i2c: exynos5: Calculate t_scl_l, t_scl_h according to i2c spec

Previously the duty cycle was divided equally into h_scl_l, t_scl_h.
This makes the low period of the SCL clock in Fast Mode is only 1.25us
which is way lower than the minimal value (1.3) specified in i2c
specification. In order to make sure t_scl_l, t_scl_h always fullfill
i2c specification, this commit calculates t_scl_l using this formula:

t_scl_l = clk_cycle *
((t_low_min + (scl_clock - t_low_min - t_high_min) / 2) / scl_clock)

where:
t_low_min is the minimal value of low period of the SCL clock in us;
t_high_min is the minimal value of high period of the SCL clock in us;
scl_clock is converted from SCL clock frequency into us.

Signed-off-by: Camel Guo <camel.guo@axis.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: exynos5: add support for atomic transfers

Add support for atomic transfers using polling mode with interrupts
intentionally disabled. This removes the warning introduced by commit
63b96983a5dd ("i2c: core: introduce callbacks for atomic transfers")
during system reboot and power-off.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.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: exynos5: Remove #ifdef guards for PM related functions

Use the new PM macros for the suspend and resume functions to be
automatically dropped by the compiler when CONFIG_PM or
CONFIG_PM_SLEEP are disabled, without having to use #ifdef guards.

This has the advantage of always compiling these functions in,
independently of any Kconfig option. Thanks to that, bugs and other
regressions are subsequently easier to catch.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230722115046.27323-7-paul@crapouillou.net
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: 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: exynos5: Fix getting the optional clock

"hsi2c_pclk" clock is optional and may not be present for some SoCs
supported by this driver. Nevertheless, in case the clock is provided
but some error happens during its getting, that error should be handled
properly. Use devm_clk_get_optional() API for that. Also report possible
errors using dev_err_probe() to handle properly -EPROBE_DEFER error (if
clock provider is not ready by the time I2C probe function is executed).

Fixes: 697ad2490c96 ("i2c: exynos5: Add bus clock support")
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Chanho Park <chanho61.park@samsung.com>
[wsa: fixed SHA1 of Fixes tag]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: exynos5: Add bus clock support

In new Exynos SoCs (like Exynos850) where HSI2C is implemented as a
part of USIv2 block, there are two clocks provided to HSI2C controller:
- PCLK: bus clock (APB), provides access to register interface
- IPCLK: operating IP-core clock; SCL is derived from this one

Both clocks have to be asserted for HSI2C to be functional in that case.

Add code to obtain and enable/disable PCLK in addition to already
handled operating clock. Make it optional though, as older Exynos SoC
variants only have one HSI2C clock.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Chanho Park <chanho61.park@samsung.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: exynos5: Add support for ExynosAutoV9 SoC

ExynosAutoV9 functioning logic mostly follows I2C_TYPE_EXYNOS7, but
timing calculation and configuration procedure is changed: e.g. only
timing_s3 has to be set now.

Another change of HSI2C controller in ExynosAutoV9 SoC is that it's now
a part of USIv2 IP-core. No changes is needed for I2C driver though, as
all USI related configuration is done in USI driver.

Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: exynos5: correct top kerneldoc

The top comment is not a kerneldoc, as W=1 build reports:

drivers/i2c/busses/i2c-exynos5.c:39: warning:
expecting prototype for i2c(). Prototype was for HSI2C_CTL() instead

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: exynos5: Preserve high speed master code

When the driver starts to send a message with the MASTER_ID field
set (high speed), the whole I2C_ADDR register is overwritten including
MASTER_ID as the SLV_ADDR_MAS field is set.

This patch preserves already written fields in I2C_ADDR when writing
SLV_ADDR_MAS.

Fixes: 8a73cd4cfa15 ("i2c: exynos5: add High Speed I2C controller driver")
Signed-off-by: Mårten Lindahl <martenli@axis.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: exynos5: don't check for irq 0

platform_get_irq never returns 0. Don't check for this. Make it clear that
the error path always returns a negative error code.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: exynos5: fix platform_get_irq error handling

If platform_get_irq returns an error, relay this error to the caller of
the probe function. Don't change all errors to -EINVAL. This breaks the
case where platform_get_irq returns -EPROBE_DEFER.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: exynos5: remove duplicate error message

platform_get_irq already prints an error message if the requested irq
was not found. Don't print another message in the driver.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: Drop stray comma in MODULE_AUTHOR statements

It is not the common usage to have a comma between the name and the
email address, so remove it.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: busses: convert to devm_platform_ioremap_resource

use devm_platform_ioremap_resource() to simplify code, it
contains platform_get_resource and devm_ioremap_resource.

Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Robert Richter <rrichter@marvell.com>
Acked-by: Thor Thayer <thor.thayer@linux.intel.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

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: exynos5: Remove IRQF_ONESHOT

The drivers sets IRQF_ONESHOT and passes only a primary handler. The IRQ
is masked while the primary is handler is invoked independently of
IRQF_ONESHOT.
With IRQF_ONESHOT the core code will not force-thread the interrupt and
this is probably not intended. I *assume* that the original author copied
the IRQ registration from another driver which passed a primary and
secondary handler and removed the secondary handler but keeping the
ONESHOT flag.

Remove IRQF_ONESHOT.

Reported-by: Benjamin Rouxel <benjamin.rouxel@uva.nl>
Tested-by: Benjamin Rouxel <benjamin.rouxel@uva.nl>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

i2c: exynos5: use core helper to mark adapter suspended

Rejecting transfers should be handled by the core. Also, this will
ensure proper locking which was forgotten in this open coded version.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: Describe the hardware variant for readability

The driver supports multiple hardware variants of Exynos I2C controller
which differ in FIFO depth, handling of interrupts and bus recovery in
HSI2C_MASTER_ST_LOSE state.

The difference in variant was a single bit set for Exynos7 variants and
implicit lack of this bit for other variants.

Make each variant explicit which also fixes the GCC warning about
documentation:

drivers/i2c/busses/i2c-exynos5.c:223: warning: Function parameter or member 'hw' not described in 'exynos_hsi2c_variant'

No change in functionality.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: simplify transfer function

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>

i2c: exynos5: rework HSI2C_MASTER_ST_LOSE state handling

HSI2C_MASTER_ST_LOSE state is not documented properly, extensive tests
show that hardware is usually able to recover from this state without
interrupting the transfer. Moreover documentation says that
such state can be caused by slave clock stretching, and should not be
treated as an error during transaction. The only place it indicates
an error is just before starting transaction. In such case bus recovery
procedure should be performed - master should pulse SCL line nine times
and then send STOP condition, it can be repeated until SDA goes high.
The procedure can be performed using manual commands HSI2C_CMD_READ_DATA
and HSI2C_CMD_SEND_STOP.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: change internal transmission timeout to 100ms

Exynos-I2C uses default timeout of 1 second for the whole transaction,
including re-transmissions due to arbitration lost errors (-EAGAIN).
To allow re-transmissions driver's internal timeout should be significantly
lower, 100ms seems to be good candidate.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: use dev_get_drvdata() to get private data in suspend/resume hooks

Several drivers call to_platform_device() to get platform_device
and pass it to platform_get_drvdata(). In platform_get_drvdata(),
the platform_device is converted back to struct device again.

Use dev_get_drvdata() to avoid platform_device/device dance.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> (for DesignWare only)
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: use core helper to get driver data

Driver core provides of_device_get_match_data which can be used
to get driver data instead of custom helper.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: de-duplicate error logs on clock setup

In case of clock setup error it is enough to log it once.
Moreover patch simplifies clock setup routines.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: simplify clock frequency handling

There is no need to keep separate settings for high and fast speed clock.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: simplify timings calculation

Instead of using cryptic loop direct calculation of timings
can be used.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: Avoid transaction timeouts due TRANSFER_DONE_AUTO not set

After commit 7999eecb7e56 ("i2c: exynos5: fix arbitration lost handling"),
some I2C transactions are failing because the TRANSFER_DONE_AUTO field is
not set in the I2C_TRANS_STATUS register so the i2c->status value is left
to -EINVAL causing the i2c->msg_complete completion to never be signaled.

For example, when reading the time of an I2C rtc on an Exynos5800 machine:

$ cat /sys/class/rtc/rtc0/time
[ 25.924594] exynos5-hsi2c 12e10000.i2c: rx timeout
[ 65.028365] max77686-rtc max77802-rtc: Fail to read time reg(-22)
cat: /sys/class/rtc/rtc0/time: Invalid argument

The Exynos5422 manual states clearly that most I2C_TRANS_STATUS reg bits
(including TRANSFER_DONE_AUTO) are cleared after the register is read. So
reading has side effects and should only be done if HSI2C_INT_I2C was set.

