i2c: s3c24xx: add support for atomic transfers

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

------------[ cut here ]------------
WARNING: CPU: 0 PID: 1518 at drivers/i2c/i2c-core.h:40 i2c_transfer+0xe8/0xf4
No atomic I2C transfer handler for 'i2c-0'
...
---[ end trace 0000000000000000 ]---

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Chanho Park <chanho61.park@samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: s3c24xx: fix transferring more than one message in polling mode

To properly handle ACK on the bus when transferring more than one
message in polling mode, move the polling handling loop from
s3c24xx_i2c_message_start() to s3c24xx_i2c_doxfer(). This way
i2c_s3c_irq_nextbyte() is always executed till the end, properly
acknowledging the IRQ bits and no recursive calls to
i2c_s3c_irq_nextbyte() are made.

While touching this, also fix finishing transfers in polling mode by
using common code path and always waiting for the bus to become idle
and disabled.

Fixes: 117053f77a5a ("i2c: s3c2410: Add polling mode support")
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: s3c24xx: fix read transfers in polling mode

To properly handle read transfers in polling mode, no waiting for the ACK
state is needed as it will never come. Just wait a bit to ensure start
state is on the bus and continue processing next bytes.

Fixes: 117053f77a5a ("i2c: s3c2410: Add polling mode support")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Chanho Park <chanho61.park@samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: s3c2410: make i2c_s3c_irq_nextbyte() void

Fix the following coccicheck warning:

drivers/i2c/busses/i2c-s3c2410.c:391:5-8: Unneeded variable: "ret".
Return "0" on line 552

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: s3c2410: 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: s3c2410: 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/20230722115310.27681-3-paul@crapouillou.net
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

i2c: s3c2410: Remove redundant dev_err()

There is no need to call the dev_err() function directly to print a custom
message when handling an error from platform_get_irq() function as
it is going to display an appropriate error message in case of a failure.

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20230726174226.2480552-1-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>

ARM: s3c: remove s3c24xx specific hacks

A number of device drivers reference CONFIG_ARM_S3C24XX_CPUFREQ or
similar symbols that are no longer available with the platform gone,
though the drivers themselves are still used on newer platforms,
so remove these hacks.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

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: s3c2410: fix IRQ check

Iff platform_get_irq() returns 0, the driver's probe() method will return 0
early (as if the method's call was successful). Let's consider IRQ0 valid
for simplicity -- devm_request_irq() can always override that decision...

Fixes: e0d1ec97853f ("i2c-s3c2410: Change IRQ to be plain integer.")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: s3c2410: fix possible NULL pointer deref on read message after write

Interrupt handler processes multiple message write requests one after
another, till the driver message queue is drained. However if driver
encounters a read message without preceding START, it stops the I2C
transfer as it is an invalid condition for the controller. At least the
comment describes a requirement "the controller forces us to send a new
START when we change direction". This stop results in clearing the
message queue (i2c->msg = NULL).

The code however immediately jumped back to label "retry_write" which
dereferenced the "i2c->msg" making it a possible NULL pointer
dereference.

The Coverity analysis:
1. Condition !is_msgend(i2c), taking false branch.
if (!is_msgend(i2c)) {

2. Condition !is_lastmsg(i2c), taking true branch.
} else if (!is_lastmsg(i2c)) {

3. Condition i2c->msg->flags & 1, taking true branch.
if (i2c->msg->flags & I2C_M_RD) {

4. write_zero_model: Passing i2c to s3c24xx_i2c_stop, which sets i2c->msg to NULL.
s3c24xx_i2c_stop(i2c, -EINVAL);

5. Jumping to label retry_write.
goto retry_write;

6. var_deref_model: Passing i2c to is_msgend, which dereferences null i2c->msg.
if (!is_msgend(i2c)) {"

All previous calls to s3c24xx_i2c_stop() in this interrupt service
routine are followed by jumping to end of function (acknowledging
the interrupt and returning). This seems a reasonable choice also here
since message buffer was entirely emptied.

Addresses-Coverity: Explicit null dereferenced
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: s3c2410: simplify getting of_device_id match data

Use of_device_get_match_data() to make the code slightly smaller.

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

i2c: s3c2410: advertise SMBus transfers using RECV_LEN

This driver implements I2C_M_RECV_LEN, so it can advertise the SMBus
transfers needing it. This also enables client devices to check for the
RECV_LEN capability.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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>

ARM/SAMSUNG EXYNOS ARM ARCHITECTURES: Use fallthrough;

Convert the various uses of fallthrough comments to fallthrough;

Done via script
Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C part
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

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: s3c2410: Mark expected switch fall-through

Mark switch cases where we are expecting to fall through.

This patch fixes the following warning:

drivers/i2c/busses/i2c-s3c2410.c: In function 'i2c_s3c_irq_nextbyte':
drivers/i2c/busses/i2c-s3c2410.c:431:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (i2c->state == STATE_READ)
^
drivers/i2c/busses/i2c-s3c2410.c:439:2: note: here
case STATE_WRITE:
^~~~

Notice that, in this particular case, the code comment is
modified in accordance with what GCC is expecting to find.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: Convert to use GPIO descriptors

The S3C2410 does some funny dance around its pins:
- First try to call back to the platform to get and control
some GPIO pins
- If this doesn't work, it tries to get a pin control handle
- If this doesn't work, it retrieves two GPIOs from the device
tree node and does nothing with them

If we're gonna retrieve two GPIOs and do nothing with them, we
might as well do it using the GPIO descriptor API. When we use
the resource management API, the code gets smaller.

