ACPI video devices get tagged by the kernel with the custom LNXVIDEO
HID so that normal pnp-id matching can be used and are handled by the
acpi-video driver.

Sometimes the ACPI nodes describing these contain a SERIAL_TYPE_I2C ACPI
resource. Before this commit the presence of this resource would cause the
i2c-core to create a /sys/bus/i2c/devices/i2c-LNXVIDEO:00 device for this
with a modalias of: "i2c:LNXVIDEO:00".

There is no i2c driver for this custom HID, the acpi-video driver binds
directly to the ACPI device /sys/bus/acpi/devices/LNXVIDEO\:00 which has
a modalias of "acpi:LNXVIDEO:" .

Not only is the creation of an i2c-client for this undesirable, it is
actually causing problems. This weird pseudo-resource claims an i2c
speed of 100KHz and typically points to the i2c bus which is used by the
touchscreen controller. Some touchscreen controllers only work properly at
400KHz, at 100KHz they cause errors like these:

i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration
i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration
i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration
i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration
silead_ts i2c-MSSL1680:00: Registers clear error -11

This commit makes the i2c-core ignore LNXVIDEO compatible ACPI devices
which has 2 positive results:

1) The bogus i2c-client for these is no longer created.
2) i2c_acpi_lookup_speed now ignores the 100KHz speed from the pseudo
i2c-resouce and properly returns 400KHz as speed for the touchscreen
i2c bus, fixing the touchscreen not working on various devies.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

- Slave mode selected in platform module if the support is detected in
  the DT.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

- Changes in Kconfig to enable I2C_DESIGNWARE_SLAVE support
- Slave functions added to core library file
- Slave abort sources added to common source file
- New driver: i2c-designware-slave added
- Changes in the Makefile to compile the I2C_DESIGNWARE_SLAVE module
  when supported by the architecture.

All the SLAVE flow is added but it is not enabled via platform
driver.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
[wsa: made a function static and one-lined a message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

0-DAY kernel test reports the following build issue on IA64 architecture
with allmodconfig.

   drivers/i2c/busses/i2c-zx2967.c: In function 'zx2967_i2c_writesb':
>> drivers/i2c/busses/i2c-zx2967.c:87:2: error: implicit declaration of function 'writesb' [-Werror=implicit-function-declaration]
     writesb(i2c->reg_base + reg, data, len);
     ^~~~~~~
   drivers/i2c/busses/i2c-zx2967.c: In function 'zx2967_i2c_readsb':
>> drivers/i2c/busses/i2c-zx2967.c:93:2: error: implicit declaration of function 'readsb' [-Werror=implicit-function-declaration]
     readsb(i2c->reg_base + reg, data, len);
     ^~~~~~
   cc1: some warnings being treated as errors

It's caused by that writesb/readsb are unavailable on IA64 architecture.
Let's drop COMPILE_TEST dependency to avoid the build issue.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Let's always use the platform device for dev_* and not sometimes the
adapter device as well. Also fix this checkpatch check:

CHECK: Macro argument 'i2c' may be better as '(i2c)' to avoid precedence issues
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Switch to using the devm_ APIs and remove the now unnecessary error
handling and most of the device removal code.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
[wsa: adapted error handling I added in previous patch]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Allow devices that use this driver to be registered via a
devicetree.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
[wsa: fixed leakage when registering GPIO failed]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Make use of struct gpio_desc which allows us to specify the active state
of the reset pin.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The driver was clearing the hold bit in the control register before
writing to the address register which resulted in a stop condition
being generated rather than a repeated start.

This issue was only observed when a system was running much
slower than a normal processor would execute.  The IP data sheet
mentions a ordering of writing to the address register before
clearing the hold.

Fixes: df8eb569 ("i2c: Add driver for Cadence I2C controller")
Signed-off-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Paresh Chaudhary <paresh.chaudhary@rockwellcollins.com>
Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch adds i2c controller driver for ZTE's zx2967 family.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch adds dt-binding documentation for zx2967 family
i2c controller.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Support for enforced STOPs will allow us to use SCCB compatible devices.

Based on a preliminary patch by Wolfram Sang.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Added myself as maintainer of the Aspeed I2C driver and the associated
I2C interrupt controller and added Joel Stanley and Benjamin
Herrenschmidt as reviewers.
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Added slave support for Aspeed I2C controller. Supports fourteen busses
present in AST24XX and AST25XX BMC SoCs by Aspeed.
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Added initial master support for Aspeed I2C controller. Supports
fourteen busses present in AST24XX and AST25XX BMC SoCs by Aspeed.
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Added device tree binding documentation for Aspeed I2C busses.
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add recent findings (IGNORE_NAK) and document in a bit more detail why
the feature is not possible.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

clk_prepare_enable() can fail here and we must check its return value.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

- Definitions were added to core library
- A example was added to designware-core.txt Documentation that shows
  how the slave can be setup using DTS

SLAVE related definitions were added to the core of the controller.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

- The functions related to I2C master mode of operation were transformed
  in a single driver.
- Common definitions were moved to i2c-designware-core.h
- The i2c-designware-core is now only a library file, the functions
  associated are in a source file called i2c-designware-common and
  are used by both i2c-designware-master and i2c-designware-slave.
- To decrease noise in namespace common i2c_dw_*() functions are
  now using ops to keep them private.
- Designware PCI driver had to be changed to match the previous ops
  functions implementation.

