I2C: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Fix i2c-tegra DMA config option processing

Tegra processors prior to Tegra186 used APB DMA for I2C requiring
CONFIG_TEGRA20_APB_DMA=y while Tegra186 and later use GPC DMA requiring
CONFIG_TEGRA186_GPC_DMA=y.

The check for if the processor uses APB DMA is inverted and so the wrong
DMA config options are checked.

This means if CONFIG_TEGRA20_APB_DMA=y but CONFIG_TEGRA186_GPC_DMA=n
with a Tegra186 or later processor the driver will incorrectly think DMA is
enabled and attempt to request DMA channels that will never be availible,
leaving the driver in a perpetual EPROBE_DEFER state.

Fixes: 48cb6356fae1 ("i2c: tegra: Add GPCDMA support")
Signed-off-by: Parker Newman <pnewman@connecttech.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Akhil R <akhilrajeev@nvidia.com>
Link: https://lore.kernel.org/r/fcfcf9b3-c8c4-9b34-2ff8-cd60a3d490bd@connecttech.com
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Fix failure during probe deferral cleanup

If the driver fails to obtain a DMA channel, it will initiate cleanup
and try to release the DMA channel that couldn't be retrieved. This will
cause a crash because the cleanup will try to dereference an ERR_PTR()-
encoded error code.

However, there's nothing to clean up at this point yet, so we can avoid
this by simply resetting the DMA channel to NULL instead of storing the
error code.

Fixes: fcc8a89a1c83 ("i2c: tegra: Share same DMA channel for RX and TX")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Tested-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: allow VI support to be compiled out

Save a bit of code for older Tegra platforms by compiling out
VI's I2C mode support that's used only for Tegra210.

$ size i2c-tegra.o
text data bss dec hex filename
11381 292 8 11681 2da1 i2c-tegra.o (full)
10193 292 8 10493 28fd i2c-tegra.o (no-dvc)
9145 292 8 9445 24e5 i2c-tegra.o (no-vi,no-dvc)

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: allow DVC support to be compiled out

Save a bit of code for newer Tegra platforms by compiling out
DVC's I2C mode support that's used only for Tegra2.

$ size i2c-tegra.o
text data bss dec hex filename
- 11381 292 8 11681 2da1 i2c-tegra.o
+ 10193 292 8 10493 28fd i2c-tegra.o

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Share same DMA channel for RX and TX

Allocate only one DMA channel for I2C and share it for both TX and RX
instead of using two different DMA hardware channels with the same
slave ID. Since I2C supports only half duplex, there is no impact on
perf with this.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Asmaa Mnebhi <asnaa@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Chris Pringle <chris.pringle@phabrix.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Tali Perry <tali.perry@nuvoton.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Fix PEC support for SMBUS block read

Update the msg->len value correctly for SMBUS block read. The discrepancy
went unnoticed as msg->len is used in SMBUS transfers only when a PEC
byte is added.

Fixes: d7583c8a5748 ("i2c: tegra: Add SMBus block read function")
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Set ACPI node as primary fwnode

Set ACPI node as the primary fwnode of I2C adapter to allow
enumeration of child devices from the ACPI table

Signed-off-by: Zubair Waheed <zwaheed@nvidia.com>
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Allocate DMA memory for DMA engine

When the I2C controllers are running in DMA mode, it is the DMA engine
that performs the memory accesses rather than the I2C controller. Pass
the DMA engine's struct device pointer to the DMA API to make sure the
correct DMA operations are used.

This fixes an issue where the DMA engine's SMMU stream ID needs to be
misleadingly set for the I2C controllers in device tree.

