
||||
|
||||
@ -1,3 +1,4 @@
|
||||
======================
|
||||
SMBus Protocol Summary
|
||||
======================
|
||||
|
||||
@ -27,17 +28,18 @@ Each transaction type corresponds to a functionality flag. Before calling a
|
||||
transaction function, a device driver should always check (just once) for
|
||||
the corresponding functionality flag to ensure that the underlying I2C
|
||||
adapter supports the transaction in question. See
|
||||
<file:Documentation/i2c/functionality> for the details.
|
||||
<file:Documentation/i2c/functionality.rst> for the details.
|
||||
|
||||
|
||||
Key to symbols
|
||||
==============
|
||||
|
||||
=============== =============================================================
|
||||
S (1 bit) : Start bit
|
||||
P (1 bit) : Stop bit
|
||||
Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0.
|
||||
A, NA (1 bit) : Accept and reverse accept bit.
|
||||
Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to
|
||||
A, NA (1 bit) : Accept and reverse accept bit.
|
||||
Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to
|
||||
get a 10 bit I2C address.
|
||||
Comm (8 bits): Command byte, a data byte which often selects a register on
|
||||
the device.
|
||||
@ -45,15 +47,17 @@ Data (8 bits): A plain data byte. Sometimes, I write DataLow, DataHigh
|
||||
for 16 bit data.
|
||||
Count (8 bits): A data byte containing the length of a block operation.
|
||||
|
||||
[..]: Data sent by I2C device, as opposed to data sent by the host adapter.
|
||||
[..]: Data sent by I2C device, as opposed to data sent by the host
|
||||
adapter.
|
||||
=============== =============================================================
|
||||
|
||||
|
||||
SMBus Quick Command
|
||||
===================
|
||||
|
||||
This sends a single bit to the device, at the place of the Rd/Wr bit.
|
||||
This sends a single bit to the device, at the place of the Rd/Wr bit::
|
||||
|
||||
A Addr Rd/Wr [A] P
|
||||
A Addr Rd/Wr [A] P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_QUICK
|
||||
|
||||
@ -64,9 +68,9 @@ SMBus Receive Byte: i2c_smbus_read_byte()
|
||||
This reads a single byte from a device, without specifying a device
|
||||
register. Some devices are so simple that this interface is enough; for
|
||||
others, it is a shorthand if you want to read the same register as in
|
||||
the previous SMBus command.
|
||||
the previous SMBus command::
|
||||
|
||||
S Addr Rd [A] [Data] NA P
|
||||
S Addr Rd [A] [Data] NA P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_READ_BYTE
|
||||
|
||||
@ -77,7 +81,9 @@ SMBus Send Byte: i2c_smbus_write_byte()
|
||||
This operation is the reverse of Receive Byte: it sends a single byte
|
||||
to a device. See Receive Byte for more information.
|
||||
|
||||
S Addr Wr [A] Data [A] P
|
||||
::
|
||||
|
||||
S Addr Wr [A] Data [A] P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_WRITE_BYTE
|
||||
|
||||
@ -86,9 +92,9 @@ SMBus Read Byte: i2c_smbus_read_byte_data()
|
||||
============================================
|
||||
|
||||
This reads a single byte from a device, from a designated register.
|
||||
The register is specified through the Comm byte.
|
||||
The register is specified through the Comm byte::
|
||||
|
||||
S Addr Wr [A] Comm [A] S Addr Rd [A] [Data] NA P
|
||||
S Addr Wr [A] Comm [A] S Addr Rd [A] [Data] NA P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_READ_BYTE_DATA
|
||||
|
||||
@ -98,9 +104,9 @@ SMBus Read Word: i2c_smbus_read_word_data()
|
||||
|
||||
This operation is very like Read Byte; again, data is read from a
|
||||
device, from a designated register that is specified through the Comm
|
||||
byte. But this time, the data is a complete word (16 bits).
|
||||
byte. But this time, the data is a complete word (16 bits)::
|
||||
|
||||
S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
|
||||
S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_READ_WORD_DATA
|
||||
|
||||
@ -116,7 +122,9 @@ This writes a single byte to a device, to a designated register. The
|
||||
register is specified through the Comm byte. This is the opposite of
|
||||
the Read Byte operation.
|
||||
|
||||
S Addr Wr [A] Comm [A] Data [A] P
|
||||
::
|
||||
|
||||
S Addr Wr [A] Comm [A] Data [A] P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_WRITE_BYTE_DATA
|
||||
|
||||
@ -126,9 +134,9 @@ SMBus Write Word: i2c_smbus_write_word_data()
|
||||
|
||||
This is the opposite of the Read Word operation. 16 bits
|
||||
of data is written to a device, to the designated register that is
|
||||
specified through the Comm byte.
|
||||
specified through the Comm byte.::
|
||||
|
||||
S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P
|
||||
S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_WRITE_WORD_DATA
|
||||
|
||||
@ -141,10 +149,10 @@ SMBus Process Call:
|
||||
===================
|
||||
|
||||
This command selects a device register (through the Comm byte), sends
|
||||
16 bits of data to it, and reads 16 bits of data in return.
|
||||
16 bits of data to it, and reads 16 bits of data in return::
|
||||
|
||||
S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A]
|
||||
S Addr Rd [A] [DataLow] A [DataHigh] NA P
|
||||
S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A]
|
||||
S Addr Rd [A] [DataLow] A [DataHigh] NA P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_PROC_CALL
|
||||
|
||||
@ -152,12 +160,14 @@ Functionality flag: I2C_FUNC_SMBUS_PROC_CALL
|
||||
SMBus Block Read: i2c_smbus_read_block_data()
|
||||
==============================================
|
||||
|
||||
This command reads a block of up to 32 bytes from a device, from a
|
||||
This command reads a block of up to 32 bytes from a device, from a
|
||||
designated register that is specified through the Comm byte. The amount
|
||||
of data is specified by the device in the Count byte.