Almost all of the "core" source is now part of the "master" source. The
difference is the functions used by both modes and they are in the
"common" source file.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

- Factor out all _master() part of code from i2c-designware-core
  and i2c-designware-platdrv to separate functions.
- Standardize all code related with MASTER mode.
- I have to take off DW_IC_INTR_TX_EMPTY from DW_IC_INTR_DEFAULT_MASK
  because it is master specific.

The purpose of this is to prepare the controller to have is I2C MASTER
flow in a separate driver. To do this first all the
functions/definitions related to the MASTER flow were identified.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The purpose of this commit is to fix some comments and styling in the
existing code due to the need of reuse this code. What is being made
here is:

- Sorted the headers files
- Corrected some comments style (capital letters, lowcase i2c)
- Reverse tree in the variables declaration
- Add/remove empty lines and tabs where needed
- Fix of misspelled word "endianness" and "transferred"
- Replaced the return variable "r" with the more standard "ret"

The value of this, besides the rules of coding style, is because I
will use this code after and it will make my future patch a lot bigger and
complicated to review. The work here won't bring any additional work to
backported fixes because is just style and reordering.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Replace '%d' by '%zu' to fix the following type of compilation warnings:

drivers/i2c/busses/i2c-at91.c:277:2: warning: format ‘%d’ expects argument of type ‘int’, but argument 5 has type ‘size_t’ [-Wformat=]
  dev_dbg(dev->dev, "wrote 0x%x, to go %d\n", *dev->buf, dev->buf_len);
  ^
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Tested-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

clk_prepare_enable() can fail here and we must check its return value.
Also, add a missing clk_disable_unprepare().
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

It is 'R-Car', not 'RCar'. No code or binding changes, only descriptive text.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Set I2C_CLASS_HWMON for xlp9xx to enable automatic probing of BMC
devices by the ipmi-ssif driver.
Signed-off-by: George Cherian <george.cherian@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Added SMBUS PCI Ids for SMBUS for Cannon Lake PCH.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[jarkko.nikula@linux.intel.com: Add entries to Documentation and Kconfig.
Cover Cannon Lake-H too]
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The newly added support for the pcc mailbox fails to build
in some configurations:

drivers/i2c/busses/i2c-xgene-slimpro.c: In function 'xgene_slimpro_i2c_probe':
drivers/i2c/busses/i2c-xgene-slimpro.c:516:25: error: implicit declaration of function 'memremap'; did you mean 'memcmp'? [-Werror=implicit-function-declaration]
drivers/i2c/busses/i2c-xgene-slimpro.c:518:13: error: 'MEMREMAP_WB' undeclared (first use in this function)
drivers/i2c/busses/i2c-xgene-slimpro.c:518:13: note: each undeclared identifier is reported only once for each function it appears in

This includes the missing header file.

Fixes: df5da47f ("i2c: xgene-slimpro: Add ACPI support by using PCC mailbox")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Commit 6c427787 ("i2c: stub: use pr_fmt") changed the DEBUG
handling and caused build warnings. Revert back to the original.

Fixes: 6c427787 ("i2c: stub: use pr_fmt")
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Instead of printing errors after mxs_i2c_pio_wait_xfer_end returns with
an error code just print a debug message.

NAKs and timeouts can occur in this situation normally, so do not treat
them as errors.
Signed-off-by: Michael Thalmeier <michael.thalmeier@hale.at>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

After removal of platform_data support, we can simplify OF handling.
of_match_device() evaluates to NULL if !CONFIG_OF or if there is no node
pointer for that device, so we can remove the check for the node ptr.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

No platform currently upstream makes use of this platform_data anymore.
The ones that did are converted to DT meanwhile. So, remove it. The old
platforms likely don't have the 'clks_per_cnt' feature, otherwise it
would have been implemented by now. And in the unlikely case they need
to setup a different bus speed, we should rather go for a generic i2c
platform data just for that.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Instead of hard coding "i2c-stub:", let's use the pr_fmt mechanism to
achieve the same more easily. This makes it easier to stay consistent
when adding new messages. Also, remove an unneeded OOM message while we
are here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch adds ACPI support by using PCC mailbox communication
interface.
Signed-off-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch refactors the code to use a single message function to
send command message.
Signed-off-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Finally, apply modern comment rules to the file header. The old style
looked very non-Linuxish and challenged my eyes for some time now. I
also added my own copyright for the period of me being the maintainer.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

They seem like cruft to me. I couldn't find any evidence that something
included from there is actually used.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The I2C core files were renamed, adapt the textfile to it.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>