i2c: at91-core: 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: Nicolas Ferre <nicolas.ferre@microchip.com>
[wsa: rebased]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: at91: Use dev_err_probe() instead of dev_err()

Change
if (IS_ERR(x)) { dev_err(...); return PTR_ERR(x); }
into
return dev_err_probe()

Also, return the correct error instead of hardcoding -ENODEV
This change has also the advantage of handling the -EPROBE_DEFER situation.

Signed-off-by: Yann Sionneau <yann@sionneau.net>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: at91: Use devm_platform_get_and_ioremap_resource()

Convert platform_get_resource(), devm_ioremap_resource() to a single
call to devm_platform_get_and_ioremap_resource(), as this is exactly
what this function does.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

I2C: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@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: at91: mark PM ops as __maybe unused

The driver uses pm_ptr(), so the PM ops could be unused.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: dab4b0e8c9a5 ("i2c: at91: remove #define CONFIG_PM")
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: at91: remove #define CONFIG_PM

Remove #define CONFIG_PM and use __maybe_unused for PM functions and
pm_ptr() for PM ops.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: at91: Send bus clear command if SDA is down

After a transfer timeout, some faulty I2C slave devices might hold down
the SDA pin. We can generate a bus clear command, hoping that the slave
might release the pins.
If the CLEAR command is not supported, we will use gpio recovery, if
available, to reset the bus.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: at91: remote default value initialization

Platform data structs are initialized by default with zero values.
Thus it becomes redundant to initialize them manually to zero (false).
Remove extra false initialization for field members in structs.

Reported-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: at91: fix clk_offset for sam9x60

In SAM9X60 datasheet, FLEX_TWI_CWGR register description mentions clock
offset of 3 cycles (compared to 4 in eg. SAMA5D3).
This is the same offset as in SAMA5D2.

Fixes: b00277923743 ("i2c: at91: add new platform support for sam9x60")
Suggested-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: at91: add support for analog filtering

Add support for analog filtering for i2c lines.
The sama5d2 and sam9x60 support this feature.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: at91: add support for advanced digital filtering

Add new platform data support for advanced digital filtering for i2c.
The sama5d2 and sam9x60 support this feature.
This digital filter allows the user to configure the maximum
width of the spikes that can be filtered.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: at91: add support for digital filtering

Add new platform data support for digital filtering for i2c.
The sama5d4, sama5d2 and sam9x60 support this feature.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: at91: add new platform support for sam9x60

Add new platform data support for the sam9x60 SoC

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: at91: fix clk_offset for sama5d2

In SAMA5D2 datasheet, TWIHS_CWGR register rescription mentions clock
offset of 3 cycles (compared to 4 in eg. SAMA5D3).

Cc: stable@vger.kernel.org # 5.2.x
[needs applying to i2c-at91.c instead for earlier kernels]
Fixes: 0ef6f3213dac ("i2c: at91: add support for new alternative command mode")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: at91: added slave mode support

Slave mode driver is based on the concept of i2c-designware driver.

Signed-off-by: Juergen Fitschen <me@jue.yt>
[ludovic.desroches@microchip.com: rework Kconfig and replace IS_ENABLED
by defined]
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: at91: split driver into core and master file

The single file i2c-at91.c has been split into core code (i2c-at91-core.c)
and master mode specific code (i2c-at91-master.c). This should enhance
maintainability and reduce ifdeffery for slave mode related code.

The code itself hasn't been touched. Shared functions only had to be made
non-static. Furthermore, includes have been cleaned up.

Signed-off-by: Juergen Fitschen <me@jue.yt>
[ludovic.desroches@microchip.com: fix checkpatch errors and use SPDX]
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>