Fixes: 7999eecb7e56 ("i2c: exynos5: fix arbitration lost handling")
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: fix arbitration lost handling

In case of arbitration lost adequate interrupt sometimes is not signaled.
As a result transfer timeouts and is not retried, as it should. To avoid
such cases code is added to check transaction status in case of every
interrupt.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Tested-by: Andi Shyti <andi.shyti@samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: disable fifo-almost-empty irq signal when necessary

Fifo-almost-empty irq signal should be disabled as soon as possible,
to avoid unnecessary interrupt storm. The best moment is when there is
no more data to feed fifo.
This patch fixes system stalls caused by IRQ storm.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Andi Shyti <andi.shyti@samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@samsung.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: exynos5: Use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS instead of open-coded

Use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS to simplify the code.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: Fix possible ABBA deadlock by keeping I2C clock prepared

The exynos5 I2C controller driver always prepares and enables a clock
before using it and then disables unprepares it when the clock is not
used anymore.

But this can cause a possible ABBA deadlock in some scenarios since a
driver that uses regmap to access its I2C registers, will first grab
the regmap lock and then the I2C xfer function will grab the prepare
lock when preparing the I2C clock. But since the clock driver also
uses regmap for I2C accesses, preparing a clock will first grab the
prepare lock and then the regmap lock when using the regmap API.

An example of this happens on the Exynos5422 Odroid XU4 board where a
s2mps11 PMIC is used and both the s2mps11 regulators and clk drivers
share the same I2C regmap.

The possible deadlock is reported by the kernel lockdep:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(sec_core:428:(regmap)->lock);
lock(prepare_lock);
lock(sec_core:428:(regmap)->lock);
lock(prepare_lock);

*** DEADLOCK ***

Fix it by leaving the code prepared on probe and use {en,dis}able in
the I2C transfer function.

This patch is similar to commit 34e81ad5f0b6 ("i2c: s3c2410: fix ABBA
deadlock by keeping clock prepared") that fixes the same bug in other
driver for an I2C controller found in Samsung SoCs.

Reported-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Anand Moon <linux.amoon@gmail.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c: exynos5: use proper errno for timeout

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: exynos: add support for HSI2C module on Exynos7

The HSI2C module on Exynos7 differs in the transfer status
bits. Transfer status bits were moved to INT_ENABLE and
INT_STATUS registers

This patch adds support for the HSI2C module on Exynos7.
1. Implementes a "hw" field in the variant struct to distinguish
the hardware.
2. Updates the dt-new compatible in dt-binding documenation

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: remove extra line and fix an assignment

This patch does the following in exynos5_i2c_message_start() function
1. Fixes an assignment
As, "i2c_auto_conf" is initialized to '0' at the beginning of the
function and HSI2C_READ_WRITE is defined as (1u << 16)

Using "|=" for the first assignment is more readable.

2. Removes an extra line

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: remove an unnecessary read of FIFO_STATUS register

This patch removes an extra read of FIFO_STATUS register in the interrrupt
service routine. Which is read again before the actual use.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: Properly use the "noirq" variants of suspend/resume

The original code for the exynos i2c controller registered for the
"noirq" variants. However during review feedback it was moved to
SIMPLE_DEV_PM_OPS without anyone noticing that it meant we were no
longer actually "noirq" (despite functions named
exynos5_i2c_suspend_noirq and exynos5_i2c_resume_noirq).

i2c controllers that might have wakeup sources on them seem to need to
resume at noirq time so that the individual drivers can actually read
the i2c bus to handle their wakeup.

NOTE: I took the original review feedback from Wolfram and added
poweroff, thaw, freeze, restore.

This patch has only been compile-tested since I don't have all the
patches needed to make my machine using this i2c driver actually
suspend/resume.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: remove unnecessary OOM messages

The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message. For example,
k.alloc and v.alloc failures use dump_stack().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: add support for HSI2C on Exynos5260 SoC

HSI2C module on Exynos5260 differs from current modules in
following ways:
1. HSI2C on Exynos5260 has fifo_depth of 16bytes
2. Module needs to be reset as a part of init sequence.