|
||||
|
||||
S Addr Wr [A] Comm [A]
|
||||
S Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P
|
||||
::
|
||||
|
||||
S Addr Wr [A] Comm [A]
|
||||
S Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_READ_BLOCK_DATA
|
||||
|
||||
@ -165,11 +175,13 @@ Functionality flag: I2C_FUNC_SMBUS_READ_BLOCK_DATA
|
||||
SMBus Block Write: i2c_smbus_write_block_data()
|
||||
================================================
|
||||
|
||||
The opposite of the Block Read command, this writes up to 32 bytes to
|
||||
The opposite of the Block Read command, this writes up to 32 bytes to
|
||||
a device, to a designated register that is specified through the
|
||||
Comm byte. The amount of data is specified in the Count byte.
|
||||
|
||||
S Addr Wr [A] Comm [A] Count [A] Data [A] Data [A] ... [A] Data [A] P
|
||||
::
|
||||
|
||||
S Addr Wr [A] Comm [A] Count [A] Data [A] Data [A] ... [A] Data [A] P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_WRITE_BLOCK_DATA
|
||||
|
||||
@ -181,10 +193,10 @@ SMBus Block Write - Block Read Process Call was introduced in
|
||||
Revision 2.0 of the specification.
|
||||
|
||||
This command selects a device register (through the Comm byte), sends
|
||||
1 to 31 bytes of data to it, and reads 1 to 31 bytes of data in return.
|
||||
1 to 31 bytes of data to it, and reads 1 to 31 bytes of data in return::
|
||||
|
||||
S Addr Wr [A] Comm [A] Count [A] Data [A] ...
|
||||
S Addr Rd [A] [Count] A [Data] ... A P
|
||||
S Addr Wr [A] Comm [A] Count [A] Data [A] ...
|
||||
S Addr Rd [A] [Count] A [Data] ... A P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_BLOCK_PROC_CALL
|
||||
|
||||
@ -197,9 +209,12 @@ SMBus host acting as a slave.
|
||||
It is the same form as Write Word, with the command code replaced by the
|
||||
alerting device's address.
|
||||
|
||||
[S] [HostAddr] [Wr] A [DevAddr] A [DataLow] A [DataHigh] A [P]
|
||||
::
|
||||
|
||||
[S] [HostAddr] [Wr] A [DevAddr] A [DataLow] A [DataHigh] A [P]
|
||||
|
||||
This is implemented in the following way in the Linux kernel:
|
||||
|
||||
* I2C bus drivers which support SMBus Host Notify should report
|
||||
I2C_FUNC_SMBUS_HOST_NOTIFY.
|
||||
* I2C bus drivers trigger SMBus Host Notify by a call to
|
||||
@ -241,6 +256,7 @@ single interrupt pin on the SMBus master, while still allowing the master
|
||||
to know which slave triggered the interrupt.
|
||||
|
||||
This is implemented the following way in the Linux kernel:
|
||||
|
||||
* I2C bus drivers which support SMBus alert should call
|
||||
i2c_setup_smbus_alert() to setup SMBus alert support.
|
||||
* I2C drivers for devices which can trigger SMBus alerts should implement
|
||||
@ -261,11 +277,11 @@ but the SMBus layer places a limit of 32 bytes.
|
||||
I2C Block Read: i2c_smbus_read_i2c_block_data()
|
||||
================================================
|
||||
|
||||
This command reads a block of bytes from a device, from a
|
||||
designated register that is specified through the Comm byte.
|
||||
This command reads a block of bytes from a device, from a
|
||||
designated register that is specified through the Comm byte::
|
||||
|
||||
S Addr Wr [A] Comm [A]
|
||||
S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P
|
||||
S Addr Wr [A] Comm [A]
|
||||
S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_READ_I2C_BLOCK
|
||||
|
||||
@ -273,11 +289,13 @@ Functionality flag: I2C_FUNC_SMBUS_READ_I2C_BLOCK
|
||||
I2C Block Write: i2c_smbus_write_i2c_block_data()
|
||||
==================================================
|
||||
|
||||
The opposite of the Block Read command, this writes bytes to
|
||||
The opposite of the Block Read command, this writes bytes to
|
||||
a device, to a designated register that is specified through the
|
||||
Comm byte. Note that command lengths of 0, 2, or more bytes are
|
||||
supported as they are indistinguishable from data.
|
||||
|
||||
S Addr Wr [A] Comm [A] Data [A] Data [A] ... [A] Data [A] P
|
||||
::
|
||||
|
||||
S Addr Wr [A] Comm [A] Data [A] Data [A] ... [A] Data [A] P
|
||||
|
||||
Functionality flag: I2C_FUNC_SMBUS_WRITE_I2C_BLOCK
|
||||
@ -1,7 +1,8 @@
|
||||
=============
|
||||
I2C and SMBus
|
||||
=============
|
||||
|
||||
I2C (pronounce: I squared C) is a protocol developed by Philips. It is a
|
||||
I2C (pronounce: I squared C) is a protocol developed by Philips. It is a
|
||||
slow two-wire protocol (variable speed, up to 400 kHz), with a high speed
|
||||
extension (3.4 MHz). It provides an inexpensive bus for connecting many
|
||||
types of devices with infrequent or low bandwidth communications needs.
|
||||
@ -24,7 +25,8 @@ implement all the common SMBus protocol semantics or messages.
|
||||
Terminology
|
||||
===========
|
||||
|
||||
When we talk about I2C, we use the following terms:
|
||||
When we talk about I2C, we use the following terms::
|
||||
|
||||
Bus -> Algorithm
|
||||
Adapter
|
||||
Device -> Driver
|
||||
@ -1,3 +1,7 @@
|
||||
=====================
|
||||
I2C Ten-bit Addresses
|
||||
=====================
|
||||
|
||||
The I2C protocol knows about two kinds of device addresses: normal 7 bit
|
||||
addresses, and an extended set of 10 bit addresses. The sets of addresses
|
||||
do not intersect: the 7 bit address 0x10 is not the same as the 10 bit
|
||||
@ -12,6 +16,7 @@ See the I2C specification for the details.
|
||||
|
||||
The current 10 bit address support is minimal. It should work, however
|
||||
you can expect some problems along the way:
|
||||
|
||||
* Not all bus drivers support 10-bit addresses. Some don't because the
|
||||
hardware doesn't support them (SMBus doesn't require 10-bit address
|
||||
support for example), some don't because nobody bothered adding the
|
||||
@ -1,3 +1,4 @@
|
||||
=================================================
|
||||
Upgrading I2C Drivers to the new 2.6 Driver Model
|
||||
=================================================
|
||||
|
||||
@ -13,21 +14,22 @@ the old to the new new binding methods.
