i2c: riic: avoid potential division by zero

Value comes from DT, so it could be 0. Unlikely, but could be.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
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: riic: Use devm_platform_ioremap_resource()

Use the devm_platform_ioremap_resource() helper instead of calling
platform_get_resource() and devm_ioremap_resource() separately.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: move drivers from strlcpy to strscpy

Follow the advice of the below link and prefer 'strscpy'. Conversion is
easy because no driver used the return value and has been done with a
simple sed invocation.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: riic: Simplify reset handling

Read reset phandle as optional instead of exclusive so that all the DT's
passing the reset phandle can be used to assert/deassert the reset line.
With this change we don't have to differentiate the RZ/G2L SoC.

With the above changes we no longer need the "renesas,riic-r9a07g044"
compatible string, so drop it from riic_i2c_dt_ids[]. No changes are
required to the r9a07g044.dtsi as we already have "renesas,riic-rz" as a
fallback compatible string.

While at it, check the return code of reset_control_deassert() as it might
fail and also add a devres action to assert the reset line.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: riic: Use platform_get_irq() to get the interrupt

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: riic: Add RZ/G2L support

RZ/G2L i2c controller is compatible with RZ/A i2c controller.
By default IP is in reset state, so need to perform release
reset before accessing any register.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: drivers: Use generic definitions for bus frequencies

Since we have generic definitions for bus frequencies, let's use them.

Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Acked-by: Robert Richter <rrichter@marvell.com>
Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
Acked-by: Elie Morisse <syniurge@gmail.com>
Acked-by: Nehal Shah <nehal-bakulchandra.shah@amd.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Chris Brandt <chris.brandt@renesas.com>
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: riic: Clear NACK in tend isr

The NACKF flag should be cleared in INTRIICNAKI interrupt processing as
description in HW manual.

This issue shows up quickly when PREEMPT_RT is applied and a device is
probed that is not plugged in (like a touchscreen controller). The result
is endless interrupts that halt system boot.

Fixes: 310c18a41450 ("i2c: riic: add driver")
Cc: stable@vger.kernel.org
Reported-by: Chien Nguyen <chien.nguyen.eb@rvc.renesas.com>
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: riic: Add Runtime PM support

- Replace explicit clock handling by Runtime PM calls,
- Streamline Runtime PM handling in error paths,
- Enable Runtime PM in .probe(),
- Disable Runtime PM in .remove(),
- Make sure the device is runtime-resumed when disabling interrupts in
.remove().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: use SPDX identifier for Renesas drivers

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: busses: make use of i2c_8bit_addr_from_msg

Because it looks neater.

For diolan, this allows factoring out some code that is now common
between if and else.

For eg20t, pch_i2c_writebytes is always called with a write in
msgs->flags, and pch_i2c_readbytes with a read.

For imx, i2c_imx_dma_write and i2c_imx_write are always called with a
write in msgs->flags, and i2c_imx_read with a read.

For qup, qup_i2c_write_tx_fifo_v1 is always called with a write in
qup->msg->flags.

For stu300, also restructure debug output for resends, since that
code as a result is only handling debug output.

Reviewed-by: Guenter Roeck <linux@roeck-us.net> [diolan]
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [efm32 and imx]
Acked-by: Linus Walleij <linus.walleij@linaro.org> [stu300]
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: riic: remove clock and frequency restrictions

Remove the restriction that the parent clock has to be a specific frequency
and also allow any speed to be supported.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: riic: fix restart condition

While modifying the driver to use the STOP interrupt, the completion of the
intermediate transfers need to wake the driver back up in order to initiate
the next transfer (restart condition). Otherwise you get never ending
interrupts and only the first transfer sent.

Fixes: 71ccea095ea1 ("i2c: riic: correctly finish transfers")
Reported-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Tested-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: riic: correctly finish transfers

This fixes the condition where the controller has not fully completed its
final transfer and leaves the bus and controller in a undesirable state.

At the end of the last transmitted byte, the existing driver would just
signal for a STOP condition to be transmitted then immediately signal
completion. However, the full STOP procedure might not have fully taken
place by the time the runtime PM shuts off the peripheral clock, leaving
the bus in a suspended state.

Alternatively, the STOP condition on the bus may have completed, but when
the next transaction is requested by the upper layer, not all the
necessary register cleanup was finished from the last transfer which made
the driver return BUS BUSY when it really wasn't.

This patch now makes all transmit and receive transactions wait for the
STOP condition to fully complete before signaling a completed transaction.
With this new method, runtime PM no longer seems to be an issue.

Fixes: 310c18a41450 ("i2c: riic: add driver")
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: don't print error when adding adapter fails

The core will do this for us now.

Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: busses: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: Make of_device_id array const

Make of_device_id array const, because all OF functions
handle it as const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: riic: add driver

Tested with a r7s72100 genmai board acessing an eeprom.

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>