There is simply no reason to be manually setting the private driver
data to NULL in the remove/fail to probe cases.  This is just extra
cruft code that can be removed.

A few notes:
* Nothing relies on drvdata being set to NULL.
* The __device_release_driver() function eventually calls
  dev_set_drvdata(dev, NULL) anyway, so there's no need to do it
  twice.
* I verified that there were no cases where xxx_get_drvdata() was
  being called in these drivers and checking for / relying on the NULL
  return value.

This could be cleaned up kernel-wide but for now just take the baby
step and remove from the i2c subsystem.
Reported-by: Wolfram Sang <wsa@the-dreams.de>
Reported-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

The remove() methods should not be marked __exit unless we are using
platform_driver_probe() which disables unbinding device from driver
via sysfs.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

After commit a000b8c1 [i2c: ocores: Add support for the GRLIB port of the
controller and use function pointers for getreg and setreg function],
compiling i2c-ocores.c for 64-bit gives the following warning:

  drivers/i2c/busses/i2c-ocores.c: In function 'ocores_i2c_of_probe':
  drivers/i2c/busses/i2c-ocores.c:334:15: warning: cast from pointer to integer of different size

Fix it by casting the pointer to long.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

If timeout error occurs in the i2c transfer then it was dumping warning
of call stack.

Remove the warning dump as there is may be possibility that some slave
devices are busy and not responding the i2c communication.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

Fix printk format warning.  dma_addr_t can be 32-bit or 64-bit,
so cast it to long long for printing.  This also matches the
printk format specifier that is already used.

drivers/i2c/busses/i2c-ismt.c:532:3: warning: format '%llX' expects argument of type 'long long unsigned int', but argument 4 has type 'dma_addr_t' [-Wformat]
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

This patch adds the SMBus Device IDs for the Intel Wellsburg PCH
Signed-off-by: James Ralston <james.d.ralston@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

This implements a very basic I2C host driver for the BCM2835 SoC. Missing
features so far are:

* 10-bit addressing.
* DMA.
Reviewed-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

Adding Seth Heasley and Myself as maintainers for the i2c-ismt drvier
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: "Heasley, Seth" <seth.heasley@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

This patch corrects checkpatch errors.

The changes has also been removed as it has less meaning with version
control tools.
Signed-off-by: Amaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

This patch corrects the display of the acpi_base unsigned hex value.
Signed-off-by: Amaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

This patch replaces hexadecimal values by constants for SMBus commands.
Signed-off-by: Amaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

Datasheet on collision:
	SMBus Collision (SMBCOL_STS)
	This bit is set when a SMBus Collision condition occurs and
	SMBus Host loses in the bus arbitration. The software should
	clear this bit and re-start SMBus operation.

As the status will be cleared in transaction_end, we can remove the
sis630_write and prepare to return -EAGAIN to retry.
Signed-off-by: Amaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

The sticky bits must be cleared at the end of the transaction by writing
a 1 to all fields.

Datasheet:
	SMBus Status (SMB_STS)
	The following registers are all sticky bits and only can be
	cleared by writing a one to their corresponding fields.
Signed-off-by: Amaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

Signed-off-by: Amaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

It was observed the Host Clock Divider was not written by the driver. It
was still set to (default) 0, if not already set by BIOS, which caused
garbage on SMBus.
This driver adds a parameters which is used to calculate the divider
appropriately for a default bitrate of 100 KHz. This new divider is only
applied if the clock divider is still default 0.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

Commit 70d46a24 "i2c: at91: add dt support to i2c-at91"
added DT only support for at91sam9x5. Building i2c-at91
without CONFIG_OF now warns about at91sam9x5_config as
being unused.

  drivers/i2c/busses/i2c-at91.c:556:30: warning: 'at91sam9x5_config' defined but not used [-Wunused-variable]

Move at91sam9x5_config under the defined(CONFIG_OF)
guard as new AT91 SoCs will be DT only.
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

The iSMT (Intel SMBus Message Transport) supports multi-master I2C/SMBus,
as well as IPMI.  It's operation is DMA-based and utilizes descriptors to
initiate transactions on the bus.