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Add GPCDMA support

Enable support for GPCDMA, which is used in I2C controllers
in Tegra 186 and above. The chips before that used APB DMA.
This change works under the presumption that all chips apart from
those supporting APB DMA is using GPCDMA.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: move drivers from strlcpy to strscpy

Follow the advice of the below link and prefer 'strscpy'. Conversion is
easy because no driver used the return value and has been done with a
simple sed invocation.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Add SMBus block read function

Emulate SMBus block read using ContinueXfer to read the length byte

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: use i2c_timings for bus clock freq

Use i2c_timings struct and corresponding methods to get bus clock frequency

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Add the ACPI support

Add support for the ACPI based device registration so that the driver
can be also enabled through ACPI table.

This does not include the ACPI support for Tegra VI and DVC I2C.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Ensure that device is suspended before driver is removed

Tegra I2C device isn't guaranteed to be suspended after removal of
the driver since driver uses pm_runtime_put() that is asynchronous and
pm_runtime_disable() cancels pending power-change requests. This means
that potentially refcount of the clocks may become unbalanced after
removal of the driver. This a very minor problem which unlikely to
happen in practice and won't cause any visible problems, nevertheless
let's replace pm_runtime_disable() with pm_runtime_force_suspend() and
use pm_runtime_put_sync() which disables RPM of the device and puts it
into suspend before driver is removed.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Use threaded interrupt

Switch to use threaded interrupt context in order to avoid checking of
"are we in interrupt?" for the code that may sleep in the IRQ handler.
I2C doesn't require a very low interrupt-handling latency, hence this
change doesn't introduce any noticeable effects.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Create i2c_writesl_vi() to use with VI I2C for filling TX FIFO

VI I2C controller has known hardware bug where immediate multiple
writes to TX_FIFO register gets stuck.

Recommended software work around is to read I2C register after
each write to TX_FIFO register to flush out the data.

This patch implements this work around for VI I2C controller.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Wait for config load atomically while in ISR

Upon a communication error, the interrupt handler can call
tegra_i2c_disable_packet_mode. This causes a sleeping poll to happen
unless the current transaction was marked atomic. Fix this by
making the poll happen atomically if we are in an IRQ.

This matches the behavior prior to the patch mentioned
in the Fixes tag.

Fixes: ede2299f7101 ("i2c: tegra: Support atomic transfers")
Cc: stable@vger.kernel.org
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Improve driver module description

Use proper spelling of "NVIDIA" and don't designate driver as Tegra2-only
since newer SoC generations are supported as well.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Clean up whitespaces, newlines and indentation

Some places in the code are missing newlines or have unnecessary
whitespaces and newlines. This creates inconsistency of the code and
hurts readability. This patch removes the unnecessary and adds necessary
whitespaces / newlines, clears indentation of the code.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Clean up and improve comments

Make all comments to be consistent in regards to capitalization and
punctuation, correct spelling and grammar errors, improve wording.

Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Clean up printk messages

This patch unifies style of all messages in the driver by starting them
with a lowercase letter and using consistent capitalization and wording
for all messages.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Clean up variable names

Rename "ret" variables to "err" in order to make code a bit more
expressive, emphasizing that the returned value is an error code.
Same vice versa, where appropriate.

Rename variable "reg" to "val" in order to better reflect the actual
usage of the variable in the code and to make naming consistent with
the rest of the code.

Use briefer names for a few members of the tegra_i2c_dev structure in
order to improve readability of the code.

All dev/&pdev->dev are replaced with i2c_dev->dev in order to have uniform
code style across the driver.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Improve formatting of variables

Reorder definition of variables in the code to have them sorted by length
and grouped logically, also replace "unsigned long" with "u32". Do this in
order to make code easier to read.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Check errors for both positive and negative values

The driver's code is inconsistent in regards to the error values checking.
The correct way should be to check both positive and negative values.
This patch cleans up the error-checks in the code. Note that the
pm_runtime_get_sync() could return positive value on success, hence only
relevant parts of the code are changed by this patch.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Factor out hardware initialization into separate function

Factor out hardware initialization into a separate function from the probe
function. The only place where runtime PM needs to be resumed during probe
is the place of hardware initialization, hence it makes sense to factor
out it in order to have a bit cleaner error handling in tegra_i2c_probe().