Signed-off-by: Linus Walleij <linus.walleij@linaro.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 157

Based on 3 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 as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

i2c: s3c2410: 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: remove i2c_lock_adapter and use i2c_lock_bus directly

The i2c_lock_adapter name is ambiguous since it is unclear if it
refers to the root adapter or the adapter you name in the argument.
The natural interpretation is the adapter you name in the argument,
but there are historical reasons for that not being the case; it
in fact locks the root adapter. Just remove the function and force
users to spell out the I2C_LOCK_ROOT_ADAPTER name to indicate what
is really going on. Also remove i2c_unlock_adapter, of course.

This patch was generated with

git grep -l 'i2c_\(un\)\?lock_adapter' \
| xargs sed -i 's/i2c_\(un\)\?lock_adapter(\([^)]*\))/'\
'i2c_\1lock_bus(\2, I2C_LOCK_ROOT_ADAPTER)/g'

followed by white-space touch-up.

Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Tested-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: Remove support for Exynos5440

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>

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: 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: s3c2410: Check clk_prepare_enable() return value

The clk_prepare_enable() function can fail so check the return
value and propagate the error in case of a failure.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: Print errno code in error logs

The driver not always prints the error code in case of a failure but this
information can be very useful for debugging. So let's print if available.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: Cleanup indentation and comment style

Improve the readability by:
- fixing indentation,
- switching to proper block comments,
- removing spurious blank lines,
- checkpatch: void function return statements are not generally useful,
- checkpatch: braces {} are not necessary for any arm of this
statement,
- checkpatch: missing a blank line after declarations.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: Minor function-level comment cleanup

Cleanup the weird function-level comments and remove obvious
documentation for probe/remove.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: Add missing clock unprepare on probe() error path

If during probe() the s3c24xx_i2c_init() failed, the clock was left in
disabled but prepared state.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: 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: s3c2410: remove superfluous runtime PM calls

RuntimePM of the adapter device is now taken care of by the core. So, we
can remove these calls.

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

i2c: s3c2410: enable RuntimePM before registering to the core

The core may register clients attached to this master which may use
funtionality from the master. So, RuntimePM must be enabled before, otherwise
this will fail. While here, move drvdata, too.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Kukjin Kim <kgene@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c: constify platform_device_id

The platform_device_id is not modified by these drivers and core uses it
as const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: fix oops in suspend callback for non-dt platforms

Initialize sysreg by default, otherwise driver will crash in suspend
callback when not using DT.

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Fixes: a7750c3ef01223 ("i2c: s3c2410: Handle i2c sys_cfg register in i2c driver")

i2c: s3c2410: fix ABBA deadlock by keeping clock prepared

This patch solves deadlock between clock prepare mutex and regmap mutex reported
by Tomasz Figa in [1] by implementing solution from [2]: "always leave the clock
of the i2c controller in a prepared state".

[1] https://lkml.org/lkml/2014/7/2/171
[2] https://lkml.org/lkml/2014/7/2/207

On each i2c transfer handled by s3c24xx_i2c_xfer(), clk_prepare_enable() was
called, which calls clk_prepare() then clk_enable(). clk_prepare() takes
prepare_lock mutex before proceeding. Note that i2c transfer functions are
invoked from many places in kernel, typically with some other additional lock
held.

It may happen that function on CPU1 (e.g. regmap_update_bits()) has taken a
mutex (i.e. regmap lock mutex) then it attempts i2c communication in order to
proceed (so it needs to obtain clock related prepare_lock mutex during transfer
preparation stage due to clk_prepare() call). At the same time other task on
CPU0 wants to operate on clock (e.g. to (un)prepare clock for some other reason)
so it has taken prepare_lock mutex.

CPU0: CPU1:
clk_disable_unused() regulator_disable()
clk_prepare_lock() map->lock(map->lock_arg)
regmap_read() s3c24xx_i2c_xfer()
map->lock(map->lock_arg) clk_prepare_lock()

Implemented solution from [2] leaves i2c clock prepared. Preparation is done in
s3c24xx_i2c_probe() function. Without this patch, it is immediately unprepared
by clk_disable_unprepare() call. I've replaced this call with clk_disable() and
I've added clk_unprepare() call in s3c24xx_i2c_remove().

The s3c24xx_i2c_xfer() function now uses clk_enable() instead of
clk_prepare_enable() (and clk_disable() instead of clk_unprepare_disable()).

Signed-off-by: Paul Osmialowski <p.osmialowsk@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c: s3c2410: Handle i2c sys_cfg register in i2c driver

Let's handle i2c interrupt re-configuration in i2c driver. This will
help us in removing some soc specific checks from machine files and
will help in removing static iomapping of SYS register in exynos.c

Also handle saving and restoring of SYS_I2C_CFG register during
suspend and resume of i2c driver.

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

i2c: remove FSF address

We have a central copy of the GPL for that. Some addresses were already
outdated.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

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>

treewide: Fix typo in printk

This patch fix spelling typo in printk within vairous
part of the code.

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

i2c: s3c2410: resume the I2C controller earlier

When the wake-up is triggered by the PMIC RTC, the RTC driver is trying
to read the PMIC interrupt status over I2C and fails because the I2C
controller is not resumed yet.
Let's resume the I2C controller earlier in the _noirq phase
(as other hardwares are doing), so we can properly get the wake-up
condition.

[tomasz: Also fixes certain issues on Exynos4-based boards.]

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Acked-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-s3c2410: Drop class based scanning to improve bootup time

This driver has been flagged to drop class based instantiation. The removal
improves boot-up time and is unneeded for embedded controllers. Users have been
warned to switch for some time now, so we can actually do the removal. Keep the
DEPRECATED flag, so the core can inform users that the behaviour finally
changed now. After another transition period, this flag can go, too.
While we are here, remove the indentation for the array setup because
such things always break after some time.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Sachin Kamat <sachin.kamat@samsung.com>

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: s3c2410: resume race fix

Don't unmark the device as suspended until after it's been re-setup.

