i2c: stm32f7: add support for stm32mp25 soc

The stm32mp25 has only a single interrupt line used for both
events and errors. In order to cope with that, reorganise the
error handling code so that it can be called either from the
common handler (used in case of SoC having only a single IT line)
and the error handler for others.
The CR1 register also embeds a new FMP bit, necessary when running
at Fast Mode Plus frequency. This bit should be used instead of
the SYSCFG bit used on other platforms.
Add a new compatible to distinguish between the SoCs and two
boolean within the setup structure in order to know if the
platform has a single/multiple IT lines and if the FMP bit
within CR1 is available or not.

Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: perform I2C_ISR read once at beginning of event isr

Move readl_relaxed of I2C_ISR register at beginning of event isr
so that it done once for both master & slave handling.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: simplify status messages in case of errors

Avoid usage of __func__ when reporting an error message
since dev_err/dev_dbg are already providing enough details
to identify the source of the message.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: perform most of irq job in threaded handler

The irq handling is currently split between the irq handler
and the threaded irq handler. Some of the handling (such as
dma related stuffs) done within the irq handler might sleep or
take some time leading to issues if the kernel is built with
realtime constraints. In order to fix that, perform an overall
rework to perform most of the job within the threaded handler
and only keep fifo access in the non threaded handler.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: use dev_err_probe upon calls of devm_request_irq

Convert error handling upon calls of devm_request_irq functions during
the probe of the driver.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: Use devm_clk_get_enabled()

Replace the pair of functions, devm_clk_get() and
clk_prepare_enable(), with a single function
devm_clk_get_enabled().

Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: add description of atomic in struct stm32f7_i2c_dev

Add missing description of the atomic boolean in struct stm32f7_i2c_dev.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: Add atomic_xfer method to driver

Add an atomic_xfer method to the driver so that it behaves correctly
when controlling a PMIC that is responsible for device shutdown.

The atomic_xfer method added is similar to the one from the i2c-mv64xxx
driver. When running an atomic_xfer a bool flag in the driver data is
set, the interrupt is not unmasked on transfer start, and the IRQ
handler is manually invoked while waiting for pending transfers to
complete.

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: Fix PEC handling in case of SMBUS transfers

In case of SMBUS byte read with PEC enabled, the whole transfer
is split into two commands. A first write command, followed by
a read command. The write command does not have any PEC byte
and a PEC byte is appended at the end of the read command.
(cf Read byte protocol with PEC in SMBUS specification)

Within the STM32 I2C controller, handling (either sending
or receiving) of the PEC byte is done via the PECBYTE bit in
register CR2.

Currently, the PECBYTE is set at the beginning of a transfer,
which lead to sending a PEC byte at the end of the write command
(hence losing the real last byte), and also does not check the
PEC byte received during the read command.

This patch corrects the function stm32f7_i2c_smbus_xfer_msg
in order to only set the PECBYTE during the read command.

Fixes: 9e48155f6bfe ("i2c: i2c-stm32f7: Add initial SMBus protocols support")
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32: Do not check for 0 return after calling platform_get_irq()

It is not possible for platform_get_irq() to return 0. Use the
return value from platform_get_irq().

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Link: https://lore.kernel.org/r/20230731112755.1943630-1-ruanjinjie@huawei.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

i2c: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Asmaa Mnebhi <asnaa@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Chris Pringle <chris.pringle@phabrix.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Tali Perry <tali.perry@nuvoton.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32: add support for the STM32MP13 soc

Add a new compatible for the stm32mp13. Fast Mode Plus control
register address differ from the one for STM32MP15.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: remove noisy and imprecise log messages

The log messages talk about 'bus recovery' while it is not a bus
recovery with 9 pulses but merely a controller reset. Controller resets
are not worth log messages. The 'bus busy' message should be emitted by
upper layers, a busy bus may be expected in some cases.

Signed-off-by: Wolfram Sang <wsa@kernel.org>
Reviewed-by: Alain Volmat <alain.volmat@foss.st.com>

i2c: stm32: get rid of stm32f7_i2c_release_bus return value

Function stm32f7_i2c_release_bus is always returning 0, hence it
should be a void function. Update the function and remove the
return value error checking code in caller functions.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: use proper DMAENGINE API for termination

dmaengine_terminate_all() is deprecated in favor of explicitly saying if
it should be sync or async. Here, we use dmaengine_terminate_sync in
i2c_xfer and i2c_smbus_xfer handlers and rely on
dmaengine_terminate_async within interrupt handlers
(transmission error cases).
dmaengine_synchronize is added within i2c_xfer and i2c_smbus_xfer handler
to finalize terminate started in interrupt handlers.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: stop dma transfer in case of NACK

In case of receiving a NACK, the dma transfer should be stopped
to avoid feeding data into the FIFO.
Also ensure to properly return the proper error code and avoid
waiting for the end of the dma completion in case of
error happening during the transmission.

Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: recover the bus on access timeout

When getting an access timeout, ensure that the bus is in a proper
state prior to returning the error.

Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver")
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: flush TX FIFO upon transfer errors

While handling an error during transfer (ex: NACK), it could
happen that the driver has already written data into TXDR
before the transfer get stopped.
This commit add TXDR Flush after end of transfer in case of error to
avoid sending a wrong data on any other slave upon next transfer.

Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver")
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: add SMBus-Alert support

Add support for the SMBus-Alert protocol to the STM32F7 that has
dedicated control and status logic.

If SMBus-Alert is used, the SMBALERT# pin must be configured as alternate
function for I2C Alert.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: fix reference leak when pm_runtime_get_sync fails

The PM reference count is not expected to be incremented on
return in these stm32f7_i2c_xx serious functions.

However, pm_runtime_get_sync will increment the PM reference
count even failed. Forgetting to putting operation will result
in a reference leak here.

Replace it with pm_runtime_resume_and_get to keep usage
counter balanced.

Fixes: ea6dd25deeb5 ("i2c: stm32f7: add PM_SLEEP suspend/resume support")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: avoid ifdef CONFIG_PM_SLEEP for pm callbacks

Avoid CONFIG_PM preprocessor check for pm suspend/resume
callbacks and identify the functions with __maybe_unused.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: Remove useless error message

Fix the following coccicheck report:

drivers/i2c/busses/i2c-stm32f7.c:2032:3-10 : platform_get_irq :
line 2032 is redundant because platform_get_irq() already prints an error

Remove dev_err() messages after platform_get_irq() failures.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Reviewed-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: indicate the address being accessed on errors

To help debugging issues, add the address of the slave being
accessed when getting an error.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: add support for DNF i2c-digital-filter binding

Add the support for the i2c-digital-filter binding, allowing to enable
the digital filter via the device-tree and indicate its value in the DT.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: support DT binding i2c-analog-filter

Replace driver internally coded enabling/disabling of the
analog-filter with the DT binding "i2c-analog-filter".

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: remove redundant error print in stm32f7_i2c_probe

Coccinelle reports a redundant error print in stm32f7_i2c_probe.
As 'platform_get_irq' already prints the error message, error
print here is redundant and can be removed.

Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: fix configuration of the digital filter

The digital filter related computation are present in the driver
however the programming of the filter within the IP is missing.
The maximum value for the DNF is wrong and should be 15 instead of 16.

Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver")

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

PM: sleep: Add dev_wakeup_path() helper

Add dev_wakeup_path() helper to avoid to spread
dev->power.wakeup_path test in drivers.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

i2c: stm32: Simplify with dev_err_probe()

Common pattern of handling deferred probe can be simplified with
dev_err_probe(). Less code and the error value gets printed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32: fix error message on upon dma_request_chan & defer handling

DMA usage is optional for the I2C driver. check for the -ENODEV
error in order to avoid displaying an error when no DMA
has been requested.
Cleaning up the error messages during probe, remove the additional
-EPROBE_DEFER within probe function since additional error message
doesn't give much more information than what is already reported
within the stm32_i2c_dma_request function.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32: name slave slot to ease maintenance

Name slave slots in order to ease code maintenance.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: Add SMBus Host-Notify protocol support

Rely on the core functions to implement the host-notify
protocol via the a I2C slave device.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: stm32f7: prevent array underflow in stm32f7_get_lower_rate()

We want to break with "i" set to zero whether we find the rate we want
or not. In the current code, if we don't find the rate we want then it
exits the loop with "i" set to -1 and results in an array underflow.

Fixes: 09cc9a3bce91 ("i2c: stm32f7: allows for any bus frequency")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: allows for any bus frequency

Do not limitate to the 3 (100KHz, 400KHz, 1MHz) bus frequency but
instead allows any frequency (if it matches timing requirements).
Depending on the requested frequency, use the spec data from either
Standard, Fast or Fast Plus mode.

Hardcoding of min/max bus frequencies is removed and is instead computed.