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Factor out register polling into separate function

Factor out register polling into a separate function in order to remove
boilerplate code and make code cleaner.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Factor out packet header setup from tegra_i2c_xfer_msg()

The code related to packet header setting up is a bit messy and makes
tegra_i2c_xfer_msg() more difficult to read than it could be. Let's
factor the packet header setup from tegra_i2c_xfer_msg() into separate
function in order to make code easier to read and follow.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Factor out error recovery from tegra_i2c_xfer_msg()

Factor out error recovery code from tegra_i2c_xfer_msg() in order to
make this function easier to read and follow.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Rename wait/poll functions

Drop '_timeout' postfix from the wait/poll completion function names in
order to make the names shorter, making code cleaner a tad.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Remove "dma" variable from tegra_i2c_xfer_msg()

The "dma" variable of tegra_i2c_xfer_msg() function doesn't bring much in
regards to readability and generation of the code.

Besides readability, it's also not very nice that the is_curr_dma_xfer
is initialized in tegra_i2c_xfer_msg() and then could be overridden by
tegra_i2c_config_fifo_trig(). In a result, the "dma" variable creates
slight confusion since it's not instantly obvious why it's set after
tegra_i2c_config_fifo_trig().

Hence should be better to have the variable removed. This makes code
more consistent.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Remove redundant check in tegra_i2c_issue_bus_clear()

The tegra_i2c_wait_for_config_load() checks for 'has_config_load_reg' by
itself, hence there is no need to duplicate the check.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Remove likely/unlikely from the code

The likely/unlikely annotations should be used only in a hot paths of
performance-critical code. The I2C driver doesn't have such paths, and
thus, there is no justification for usage of likely/unlikely annotations
in the code. Hence remove them.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Remove outdated barrier()

The barrier() was intended to reduce possibility of racing with the
interrupt handler, but driver's code evolved significantly and today's
driver enables interrupt only when it waits for completion notification.
Hence barrier() has no good use anymore, let's remove it.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Clean up variable types

Don't use signed types for unsigned values and use consistent types
for sibling variables.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Reorder location of functions in the code

Reorder location of functions in the code in order to have definition
of functions closer to the place of the invocation. This change makes
easier to navigate around the code and removes the need to have a
prototype for tegra_i2c_init().

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Clean up probe function

The driver's probe function code is a bit difficult to read. This patch
reorders code of the probe function, forming groups of code that are easy
to work with. The probe tear-down order now matches the driver-removal
order.

Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Move out all device-tree parsing into tegra_i2c_parse_dt()

Move out code related to device-tree parsing from the probe function into
tegra_i2c_parse_dt() in order to make code more consistent.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Use clk-bulk helpers

Use clk-bulk helpers and factor out clocks initialization into separate
function in order to make code cleaner.

The clocks initialization now performed after reset-control initialization
in order to avoid a noisy -PROBE_DEFER errors on T186+ from the clk-bulk
helper which doesn't silence this error code. Hence reset_control_get()
now may return -EPROBE_DEFER on newer Tegra SoCs because they use BPMP
driver that provides reset controls and BPMP doesn't come up early during
boot. Previously rst was protected by the clocks retrieval and now this
patch makes dev_err_probe() to be used for the rst error handling.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Use platform_get_irq()

Use common helper for retrieval of the interrupt number in order to make
code cleaner. Note that platform_get_irq() prints error message by itself.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Use devm_platform_get_and_ioremap_resource()

Driver now uses devm_platform_get_and_ioremap_resource() which replaces
the typical boilerplate code and makes code cleaner.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Use reset_control_reset()

Use a single reset_control_reset() instead of assert/deasset couple in
order to make code cleaner a tad. Note that the reset_control_reset()
uses 1 microsecond delay instead of 2 that was used previously, but this
shouldn't matter because one microsecond is a default reset time for most
of Tegra peripherals and TRM doesn't mention anything special in regards
to I2C controller's reset propagation time.