|
||||
Example old-style driver
|
||||
------------------------
|
||||
|
||||
::
|
||||
|
||||
struct example_state {
|
||||
struct example_state {
|
||||
struct i2c_client client;
|
||||
....
|
||||
};
|
||||
};
|
||||
|
||||
static struct i2c_driver example_driver;
|
||||
static struct i2c_driver example_driver;
|
||||
|
||||
static unsigned short ignore[] = { I2C_CLIENT_END };
|
||||
static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
|
||||
static unsigned short ignore[] = { I2C_CLIENT_END };
|
||||
static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
|
||||
|
||||
I2C_CLIENT_INSMOD;
|
||||
I2C_CLIENT_INSMOD;
|
||||
|
||||
static int example_attach(struct i2c_adapter *adap, int addr, int kind)
|
||||
{
|
||||
static int example_attach(struct i2c_adapter *adap, int addr, int kind)
|
||||
{
|
||||
struct example_state *state;
|
||||
struct device *dev = &adap->dev; /* to use for dev_ reports */
|
||||
int ret;
|
||||
@ -59,31 +61,31 @@ static int example_attach(struct i2c_adapter *adap, int addr, int kind)
|
||||
dev_info(dev, "example client created\n");
|
||||
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
static int example_detach(struct i2c_client *client)
|
||||
{
|
||||
static int example_detach(struct i2c_client *client)
|
||||
{
|
||||
struct example_state *state = i2c_get_clientdata(client);
|
||||
|
||||
i2c_detach_client(client);
|
||||
kfree(state);
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
static int example_attach_adapter(struct i2c_adapter *adap)
|
||||
{
|
||||
static int example_attach_adapter(struct i2c_adapter *adap)
|
||||
{
|
||||
return i2c_probe(adap, &addr_data, example_attach);
|
||||
}
|
||||
}
|
||||
|
||||
static struct i2c_driver example_driver = {
|
||||
.driver = {
|
||||
static struct i2c_driver example_driver = {
|
||||
.driver = {
|
||||
.owner = THIS_MODULE,
|
||||
.name = "example",
|
||||
.pm = &example_pm_ops,
|
||||
},
|
||||
.attach_adapter = example_attach_adapter,
|
||||
.detach_client = example_detach,
|
||||
};
|
||||
};
|
||||
|
||||
|
||||
Updating the client
|
||||
@ -93,38 +95,38 @@ The new style binding model will check against a list of supported
|
||||
devices and their associated address supplied by the code registering
|
||||
the busses. This means that the driver .attach_adapter and
|
||||
.detach_client methods can be removed, along with the addr_data,
|
||||
as follows:
|
||||
as follows::
|
||||
|
||||
- static struct i2c_driver example_driver;
|
||||
- static struct i2c_driver example_driver;
|
||||
|
||||
- static unsigned short ignore[] = { I2C_CLIENT_END };
|
||||
- static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
|
||||
- static unsigned short ignore[] = { I2C_CLIENT_END };
|
||||
- static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
|
||||
|
||||
- I2C_CLIENT_INSMOD;
|
||||
- I2C_CLIENT_INSMOD;
|
||||
|
||||
- static int example_attach_adapter(struct i2c_adapter *adap)
|
||||
- {
|
||||
- return i2c_probe(adap, &addr_data, example_attach);
|
||||
- }
|
||||
- static int example_attach_adapter(struct i2c_adapter *adap)
|
||||
- {
|
||||
- return i2c_probe(adap, &addr_data, example_attach);
|
||||
- }
|
||||
|
||||
static struct i2c_driver example_driver = {
|
||||
- .attach_adapter = example_attach_adapter,
|
||||
- .detach_client = example_detach,
|
||||
}
|
||||
static struct i2c_driver example_driver = {
|
||||
- .attach_adapter = example_attach_adapter,
|
||||
- .detach_client = example_detach,
|
||||
}
|
||||
|
||||
Add the probe and remove methods to the i2c_driver, as so:
|
||||
Add the probe and remove methods to the i2c_driver, as so::
|
||||
|
||||
static struct i2c_driver example_driver = {
|
||||
+ .probe = example_probe,
|
||||
+ .remove = example_remove,
|
||||
}
|
||||
static struct i2c_driver example_driver = {
|
||||
+ .probe = example_probe,
|
||||
+ .remove = example_remove,
|
||||
}
|
||||
|
||||
Change the example_attach method to accept the new parameters
|
||||
which include the i2c_client that it will be working with:
|
||||
which include the i2c_client that it will be working with::
|
||||
|
||||
- static int example_attach(struct i2c_adapter *adap, int addr, int kind)
|
||||
+ static int example_probe(struct i2c_client *client,
|
||||
+ const struct i2c_device_id *id)
|
||||
- static int example_attach(struct i2c_adapter *adap, int addr, int kind)
|
||||
+ static int example_probe(struct i2c_client *client,
|
||||
+ const struct i2c_device_id *id)
|
||||
|
||||
Change the name of example_attach to example_probe to align it with the
|
||||
i2c_driver entry names. The rest of the probe routine will now need to be
|
||||
@ -132,57 +134,59 @@ changed as the i2c_client has already been setup for use.
