Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NBarry Song <Baohua.Song@csr.com>

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: NJaemin Yoo <jmin.yoo@samsung.com>
Tested-by: NPrasanna Kumar <prasanna.ps@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Make them conform more to established standards.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NGiridhar Maruthy <giridhar.m@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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

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

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

err_noclk label redirects to a simple return statement. Move the
return statement to the caller location and remove the label.
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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

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: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Reviewed-by: NDaniel Kurtz <djkurtz@chromium.org>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

"Whether" is misspelled in various comments across the tree; this
fixes them. No code changes.
Signed-off-by: NAdam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Store the requested gpios so that they can be freed on error/removal.
Signed-off-by: NAbhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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

Store the requested gpios so that they can be freed on error/removal.
Signed-off-by: NAbhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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

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

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

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

This patch adds support for pin configuration using pinctrl subsystem
to the i2c-s3c2410 driver.
Signed-off-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

A small code saving and less error handling to worry about.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Convert clk_enable/clk_disable to clk_prepare_enable/clk_disable_unprepare
calls as required by common clock framework.
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NMauro 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

There's no point in using _sync() as we don't really care if the suspend
has completed immediately.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

This commit fixes warning introduced in 27452498 ("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: NKarol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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

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: NTomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: NKarol Lewandowski <k.lewandowsk@samsung.com>
Tested-by: NTomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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: NKarol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Use standard of_match_ptr() to avoid defining variable unused
in non device tree builds.
Signed-off-by: NKarol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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

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

Be a bit more friendly.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

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

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

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: NThomas Abraham <thomas.abraham@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

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: NYong Zhang <yong.zhang0@gmail.com>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NBarry Song <21cnbao@gmail.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

Signed-off-by: NHuisung Kang <hs1218.kang@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>