In addition don't ignore potential error of the reset control by emitting
a noisy warning if it fails, which will indicate an existence of a severe
problem, while still allow machine to boot up.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Remove error message used for devm_request_irq() failure

The error message prints number of vIRQ, which isn't a useful information.
In practice devm_request_irq() never fails, hence let's remove the bogus
message in order to make code cleaner.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Runtime PM always available on Tegra

The runtime PM is guaranteed to be always available on Tegra after commit
40b2bb1b132a ("ARM: tegra: enforce PM requirement"). Hence let's remove
all the RPM-availability checking and handling from the code.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Remove i2c_dev.clk_divisor_non_hs_mode member

The "non_hs_mode" divisor value is fixed, thus there is no need to have
the variable i2c_dev.clk_divisor_non_hs_mode struct member. Let's remove
it and move the mode selection into tegra_i2c_init() where it can be
united with the timing selection.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Initialize div-clk rate unconditionally

It doesn't make sense to conditionalize the div-clk rate changes because
rate is fixed and it won't ever change once it's set at the driver's probe
time. All further changes are NO-OPs because CCF caches rate and skips
rate-change if rate is unchanged.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Mask interrupt in tegra_i2c_issue_bus_clear()

The tegra_i2c_issue_bus_clear() may fail and in this case BUS_CLR_DONE
stays unmasked. Hence let's mask it for consistency. This patch doesn't
fix any known problems.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Handle potential error of tegra_i2c_flush_fifos()

Technically the tegra_i2c_flush_fifos() may fail and transfer should be
aborted in this case, but this shouldn't ever happen in practice unless
there is a bug somewhere in the driver. Let's add the error check just
for completeness.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Add missing pm_runtime_put()

The pm_runtime_get_sync() always bumps refcount regardless of whether it
succeeds or fails. Hence driver is responsible for restoring of the RPM
refcounting. This patch adds missing RPM puts which restore refcounting
in a case of pm_runtime_get_sync() error.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Make tegra_i2c_flush_fifos() usable in atomic transfer

The tegra_i2c_flush_fifos() shouldn't sleep in atomic transfer and jiffies
are not updating if interrupts are disabled. Let's switch to use iopoll
API helpers for register-polling. The iopoll API provides helpers for both
atomic and non-atomic cases.

Note that this patch doesn't fix any known problem because normally FIFO
is flushed at the time of starting a new transfer.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Avoid tegra_i2c_init_dma() for Tegra210 vi i2c

VI I2C is on host1x bus so APB DMA can't be used for Tegra210 VI
I2C and there are no tx and rx dma channels for VI I2C.

So, avoid attempt of requesting DMA channels.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Fix runtime resume to re-init VI I2C

VI I2C is on host1x bus and is part of VE power domain.

During suspend/resume VE power domain goes through power off/on.

So, controller reset followed by i2c re-initialization is required
after the domain power up.

This patch fixes it.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Fix the error path in tegra_i2c_runtime_resume

tegra_i2c_runtime_resume does not disable prior enabled clocks
properly.

This patch fixes it.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Remove NULL pointer check before clk_enable/disable/prepare/unprepare

clk_enable, clk_disable, clk_prepare, and clk_unprepare APIs have
implementation for checking clk pointer not NULL and clock consumers
can safely call these APIs without NULL pointer check.

So, this patch cleans up Tegra i2c driver to remove explicit checks
before these APIs.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Don't mark VI I2C as IRQ safe runtime PM

Tegra VI I2C is part of VE power domain and typically used for
camera usecases.

VE power domain is not always on and is non-IRQ safe. So, IRQ safe
device cannot be attached to a non-IRQ safe domain as it prevents
powering off the PM domain and generic power domain driver will warn.

Current driver marks all I2C devices as IRQ safe and VI I2C device
does not require IRQ safe as it will not be used for atomic transfers.