|
||||
|
||||
The necessary client fields have already been setup before
|
||||
the probe function is called, so the following client setup
|
||||
can be removed:
|
||||
can be removed::
|
||||
|
||||
- example->client.addr = addr;
|
||||
- example->client.flags = 0;
|
||||
- example->client.adapter = adap;
|
||||
-
|
||||
- strscpy(client->i2c_client.name, "example", sizeof(client->i2c_client.name));
|
||||
- example->client.addr = addr;
|
||||
- example->client.flags = 0;
|
||||
- example->client.adapter = adap;
|
||||
-
|
||||
- strscpy(client->i2c_client.name, "example", sizeof(client->i2c_client.name));
|
||||
|
||||
The i2c_set_clientdata is now:
|
||||
The i2c_set_clientdata is now::
|
||||
|
||||
- i2c_set_clientdata(&state->client, state);
|
||||
+ i2c_set_clientdata(client, state);
|
||||
- i2c_set_clientdata(&state->client, state);
|
||||
+ i2c_set_clientdata(client, state);
|
||||
|
||||
The call to i2c_attach_client is no longer needed, if the probe
|
||||
routine exits successfully, then the driver will be automatically
|
||||
attached by the core. Change the probe routine as so:
|
||||
attached by the core. Change the probe routine as so::
|
||||
|
||||
- ret = i2c_attach_client(&state->i2c_client);
|
||||
- if (ret < 0) {
|
||||
- dev_err(dev, "failed to attach client\n");
|
||||
- kfree(state);
|
||||
- return ret;
|
||||
- }
|
||||
- ret = i2c_attach_client(&state->i2c_client);
|
||||
- if (ret < 0) {
|
||||
- dev_err(dev, "failed to attach client\n");
|
||||
- kfree(state);
|
||||
- return ret;
|
||||
- }
|
||||
|
||||
|
||||
Remove the storage of 'struct i2c_client' from the 'struct example_state'
|
||||
as we are provided with the i2c_client in our example_probe. Instead we
|
||||
store a pointer to it for when it is needed.
|
||||
|
||||
struct example_state {
|
||||
- struct i2c_client client;
|
||||
+ struct i2c_client *client;
|
||||
::
|
||||
|
||||
the new i2c client as so:
|
||||
struct example_state {
|
||||
- struct i2c_client client;
|
||||
+ struct i2c_client *client;
|
||||
|
||||
- struct device *dev = &adap->dev; /* to use for dev_ reports */
|
||||
+ struct device *dev = &i2c_client->dev; /* to use for dev_ reports */
|
||||
the new i2c client as so::
|
||||
|
||||
- struct device *dev = &adap->dev; /* to use for dev_ reports */
|
||||
+ struct device *dev = &i2c_client->dev; /* to use for dev_ reports */
|
||||
|
||||
And remove the change after our client is attached, as the driver no
|
||||
longer needs to register a new client structure with the core:
|
||||
longer needs to register a new client structure with the core::
|
||||
|
||||
- dev = &state->i2c_client.dev;
|
||||
- dev = &state->i2c_client.dev;
|
||||
|
||||
In the probe routine, ensure that the new state has the client stored
|
||||
in it:
|
||||
in it::
|
||||
|
||||
static int example_probe(struct i2c_client *i2c_client,
|
||||
static int example_probe(struct i2c_client *i2c_client,
|
||||
const struct i2c_device_id *id)
|
||||
{
|
||||
{
|
||||
struct example_state *state;
|
||||
struct device *dev = &i2c_client->dev;
|
||||
struct device *dev = &i2c_client->dev;
|
||||
int ret;
|
||||
|
||||
state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
|
||||
@ -191,48 +195,50 @@ static int example_probe(struct i2c_client *i2c_client,
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
+ state->client = i2c_client;
|
||||
+ state->client = i2c_client;
|
||||
|
||||
Update the detach method, by changing the name to _remove and
|
||||
to delete the i2c_detach_client call. It is possible that you
|
||||
can also remove the ret variable as it is not needed for any
|
||||
of the core functions.
|
||||
|
||||
- static int example_detach(struct i2c_client *client)
|
||||
+ static int example_remove(struct i2c_client *client)
|
||||
{
|
||||
::
|
||||
|
||||
- static int example_detach(struct i2c_client *client)
|
||||
+ static int example_remove(struct i2c_client *client)
|
||||
{
|
||||
struct example_state *state = i2c_get_clientdata(client);
|
||||
|
||||
- i2c_detach_client(client);
|
||||
- i2c_detach_client(client);
|
||||
|
||||
And finally ensure that we have the correct ID table for the i2c-core
|
||||
and other utilities:
|
||||
and other utilities::
|
||||
|
||||
+ struct i2c_device_id example_idtable[] = {
|
||||
+ { "example", 0 },
|
||||
+ { }
|
||||
+};
|
||||
+
|
||||
+MODULE_DEVICE_TABLE(i2c, example_idtable);
|
||||
+ struct i2c_device_id example_idtable[] = {
|
||||
+ { "example", 0 },
|
||||
+ { }
|
||||
+};
|
||||
+
|
||||
+MODULE_DEVICE_TABLE(i2c, example_idtable);
|
||||
|
||||
static struct i2c_driver example_driver = {
|
||||
.driver = {
|
||||
static struct i2c_driver example_driver = {
|
||||
.driver = {
|
||||
.owner = THIS_MODULE,
|
||||
.name = "example",
|
||||
},
|
||||
+ .id_table = example_ids,
|
||||
+ .id_table = example_ids,
|
||||
|
||||
|
||||
Our driver should now look like this:
|
||||
Our driver should now look like this::
|
||||
|
||||
struct example_state {
|
||||
struct example_state {
|
||||
struct i2c_client *client;
|
||||
....
|
||||
};
|
||||
};
|
||||
|
||||
static int example_probe(struct i2c_client *client,
|
||||
const struct i2c_device_id *id)
|
||||
{
|
||||
static int example_probe(struct i2c_client *client,
|
||||
const struct i2c_device_id *id)
|
||||
{
|
||||
struct example_state *state;
|
||||
struct device *dev = &client->dev;
|
||||
|
||||
@ -250,25 +256,25 @@ static int example_probe(struct i2c_client *client,
|
||||
dev_info(dev, "example client created\n");
|
||||
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
static int example_remove(struct i2c_client *client)
|
||||
{
|
||||
static int example_remove(struct i2c_client *client)
|
||||
{
|
||||
struct example_state *state = i2c_get_clientdata(client);
|
||||
|
||||
kfree(state);
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
static struct i2c_device_id example_idtable[] = {
|
||||
static struct i2c_device_id example_idtable[] = {
|
||||
{ "example", 0 },
|
||||
{ }
|
||||
};
|
||||
};
|
||||
|
||||
MODULE_DEVICE_TABLE(i2c, example_idtable);
|
||||
MODULE_DEVICE_TABLE(i2c, example_idtable);
|
||||
|
||||
static struct i2c_driver example_driver = {
|
||||
.driver = {
|
||||
static struct i2c_driver example_driver = {
|
||||
.driver = {
|
||||
.owner = THIS_MODULE,
|
||||
.name = "example",
|
||||
.pm = &example_pm_ops,
|
||||
@ -276,4 +282,4 @@ static struct i2c_driver example_driver = {
|
||||
.id_table = example_idtable,
|
||||
.probe = example_probe,
|
||||
.remove = example_remove,
|
||||
};
|
||||
};
|
||||
@ -1,3 +1,7 @@
|
||||
===================
|
||||
Writing I2C Clients
|
||||
===================
|
||||
|
||||
This is a small guide for those who want to write kernel drivers for I2C
|
||||
or SMBus devices, using Linux as the protocol host/master (not slave).
