Trivial fix to spelling mistakes in dev_dbg messages
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There is a difference between attempts and retries.
Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The else branch cannot be taken as i will always equal num.
Get rid of the whole construct.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
exynos5_i2c_xfer contains lots of dead code, let's remove it and simplify
the rest. The patch should not introduce functional changes.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Suggested-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Andi Shyti <andi@etezian.org>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Low-level controller enable function __i2c_dw_enable is overloaded to
also handle disabling. What's worse, even though the documentation
requires polling the IC_ENABLE_STATUS register when disabling, this
is not done: polling needs to be requested specifically by calling
__i2c_dw_enable_and_wait, which can also poll on enabling, but that
doesn't work if the IC_ENABLE_STATUS register is not implemented.
This is quite confusing if not in fact backwards.
Especially since the documentation says that disabling should be
followed by polling, the driver should be using a separate function
where it does one-shot disables to make the optimization stand out.
This refactors the two functions so that requested status is given
in the name rather than in a boolean argument. Specifically:
- __i2c_dw_enable: enable without polling (in accordance with docs)
- __i2c_dw_disable: disable and do poll (also as suggested by docs)
- __i2c_dw_disable_nowait: disable without polling (Linux-specific)
No functional change.
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
[wsa: fixed blank lines in header file]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Returning zero is wrong in this case.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 174a13aa86 ("i2c: Add viperboard i2c master driver")
Returning -1 (-EPERM) is not appropriate here, go with -EIO.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 1b144df1d7 ("i2c: New PMC MSP71xx TWI bus driver")
Returning zero is wrong in this case.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 1b144df1d7 ("i2c: New PMC MSP71xx TWI bus driver")
Not all revisions of DW I2C controller implement the enable status register.
On platforms where that's the case (e.g. BG2CD and SPEAr ARM SoCs), waiting
for enable will time out as reading the unimplemented register yields zero.
It was observed that reading the IC_ENABLE_STATUS register once suffices to
avoid getting it stuck on Bay Trail hardware, so replace polling with one
dummy read of the register.
Fixes: fba4adbbf6 ("i2c: designware: must wait for enable")
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Tested-by: Ben Gardner <gardner.ben@gmail.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
These days, the I2C core ensures that the embedded adapter device
ignores the PM states of its children already. Because the adapter
device is an opaque logical device, there is no need for drivers to
repeat that again.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
axxia_i2c_init() uses clk_get_rate() for idev->i2c_clk. clk_get_rate()
should only be called if the clock is enabled, so ensure that by moving
the clk_prepare_enable() call before the call to axxia_i2c_init().
Found by Linux Driver Verification project (linuxtesting.org).
Fixes: 08678b850c ("i2c: axxia: Add I2C driver for AXM55xx")
Signed-off-by: Tobias Jordan <Tobias.Jordan@elektrobit.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Give a clear testcase for people wishing to change this code. It is also
a reminder for me if people ask about it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
It allows mlxcpld driver to be connected to pre-defined adapter number
equal or greater than one, in order to avoid current limitation, assuming
usage of id number one only.
Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
It fixes report about supported functionality.
Functionality can be different up to CPLD capability.
Fixes: 6bec23bff9 (i2c: mlxcpld: add master driver for mellanox systems)
Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
It adds support for smbus block read transaction. CPLD smbus block read bit
of capability register is verified during driver initialization, and driver
data is updated if such capability is available. In case an upper layer
requests a read transaction of length one and expects that length will be
the first received byte, driver will notify CPLD about SMBus block read
transaction flavor, so CPLD will know to execute such kind of transaction.
Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
It adds support for extended length of read and write transactions.
New CPLD logic allows double size of the read and write transactions
length. This feature is verified through capability register, which is
renamed from unclear LPF_REG to CPBLTY_REG. Two bits 5 and 6 of these
register are used for length capability detection, while only 01
combination indicates support of extended transaction length.
Others mean lack of such support.
Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The usage of of_device_get_match_data() reduce the code size a bit.