The main race would be w.r.t. an i2c driver that gets resumed at the same
time (asyncronously), that is allowed to do a transfer since suspended
is set to 0 before reinit, but really should have seen the -EIO return
instead.

Signed-off-by: Olof Johansson <olof@lixom.net>
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>
Cc: stable@kernel.org

i2c: s3c2410: Leave the bus disabled unless it is in use

There is a rather odd feature of the exynos i2c controller that if it
is left enabled, it can lock itself up with the clk line held low.
This makes the bus unusable.

Unfortunately, the s3c24xx_i2c_set_master() function does not notice
this, and reports a timeout. From then on the bus cannot be used until
the AP is rebooted.

The problem happens when any sort of interrupt occurs (e.g. due to a
bus transition) when we are not in the middle of a transaction. We
have seen many instances of this when U-Boot leaves the bus apparently
happy, but Linux cannot access it.

The current code is therefore pretty fragile.

This fixes things by leaving the bus disabled unless we are actually
in a transaction. We enable the bus at the start of the transaction and
disable it at the end. That way we won't get interrupts and will not
lock up the bus.

It might be possible to clear pending interrupts on start-up, but this
seems to be a more robust solution. We can't service interrupts when
we are not in a transaction, and anyway would rather not lock up the
bus while we try.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-s3c2410: deprecate class based instantiation

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>

i2c: s3c2410: fix quirk usage for 64-bit

If used 64 bit compiler GCC warns that:

drivers/i2c/busses/i2c-s3c2410.c: In function ‘s3c24xx_get_device_quirks’:
drivers/i2c/busses/i2c-s3c2410.c:168:10: warning: cast from pointer to integer
of different size [-Wpointer-to-int-cast]

This patch fixes this by converting "unsigned int" to "kernel_ulong_t".

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

i2c: s3c2410: dont need CPU_FREQ transitions for exynos series

For Exynos4 and Exynos5 SoCs from Samsung the i2c clock is based
on a fixed 66 MHz peripheral clock, and therefore is completely
independent of the cpu frequency.
Thus, registering for a CPU freq notifier is very wasteful.

This patch modifes the code such that, i2c bus registers to
cpu_freq_transition only if CONFIG_CPU_FREQ_S3C24XX is enabled.

This change should save a bunch of cpufreq transitions calls
which does not apply to exynos SoCs.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: Add polling mode support

This patch adds polling mode support for i2c-s3c2410 driver.The
SATA PHY controller's CMU and TRSV block's are of I2C register
map in exynos5250.These blocks can be configured using i2c.

But i2c controller instance on which these block's sits lacks an
interrupt line.Also the current i2c-s3c2410 driver is only interrupt
driven, thus a polling mode support is required in the driver for
supporting this controller. This patch adds this support to the driver.

Signed-off-by: Vasanth Ananthan <vasanth.a@samsung.com>
Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: Include linux/of.h header

'of_match_ptr' is defined in linux/of.h. Include it explicitly to
avoid build breakage in the future.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: fix clk_disable/clk_unprepare WARNings

commit d16933b33914a6dff38a4ecbe8edce44a17898e8 "i2c: s3c2410: Move
location of clk_prepare_enable() call in probe function" refactored
clk_enable and clk_disable calls yet neglected to remove the
clk_disable_unprepare call in the module's remove().

It helps remove warnings on an arndale during unbind:

echo 12c90000.i2c > /sys/bus/platform/devices/12c90000.i2c/driver/unbind

------------[ cut here ]------------
WARNING: CPU: 0 PID: 2548 at drivers/clk/clk.c:842 clk_disable+0x18/0x24()
Modules linked in:
CPU: 0 PID: 2548 Comm: bash Not tainted 3.11.0-next-20130916-00003-gf4bddbc #6
[<c0014d48>] (unwind_backtrace+0x0/0xf8) from [<c00117d0>] (show_stack+0x10/0x14)
[<c00117d0>] (show_stack+0x10/0x14) from [<c0361be8>] (dump_stack+0x6c/0xac)
[<c0361be8>] (dump_stack+0x6c/0xac) from [<c001d864>] (warn_slowpath_common+0x64/0x88)
[<c001d864>] (warn_slowpath_common+0x64/0x88) from [<c001d8a4>] (warn_slowpath_null+0x1c/0x24)
[<c001d8a4>] (warn_slowpath_null+0x1c/0x24) from [<c02c4a64>] (clk_disable+0x18/0x24)
[<c02c4a64>] (clk_disable+0x18/0x24) from [<c028d0b0>] (s3c24xx_i2c_remove+0x28/0x70)
[<c028d0b0>] (s3c24xx_i2c_remove+0x28/0x70) from [<c0217a10>] (platform_drv_remove+0x18/0x1c)
[<c0217a10>] (platform_drv_remove+0x18/0x1c) from [<c0216358>] (__device_release_driver+0x58/0xb4)
[<c0216358>] (__device_release_driver+0x58/0xb4) from [<c02163d0>] (device_release_driver+0x1c/0x28)
[<c02163d0>] (device_release_driver+0x1c/0x28) from [<c02153c0>] (unbind_store+0x58/0x90)
[<c02153c0>] (unbind_store+0x58/0x90) from [<c0214c90>] (drv_attr_store+0x20/0x2c)
[<c0214c90>] (drv_attr_store+0x20/0x2c) from [<c01032c0>] (sysfs_write_file+0x168/0x198)
[<c01032c0>] (sysfs_write_file+0x168/0x198) from [<c00ae1c0>] (vfs_write+0xb0/0x194)
[<c00ae1c0>] (vfs_write+0xb0/0x194) from [<c00ae594>] (SyS_write+0x3c/0x70)
[<c00ae594>] (SyS_write+0x3c/0x70) from [<c000e3e0>] (ret_fast_syscall+0x0/0x30)
---[ end trace 4c9f9403066f57a6 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 2548 at drivers/clk/clk.c:751 clk_unprepare+0x14/0x1c()
Modules linked in:
CPU: 0 PID: 2548 Comm: bash Tainted: G W 3.11.0-next-20130916-00003-gf4bddbc #6
[<c0014d48>] (unwind_backtrace+0x0/0xf8) from [<c00117d0>] (show_stack+0x10/0x14)
[<c00117d0>] (show_stack+0x10/0x14) from [<c0361be8>] (dump_stack+0x6c/0xac)
[<c0361be8>] (dump_stack+0x6c/0xac) from [<c001d864>] (warn_slowpath_common+0x64/0x88)
[<c001d864>] (warn_slowpath_common+0x64/0x88) from [<c001d8a4>] (warn_slowpath_null+0x1c/0x24)
[<c001d8a4>] (warn_slowpath_null+0x1c/0x24) from [<c02c5834>] (clk_unprepare+0x14/0x1c)
[<c02c5834>] (clk_unprepare+0x14/0x1c) from [<c028d0b8>] (s3c24xx_i2c_remove+0x30/0x70)
[<c028d0b8>] (s3c24xx_i2c_remove+0x30/0x70) from [<c0217a10>] (platform_drv_remove+0x18/0x1c)
[<c0217a10>] (platform_drv_remove+0x18/0x1c) from [<c0216358>] (__device_release_driver+0x58/0xb4)
[<c0216358>] (__device_release_driver+0x58/0xb4) from [<c02163d0>] (device_release_driver+0x1c/0x28)
[<c02163d0>] (device_release_driver+0x1c/0x28) from [<c02153c0>] (unbind_store+0x58/0x90)
[<c02153c0>] (unbind_store+0x58/0x90) from [<c0214c90>] (drv_attr_store+0x20/0x2c)
[<c0214c90>] (drv_attr_store+0x20/0x2c) from [<c01032c0>] (sysfs_write_file+0x168/0x198)
[<c01032c0>] (sysfs_write_file+0x168/0x198) from [<c00ae1c0>] (vfs_write+0xb0/0x194)
[<c00ae1c0>] (vfs_write+0xb0/0x194) from [<c00ae594>] (SyS_write+0x3c/0x70)
[<c00ae594>] (SyS_write+0x3c/0x70) from [<c000e3e0>] (ret_fast_syscall+0x0/0x30)
---[ end trace 4c9f9403066f57a7 ]---

Signed-off-by: Kim Phillips <kim.phillips@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: move OF helpers into the core

I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.

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

i2c: use dev_get_platdata()

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

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

drivers/i2c/busses: don't check resource with devm_ioremap_resource

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Barry Song <Baohua.Song@csr.com>

i2c: s3c2410: Add SMBus emulation for block read

SMBus read and write are supported by the emulation layer of i2c
framework if the controller doesn't have SMBus features.

I2C_M_RECV_LEN flag is used to let i2c drivers know rx length is not
yet determined but will be read to the first byte in rx buffer.

s3c2410 doesn't handle this flag. So only one byte is read from slave.
There fore following two features are added to the driver code.

1. skip rx length check if I2C_M_RECV_LEN is set and the length is 1.
2. add actual bytes to the rx length after reading first bytes if
I2C_M_RECV_LEN.

I2C_M_RECV_LEN is only set for SMBus command. So this code does not
affect legacy codes which only use i2c command for s3c2410.

Signed-off-by: Jaemin Yoo <jmin.yoo@samsung.com>
Tested-by: Prasanna Kumar <prasanna.ps@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: fixup the styling of the newly moved register definitions

Make them conform more to established standards.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: move mach/regs-iic.h into i2c-s3c2410 device driver

The register definitions are only used in the driver itself.
This also removes the last dependency on plat/ includes from the
i2c driver.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: s3c2410: Add quirk to exclude GPIO config for exynos5440

Signed-off-by: Giridhar Maruthy <giridhar.m@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Remove err_cpufreq label

err_cpufreq label is now used only once. It can be removed and related
code can be moved to the caller location.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Move location of clk_prepare_enable() call in probe function

In i2c-s3c2410 driver probe, only s3c24xx_i2c_init() needs the I2C clock
to be enabled. Moving clk_prepare_enable() and clk_disable_unprepare()
calls to around this function simplifies the return path of probe call.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Convert to use devm_* APIs

i2c-s3c2410 driver is modified to use devm_clk_get()
and devm_request_irq(). This also simplifies the
return path in driver's probe.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Remove unnecessary label err_noclk

err_noclk label redirects to a simple return statement. Move the
return statement to the caller location and remove the label.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: Convert to devm_ioremap_resource()

Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.

devm_ioremap_resource() provides its own error messages so all explicit
error messages can be removed from the failure code paths.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

i2c: s3c2410: Remove recently introduced performance overheads

The changes in "i2c-s3c2410: use exponential back off while polling for
bus idle" remove the initial busy wait for I2C transfers to complete and
replace it with usleep_range() calls which will schedule.

Since for older SoCs I2C transfers would usually complete within an
extremely small number of CPU cycles there is a win from not having to
schedule. This happens because on the older SoCs the cores run at a
smaller multiple of the speeds that the I2C bus is operating at; on more
modern SoCs the busy wait is less likely to be effective.

Fix the issue by restoring the busy wait, reducing the number of spins
from 20 to 3 which covers the overwhelming majority of I2C transfers on
the SoCs where the busy wait is effective.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Fix misspellings of "whether" in comments.