|
||||
|
||||
@ -12,7 +16,7 @@ General remarks
|
||||
Try to keep the kernel namespace as clean as possible. The best way to
|
||||
do this is to use a unique prefix for all global symbols. This is
|
||||
especially important for exported symbols, but it is a good idea to do
|
||||
it for non-exported symbols too. We will use the prefix `foo_' in this
|
||||
it for non-exported symbols too. We will use the prefix ``foo_`` in this
|
||||
tutorial.
|
||||
|
||||
|
||||
@ -25,15 +29,17 @@ routines, and should be zero-initialized except for fields with data you
|
||||
provide. A client structure holds device-specific information like the
|
||||
driver model device node, and its I2C address.
|
||||
|
||||
static struct i2c_device_id foo_idtable[] = {
|
||||
::
|
||||
|
||||
static struct i2c_device_id foo_idtable[] = {
|
||||
{ "foo", my_id_for_foo },
|
||||
{ "bar", my_id_for_bar },
|
||||
{ }
|
||||
};
|
||||
};
|
||||
|
||||
MODULE_DEVICE_TABLE(i2c, foo_idtable);
|
||||
MODULE_DEVICE_TABLE(i2c, foo_idtable);
|
||||
|
||||
static struct i2c_driver foo_driver = {
|
||||
static struct i2c_driver foo_driver = {
|
||||
.driver = {
|
||||
.name = "foo",
|
||||
.pm = &foo_pm_ops, /* optional */
|
||||
@ -49,7 +55,7 @@ static struct i2c_driver foo_driver = {
|
||||
|
||||
.shutdown = foo_shutdown, /* optional */
|
||||
.command = foo_command, /* optional, deprecated */
|
||||
}
|
||||
}
|
||||
|
||||
The name field is the driver name, and must not contain spaces. It
|
||||
should match the module name (if the driver can be compiled as a module),
|
||||
@ -64,16 +70,18 @@ below.
|
||||
Extra client data
|
||||
=================
|
||||
|
||||
Each client structure has a special `data' field that can point to any
|
||||
Each client structure has a special ``data`` field that can point to any
|
||||
structure at all. You should use this to keep device-specific data.
|
||||
|
||||
::
|
||||
|
||||
/* store the value */
|
||||
void i2c_set_clientdata(struct i2c_client *client, void *data);
|
||||
|
||||
/* retrieve the value */
|
||||
void *i2c_get_clientdata(const struct i2c_client *client);
|
||||
|
||||
Note that starting with kernel 2.6.34, you don't have to set the `data' field
|
||||
Note that starting with kernel 2.6.34, you don't have to set the ``data`` field
|
||||
to NULL in remove() or if probe() failed anymore. The i2c-core does this
|
||||
automatically on these occasions. Those are also the only times the core will
|
||||
touch this field.
|
||||
@ -92,25 +100,25 @@ but many chips have some kind of register-value idea that can easily
|
||||
be encapsulated.
|
||||
|
||||
The below functions are simple examples, and should not be copied
|
||||
literally.
|
||||
literally::
|
||||
|
||||
int foo_read_value(struct i2c_client *client, u8 reg)
|
||||
{
|
||||
int foo_read_value(struct i2c_client *client, u8 reg)
|
||||
{
|
||||
if (reg < 0x10) /* byte-sized register */
|
||||
return i2c_smbus_read_byte_data(client, reg);
|
||||
else /* word-sized register */
|
||||
return i2c_smbus_read_word_data(client, reg);
|
||||
}
|
||||
}
|
||||
|
||||
int foo_write_value(struct i2c_client *client, u8 reg, u16 value)
|
||||
{
|
||||
int foo_write_value(struct i2c_client *client, u8 reg, u16 value)
|
||||
{
|
||||
if (reg == 0x10) /* Impossible to write - driver error! */
|
||||
return -EINVAL;
|
||||
else if (reg < 0x10) /* byte-sized register */
|
||||
return i2c_smbus_write_byte_data(client, reg, value);
|
||||
else /* word-sized register */
|
||||
return i2c_smbus_write_word_data(client, reg, value);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
Probing and attaching
|
||||
@ -145,6 +153,8 @@ I2C device drivers using this binding model work just like any other
|
||||
kind of driver in Linux: they provide a probe() method to bind to
|
||||
those devices, and a remove() method to unbind.
|
||||
|
||||
::
|
||||
|
||||
static int foo_probe(struct i2c_client *client,
|
||||
const struct i2c_device_id *id);
|
||||
static int foo_remove(struct i2c_client *client);
|
||||
@ -240,37 +250,41 @@ When the kernel is booted, or when your foo driver module is inserted,
|
||||
you have to do some initializing. Fortunately, just registering the
|
||||
driver module is usually enough.
|
||||
|
||||
static int __init foo_init(void)
|
||||
{
|
||||
::
|
||||
|
||||
static int __init foo_init(void)
|
||||
{
|
||||
return i2c_add_driver(&foo_driver);
|
||||
}
|
||||
module_init(foo_init);
|
||||
}
|
||||
module_init(foo_init);
|
||||
|
||||
static void __exit foo_cleanup(void)
|
||||
{
|
||||
static void __exit foo_cleanup(void)
|
||||
{
|
||||
i2c_del_driver(&foo_driver);
|
||||
}
|
||||
module_exit(foo_cleanup);
|
||||
}
|
||||
module_exit(foo_cleanup);
|
||||
|
||||
The module_i2c_driver() macro can be used to reduce above code.
|
||||
The module_i2c_driver() macro can be used to reduce above code.