Hence, Following changes are involved.
1. Add a new compatible string and Updates the Documentation dt bindings.
2. Introduce a variant struct to support the changes in H/W
3. Reset the module during init. Thus, bringing the module back
to default state irrespective of what firmware did with it.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: remove unnecessary cast of void pointer

Remove unnecessary cast of void pointer, because 'algo_data' of
'struct i2c_adapter' is a void pointer. Casting the void pointer
is redundant. The conversion from void pointer to any other
pointer type is guaranteed by the C programming language.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: add CONFIG_PM_SLEEP to suspend/resume functions

Add CONFIG_PM_SLEEP to suspend/resume functions to fix the following
build warning when CONFIG_PM_SLEEP is not selected. This is because
sleep PM callbacks defined by SIMPLE_DEV_PM_OPS are only used when
the CONFIG_PM_SLEEP is enabled.

warning: 'exynos5_i2c_suspend_noirq' defined but not used [-Wunused-function]
warning: 'exynos5_i2c_resume_noirq' defined but not used [-Wunused-function]

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: delete non-required instances of include <linux/init.h>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

treewide: Fix typos in printk

Correct spelling typo in various part of kernel

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

i2c: exynos5: Remove incorrect clk_disable_unprepare

clk_disable_unprepare in remove causes an imbalance and hence gives
the below crash on module remove. While at it also remove some
duplicate code from probe.

/ $ rmmod i2c-exynos5
[ 6.996374] ------------[ cut here ]------------
[ 6.999523] WARNING: CPU: 2 PID: 1137 at drivers/clk/clk.c:842 clk_disable+0x18/0x24()
[ 7.007403] Modules linked in: i2c_exynos5(-)
[ 7.011747] CPU: 2 PID: 1137 Comm: rmmod Not tainted 3.12.0-next-20131105-00083-g16f4799-dirty #21
[ 7.020696] [<c0014e0c>] (unwind_backtrace+0x0/0xf4) from [<c0011784>] (show_stack+0x10/0x14)
[ 7.029190] [<c0011784>] (show_stack+0x10/0x14) from [<c037acd4>] (dump_stack+0x7c/0xb0)
[ 7.037255] [<c037acd4>] (dump_stack+0x7c/0xb0) from [<c001e0ac>] (warn_slowpath_common+0x6c/0x88)
[ 7.046190] [<c001e0ac>] (warn_slowpath_common+0x6c/0x88) from [<c001e164>] (warn_slowpath_null+0x1c/0x24)
[ 7.055818] [<c001e164>] (warn_slowpath_null+0x1c/0x24) from [<c02dcde4>] (clk_disable+0x18/0x24)
[ 7.064670] [<c02dcde4>] (clk_disable+0x18/0x24) from [<bf0002d4>] (exynos5_i2c_remove+0x1c/0x34 [i2c_exynos5])
[ 7.074736] [<bf0002d4>] (exynos5_i2c_remove+0x1c/0x34 [i2c_exynos5]) from [<c02274a8>] (__device_release_driver+0x58/0xb0)
[ 7.085836] [<c02274a8>] (__device_release_driver+0x58/0xb0) from [<c0227b88>] (driver_detach+0xac/0xb0)
[ 7.095291] [<c0227b88>] (driver_detach+0xac/0xb0) from [<c02271c0>] (bus_remove_driver+0x4c/0xa0)
[ 7.104227] [<c02271c0>] (bus_remove_driver+0x4c/0xa0) from [<c00725dc>] (SyS_delete_module+0x124/0x194)
[ 7.113682] [<c00725dc>] (SyS_delete_module+0x124/0x194) from [<c000e2e0>] (ret_fast_syscall+0x0/0x30)
[ 7.122957] ---[ end trace 23bb6e4e0bf52196 ]---

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: exynos5: add High Speed I2C controller driver

Adds support for High Speed I2C driver found in Exynos5 and
later SoCs from Samsung.

Driver only supports Device Tree method.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Taekgyun Ko <taeggyun.ko@samsung.com>
Reviewed-by: Simon Glass <sjg@google.com>
Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
Signed-off-by: Andrew Bresticker <abrestic@google.com>
[wsa: rebased to v3.12-rc4 (no of_i2c.h anymore)]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>