Also, the only way to call mtk_i2c_probe() is to match an entry in
mtk_i2c_of_match[], so of_id cannot be NULL.
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The Exynos5440 is not actively developed, there are no development
boards available and probably there are no real products with it.
Remove wide-tree support for Exynos5440.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Restoring configuration registers is only needed when we hand control
to the firmware. This is never the case with runtime power
management. The device will autosuspend whenever not used, so avoid
useless register writes by defining suspend/resume only, and not
runtime_suspend/runtime_resume.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
With FIFO enabled it is possible to read multiple bytes
at once in the interrupt handler as long as RXRDY is
set. This may also reduce the number of interrupts.
This patch polls RXRDY and reads all available bytes at
once.
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
[wsa: reformatted comment]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds a generic DMA API to implement DMA support for i2c-stm32fx
drivers
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds slave support for I2C controller embedded in STM32F7 SoC
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds support for 10-bit device address for STM32F7 I2C
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We found the I2C controller count register is unreliable sometimes,
that will cause I2C to lose data. Thus we can read the data count
from 'i2c_dev->count' instead of the I2C controller count register.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add one flag to indicate if the i2c controller has been in suspend state,
which can prevent i2c accesses after i2c controller is suspended following
system suspend.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Remove dependencies on HAS_DMA where a Kconfig symbol depends on another
symbol that implies HAS_DMA, and, optionally, on "|| COMPILE_TEST".
In most cases this other symbol is an architecture or platform specific
symbol, or PCI.
Generic symbols and drivers without platform dependencies keep their
dependencies on HAS_DMA, to prevent compiling subsystems or drivers that
cannot work anyway.
This simplifies the dependencies, and allows to improve compile-testing.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
On some systems, the BIOS expects certain SMBus register values to
match the hardware defaults. Restore these configuration registers at
shutdown time to avoid confusing the BIOS. This avoids hard-locking
such systems upon reboot.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org
Saving the original value of register SMBSLVCMD in
i801_enable_host_notify() doesn't work, because this function is
called not only at probe time but also at resume time. Do it in
i801_probe() instead, so that the saved value is not overwritten at
resume time.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 22e94bd677 ("i2c: i801: store and restore the SLVCMD register at load and unload")
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org # v4.10+
Pull i2c updates from Wolfram Sang:
-I2C core now reports proper OF style module alias. I'd like to repeat
the note from the commit msg here (Thanks, Javier!):
NOTE: This patch may break out-of-tree drivers that were relying
on this behavior, and only had an I2C device ID table even
when the device was registered via OF.
There are no remaining drivers in mainline that do this, but
out-of-tree drivers have to be fixed and define a proper OF
device ID table to have module auto-loading working.
- new driver for the SynQuacer I2C controller
- major refactoring of the QUP driver
- the piix4 driver now uses request_muxed_region which should fix a
long standing resource conflict with the sp5100_tco watchdog
- a bunch of small core & driver improvements
* 'i2c/for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (53 commits)
i2c: add support for Socionext SynQuacer I2C controller
dt-bindings: i2c: add binding for Socionext SynQuacer I2C
i2c: Update i2c_trace_msg static key to modern api
i2c: fix parameter of trace_i2c_result
i2c: imx: avoid taking clk_prepare mutex in PM callbacks
i2c: imx: use clk notifier for rate changes
i2c: make i2c_check_addr_validity() static
i2c: rcar: fix mask value of prohibited bit
dt-bindings: i2c: document R8A77965 bindings
i2c: pca-platform: drop gpio from platform data
i2c: pca-platform: use device_property_read_u32
i2c: pca-platform: unconditionally use devm_gpiod_get_optional
sh: sh7785lcr: add GPIO lookup table for i2c controller reset
i2c: qup: reorganization of driver code to remove polling for qup v2
i2c: qup: reorganization of driver code to remove polling for qup v1
i2c: qup: send NACK for last read sub transfers
i2c: qup: fix buffer overflow for multiple msg of maximum xfer len
i2c: qup: change completion timeout according to transfer length
i2c: qup: use the complete transfer length to choose DMA mode
i2c: qup: proper error handling for i2c error in BAM mode
...