The iSMT hardware can act as both a master and a target, although this
driver only supports being a master.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Bill Brown <bill.e.brown@intel.com>
Tested-by: Seth Heasley <seth.heasley@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

By default there should be no stop bit on I2C between single messages
within transfers. Fix the driver to comply and only send a stop bit at
the end of transfers or if I2C_M_STOP is set.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

Eliminate an open-coded "goto" loop by introducing a function.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

In a timeout case return an error immediately from the driver's
.master_xfer() method, instead of continuing and letting higher layers
fail.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

Reduce 2 boolean functions from "if (condition) return 1; return 0;" to
"return condition;"
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

This patch drops the i2c timing tables from this driver and instead
derives the timing based from the requested clock sleep. The timing
tables were completely wrong anyway when observed on a scope.

This new algorithm is also only derived by using a scope, but it seems
to produce much more accurate result.
Signed-off-by: Marek Vasut <marex@denx.de>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
[wsa: changed messages from dev_err to dev_warn]
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

This patch adds the PCU SMBus DeviceID for the Intel Avoton SOC.
Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

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>

Add support for the PIO mode and mixed PIO/DMA mode support. The mixed
PIO/DMA is the default mode of operation. This shall leverage overhead
that the driver creates due to setting up DMA descriptors even for very
short transfers.

The current boundary between PIO/DMA 8 bytes, transfers shorter than 8
bytes are transfered by PIO, longer transfers use DMA. The performance
of write transfers remains unchanged, while there is a minor improvement
of read performance. Reading 16KB EEPROM with DMA-only operations gives
a read speed of 39.5KB/s, while with then new mixed-mode the speed is
blazing 40.6KB/s.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram 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: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram 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: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram 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: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram 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: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

cppcheck rightfully reports those as "reassigned a value before the old
one has been used."
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Linus Walleij <linus.walleij@stericsson.com>

Amend the I2C nomadik pin controller to optionally take a pin control
handle and set the state of the pins to:

- "default" on boot, resume and before performing an i2c transfer
- "idle" after initial default, after resume default, and after each
   i2c xfer
- "sleep" on suspend()

This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle, and for runtime cases inbetween
I2C transfers.
Signed-off-by: Patrice Chotard <patrice.chotard@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[wsa: fixed braces on one else-branch]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Acked-by: Ludovic Ddesroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

NVIDIA's Tegra114 has following enhanced feature in i2c controller:
- Enable/disable control for per packet transfer complete interrupt.
  Earlier SoCs could not disable this.
- Single clock source for standard/fast and HS mode clock speed.
  The clock divisor for fast/standard mode is added into the i2c
  controller to meet the HS and standard/fast mode of clock speed
  from single source.

Add support for the above feature to make it functional on T114 SOCs.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Intel Lynxpoint has two I2C controllers. These controllers are enumerated
from ACPI namespace with IDs INT33C2 and INT33C3. Add support for these to
the I2C DesignWare platform driver.

This is based on the work of Dirk Brandewie.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

In order to save power the device should be put to low power states
whenever it is not being used. We implement this by enabling minimal
runtime PM support.

There isn't much to do for the device itself as it is disabled once the
last transfer is completed but subsystem/domain runtime PM hooks can save
more power by power gating the device etc.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

If IC_EMPTYFIFO_HOLD_MASTER_EN is set to one, the DesignWare I2C controller
doesn't generate STOP on the bus when the FIFO is empty. This violates the
rules of Linux I2C stack as it requires that the STOP is issued once the
i2c_transfer() is finished.

However, there is no way to detect this from the hardware registers, so we
must make sure that the STOP bit is always set once the last byte of the
last message is transferred.

This patch is based on the work of Dirk Brandewie.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

avoid these checkpatch.pl issues :
- ERROR: "foo * bar" should be "foo *bar"
- ERROR: switch and case should be at the same indent
- ERROR: "(foo*)" should be "(foo *)"
- ERROR: do not use assignment in if condition
- ERROR: space required before the open parenthesis '('
- WARNING: suspect code indent for conditional statements
- WARNING: quoted string split across lines
- WARNING: space prohibited between function name and open parenthesis '('
- WARNING: line over 80 characters
also add spaces around some "+", "=", "*"
Signed-off-by: Laurent Navet <laurent.navet@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

As the at24 driver is able handle a bunch of serial storage chips other than
EEPROMs this is now mentioned in Kconfig.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c_smbus_process_call has no users in the kernel, so this can be
removed. Documentation for the same has been updated accordingly.

Fixes following sparse warning.
drivers/i2c/i2c-core.c:1871:5: warning: symbol 'i2c_smbus_process_call'
was not declared. Should it be static?

[wsa: updated the documentation]
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>