|
||||
|
||||
module_i2c_driver(foo_driver);
|
||||
module_i2c_driver(foo_driver);
|
||||
|
||||
Note that some functions are marked by `__init'. These functions can
|
||||
Note that some functions are marked by ``__init``. These functions can
|
||||
be removed after kernel booting (or module loading) is completed.
|
||||
Likewise, functions marked by `__exit' are dropped by the compiler when
|
||||
Likewise, functions marked by ``__exit`` are dropped by the compiler when
|
||||
the code is built into the kernel, as they would never be called.
|
||||
|
||||
|
||||
Driver Information
|
||||
==================
|
||||
|
||||
/* Substitute your own name and email address */
|
||||
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"
|
||||
MODULE_DESCRIPTION("Driver for Barf Inc. Foo I2C devices");
|
||||
::
|
||||
|
||||
/* a few non-GPL license types are also allowed */
|
||||
MODULE_LICENSE("GPL");
|
||||
/* Substitute your own name and email address */
|
||||
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"
|
||||
MODULE_DESCRIPTION("Driver for Barf Inc. Foo I2C devices");
|
||||
|
||||
/* a few non-GPL license types are also allowed */
|
||||
MODULE_LICENSE("GPL");
|
||||
|
||||
|
||||
Power Management
|
||||
@ -323,6 +337,8 @@ commands, but only some of them understand plain I2C!
|
||||
Plain I2C communication
|
||||
-----------------------
|
||||
|
||||
::
|
||||
|
||||
int i2c_master_send(struct i2c_client *client, const char *buf,
|
||||
int count);
|
||||
int i2c_master_recv(struct i2c_client *client, char *buf, int count);
|
||||
@ -334,6 +350,8 @@ to read/write (must be less than the length of the buffer, also should be
|
||||
less than 64k since msg.len is u16.) Returned is the actual number of bytes
|
||||
read/written.
|
||||
|
||||
::
|
||||
|
||||
int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msg,
|
||||
int num);
|
||||
|
||||
@ -343,13 +361,15 @@ stop bit is sent between transaction. The i2c_msg structure contains
|
||||
for each message the client address, the number of bytes of the message
|
||||
and the message data itself.
|
||||
|
||||
You can read the file `i2c-protocol' for more information about the
|
||||
You can read the file ``i2c-protocol`` for more information about the
|
||||
actual I2C protocol.
|
||||
|
||||
|
||||
SMBus communication
|
||||
-------------------
|
||||
|
||||
::
|
||||
|
||||
s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
|
||||
unsigned short flags, char read_write, u8 command,
|
||||
int size, union i2c_smbus_data *data);
|
||||
@ -357,6 +377,8 @@ SMBus communication
|
||||
This is the generic SMBus function. All functions below are implemented
|
||||
in terms of it. Never use this function directly!
|
||||
|
||||
::
|
||||
|
||||
s32 i2c_smbus_read_byte(struct i2c_client *client);
|
||||
s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value);
|
||||
s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command);
|
||||
@ -376,7 +398,7 @@ in terms of it. Never use this function directly!
|
||||
const u8 *values);
|
||||
|
||||
These ones were removed from i2c-core because they had no users, but could
|
||||
be added back later if needed:
|
||||
be added back later if needed::
|
||||
|
||||
s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value);
|
||||
s32 i2c_smbus_process_call(struct i2c_client *client,
|
||||
@ -389,7 +411,7 @@ transactions return 0 on success; the 'read' transactions return the read
|
||||
value, except for block transactions, which return the number of values
|
||||
read. The block buffers need not be longer than 32 bytes.
|
||||
|
||||
You can read the file `smbus-protocol' for more information about the
|
||||
You can read the file ``smbus-protocol`` for more information about the
|
||||
actual SMBus protocol.
|
||||
|
||||
|
||||
@ -397,7 +419,7 @@ General purpose routines
|
||||
========================
|
||||
|
||||
Below all general purpose routines are listed, that were not mentioned
|
||||
before.
|
||||
before::
|
||||
|
||||
/* Return the adapter number for a specific adapter */
|
||||
int i2c_adapter_id(struct i2c_adapter *adap);
|
||||
@ -104,6 +104,7 @@ needed).
|
||||
fb/index
|
||||
fpga/index
|
||||
hid/index
|
||||
i2c/index
|
||||
iio/index
|
||||
infiniband/index
|
||||
leds/index
|
||||
|
||||
@ -17,7 +17,7 @@ kernel's SPI core subsystem.
|
||||
|
||||
The driver does not probe for supported chips, since the SI18IS602/603 does not
|
||||
support Chip ID registers. You will have to instantiate the devices explicitly.
|
||||
Please see Documentation/i2c/instantiating-devices for details.
|
||||
Please see Documentation/i2c/instantiating-devices.rst for details.