"Whether" is misspelled in various comments across the tree; this
fixes them. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

i2c: s3c2410: Fix code to free gpios

Store the requested gpios so that they can be freed on error/removal.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Add fix for i2c suspend/resume

The I2C driver makes a gpio_request during initialization. This request
happens again on resume and fails due to the earlier successful request.
Re-factor the code to only initialize the gpios during probe.

Errors on resume without this:
[ 16.020000] s3c-i2c s3c2440-i2c.0: gpio [42] request failed
[ 16.020000] s3c-i2c s3c2440-i2c.1: gpio [44] request failed
[ 16.020000] s3c-i2c s3c2440-i2c.2: gpio [6] request failed

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Fix code to free gpios

Store the requested gpios so that they can be freed on error/removal.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: do not special case HDMIPHY stuck bus detection

Commit "i2c-s3c2410: Add HDMIPHY quirk for S3C2440" added support for
HDMIPHY with some special handling in s3c24xx_i2c_set_master:

"due to unknown reason (probably HW bug in HDMIPHY and/or the controller)
a transfer fails to finish. The controller hangs after sending the last
byte, the workaround for this bug is resetting the controller after each
transfer"

The "unknown reason" was that the proper sequence for generating a STOP
condition wasn't being followed as per the datasheet. Since this is fixed
by "PATCH: i2c-s3c2410: do not generate STOP for QUIRK_HDMIPHY buses",
remove the special handling.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: use exponential back off while polling for bus idle

Usually, the i2c controller has finished emitting the i2c STOP before the
driver reaches the bus idle polling loop. Optimize for this most common
case by reading IICSTAT first and potentially skipping the loop.

If the cpu is faster than the hardware, we wait for bus idle in a polling
loop. However, since the duration of one iteration of the loop is
dependent on cpu freq, and this i2c IP is used on many different systems,
use a time based loop timeout (5 ms).

We would like very low latencies to detect bus idle for the normal
'fast' case. However, if a device is slow to release the bus for some
reason, it could hold off the STOP generation for up to several
milliseconds. Rapidly polling for bus idle would seriously load the CPU
while waiting for it to release the bus. So, use a partial exponential
backoff as a compromise between idle detection latency and cpu load.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: do not generate STOP for QUIRK_HDMIPHY

The datasheet says that the STOP sequence should be:
1) I2CSTAT.5 = 0 - Clear BUSY (or 'generate STOP')
2) I2CCON.4 = 0 - Clear IRQPEND
3) Wait until the stop condition takes effect.
4*) I2CSTAT.4 = 0 - Clear TXRXEN

Where, step "4*" is only for buses with the "HDMIPHY" quirk.

However, after much experimentation, it appears that:
a) normal buses automatically clear BUSY and transition from
Master->Slave when they complete generating a STOP condition.
Therefore, step (3) can be done in doxfer() by polling I2CCON.4
after starting the STOP generation here.
b) HDMIPHY bus does neither, so there is no way to do step 3.
There is no indication when this bus has finished generating STOP.

In fact, we have found that as soon as the IRQPEND bit is cleared in
step 2, the HDMIPHY bus generates the STOP condition, and then immediately
starts transferring another data byte, even though the bus is supposedly
stopped. This is presumably because the bus is still in "Master" mode,
and its BUSY bit is still set.

To avoid these extra post-STOP transactions on HDMI phy devices, we just
disable Serial Output on the bus (I2CSTAT.4 = 0) directly, instead of
first generating a proper STOP condition. This should float SDA & SCK
terminating the transfer. Subsequent transfers start with a proper START
condition, and proceed normally.

The HDMIPHY bus is an internal bus that always has exactly two devices,
the host as Master and the HDMIPHY device as the slave. Skipping the STOP
condition has been tested on this bus and works.

Also, since we disable the bus directly from the isr, we can skip the bus
idle polling loop at the end of doxfer().

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: grab adapter lock while changing i2c clock

We probably don't want to change I2C frequency while a transfer is in
progress. The current implementation grabs a spinlock, but that only
protected the writes to IICCON when starting a message, it didn't protect
against clock changes in the middle of a transaction.

Note: The i2c-core already grabs the adapter lock before calling
s3c24xx_i2c_doxfer(), which ensures that only one caller is issuing a
xfer at a time. This means it is not necessary to disable interrupts
(spin_lock_irqsave) when changing frequencies, since there won't be
any i2c interrupts if there is no on-going xfer.

Lastly, i2c_lock_adapter() may cause the cpufreq_transition to sleep if
if a xfer is in progress, but this is ok since cpufreq notifiers are
called in a kernel thread, and there are already cases where it could
sleep, such as when using i2c to update the output of a voltage
regulator.

Note: the cpufreq part of this change has no functional affect on
exynos, where the i2c clock is independent of the cpufreq.
But, there is a slight perfomance boost since we no longer need to
lock/unlock an additional spinlock.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Add support for pinctrl

This patch adds support for pin configuration using pinctrl subsystem
to the i2c-s3c2410 driver.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Convert to devm_request_and_ioremap()

A small code saving and less error handling to worry about.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Refactor ifdefs for PM_SLEEP

Use the PM_SLEEP ifdef for system suspend and resume. This is partly
in preparation for adding runtime operations and partly because a user
may in theory choose to enable runtime suspend but not system suspend.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: use clk_prepare_enable and clk_disable_unprepare

Convert clk_enable/clk_disable to clk_prepare_enable/clk_disable_unprepare
calls as required by common clock framework.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

ARM: samsung: move platform_data definitions

Platform data for device drivers should be defined in
include/linux/platform_data/*.h, not in the architecture
and platform specific directories.