This is a cleaned up version of the I2C controller driver for
the Fujitsu F_I2C IP, which was never supported upstream, and
has now been incorporated into the Socionext SynQuacer SoC.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
[wsa: updated MAINTAINERS entry and removed two empty lines]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This is unsafe, as the runtime PM callbacks are called from the PM
workqueue, so this may deadlock when handling an i2c attached clock,
which may already hold the clk_prepare mutex from another context.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Instead of repeatedly calling clk_get_rate for each transfer, register
a clock notifier to update the cached divider value each time the clock
rate actually changes.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This removes the entire architecture code for blackfin, cris, frv, m32r,
metag, mn10300, score, and tile, including the associated device drivers.
I have been working with the (former) maintainers for each one to ensure
that my interpretation was right and the code is definitely unused in
mainline kernels. Many had fond memories of working on the respective
ports to start with and getting them included in upstream, but also saw
no point in keeping the port alive without any users.
In the end, it seems that while the eight architectures are extremely
different, they all suffered the same fate: There was one company
in charge of an SoC line, a CPU microarchitecture and a software
ecosystem, which was more costly than licensing newer off-the-shelf
CPU cores from a third party (typically ARM, MIPS, or RISC-V). It seems
that all the SoC product lines are still around, but have not used the
custom CPU architectures for several years at this point. In contrast,
CPU instruction sets that remain popular and have actively maintained
kernel ports tend to all be used across multiple licensees.
The removal came out of a discussion that is now documented at
https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
marking any ports as deprecated but remove them all at once after I made
sure that they are all unused. Some architectures (notably tile, mn10300,
and blackfin) are still being shipped in products with old kernels,
but those products will never be updated to newer kernel releases.
After this series, we still have a few architectures without mainline
gcc support:
- unicore32 and hexagon both have very outdated gcc releases, but the
maintainers promised to work on providing something newer. At least
in case of hexagon, this will only be llvm, not gcc.
- openrisc, risc-v and nds32 are still in the process of finishing their
support or getting it added to mainline gcc in the first place.
They all have patched gcc-7.3 ports that work to some degree, but
complete upstream support won't happen before gcc-8.1. Csky posted
their first kernel patch set last week, their situation will be similar.
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Merge tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pul removal of obsolete architecture ports from Arnd Bergmann:
"This removes the entire architecture code for blackfin, cris, frv,
m32r, metag, mn10300, score, and tile, including the associated device
drivers.
I have been working with the (former) maintainers for each one to
ensure that my interpretation was right and the code is definitely
unused in mainline kernels. Many had fond memories of working on the
respective ports to start with and getting them included in upstream,
but also saw no point in keeping the port alive without any users.
In the end, it seems that while the eight architectures are extremely
different, they all suffered the same fate: There was one company in
charge of an SoC line, a CPU microarchitecture and a software
ecosystem, which was more costly than licensing newer off-the-shelf
CPU cores from a third party (typically ARM, MIPS, or RISC-V). It
seems that all the SoC product lines are still around, but have not
used the custom CPU architectures for several years at this point. In
contrast, CPU instruction sets that remain popular and have actively
maintained kernel ports tend to all be used across multiple licensees.
[ See the new nds32 port merged in the previous commit for the next
generation of "one company in charge of an SoC line, a CPU
microarchitecture and a software ecosystem" - Linus ]
The removal came out of a discussion that is now documented at
https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
marking any ports as deprecated but remove them all at once after I
made sure that they are all unused. Some architectures (notably tile,
mn10300, and blackfin) are still being shipped in products with old
kernels, but those products will never be updated to newer kernel
releases.
After this series, we still have a few architectures without mainline
gcc support:
- unicore32 and hexagon both have very outdated gcc releases, but the
maintainers promised to work on providing something newer. At least
in case of hexagon, this will only be llvm, not gcc.
