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i3c: Add sysfs ABI spec

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Document sysfs files/directories/symlinks exposed by the I3C subsystem.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Boris Brezillon 2017-12-14 10:43:47 +01:00
parent bd360e8175
commit a9f3edd0dd
1 changed files with 146 additions and 0 deletions
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What: /sys/bus/i3c/devices/i3c-<bus-id>
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
An I3C bus. This directory will contain one sub-directory per
I3C device present on the bus.
What: /sys/bus/i3c/devices/i3c-<bus-id>/current_master
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
Expose the master that owns the bus (<bus-id>-<master-pid>) at
the time this file is read. Note that bus ownership can change
overtime, so there's no guarantee that when the read() call
returns, the value returned is still valid.
What: /sys/bus/i3c/devices/i3c-<bus-id>/mode
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
I3C bus mode. Can be "pure", "mixed-fast" or "mixed-slow". See
the I3C specification for a detailed description of what each
of these modes implies.
What: /sys/bus/i3c/devices/i3c-<bus-id>/i3c_scl_frequency
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
The frequency (expressed in Hz) of the SCL signal when
operating in I3C SDR mode.
What: /sys/bus/i3c/devices/i3c-<bus-id>/i2c_scl_frequency
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
The frequency (expressed in Hz) of the SCL signal when
operating in I2C mode.
What: /sys/bus/i3c/devices/i3c-<bus-id>/dynamic_address
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
Dynamic address assigned to the master controller. This
address may change if the bus is re-initialized.
What: /sys/bus/i3c/devices/i3c-<bus-id>/bcr
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
BCR stands for Bus Characteristics Register and express the
device capabilities in term of speed, maximum read/write
length, etc. See the I3C specification for more details.
This entry describes the BCR of the master controller driving
the bus.
What: /sys/bus/i3c/devices/i3c-<bus-id>/dcr
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
DCR stands for Device Characteristics Register and express the
device capabilities in term of exposed features. See the I3C
specification for more details.
This entry describes the DCR of the master controller driving
the bus.
What: /sys/bus/i3c/devices/i3c-<bus-id>/pid
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
PID stands for Provisional ID and is used to uniquely identify
a device on a bus. This PID contains information about the
vendor, the part and an instance ID so that several devices of
the same type can be connected on the same bus.
See the I3C specification for more details.
This entry describes the PID of the master controller driving
the bus.
What: /sys/bus/i3c/devices/i3c-<bus-id>/hdrcap
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
Expose the HDR (High Data Rate) capabilities of a device.
Returns a list of supported HDR mode, each element is separated
by space. Modes can be "hdr-ddr", "hdr-tsp" and "hdr-tsl".
See the I3C specification for more details about these HDR
modes.
This entry describes the HDRCAP of the master controller
driving the bus.
What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
An I3C device present on I3C bus identified by <bus-id>. Note
that all devices are represented including the master driving
the bus.
What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/dynamic_address
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
Dynamic address assigned to device <bus-id>-<device-pid>. This
address may change if the bus is re-initialized.
What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/bcr
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
BCR stands for Bus Characteristics Register and express the
device capabilities in term of speed, maximum read/write
length, etc. See the I3C specification for more details.
What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/dcr
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
DCR stands for Device Characteristics Register and express the
device capabilities in term of exposed features. See the I3C
specification for more details.
What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/pid
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
PID stands for Provisional ID and is used to uniquely identify
a device on a bus. This PID contains information about the
vendor, the part and an instance ID so that several devices of
the same type can be connected on the same bus.
See the I3C specification for more details.
What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/hdrcap
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
Expose the HDR (High Data Rate) capabilities of a device.
Returns a list of supported HDR mode, each element is separated
by space. Modes can be "hdr-ddr", "hdr-tsp" and "hdr-tsl".
See the I3C specification for more details about these HDR
modes.
What: /sys/bus/i3c/devices/<bus-id>-<device-pid>
KernelVersion: 5.0
Contact: linux-i3c@vger.kernel.org
Description:
These directories are just symbolic links to
/sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>.