This patch has fix to make VI I2C as non-IRQ safe.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: tegra: Add support for the VI I2C on Tegra210

Tegra210 has an extra instance of the I2C controller that is in the
domain of host1x and usually used for camera use-cases. The programming
model for the VI variant of the controller is roughly the same as for
the other variants, except that the I2C registers start at an offset
and are spaced further apart. VI I2C also doesn't support slave mode.

Signed-off-by: Thierry Reding <treding@nvidia.com>

i2c: tegra: Use FIELD_PREP/FIELD_GET macros

Using these macros helps increase readability of the code.

Signed-off-by: Thierry Reding <treding@nvidia.com>

i2c: tegra: Synchronize DMA before termination

DMA transfer could be completed, but CPU (which handles DMA interrupt)
may get too busy and can't handle the interrupt in a timely manner,
despite of DMA IRQ being raised. In this case the DMA state needs to
synchronized before terminating DMA transfer in order not to miss the
DMA transfer completion.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

i2c: tegra: Better handle case where CPU0 is busy for a long time

Boot CPU0 always handle I2C interrupt and under some rare circumstances
(like running KASAN + NFS root) it may stuck in uninterruptible state for
a significant time. In this case we will get timeout if I2C transfer is
running on a sibling CPU, despite of IRQ being raised. In order to handle
this rare condition, the IRQ status needs to be checked after completion
timeout.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

i2c: tegra: Keep IRQs enabled during suspend/resume

One of the I2C controllers on Tegra SoCs is typically connected to a
system PMIC, which provides controls for critical power supplies for
most platforms.

Some drivers, such as PCI, need to disable these regulators during a
very late stage during suspend and resume them at a very early stage
during resume.

To support these use-cases, keep interrupts disabled during suspend/
resume.

Suggested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

i2c: tegra: Restore pinmux on system resume

Depending on the board design, the I2C controllers found on Tegra SoCs
may require pinmuxing in order to function. This is done as part of the
driver's runtime suspend/resume operations. However, the PM core does
not allow devices to go into runtime suspend during system sleep to
avoid potential races with the suspend/resume of their parents.

As a result of this, when Tegra SoCs resume from system suspend, their
I2C controllers may have lost the pinmux state in hardware, whereas the
pinctrl subsystem is not aware of this. To fix this, make sure that if
the I2C controller is not runtime suspended, the runtime suspend code is
still executed in order to disable the module clock (which we don't need
to be enabled during sleep) and set the pinmux to the idle state.

Conversely, make sure that the I2C controller is properly resumed when
waking up from sleep so that pinmux settings are properly restored.

This fixes a bug seen with DDC transactions to an HDMI monitor timing
out when resuming from system suspend.

Signed-off-by: Thierry Reding <treding@nvidia.com>

Revert "i2c: tegra: Fix suspending in active runtime PM state"

This reverts commit 9f42de8d4ec2304f10bbc51dc0484f3503d61196.

It's not safe to use pm_runtime_force_{suspend,resume}(), especially
during the noirq phase of suspend. See also the guidance provided in
commit 1e2ef05bb8cf ("PM: Limit race conditions between runtime PM
and system sleep (v2)").

Signed-off-by: Thierry Reding <treding@nvidia.com>

Revert "i2c: tegra: Better handle case where CPU0 is busy for a long time"

This reverts commit a900aeac253729411cf33c6cb598c152e9e4137f because
regressions were showing up.

Suggested-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/dmaengine/20200319201140.17451-1-digetx@gmail.com/
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Revert "i2c: tegra: Synchronize DMA before termination"

This reverts commit 8814044fe0fa182abc9ff818d3da562de98bc9a7 because
regressions were showing up.

Suggested-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/dmaengine/20200319201140.17451-1-digetx@gmail.com/
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Synchronize DMA before termination

DMA transfer could be completed, but CPU (which handles DMA interrupt)
may get too busy and can't handle the interrupt in a timely manner,
despite of DMA IRQ being raised. In this case the DMA state needs to
synchronized before terminating DMA transfer in order not to miss the
DMA transfer completion.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Better handle case where CPU0 is busy for a long time

Boot CPU0 always handle I2C interrupt and under some rare circumstances
(like running KASAN + NFS root) it may stuck in uninterruptible state for
a significant time. In this case we will get timeout if I2C transfer is
running on a sibling CPU, despite of IRQ being raised. In order to handle
this rare condition, the IRQ status needs to be checked after completion
timeout.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: drivers: Use generic definitions for bus frequencies

Since we have generic definitions for bus frequencies, let's use them.

Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Acked-by: Robert Richter <rrichter@marvell.com>
Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
Acked-by: Elie Morisse <syniurge@gmail.com>
Acked-by: Nehal Shah <nehal-bakulchandra.shah@amd.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Chris Brandt <chris.brandt@renesas.com>
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Check DMA completion status in addition to left time

It is more robust to check completion status in addition to the left time
in a case of DMA transfer because transfer's completion happens in two
phases [one is ISR, other is tasklet] and thus it is possible that DMA is
completed while I2C completion awaiting times out because of the deferred
notification done by the DMA driver. The DMA completion status becomes
100% actual after DMA synchronization. This fixes spurious DMA timeouts
when system is under load.

Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Always terminate DMA transfer

It is possible that I2C could error out in the middle of DMA transfer and
in this case DMA channel needs to be reset, otherwise a follow up transfer
will fail because DMA channel stays blocked.

Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Use relaxed versions of readl/writel

There is nothing to synchronize in regards to memory accesses for PIO
transfers and for DMA transfers the DMA API takes care of the syncing.

Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Rename I2C_PIO_MODE_MAX_LEN to I2C_PIO_MODE_PREFERRED_LEN

DMA is preferred for a larger transfers, while PIO is preferred for a
smaller transfers to avoid unnecessary DMA overhead. There is no strict
size limitations for the PIO-mode transfers, so let's rename the constant
for clarity.

Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Support atomic transfers

System shutdown may happen with interrupts being disabled and in this case
kernel may hang if atomic transfer isn't supported by driver.

There were several occurrences where I found my Nexus 7 completely
discharged despite of being turned off and then one day I spotted this in
the log:

reboot: Power down
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at drivers/i2c/i2c-core.h:40 i2c_transfer+0x95/0x9c
No atomic I2C transfer handler for 'i2c-1'
Modules linked in: tegra30_devfreq
CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.4.0-next-20191202-00120-gf7ecd80fb803-dirty #3195
Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
[<c010e4b5>] (unwind_backtrace) from [<c010a0fd>] (show_stack+0x11/0x14)
[<c010a0fd>] (show_stack) from [<c09995e5>] (dump_stack+0x85/0x94)
[<c09995e5>] (dump_stack) from [<c011f3d1>] (__warn+0xc1/0xc4)
[<c011f3d1>] (__warn) from [<c011f691>] (warn_slowpath_fmt+0x61/0x78)
[<c011f691>] (warn_slowpath_fmt) from [<c069a8dd>] (i2c_transfer+0x95/0x9c)
[<c069a8dd>] (i2c_transfer) from [<c05667f1>] (regmap_i2c_read+0x4d/0x6c)
[<c05667f1>] (regmap_i2c_read) from [<c0563601>] (_regmap_raw_read+0x99/0x1cc)
[<c0563601>] (_regmap_raw_read) from [<c0563757>] (_regmap_bus_read+0x23/0x38)
[<c0563757>] (_regmap_bus_read) from [<c056293d>] (_regmap_read+0x3d/0xfc)
[<c056293d>] (_regmap_read) from [<c0562d3b>] (_regmap_update_bits+0x87/0xc4)
[<c0562d3b>] (_regmap_update_bits) from [<c0563add>] (regmap_update_bits_base+0x39/0x50)
[<c0563add>] (regmap_update_bits_base) from [<c056fd39>] (max77620_pm_power_off+0x29/0x2c)
[<c056fd39>] (max77620_pm_power_off) from [<c013bbdd>] (__do_sys_reboot+0xe9/0x170)
[<c013bbdd>] (__do_sys_reboot) from [<c0101001>] (ret_fast_syscall+0x1/0x28)
Exception stack(0xde907fa8 to 0xde907ff0)
7fa0: 00000000 00000000 fee1dead 28121969 4321fedc 00000000
7fc0: 00000000 00000000 00000000 00000058 00000000 00000000 00000000 00000000
7fe0: 0045adf0 bed9abb8 004444a0 b6c666d0
---[ end trace bdd18f87595b1a5e ]---