This moves such data out of the samsung include directories

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Wolfram Sang (embedded platforms)" <w.sang@pengutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Bryan Wu <bryan.wu@canonical.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Chris Ball <cjb@laptop.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: Liam Girdwood <lrg@ti.com>
Cc: linux-samsung-soc@vger.kernel.org

i2c-s3c2410: Use plain pm_runtime_put()

There's no point in using _sync() as we don't really care if the suspend
has completed immediately.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: s3c2410: Fix pointer type passed to of_match_node()

This commit fixes warning introduced in 27452498a ("i2c-s3c2410: Rework
device type handling"):

drivers/i2c/busses/i2c-s3c2410.c: In function 's3c24xx_get_device_quirks':
drivers/i2c/busses/i2c-s3c2410.c:125: warning: passing argument 1 of 'of_match_node' from incompatible pointer type
include/linux/of.h:245: note: expected 'const struct of_device_id *' but argument is of type 'const struct of_device_id (*)[4]'

Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: Split I2C_M_NOSTART support out of I2C_FUNC_PROTOCOL_MANGLING

Since there are uses for I2C_M_NOSTART which are much more sensible and
standard than most of the protocol mangling functionality (the main one
being gather writes to devices where something like a register address
needs to be inserted before a block of data) create a new I2C_FUNC_NOSTART
for this feature and update all the users to use it.

Also strengthen the disrecommendation of the protocol mangling while we're
at it.

In the case of regmap-i2c we remove the requirement for mangling as
I2C_M_NOSTART is the only mangling feature which is being used.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

i2c-s3c2410: Add HDMIPHY quirk for S3C2440

This patch adds support for s3c2440 I2C bus controller dedicated HDMIPHY device on
Exynos4 platform. Some quirks are introduced due to differences between HDMIPHY
and other I2C controllers on Exynos4. These differences are:
- no GPIOs, HDMIPHY is inside the SoC and the controller is connected
internally
- due to unknown reason (probably HW bug in HDMIPHY and/or the controller) a
transfer fails to finish. The controller hangs after sending the last byte,
the workaround for this bug is resetting the controller after each transfer

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Tested-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c-s3c2410: Rework device type handling

Reorganize driver a bit to better handle device tree-based systems:

- move machine type to driver's private structure instead of
quering platform device variants in runtime

- replace s3c24xx_i2c_type enum with unsigned int that holds
bitmask with revision-specific quirks

Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c-s3c2410: Drop unused define

Use standard of_match_ptr() to avoid defining variable unused
in non device tree builds.

Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c-s3c2410: Add stub runtime power management

Add stub runtime_pm calls which go through the flow of enabling and
disabling but don't actually do anything with the device itself as
there's nothing useful we can do. This provides the core PM framework
with information about when the device is idle, enabling chip wide
power savings.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c-s3c2410: Convert to devm_kzalloc()

Saves remembering to call kfree(). There's some kfree()s used by the
resource still, these will be removed in 3.3 using the newly added
devm_request_and_ioremap().

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c-s3c2410: Fix return code of s3c24xx_i2c_parse_dt_gpio

s3c24xx_i2c_parse_dt_gpio is called when cfg_gpio is not defined
in the platform data of the i2c device. When DT is not enabled,
the above function always returns -EINVAL. Since there can be
some i2c devices which don't need to configure any gpio lines,
the probe of such devices would fail here. Changing the default
return value to success would fix this issue.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: i2c-s3c2410: Add a cpu_relax() to busy wait for bus idle

Be a bit more friendly.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Add device tree support

Add device tree probe support for Samsung's s3c2410 i2c driver.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Keep a copy of platform data and use it

The platform data is copied into driver's private data and the copy is
used for all access to the platform data. This simpifies the addition
of device tree support for the i2c-s3c2410 driver.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: irq: Remove IRQF_DISABLED

Since commit [c58543c8: genirq: Run irq handlers with interrupts disabled],
We run all interrupt handlers with interrupts disabled
and we even check and yell when an interrupt handler
returns with interrupts enabled (see commit [b738a50a:
genirq: Warn when handler enables interrupts]).

So now this flag is a NOOP and can be removed.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Remove useless break code

Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Fix typo 'i2s' -> 'i2c'

Signed-off-by: Huisung Kang <hs1218.kang@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: Remove unneeded inclusions of <linux/i2c-id.h>

These drivers don't use anything which is defined in <linux/i2c-id.h>.
This header file was never meant to be included directly anyway, and
will be deleted soon.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Dave Airlie <airlied@linux.ie>
Cc: Hans Verkuil <hverkuil@xs4all.nl>

i2c-s3c2410: Enable i2c clock only when doing some transfert

This patch modify the s3c2410 i2c driver behaviour to enable the
i2c clock only when needed. I'm not sure if this has a big impact
on power usage but at least it's fixing a bug with the uda1380
codec which needs to be hard reset'ed if the i2c clock is enabled
before it's powered on (at least on h1940).

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: fix calculation of SDA line delay

S3C2440 style I2C controller uses PCLK to calculate the SDA line delay.
The driver wrongly assumed that this delay is calculated from the
frequency that the controller is operating on. This patch fixes this
issue.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: Use <linux/io.h> instead of <asm/io.h>

As warned by checkpatch.pl, <linux/io.h> should be used instead of
<asm/io.h>.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

i2c-s3c2410: Remove unconditional 1ms delay on each transfer

The S3C I2C controller indicates completion of I2C transfers before
the bus has a stop condition on it. In order to ensure that we do not
attempt to start a new transfer before the bus is idle the driver
currently inserts a 1ms delay. This is vastly larger than is generally
required and has a visible effect on performance under load, such as
when bringing up audio CODECs or reading back status information with
non-bulk I2C reads.

Replace the sleep with a spin on the IIC status register for up to 1ms.
This will busy wait but testing on my SMDK6410 system indicates that
the overwhelming majority of transactions complete on the first spin,
with maximum latencies of less than 10 spins so the absolute overhead
of busy waiting should be at worst comprable to msleep(), and the
overall system performance is dramatically improved.

