Using autosuspend helps to reduce the resume latency in situations where
another I2C message is going to be started soon. For example with HID over
I2C touch panels we get several messages in a short period of time while
the touch panel is in use.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This is not an atomic context so there is no need to use mdelay() but
instead use usleep_range().
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The correct way to disable or enable the controller is to wait until the
DW_IC_ENABLE_STATUS register bit matches the bit we program into DW_IC_ENABLE
register. This procedure is described in the DesignWare I2C databook.

By doing this we can be sure that the controller is in correct state once
the function returns.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

It is not good idea to mix static and dynamic I2C adapter numbering. In
this particular case on Lynxpoint we had graphics I2C adapter which took
the first numbers preventing the designware I2C driver from using the
adapter numbers it preferred.

Since Lynxpoint support was just introduced and there is no hardware available
outside Intel we can fix this by switching to use dynamic adapter numbering
instead of static.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This makes the error handling much more simpler than open-coding everything
and in addition makes the probe function smaller an tidier.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

With dev_err() we can get the device instance printed as well and is pretty
much standard to use dev_* macros in the drivers anyway. In addition
correct the indentation of probe() arguments.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This makes the error handling much more simpler than open-coding everything
and in addition makes the probe function smaller and tidier.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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>

i2c_del_adapter() always returns 0. So all checks testing whether it will be
non zero will always evaluate to false and the conditional code is dead code.
This patch updates all callers of i2c_del_mux_adapter() to ignore the return
value and assume that it will always succeed (which it will). In a subsequent
patch the return type of i2c_del_adapter() will be made void.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NBen Hutchings <bhutchings@solarflare.com>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This eliminates having an #ifdef returning NULL for the case
when OF is disabled.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Acked-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Update the code to use devm_* API so that driver core will manage
resources.
Signed-off-by: NVishwanathrao Badarkhe, Manish <manishv.b@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Since we have generic i2c bus recover routines now, these custom ones
need to be renamed to fix the namespace clash. Proper conversion needs
to be done by someone who has access to the hardware.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

GPIOs may not be available immediately when i2c-gpio looks for them.
Implement support for deferred probing so that probing can be
attempted again later when GPIO pins are finally available.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Tested-by: NBo Shen <voice.shen@atmel.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>

(SMATCH) drivers/i2c/busses/i2c-ismt.c:186:14: warning: duplicate const
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Tegra only supports, and always enables, device tree. Remove all ifdefs
and runtime checks for DT support from the driver. Platform data is
therefore no longer required. Delete the header that defines it.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The commit: "i2c-core: dt: Pick i2c bus number from i2c alias if
present" adds support for automatically picking the bus number based
on the alias ID.  Remove the now unnecessary code from i2c-pxa that
did the same thing.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This patch adds the iSMT SMBus Controller DeviceIDs for the Intel Avoton SOC.
Signed-off-by: NSeth Heasley <seth.heasley@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

NVIDIA's Tegra SoC allows read/write of controller register only
if controller clock is enabled. System hangs if read/write happens
to registers without enabling clock.

clk_prepare_enable() can be fail due to unknown reason and hence
adding check for return value of this function. If this function
success then only access register otherwise return to caller with
error.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

Remove !S390 dependency from i2c Kconfig, since s390 now supports PCI, HAS_IOMEM
and HAS_DMA, however we need to add a couple of GENERIC_HARDIRQS dependecies to
fix compile and link errors like these:

ERROR: "devm_request_threaded_irq" [drivers/i2c/i2c-smbus.ko] undefined!
ERROR: "devm_request_threaded_irq" [drivers/i2c/busses/i2c-ocores.ko] undefined!

Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

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: NWolfram Sang <wsa@the-dreams.de>
Reported-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram 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: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NWolfram 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: NJayachandran C <jchandra@broadcom.com>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Acked-by: NAndreas Larsson <andreas@gaisler.com>
Signed-off-by: NWolfram 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: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NWolfram 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: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NWolfram Sang <wolfram@the-dreams.de>

This patch adds the SMBus Device IDs for the Intel Wellsburg PCH
Signed-off-by: NJames Ralston <james.d.ralston@intel.com>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram 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: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NWolfram 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: NAmaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wolfram@the-dreams.de>

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

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

Signed-off-by: NAmaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram 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: NAlexander Stein <alexander.stein@systec-electronic.com>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram 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: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NWolfram 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: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NBill Brown <bill.e.brown@intel.com>
Tested-by: NSeth Heasley <seth.heasley@intel.com>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram 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: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NWolfram Sang <wolfram@the-dreams.de>

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