Add i2c bus recovery infrastructure to i2c adapters as specified in the i2c
protocol Rev. 03 section 3.1.16 titled "Bus clear".

http://www.nxp.com/documents/user_manual/UM10204.pdf

Sometimes during operation i2c bus hangs and we need to give dummy clocks to
slave device to start the transfer again. Now we may have capability in the bus
controller to generate these clocks or platform may have gpio pins which can be
toggled to generate dummy clocks. This patch supports both.

This patch also adds in generic bus recovery routines gpio or scl line based
which can be used by bus controller. In addition controller driver may provide
its own version of the bus recovery routine.

This doesn't support multi-master recovery for now.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
[wsa: changed gpio type to int and minor reformatting]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This allows you to get the equivalent functionality of
i2c_add_numbered_adapter() with all data in the device tree and no
special case code in your driver.  This is a common device tree
technique.

For quick reference, the FDT syntax for using an alias to provide an
ID looks like:
  aliases {
    i2c0 = &i2c_0;
    i2c1 = &i2c_1;
  };
Signed-off-by: NDoug Anderson <dianders@chromium.org>
[wsa: removed one check from static function. We know our callers]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

My old e-mail address is no longer working.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
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>

MAX_IDR_MASK is another weirdness in the idr interface.  As idr covers
whole positive integer range, it's defined as 0x7fffffff or INT_MAX.

Its usage in idr_find(), idr_replace() and idr_remove() is bizarre.
They basically mask off the sign bit and operate on the rest, so if
the caller, by accident, passes in a negative number, the sign bit
will be masked off and the remaining part will be used as if that was
the input, which is worse than crashing.

The constant is visible in idr.h and there are several users in the
kernel.

* drivers/i2c/i2c-core.c:i2c_add_numbered_adapter()

  Basically used to test if adap->nr is a negative number which isn't
  -1 and returns -EINVAL if so.  idr_alloc() already has negative
  @start checking (w/ WARN_ON_ONCE), so this can go away.

* drivers/infiniband/core/cm.c:cm_alloc_id()
  drivers/infiniband/hw/mlx4/cm.c:id_map_alloc()

  Used to wrap cyclic @start.  Can be replaced with max(next, 0).
  Note that this type of cyclic allocation using idr is buggy.  These
  are prone to spurious -ENOSPC failure after the first wraparound.

* fs/super.c:get_anon_bdev()

  The ID allocated from ida is masked off before being tested whether
  it's inside valid range.  ida allocated ID can never be a negative
  number and the masking is unnecessary.

Update idr_*() functions to fail with -EINVAL when negative @id is
specified and update other MAX_IDR_MASK users as described above.

This leaves MAX_IDR_MASK without any user, remove it and relocate
other MAX_IDR_* constants to lib/idr.c.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: "Marciniszyn, Mike" <mike.marciniszyn@intel.com>
Cc: Jack Morgenstein <jackm@dev.mellanox.co.il>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: NWolfram Sang <wolfram@the-dreams.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert to the much saner new idr interface.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Wolfram Sang <wolfram@the-dreams.de>
Tested-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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>

Reduce 2 boolean functions from "if (condition) return 1; return 0;" to
"return condition;"
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NWolfram 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: NMarek Vasut <marex@denx.de>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
[wsa: changed messages from dev_err to dev_warn]
Signed-off-by: NWolfram Sang <wolfram@the-dreams.de>

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

Migrate Tegra clock support to drivers/clk/tegra, this involves
moving:
1. definition of tegra_cpu_car_ops to clk.c
2. definition of reset functions to clk-peripheral.c
3. change parent of cpu clock.
4. Remove legacy clock initialization.
5. Initialize clocks using DT.
6. Remove all instance of mach/clk.h
Signed-off-by: NPrashant Gaikwad <pgaikwad@nvidia.com>
[swarren: use to_clk_periph_gate().]
Signed-off-by: NStephen Warren <swarren@nvidia.com>

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>

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: NMarek Vasut <marex@denx.de>
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>

cppcheck rightfully reports those as "reassigned a value before the old
one has been used."
Signed-off-by: NWolfram 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: NPatrice Chotard <patrice.chotard@stericsson.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
[wsa: fixed braces on one else-branch]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>