The main risk is poor interaction with multimaster systems where
we may miss the bus going idle before the next transaction. Defend
against this by falling back to the original 1ms delay after 20 spins.

The overall effect in my testing is an approximately 20% improvement
in kernel startup time.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

const: constify remaining dev_pm_ops

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

i2c-s3c2410: s3c24xx_i2c_init: don't clobber IICLC value

s3c24xx_i2c_init() was overwriting the IICLC value set just above in
s3c24xx_i2c_clockrate() with zero, effectively disabling the platform
line control setting.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

I2C: Rework i2c-s3c2410 suspend_late()/resume() V2

This is V2 of the i2c-s3c2410 dev_pm_ops patch.

The callbacks are converted for CONFIG_SUSPEND like this:
suspend_late() -> suspend_noirq()
resume() -> resume()

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

i2c-s3c2410: use resource_size()

Change the usage of res->end-res->start to resource_size(), missed
by the last patch to change this.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: move to using platform idtable to match devices

Change to using platform id table to match either of the two supported
platform device names in the driver. This simplifies the driver init and
exit code

Note, log messages will now be prefixed with 's3c-i2c' instead of the
driver name, so output will be of the form of:

s3c-i2c s3c2440-i2c.0: slave address 0x10

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: i2c-s3c2410: Initialise Samsung I2C controller early

This is required in order to ensure that core system devices such as
voltage regulators attached via I2C are avaiable early in boot.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Simplify bus frequency calculation

The platform data for the i2c-s3c2410 driver used to allow a min,
max and desired frequency for the I2C bus. This patch reduces it
to simply a desired frequency ceiling and corrects all the uses
of the platform data appropriately.

This means, for example, that on a system with a 66MHz fclk, a
request for 100KHz will achieve 65KHz which is safe and
acceptable, rather than 378KHz which it would have achieved
without this change.

Signed-off-by: Simtec Linux Team <linux@simtec.co.uk>
Signed-off-by: Daniel Silverstone <dsilvers@simtec.co.uk>
[ben-linux@fluff.org: tidy subject and description]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: sda_delay should be in ns, not clock ticks

The sda_delay field should be specified in ns, not in clock ticks
as when using cpufreq we could be changing the bus rate.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>

i2c: Get rid of remaining bus_id access

Use dev_name(dev) instead of accessing dev.bus_id directly, as the
latter is going away soon.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>

i2c-s3c2410: Change IRQ to be plain integer.

Change the code to use a plain integer as the holder
for the IRQ for the device and use platform_get_irq()
to find it.

This makes the code slightly neater, and easier to get
the IRQ number.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Allow more than one i2c-s3c2410 adapter

Newer SoCs such as the S3C6410 have 2 instances of this i2c
controller block in and thus require the ability to create
two seperate busses from this.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Remove default platform data.

The platform data should now always be present when the device
is initialised, so we can remove the default platform data in
the driver.

All the device initialisation points in the board specific code
should already have been changed to initialise this as necessary.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Use platform data for gpio configuration

Add a callback to set the gpio configuration for the
i2c device instead of a set include. This also allows
the remvoal of the machine gpio and hardware files.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Fixup style problems from checkpatch.pl

Fixup the 36 warnings and errors generated from running
checkpatch.pl on the driver. The warnings are too numerous
to be listed here.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: fix check for being in suspend.

As noted by Julia Lawall <julia@diku.dk>, we can never
trigger the check for being in suspend due to the result
of !readl(i2c->regs + S3C2410_IICCON) & S3C2410_IICCON_IRQEN
always being 0.

Add suspend/resume hooks to stop i2c transactions happening
until the driver has been resumed.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-s3c2410: Correct use of ! and &

In commit e6bafba5b4765a5a252f1b8d31cbf6d2459da337, a bug was fixed that
involved converting !x & y to !(x & y). The code below shows the same
pattern, and thus should perhaps be fixed in the same way. In particular,
the result of !readl(i2c->regs + S3C2410_IICCON) & S3C2410_IICCON_IRQEN is
always 0.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@ expression E; constant C; @@
(
!E & !C
|
- !E & C
+ !(E & C)
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

[ARM] S3C: Move i2c headers to arch/arm/plat-s3c/include/plat.

Move the i2c headers to arch/arm/plat-s3c/include/plat
ready to clean out the old include directories.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

[ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach

This just leaves include/asm-arm/plat-* to deal with.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] Remove asm/hardware.h, use asm/arch/hardware.h instead

Remove includes of asm/hardware.h in addition to asm/arch/hardware.h.
Then, since asm/hardware.h only exists to include asm/arch/hardware.h,
update everything to directly include asm/arch/hardware.h and remove
asm/hardware.h.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

i2c: S3C24XX I2C frequency scaling support.

Add support for CPU frequency scaling to the S3C24XX I2C driver.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: S3C2410: Pass the I2C bus number via drivers platform data

Allow the platform data to specify the bus bumber that the
new I2C bus will be given. This is to allow the use of the
board registration mechanism to specify the new style of
I2C device registration which allows boards to provide a
list of attached devices.

Note, as discussed on the mailing list, we have dropped
backwards compatibility of adding an dynamic bus number
as it should not affect most boards to have the bus pinned
to 0 if they have either not specified platform data for
driver. Any board supplying platform data will automatically
have the bus_num field set to 0, and anyone who needs the
driver on a different bus number can supply platform data
to set bus_num.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: Let bus drivers add SPD to their class

Let general purpose I2C/SMBus bus drivers add SPD to their class. Once
this is done, we will be able to tell the eeprom driver to only probe
for SPD EEPROMs and similar on these buses.