The atomic transferring is implemented by enforcing PIO mode for the
transfer and by polling interrupt status until transfer is completed or
failed.

Now system shuts down properly every time.

Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Prevent interrupt triggering after transfer timeout

Potentially it is possible that interrupt may fire after transfer timeout.
That may not end up well for the next transfer because interrupt handling
may race with hardware resetting.

This is very unlikely to happen in practice, but anyway let's prevent the
potential problem by enabling interrupt only at the moments when it is
actually necessary to get some interrupt event.

Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Properly disable runtime PM on driver's probe error

One of the recent Tegra I2C commits made a change that resumes runtime PM
during driver's probe, but it missed to put the RPM in a case of error.
Note that it's not correct to use pm_runtime_status_suspended because it
breaks RPM refcounting.

Fixes: 8ebf15e9c869 ("i2c: tegra: Move suspend handling to NOIRQ phase")
Cc: <stable@vger.kernel.org> # v5.4+
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Fix suspending in active runtime PM state

I noticed that sometime I2C clock is kept enabled during suspend-resume.
This happens because runtime PM defers dynamic suspension and thus it may
happen that runtime PM is in active state when system enters into suspend.
In particular I2C controller that is used for CPU's DVFS is often kept ON
during suspend because CPU's voltage scaling happens quite often.

Fixes: 8ebf15e9c869 ("i2c: tegra: Move suspend handling to NOIRQ phase")
Cc: <stable@vger.kernel.org> # v5.4+
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Use dma_request_chan() directly for channel request

dma_request_slave_channel_reason() is:
#define dma_request_slave_channel_reason(dev, name) \
dma_request_chan(dev, name)

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Move suspend handling to NOIRQ phase

Commit acc8abcb2a9c ("i2c: tegra: Add suspend-resume support") added
suspend support for the Tegra I2C driver and following this change on
Tegra30 the following WARNING is seen on entering suspend ...