|
||||
|
||||
|
||||
Usage Notes
|
||||
|
||||
48
MAINTAINERS
48
MAINTAINERS
@ -666,7 +666,7 @@ ALI1563 I2C DRIVER
|
||||
M: Rudolf Marek <r.marek@assembler.cz>
|
||||
L: linux-i2c@vger.kernel.org
|
||||
S: Maintained
|
||||
F: Documentation/i2c/busses/i2c-ali1563
|
||||
F: Documentation/i2c/busses/i2c-ali1563.rst
|
||||
F: drivers/i2c/busses/i2c-ali1563.c
|
||||
|
||||
ALLEGRO DVT VIDEO IP CORE DRIVER
|
||||
@ -6741,7 +6741,7 @@ L: linux-i2c@vger.kernel.org
|
||||
S: Supported
|
||||
F: drivers/i2c/muxes/i2c-mux-gpio.c
|
||||
F: include/linux/platform_data/i2c-mux-gpio.h
|
||||
F: Documentation/i2c/muxes/i2c-mux-gpio
|
||||
F: Documentation/i2c/muxes/i2c-mux-gpio.rst
|
||||
|
||||
GENERIC HDLC (WAN) DRIVERS
|
||||
M: Krzysztof Halasa <khc@pm.waw.pl>
|
||||
@ -7497,14 +7497,14 @@ I2C CONTROLLER DRIVER FOR NVIDIA GPU
|
||||
M: Ajay Gupta <ajayg@nvidia.com>
|
||||
L: linux-i2c@vger.kernel.org
|
||||
S: Maintained
|
||||
F: Documentation/i2c/busses/i2c-nvidia-gpu
|
||||
F: Documentation/i2c/busses/i2c-nvidia-gpu.rst
|
||||
F: drivers/i2c/busses/i2c-nvidia-gpu.c
|
||||
|
||||
I2C MUXES
|
||||
M: Peter Rosin <peda@axentia.se>
|
||||
L: linux-i2c@vger.kernel.org
|
||||
S: Maintained
|
||||
F: Documentation/i2c/i2c-topology
|
||||
F: Documentation/i2c/i2c-topology.rst
|
||||
F: Documentation/i2c/muxes/
|
||||
F: Documentation/devicetree/bindings/i2c/i2c-mux*
|
||||
F: Documentation/devicetree/bindings/i2c/i2c-arb*
|
||||
@ -7524,8 +7524,8 @@ I2C OVER PARALLEL PORT
|
||||
M: Jean Delvare <jdelvare@suse.com>
|
||||
L: linux-i2c@vger.kernel.org
|
||||
S: Maintained
|
||||
F: Documentation/i2c/busses/i2c-parport
|
||||
F: Documentation/i2c/busses/i2c-parport-light
|
||||
F: Documentation/i2c/busses/i2c-parport.rst
|
||||
F: Documentation/i2c/busses/i2c-parport-light.rst
|
||||
F: drivers/i2c/busses/i2c-parport.c
|
||||
F: drivers/i2c/busses/i2c-parport-light.c
|
||||
|
||||
@ -7559,7 +7559,7 @@ I2C-TAOS-EVM DRIVER
|
||||
M: Jean Delvare <jdelvare@suse.com>
|
||||
L: linux-i2c@vger.kernel.org
|
||||
S: Maintained
|
||||
F: Documentation/i2c/busses/i2c-taos-evm
|
||||
F: Documentation/i2c/busses/i2c-taos-evm.rst
|
||||
F: drivers/i2c/busses/i2c-taos-evm.c
|
||||
|
||||
I2C-TINY-USB DRIVER
|
||||
@ -7573,19 +7573,19 @@ I2C/SMBUS CONTROLLER DRIVERS FOR PC
|
||||
M: Jean Delvare <jdelvare@suse.com>
|
||||
L: linux-i2c@vger.kernel.org
|
||||
S: Maintained
|
||||
F: Documentation/i2c/busses/i2c-ali1535
|
||||
F: Documentation/i2c/busses/i2c-ali1563
|
||||
F: Documentation/i2c/busses/i2c-ali15x3
|
||||
F: Documentation/i2c/busses/i2c-amd756
|
||||
F: Documentation/i2c/busses/i2c-amd8111
|
||||
F: Documentation/i2c/busses/i2c-i801
|
||||
F: Documentation/i2c/busses/i2c-nforce2
|
||||
F: Documentation/i2c/busses/i2c-piix4
|
||||
F: Documentation/i2c/busses/i2c-sis5595
|
||||
F: Documentation/i2c/busses/i2c-sis630
|
||||
F: Documentation/i2c/busses/i2c-sis96x
|
||||
F: Documentation/i2c/busses/i2c-via
|
||||
F: Documentation/i2c/busses/i2c-viapro
|
||||
F: Documentation/i2c/busses/i2c-ali1535.rst
|
||||
F: Documentation/i2c/busses/i2c-ali1563.rst
|
||||
F: Documentation/i2c/busses/i2c-ali15x3.rst
|
||||
F: Documentation/i2c/busses/i2c-amd756.rst
|
||||
F: Documentation/i2c/busses/i2c-amd8111.rst
|
||||
F: Documentation/i2c/busses/i2c-i801.rst
|
||||
F: Documentation/i2c/busses/i2c-nforce2.rst
|
||||
F: Documentation/i2c/busses/i2c-piix4.rst
|
||||
F: Documentation/i2c/busses/i2c-sis5595.rst
|
||||
F: Documentation/i2c/busses/i2c-sis630.rst
|
||||
F: Documentation/i2c/busses/i2c-sis96x.rst
|
||||
F: Documentation/i2c/busses/i2c-via.rst
|
||||
F: Documentation/i2c/busses/i2c-viapro.rst
|
||||
F: drivers/i2c/busses/i2c-ali1535.c
|
||||
F: drivers/i2c/busses/i2c-ali1563.c
|
||||
F: drivers/i2c/busses/i2c-ali15x3.c
|
||||
@ -7614,7 +7614,7 @@ M: Seth Heasley <seth.heasley@intel.com>
|
||||
M: Neil Horman <nhorman@tuxdriver.com>
|
||||
L: linux-i2c@vger.kernel.org
|
||||
F: drivers/i2c/busses/i2c-ismt.c
|
||||
F: Documentation/i2c/busses/i2c-ismt
|
||||
F: Documentation/i2c/busses/i2c-ismt.rst
|
||||
|
||||
I2C/SMBUS STUB DRIVER
|
||||
M: Jean Delvare <jdelvare@suse.com>
|
||||
@ -10355,7 +10355,7 @@ L: linux-i2c@vger.kernel.org
|
||||
S: Supported
|
||||
F: drivers/i2c/busses/i2c-mlxcpld.c
|
||||
F: drivers/i2c/muxes/i2c-mux-mlxcpld.c
|
||||
F: Documentation/i2c/busses/i2c-mlxcpld
|
||||
F: Documentation/i2c/busses/i2c-mlxcpld.rst
|
||||
|
||||
MELLANOX MLXCPLD LED DRIVER
|
||||
M: Vadim Pasternak <vadimp@mellanox.com>
|
||||
@ -11976,7 +11976,7 @@ M: Andrew Lunn <andrew@lunn.ch>
|
||||
L: linux-i2c@vger.kernel.org
|
||||
S: Maintained
|
||||
F: Documentation/devicetree/bindings/i2c/i2c-ocores.txt
|
||||
F: Documentation/i2c/busses/i2c-ocores
|
||||
F: Documentation/i2c/busses/i2c-ocores.rst
|
||||
F: drivers/i2c/busses/i2c-ocores.c
|
||||
F: include/linux/platform_data/i2c-ocores.h
|
||||
|
||||
@ -14280,7 +14280,7 @@ F: net/sctp/
|
||||
SCx200 CPU SUPPORT
|
||||
M: Jim Cromie <jim.cromie@gmail.com>
|
||||
S: Odd Fixes
|
||||
F: Documentation/i2c/busses/scx200_acb
|
||||
F: Documentation/i2c/busses/scx200_acb.rst
|
||||
F: arch/x86/platform/scx200/
|
||||
F: drivers/watchdog/scx200_wdt.c
|
||||
F: drivers/i2c/busses/scx200*
|
||||
|
||||
@ -5,7 +5,7 @@
|
||||
*
|
||||
* The ATXP1 can reside on I2C addresses 0x37 or 0x4e. The chip is
|
||||
* not auto-detected by the driver and must be instantiated explicitly.