The driver do not use anymore speed identifier but instead handle
directly the frequency and figure out the spec data (necessary
for the computation of the timing register) based on the frequency.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32: don't print an error on probe deferral

Do not print an error trace when deferring probe for some resource.
Fix as well the error message in case of tx dma_request_chan failure.

Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: improve nack debug message

Add information on slave addr in the nack debug message.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: busses: convert to devm_platform_get_and_ioremap_resource

use devm_platform_get_and_ioremap_resource() to simplify code, which
contains platform_get_resource() and devm_ioremap_resource(), it also
get the resource for use by the following code.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: switch to I²C generic property parsing

Switch to the new generic functions: i2c_parse_fw_timings().

While here, replace hard coded values with standard bus frequency definitions.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: do not backup read-only PECR register

The PECR register provides received packet computed PEC value. 
It makes no sense restoring its value after a reset, and anyway,
as read-only register it cannot be restored.

Fixes: ea6dd25deeb5 ("i2c: stm32f7: add PM_SLEEP suspend/resume support")
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: add a new st, stm32mp15-i2c compatible

Add a new stm32mp15 specific compatible to handle FastMode+
registers handling which is different on the stm32mp15 compared
to the stm32f7 or stm32h7.
Indeed, on the stm32mp15, the FastMode+ set and clear registers
are separated while on the other platforms (F7 or H7) the control
is done in a unique register.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: disable/restore Fast Mode Plus bits in low power modes

Defer the initial enabling of the Fast Mode Plus bits after the
stm32f7_i2c_setup_timing call in probe function in order to avoid
enabling them if speed is downgraded.
Clear & restore the Fast Mode Plus bits in the suspend/resume
handlers of the driver.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: allow controller to be wakeup-source

Allow the i2c-stm32f7 controller to become a wakeup-source
of the system. In such case, when a slave is registered to the
I2C controller, receiving a I2C message targeting that registered
slave address wakes up the suspended system.

In order to be able to wake-up, the I2C controller DT node
must have the property wakeup-source defined and a slave
must be registered.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: add PM_SLEEP suspend/resume support

Backup/restore I2C registers as part of the suspend/resume
handlers. The device is marked as suspended to ensure that
transfers are rejected during the suspended period.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: fix 10-bits check in slave free id search loop

Fix a typo in the free slave id search loop. Instead of I2C_CLIENT_PEC,
it should have been I2C_CLIENT_TEN. The slave id 1 can only handle 7-bit
addresses and thus is not eligible in case of 10-bit addresses.
As a matter of fact none of the slave id support I2C_CLIENT_PEC, overall
check is performed at the beginning of the stm32f7_i2c_reg_slave function.

Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support")
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: report dma error during probe

Distinguish between the case where dma information is not provided
within the DT and the case of an error during the dma init.
Exit the probe with error in case of an error during dma init.

Fixes: bb8822cbbc53 ("i2c: i2c-stm32: Add generic DMA API")
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: fix & reorder remove & probe error handling

Add missing dma channels free calls in case of error during probe
and reorder the remove function so that dma channels are freed after
the i2c adapter is deleted.
Overall, reorder the remove function so that probe error handling order
and remove function order are same.

Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: rework slave_id allocation

The IP can handle two slave addresses. One address can either be
7 bits or 10 bits while the other can only be 7 bits.
In order to ensure that a 10 bits address can always be allocated
(assuming there is only one 7 bits address already allocated),
pick up the 7-bits only address slot in priority when performing a 7-bits
address allocation.

Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support")
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: remove warning when compiling with W=1

Remove the following warning:

drivers/i2c/busses/i2c-stm32f7.c:315:
warning: cannot understand function prototype:
'struct stm32f7_i2c_spec i2c_specs[] =

Replace a comment starting with /** by simply /* to avoid having
it interpreted as a kernel-doc comment.

Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver")
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: fix a race in slave mode with arbitration loss irq

When in slave mode, an arbitration loss (ARLO) may be detected before the
slave had a chance to detect the stop condition (STOPF in ISR).
This is seen when two master + slave adapters switch their roles. It
provokes the i2c bus to be stuck, busy as SCL line is stretched.
- the I2C_SLAVE_STOP event is never generated due to STOPF flag is set but
don't generate an irq (race with ARLO irq, STOPIE is masked). STOPF flag
remains set until next master xfer (e.g. when STOPIE irq get unmasked).
In this case, completion is generated too early: immediately upon new
transfer request (then it doesn't send all data).
- Some data get stuck in TXDR register. As a consequence, the controller
stretches the SCL line: the bus gets busy until a future master transfer
triggers the bus busy / recovery mechanism (this can take time... and
may never happen at all)

So choice is to let the STOPF being detected by the slave isr handler,
to properly handle this stop condition. E.g. don't mask IRQs in error
handler, when the slave is running.

Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: fix first byte to send in slave mode

The slave-interface documentation [1] states "the bus driver should
transmit the first byte" upon I2C_SLAVE_READ_REQUESTED slave event:
- 'val': backend returns first byte to be sent
The driver currently ignores the 1st byte to send on this event.

[1] https://www.kernel.org/doc/Documentation/i2c/slave-interface

Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: Make structure stm32f7_i2c_algo constant

Static structure stm32f7_i2c_algo, of type i2c_algorithm, is used only
when it is assigned to constant field algo of a variable having type
i2c_adapter. As stm32f7_i2c_algo is therefore never modified, make it
const as well to protect it from unintended modification.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Acked-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: Add I2C_SMBUS_I2C_BLOCK_DATA support

This patch adds the support of I2C_SMBUS_I2C_BLOCK_DATA transaction type
for the stm32f7 SMBUS Controller.
Use emulated I2C_SMBUS_I2C_BLOCK_DATA transactions as there is no specific
hardware in STM32 I2C to manage this (e.g. like no need for PEC here).
Emulated transfer will fall back calling i2c transfer method where there's
already support for DMAs for example.
So, use the I2C_FUNC_SMBUS_I2C_BLOCK in stm32f7_i2c_func(), and rely on
emulated transfer by returning -EOPNOTSUPP in the smbus_xfer() routine
for such a case.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: fix the get_irq error cases

During probe, return the "get_irq" error value instead of -EINVAL which
allows the driver to be deferred probed if needed.
Fix also the case where of_irq_get() returns a negative value.
Note :
On failure of_irq_get() returns 0 or a negative value while
platform_get_irq() returns a negative value.

Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver")
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: improve loopback in timing algorithm

This avoids useless loops inside the I2C timing algorithm.
Actually, we support only one possible solution per prescaler value.
So after finding a solution with a prescaler, the algorithm can
switch directly to the next prescaler value.

Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: Fix SDADEL minimum formula

It conforms with Reference Manual I2C timing section.

Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver")
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: add PM Runtime support

Use PM Runtime API to enable/disable clock

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: SYSCFG Fast Mode Plus support for I2C STM32F7

Read SYSCFG bindings to set Fast Mode Plus bits if Fast Mode Plus
speed is selected.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: fix documentation typo

Some data structure members were either misspelled or missing.

Fixes: aeb068c572 ("i2c: i2c-stm32f7: add driver")
Fixes: 380b8a85e7 ("i2c: i2c-stm32f7: Add initial SMBus protocols support")
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: Implement I2C release mechanism

Feature prevents I2C lock-ups. Mechanism resets I2C state machine
and releases SCL/SDA signals but preserves I2C registers.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: Add DMA support

This patch adds DMA support for i2c-stm32f7 driver

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>

i2c: i2c-stm32f7: Add initial SMBus protocols support

This patch adds SMBus support for I2C controller embedded in STM32F7 Soc.
All SMBus protocols are implemented except SMBus-specific protocols like
SMBus Host Notification and SMBus Alert protocols.

Implemented: SMBus Quick command, Send byte, Receive byte, Write byte/word,
read byte/word, Process call, Block write/read and Block write-block read
process call.

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>

i2c: i2c-stm32f7: Add slave support

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>

i2c: i2c-stm32f7: Add 10-bit address support

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>

i2c: i2c-stm32f7: fix no check on returned setup

Before assigning returned setup structure check if not null

Fixes: 463a9215f3ca7600b5ff ("i2c: stm32f7: fix setup structure")
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c: stm32: Fix copyrights

Uniformize STMicroelectronics copyrights headers and add SPDX
identifier.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Acked-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Acked-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: make structure stm32f7_setup static const

The structure stm32f7_setup is local to the source and does not need
to be in global scope, make it static const.

Cleans up sparse warning:
symbol 'stm32f7_setup' was not declared. Should it be static?

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: stm32f7: fix setup structure

I2C drive setup structure is not properly allocated.
Make it static instead of pointer to store driver data.

Fixes: aeb068c5721485 ("i2c: i2c-stm32f7: add driver")
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-stm32f7: add driver

This patch adds initial support for the STM32F7 I2C controller.

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>