Note that I took a conservative approach here, adding I2C_CLASS_SPD to
many drivers that have no idea whether they can host SPD EEPROMs or not.
This is to make sure that the eeprom driver doesn't stop probing buses
where SPD EEPROMs or equivalent live.

So, bus driver maintainers and users should feel free to remove the SPD
class from drivers those buses never have SPD EEPROMs or they don't
want the eeprom driver to bind to them. Likewise, feel free to add the
SPD class to any bus driver I might have missed.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

I2C: S3C2410: Add MODULE_ALIAS() for s3c2440 device.

Add a MODULE_ALIAS() statement for the i2c-s3c2410 controller
to ensure that it can be autoloaded on the S3C2440 systems that
we support.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

I2C: S3C2410: Fixup error codes returned rom a transfer.

The driver should be returning -ENXIO for transfers that do not
pass the initial address byte stage.

Note, also small tidyups to the driver comments in the area.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

I2C: S3C2410: Check ACK on byte transmission

We should check for the reception of an ACK after transmitting each
data byte. The address send has been correctly checking this, but the
data write byte state should have also been checking for these failures.

As part of the same fix, we remove the ACK checking from the receive
path where it should not have been checking for an ACK which our hardware
was sending.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: Fix platform driver hotplug/coldplug

Since 43cc71eed1250755986da4c0f9898f9a635cb3bf, the platform
modalias is prefixed with "platform:". Add MODULE_ALIAS() to the
hotpluggable I2C platform drivers, to allow module auto loading.

[ db: add some more drivers ]

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

i2c: Replace remaining __FUNCTION__ occurrences

__FUNCTION__ is gcc-specific, use __func__.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

i2c-s3c2410: Build fix

Fixup the include files after the arch moves that
where included in 2.6.23.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

i2c-s3c2410: Fix build warning

Fix for the following build warning:
CC drivers/i2c/busses/i2c-s3c2410.o
drivers/i2c/busses/i2c-s3c2410.c: In function 's3c24xx_i2c_probe':
drivers/i2c/busses/i2c-s3c2410.c:839: warning: format '%ld' expects type 'long int', but argument 4 has type 'resource_size_t'

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

i2c-s3c2410: Fix bug in releasing driver

When compiled as a module, the i2c-s3c2410 driver does not
free either the IRQ or the i2c adapter it attached to the system.

As part of this fix, move to the usual kernel style
of freeing items as part of the probe error path
making the remove process easier.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

i2c-s3c2410: Fix I2C SDA to SCL setup time

Fix the setup time for SDA to SCL due to the way
the S3C24XX I2C controller works.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

i2c: SPIN_LOCK_UNLOCKED cleanup

SPIN_LOCK_UNLOCKED cleanup, use __SPIN_LOCK_UNLOCKED instead.

Signed-off-by: Milind Arun Choudhary <milindchoudhary@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

[PATCH] remove many unneeded #includes of sched.h

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.

(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.

(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

i2c: Constify i2c_algorithm declarations, part 2

i2c: Constify i2c_algorithm declarations, part 2

Make struct i2c_algorithm declarations const in all i2c bus drivers
where it is possible.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] irq-flags: misc drivers: Use the new IRQF_ constants

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[ARM] Move asm/hardware/clock.h to linux/clk.h

This is needs to be visible to other architectures using the AMBA
bus and peripherals.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] Remove clk_use()/clk_unuse()

It seems that clk_use() and clk_unuse() are additional complexity
which isn't required anymore. Remove them from the clock framework
to avoid the additional confusion which they cause, and update all
ARM machine types except for OMAP.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[DRIVER MODEL] Convert platform drivers to use struct platform_driver

This allows us to eliminate the casts in the drivers, and eventually
remove the use of the device_driver function pointer methods for
platform device drivers.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

[DRIVER MODEL] Add missing driver_unregister in i2c-s3c2410 failure path.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

Create platform_device.h to contain all the platform device details.
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] Owner field additions to many i2c drivers, 2 of 5

This patch updates the .owner field for various struct xxxx_driver variables,
other than pci_driver.

Signed-off-by: Laurent Riffard <laurent.riffard@free.fr>
Signed-off-by: Jean Delvare <khali@linux-fr>
Acked-by: Mark A. Greer <mgreer@mvista.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Deepak Saxena <dsaxena@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] DRIVER MODEL: Get rid of the obsolete tri-level suspend/resume callbacks

In PM v1, all devices were called at SUSPEND_DISABLE level. Then
all devices were called at SUSPEND_SAVE_STATE level, and finally
SUSPEND_POWER_DOWN level. However, with PM v2, to maintain
compatibility for platform devices, I arranged for the PM v2
suspend/resume callbacks to call the old PM v1 suspend/resume
callbacks three times with each level in order so that existing
drivers continued to work.

Since this is obsolete infrastructure which is no longer necessary,
we can remove it. Here's an (untested) patch to do exactly that.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] I2C: Kill i2c_algorithm.name (1/7)

The name member of the i2c_algorithm is never used, although all
drivers conscientiously fill it. We can drop it completely, this
structure doesn't need to have a name.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] Spelling fixes for drivers/i2c.

Here are some spelling corrections for drivers/i2c.

occured -> occurred
intialization -> initialization
Everytime -> Every time
transfering -> transferring
relevent -> relevant
continous -> continuous
neccessary -> necessary
explicitely -> explicitly
Celcius -> Celsius
differenciate -> differentiate

Signed-off-by: Steven Cole <elenstev@mesatop.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] I2C: drivers/i2c/*: #include <linux/config.h> cleanup

Files that don't use CONFIG_* stuff shouldn't include config.h
Files that use CONFIG_* stuff should include config.h

It's that simple. ;-)

Signed-off-by: Alexey Dobriyan <adobriyan@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!