It is possible that after entering runtime PM suspend the controller
context is lost due the fact that its power is removed. This happens for
example on Asus T100, an Intel Baytrail based tablet/laptop.

In order to get the controller back to functional state, we need to
implement runtime PM hooks which will re-initialize the hardware during
runtime PM resume. We can re-use the existing system suspend hooks as the
steps to resume/suspend the controller are the same.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Userspace can initiate system suspend on arbitrary times which means that
device drivers must make sure that their device gets quiesced before system
suspend is entered. Therefore disable the I2C host controller in the driver
system suspend hook.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Arnd said in another patch:

"As far as I can tell, this driver must have produced this
error for as long as it has been merged into the mainline kernel, but
it was never part of the normal build tests:

drivers/i2c/busses/i2c-nuc900.c: In function 'nuc900_i2c_probe':
drivers/i2c/busses/i2c-nuc900.c:601:17: error: request for member
'apbfreq' in something not a structure or union
  ret = (i2c->clk.apbfreq)/(pdata->bus_freq * 5) - 1;
                 ^
This is an attempt to get the driver to build and possibly
work correctly, although I do wonder whether we should just
remove it, as it has clearly never worked."

I agree with removing it since nobody showed interest in Arnd's fixup
patch.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: Wan ZongShun <mcuos.com@gmail.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>

Since IMX serial SOCs support low bus freq mode, some clocks freq
may change to save power. I2C needs to check the clock source and
update the divider.

For example:
i.MX6SL I2C clk is from IPG_PERCLK which is sourced from IPG_CLK.
Under normal operation, IPG_CLK is 66MHz, ipg_perclk is at 22MHz.
In low bus freq mode, IPG_CLK is at 12MHz and IPG_PERCLK is down
to 4MHz. So the I2C driver must update the divider register for
each transaction when the current IPG_PERCLK is not equal to the
clock of previous transaction.
Signed-off-by: Fugang Duan  <B38611@freescale.com>
[wsa: removed an outdated comment and simplified debug output]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Test i2c device Maxim max44009, datasheet is located at:
http://www.maximintegrated.com/datasheet/index.mvp/id/7175

The max44009 support repeat operation like:
read -> repeat restart -> read/write

The current i2c imx host controller driver don't support this
operation that causes i2c bus hang due to "MTX" is cleared in
.i2c_imx_read(). If "read" is the last message there have no problem,
so the current driver supports all SMbus operation like:
write -> repeat restart -> read/write

IMX i2c controller for master receiver has some limitation:
- If it is the last byte for one operation, it must generate STOP
  signal before read I2DR to prevent controller from generating another
  clock cycle.
- If it is the last byte in the read, and then do repeat restart, it must
  set "MTX" before read I2DR to prevent controller from generating another
  extra clock cycle.

The patch is to fix the issue.
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Make clear that the driver is GPL v2 only. Remove FSF address. Remove
filename in comment. Update copyright information.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Remove some obvious comments, remove some superfluous debug output (the
error code carries the same information), some white space fixing...
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Status register and enable register are identical regarding their
layout. Use the bit definitions for both.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The i2c core has per-adapter locks, so no need to protect again.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The old macros made it harder to see what was actually happening.
Replace them with something more readable.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Setting up a read or write message is similar enough to be done in one
function. Also, move a helper function into the new function since it is
only used here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

We should always check if the bus is free, independently if it is a read
or write. It should be done before the first message, though. After
that, we ourselves keep the bus busy. Remove a 'ret' assignment which
only silenced a build warning.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Remove the seperate functions and use designated constants. As readable
but less overhead. Actually, this is even more readable since the old
function used a mix of "=" and "|=".
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Remove the seperate functions and use designated constants. As readable
but less overhead.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

We use devm, so irq number is only needed during probe.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Very basic operations, just called once, can also go to the caller.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