- openrisc, risc-v and nds32 are still in the process of finishing
their support or getting it added to mainline gcc in the first
place. They all have patched gcc-7.3 ports that work to some
degree, but complete upstream support won't happen before gcc-8.1.
Csky posted their first kernel patch set last week, their situation
will be similar
[ Palmer Dabbelt points out that RISC-V support is in mainline gcc
since gcc-7, although gcc-7.3.0 is the recommended minimum - Linus ]"
This really says it all:
2498 files changed, 95 insertions(+), 467668 deletions(-)
* tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits)
MAINTAINERS: UNICORE32: Change email account
staging: iio: remove iio-trig-bfin-timer driver
tty: hvc: remove tile driver
tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers
serial: remove tile uart driver
serial: remove m32r_sio driver
serial: remove blackfin drivers
serial: remove cris/etrax uart drivers
usb: Remove Blackfin references in USB support
usb: isp1362: remove blackfin arch glue
usb: musb: remove blackfin port
usb: host: remove tilegx platform glue
pwm: remove pwm-bfin driver
i2c: remove bfin-twi driver
spi: remove blackfin related host drivers
watchdog: remove bfin_wdt driver
can: remove bfin_can driver
mmc: remove bfin_sdh driver
input: misc: remove blackfin rotary driver
input: keyboard: remove bf54x driver
...
The blackfin architecture is getting removed, so the
twi driver can also be removed.
Acked-by: Aaron Wu <aaron.wu@analog.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
According to documentation, Bit 7 of ICMSR is unused and 0 should be
written to it. Fix the mask accordingly.
Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
[wsa: edited commit message]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Merge tag 'at24-4.17-updates-for-wolfram' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into i2c/for-4.17
"three new special cases for device tree compatible strings"
Use device_property_read_u32 instead of of_property_read_u32_index to
lookup the "clock-frequency" property.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allow for the reset-gpios property to be defined in the device tree
or via a GPIO lookup table.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Following are the major issues in current driver code
1. The current driver simply assumes the transfer completion
whenever its gets any non-error interrupts and then simply do the
polling of available/free bytes in FIFO.
2. The block mode is not working properly since no handling in
being done for OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_READ.
3. An i2c transfer can contain multiple message and QUP v2
supports reconfiguration during run in which the mode should be same
for all the sub transfer. Currently the mode is being programmed
before every sub transfer which is functionally wrong. If one message
is less than FIFO length and other message is greater than FIFO
length, then transfers will fail.
Because of above, i2c v2 transfers of size greater than 64 are failing
with following error message
i2c_qup 78b6000.i2c: timeout for fifo out full
To make block mode working properly and move to use the interrupts
instead of polling, major code reorganization is required. Following
are the major changes done in this patch
1. Remove the polling of TX FIFO free space and RX FIFO available
bytes and move to interrupts completely. QUP has QUP_MX_OUTPUT_DONE,
QUP_MX_INPUT_DONE, OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_REQ
interrupts to handle FIFO’s properly so check all these interrupts.
2. Determine the mode for transfer before starting by checking
all the tx/rx data length in each message. The complete message can be
transferred either in DMA mode or Programmed IO by FIFO/Block mode.
in DMA mode, both tx and rx uses same mode but in PIO mode, the TX and
RX can be in different mode.
3. During write, For FIFO mode, TX FIFO can be directly written
without checking for FIFO space. For block mode, the QUP will generate
OUT_BLOCK_WRITE_REQ interrupt whenever it has block size of available
space.
4. During read, both TX and RX FIFO will be used. TX will be used
for writing tags and RX will be used for receiving the data. In QUP,
TX and RX can operate in separate mode so configure modes accordingly.
5. For read FIFO mode, wait for QUP_MX_INPUT_DONE interrupt which
will be generated after all the bytes have been copied in RX FIFO. For
read Block mode, QUP will generate IN_BLOCK_READ_REQ interrupts
whenever it has block size of available data.
6. Split the transfer in chunk of one QUP block size(256 bytes)
and schedule each block separately. QUP v2 supports reconfiguration
during run in which QUP can transfer multiple blocks without issuing a
stop events.