|
||||
* See Documentation/i2c/instantiating-devices for more information.
|
||||
* See Documentation/i2c/instantiating-devices.rst for more information.
|
||||
*/
|
||||
|
||||
#include <linux/kernel.h>
|
||||
|
||||
@ -197,7 +197,7 @@ static int smm665_read_adc(struct smm665_data *data, int adc)
|
||||
if (rv != -ENXIO) {
|
||||
/*
|
||||
* We expect ENXIO to reflect NACK
|
||||
* (per Documentation/i2c/fault-codes).
|
||||
* (per Documentation/i2c/fault-codes.rst).
|
||||
* Everything else is an error.
|
||||
*/
|
||||
dev_dbg(&client->dev,
|
||||
|
||||
@ -54,7 +54,7 @@ config I2C_CHARDEV
|
||||
Say Y here to use i2c-* device files, usually found in the /dev
|
||||
directory on your system. They make it possible to have user-space
|
||||
programs use the I2C bus. Information on how to do this is
|
||||
contained in the file <file:Documentation/i2c/dev-interface>.
|
||||
contained in the file <file:Documentation/i2c/dev-interface.rst>.
|
||||
|
||||
This support is also available as a module. If so, the module
|
||||
will be called i2c-dev.
|
||||
@ -107,7 +107,7 @@ config I2C_STUB
|
||||
especially for certain kinds of sensor chips.
|
||||
|
||||
If you do build this module, be sure to read the notes and warnings
|
||||
in <file:Documentation/i2c/i2c-stub>.
|
||||
in <file:Documentation/i2c/i2c-stub.rst>.
|
||||
|
||||
If you don't know what to do here, definitely say N.
|
||||
|
||||
|
||||
@ -1206,7 +1206,7 @@ config I2C_PARPORT
|
||||
and makes it easier to add support for new devices.
|
||||
|
||||
An adapter type parameter is now mandatory. Please read the file
|
||||
Documentation/i2c/busses/i2c-parport for details.
|
||||
Documentation/i2c/busses/i2c-parport.rst for details.
|
||||
|
||||
Another driver exists, named i2c-parport-light, which doesn't depend
|
||||
on the parport driver. This is meant for embedded systems. Don't say
|
||||
|
||||
@ -77,7 +77,7 @@
|
||||
* SMBus Host Notify yes
|
||||
* Interrupt processing yes
|
||||
*
|
||||
* See the file Documentation/i2c/busses/i2c-i801 for details.
|
||||
* See the file Documentation/i2c/busses/i2c-i801.rst for details.
|
||||
*/
|
||||
|
||||
#include <linux/interrupt.h>
|
||||
|
||||
@ -125,7 +125,7 @@ static int taos_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
|
||||
/*
|
||||
* Voluntarily dropping error code of kstrtou8 since all
|
||||
* error code that it could return are invalid according
|
||||
* to Documentation/i2c/fault-codes.
|
||||
* to Documentation/i2c/fault-codes.rst.
|
||||
*/
|
||||
if (kstrtou8(p + 1, 16, &data->byte))
|
||||
return -EPROTO;
|
||||
|
||||
@ -2206,7 +2206,7 @@ static int i2c_detect_address(struct i2c_client *temp_client,
|
||||
dev_warn(&adapter->dev,
|
||||
"This adapter will soon drop class based instantiation of devices. "
|
||||
"Please make sure client 0x%02x gets instantiated by other means. "
|
||||
"Check 'Documentation/i2c/instantiating-devices' for details.\n",
|
||||
"Check 'Documentation/i2c/instantiating-devices.rst' for details.\n",
|
||||
info.addr);
|
||||
|
||||
dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
|
||||
@ -2236,7 +2236,7 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
|
||||
if (adapter->class == I2C_CLASS_DEPRECATED) {
|
||||
dev_dbg(&adapter->dev,
|
||||
"This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
|
||||
"If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n",
|
||||
"If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n",
|
||||
driver->driver.name);
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -693,7 +693,7 @@ static int iio_dummy_remove(struct iio_sw_device *swd)
|
||||
* Varies depending on bus type of the device. As there is no device
|
||||
* here, call probe directly. For information on device registration
|
||||
* i2c:
|
||||
* Documentation/i2c/writing-clients
|
||||
* Documentation/i2c/writing-clients.rst
|
||||
* spi:
|
||||
* Documentation/spi/spi-summary
|
||||
*/
|
||||
|
||||
@ -14,7 +14,7 @@
|
||||
*/
|
||||
/*
|
||||
* It would be more efficient to use i2c msgs/i2c_transfer directly but, as
|
||||
* recommened in .../Documentation/i2c/writing-clients section
|
||||
* recommended in .../Documentation/i2c/writing-clients.rst section
|
||||
* "Sending and receiving", using SMBus level communication is preferred.
|
||||
*/
|
||||
|
||||
|
||||
@ -521,7 +521,7 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
|
||||
*
|
||||
* The return codes from the @master_xfer{_atomic} fields should indicate the
|
||||
* type of error code that occurred during the transfer, as documented in the
|
||||
* Kernel Documentation file Documentation/i2c/fault-codes.
|
||||
* Kernel Documentation file Documentation/i2c/fault-codes.rst.
|
||||
*/
|
||||
struct i2c_algorithm {
|
||||
/*
|
||||
|
||||
Loading…
Reference in New Issue
Block a user