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

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

Switch the device tree to the new compatibles introduced in the i2c drivers
to have a common pattern accross all Allwinner SoCs.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use devm_gpio_request() to make cleanup paths simpler.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Violeta Menendez <violeta.menendez@codethink.co.uk>
Reviewed-by: Ian Molton <ian.molton@codethink.co.uk>
Tested-by: Violeta Menendez <violeta.menendez@codethink.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The i2c-eg20t driver is for a companion chip to the Intel Atom E600
series processors. These are 32-bit x86 processors so the driver is
only needed on X86_32. Add COMPILE_TEST as an alternative, so that the
driver can still be build-tested elsewhere.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Newer SoCs have so fast input clocks that the ICCL/H registers only
count every second clock to have a meaningful 9-bit range. The driver
was already prepared for that happening, but didn't use it so far.
Add the proper DT configuration for SoCs that need it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Due to misconfiguration, it can happen that the calculated timing
parameters are out of range. Bail out if that happens. We can also
simplify some logic later because of the verified value. Also, make the
printouts of the values more precise by adding the hex-prefixes.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

sh_mobile_i2c_init() could detect wrong settings, but didn't bail out,
so it would continue unconfigured. Fix this.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Following the KISS principle, remove unneeded stuff.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This is what devm was made for. No rollback mechanism needed, remove the
hook parameter from the irq setup function and simplify it. While we are
here change some variables to proper types.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Convert the easy parts to devm. irqs will be converted in a seperate
patch to keep diffs readable.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

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

Use standard i2c error codes for i2c failures. Also, don't print
something on timeout since it happens regularly with i2c. Simplify some,
logic, too.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

No functional change, binaries are identical.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

HSI2C module on Exynos5260 differs from current modules in
following ways:
1.  HSI2C on Exynos5260 has fifo_depth of 16bytes
2.  Module needs to be reset as a part of init sequence.

Hence, Following changes are involved.
1. Add a new compatible string and Updates the Documentation dt bindings.
2. Introduce a variant struct to support the changes in H/W
3. Reset the module during init. Thus, bringing the module back
to default state irrespective of what firmware did with it.
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This adds some more warnings to the i2c-arb-gpio-challenge docs to
help encourage people not to use it in their designs unless they have
no choice.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Fixed most checkpatch.pl issues
Signed-off-by: Richard Leitner <me@g0hl1n.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

For !CONFIG_PM_RUNTIME, the device were never put back into active
state while resuming.

For CONFIG_PM_RUNTIME, we blindly trusted the device to be inactive
while we were about to handle it at suspend late, which is just too
optimistic.

Even if the driver uses pm_runtime_put_sync() after each tranfer to
return it's runtime PM resources, there are no guarantees this will
actually mean the device will inactivated. The reason is that the PM
core will prevent runtime suspend during system suspend, and thus when
a transfer occurs during the early phases of system suspend the device
will be kept active after the transfer.

To handle both issues above, use pm_runtime_force_suspend|resume() from
the system suspend|resume callbacks.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The smbus block read is not currently supported for imx i2c devices.
This patchset adds the support to imx i2c bus so that blocks of data
can be read using SMbus block reads.(using i2c_smbus_read_block_data()
function from the i2c_core.c.). Tested with 3.10.9 kernel.
Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Kaushal Butala <kaushalkernelmailinglist@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The Allwinner A10 compatibles were following a slightly different compatible
patterns than the rest of the SoCs for historical reasons. Move to the other
pattern for consistency across all Allwinner Socs.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
[wsa: dropped binding OK as per
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-February/229438.html]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Pull two powerpc fixes from Ben Herrenschmidt:
 "Here are a couple of fixes for 3.15.  One from Anton fixes a nasty
  regression I introduced when trying to fix a loss of irq_work whose
  consequences is that we can completely lose timer interrupts on a
  CPU... not pretty.

  The other one is a change to our PCIe reset hook to use a firmware
  call instead of direct config space accesses to trigger a fundamental
  reset on the root port.  This is necessary so that the FW gets a
  chance to disable the link down error monitoring, which would
  otherwise trip and cause subsequent fatal EEH error"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: irq work racing with timer interrupt can result in timer interrupt hang
  powerpc/powernv: Reset root port in firmware

Pull two btrfs fixes from Chris Mason:
 "This has two fixes that we've been testing for 3.16, but since both
  are safe and fix real bugs, it makes sense to send for 3.15 instead"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: send, fix incorrect ref access when using extrefs
  Btrfs: fix EIO on reading file after ioctl clone works on it