7. Port the SMBus block read support for new code changes.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Following are the major issues in current driver code
1. The current driver simply assumes the transfer completion
whenever its gets any non-error interrupts and then simply do the
polling of available/free bytes in FIFO.
2. The block mode is not working properly since no handling in
being done for OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_REQ.
Because of above, i2c v1 transfers of size greater than 32 are failing
with following error message
i2c_qup 78b6000.i2c: timeout for fifo out full
To make block mode working properly and move to use the interrupts
instead of polling, major code reorganization is required. Following
are the major changes done in this patch
1. Remove the polling of TX FIFO free space and RX FIFO available
bytes and move to interrupts completely. QUP has QUP_MX_OUTPUT_DONE,
QUP_MX_INPUT_DONE, OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_REQ
interrupts to handle FIFO’s properly so check all these interrupts.
2. During write, For FIFO mode, TX FIFO can be directly written
without checking for FIFO space. For block mode, the QUP will generate
OUT_BLOCK_WRITE_REQ interrupt whenever it has block size of available
space.
3. During read, both TX and RX FIFO will be used. TX will be used
for writing tags and RX will be used for receiving the data. In QUP,
TX and RX can operate in separate mode so configure modes accordingly.
4. For read FIFO mode, wait for QUP_MX_INPUT_DONE interrupt which
will be generated after all the bytes have been copied in RX FIFO. For
read Block mode, QUP will generate IN_BLOCK_READ_REQ interrupts
whenever it has block size of available data.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
According to I2c specification, “If a master-receiver sends a
repeated START condition, it sends a not-acknowledge (A) just
before the repeated START condition”. QUP v2 supports sending
of NACK without stop with QUP_TAG_V2_DATARD_NACK so added the
same.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The BAM mode requires buffer for start tag data and tx, rx SG
list. Currently, this is being taken for maximum transfer length
(65K). But an I2C transfer can have multiple messages and each
message can be of this maximum length so the buffer overflow will
happen in this case. Since increasing buffer length won’t be
feasible since an I2C transfer can contain any number of messages
so this patch does following changes to make i2c transfers working
for multiple messages case.
1. Calculate the required buffers for 2 maximum length messages
(65K * 2).
2. Split the descriptor formation and descriptor scheduling.
The idea is to fit as many messages in one DMA transfers for 65K
threshold value (max_xfer_sg_len). Whenever the sg_cnt is
crossing this, then schedule the BAM transfer and subsequent
transfer will again start from zero.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Currently the completion timeout is being taken according to
maximum transfer length which is too high if SCL is operating in
high frequency. This patch calculates timeout on the basis of
one-byte transfer time and uses the same for completion timeout.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Currently each message length in complete transfer is being
checked for determining DMA mode and if any of the message length
is less than FIFO length then non DMA mode is being used which
will increase overhead. DMA can be used for any length and it
should be determined with complete transfer length. Now, this
patch selects DMA mode if the total length is greater than FIFO
length.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Currently the i2c error handling in BAM mode is not working
properly in stress condition.
1. After an error, the FIFO are being written with FLUSH and
EOT tags which should not be required since already these tags
have been written in BAM descriptor itself.
2. QUP state is being moved to RESET in IRQ handler in case
of error. When QUP HW encounters an error in BAM mode then it
moves the QUP STATE to PAUSE state. In this case, I2C_FLUSH
command needs to be executed while moving to RUN_STATE by writing
to the QUP_STATE register with the I2C_FLUSH bit set to 1.
3. In Error case, sometimes, QUP generates more than one
interrupt which will trigger the complete again. After an error,
the flush operation will be scheduled after doing
reinit_completion which should be triggered by BAM IRQ callback.
If the second QUP IRQ comes during this time then it will call
the complete and the transfer function will assume the all the
BAM HW descriptors have been completed.
4. The release DMA is being called after each error which
will free the DMA tx and rx channels. The error like NACK is very
common in I2C transfer and every time this will be overhead. Now,
since the error handling is proper so this release channel can be
completely avoided.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