WARNING: CPU: 2 PID: 689 at /dvs/git/dirty/git-master_l4t-upstream/kernel/drivers/i2c/i2c-core.h:54 __i2c_transfer+0x35c/0x70c
i2c i2c-4: Transfer while suspended
Modules linked in: brcmfmac brcmutil
CPU: 2 PID: 689 Comm: rtcwake Not tainted 5.3.0-rc7-g089cf7f6ecb2 #1
Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
[<c0112264>] (unwind_backtrace) from [<c010ca94>] (show_stack+0x10/0x14)
[<c010ca94>] (show_stack) from [<c0a77024>] (dump_stack+0xb4/0xc8)
[<c0a77024>] (dump_stack) from [<c0124198>] (__warn+0xe0/0xf8)
[<c0124198>] (__warn) from [<c01241f8>] (warn_slowpath_fmt+0x48/0x6c)
[<c01241f8>] (warn_slowpath_fmt) from [<c06f6c40>] (__i2c_transfer+0x35c/0x70c)
[<c06f6c40>] (__i2c_transfer) from [<c06f7048>] (i2c_transfer+0x58/0xf4)
[<c06f7048>] (i2c_transfer) from [<c06f7130>] (i2c_transfer_buffer_flags+0x4c/0x70)
[<c06f7130>] (i2c_transfer_buffer_flags) from [<c05bee78>] (regmap_i2c_write+0x14/0x30)
[<c05bee78>] (regmap_i2c_write) from [<c05b9cac>] (_regmap_raw_write_impl+0x35c/0x868)
[<c05b9cac>] (_regmap_raw_write_impl) from [<c05b984c>] (_regmap_update_bits+0xe4/0xec)
[<c05b984c>] (_regmap_update_bits) from [<c05bad04>] (regmap_update_bits_base+0x50/0x74)
[<c05bad04>] (regmap_update_bits_base) from [<c04d453c>] (regulator_disable_regmap+0x44/0x54)
[<c04d453c>] (regulator_disable_regmap) from [<c04cf9d4>] (_regulator_do_disable+0xf8/0x268)
[<c04cf9d4>] (_regulator_do_disable) from [<c04d1694>] (_regulator_disable+0xf4/0x19c)
[<c04d1694>] (_regulator_disable) from [<c04d1770>] (regulator_disable+0x34/0x64)
[<c04d1770>] (regulator_disable) from [<c04d2310>] (regulator_bulk_disable+0x28/0xb4)
[<c04d2310>] (regulator_bulk_disable) from [<c0495cd4>] (tegra_pcie_power_off+0x64/0xa8)
[<c0495cd4>] (tegra_pcie_power_off) from [<c0495f74>] (tegra_pcie_pm_suspend+0x25c/0x3f4)
[<c0495f74>] (tegra_pcie_pm_suspend) from [<c05af48c>] (dpm_run_callback+0x38/0x1d4)
[<c05af48c>] (dpm_run_callback) from [<c05afe30>] (__device_suspend_noirq+0xc0/0x2b8)
[<c05afe30>] (__device_suspend_noirq) from [<c05b1c24>] (dpm_noirq_suspend_devices+0x100/0x37c)
[<c05b1c24>] (dpm_noirq_suspend_devices) from [<c05b1ebc>] (dpm_suspend_noirq+0x1c/0x48)
[<c05b1ebc>] (dpm_suspend_noirq) from [<c017d2c0>] (suspend_devices_and_enter+0x1d0/0xa00)
[<c017d2c0>] (suspend_devices_and_enter) from [<c017dd10>] (pm_suspend+0x220/0x74c)
[<c017dd10>] (pm_suspend) from [<c017c2c8>] (state_store+0x6c/0xc8)
[<c017c2c8>] (state_store) from [<c02ef398>] (kernfs_fop_write+0xe8/0x1c4)
[<c02ef398>] (kernfs_fop_write) from [<c0271e38>] (__vfs_write+0x2c/0x1c4)
[<c0271e38>] (__vfs_write) from [<c02748dc>] (vfs_write+0xa4/0x184)
[<c02748dc>] (vfs_write) from [<c0274b7c>] (ksys_write+0x9c/0xdc)
[<c0274b7c>] (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x54)
Exception stack(0xe9f21fa8 to 0xe9f21ff0)
1fa0: 0000006c 004b2438 00000004 004b2438 00000004 00000000
1fc0: 0000006c 004b2438 004b1228 00000004 00000004 00000004 0049e78c 004b1228
1fe0: 00000004 be9809b8 b6f0bc0b b6e96206

The problem is that the Tegra PCIe driver indirectly uses I2C for
controlling some regulators and the I2C driver is now being suspended
before the PCIe driver causing the PCIe suspend to fail. The Tegra PCIe
driver is suspended during the NOIRQ phase and this cannot be changed
due to other dependencies. Therefore, we also need to move the suspend
handling for the Tegra I2C driver to the NOIRQ phase as well.

In order to move the I2C suspend handling to the NOIRQ phase we also
need to avoid calling pm_runtime_get/put() because per commit
1e2ef05bb8cf ("PM: Limit race conditions between runtime PM and system
sleep (v2)") these cannot be called early in resume. The function
tegra_i2c_init(), called during resume, calls pm_runtime_get/put() and
so move these calls outside of tegra_i2c_init(), so this function can
be used during the NOIRQ resume phase.

Fixes: acc8abcb2a9c ("i2c: tegra: Add suspend-resume support")

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Compile PM functions unconditionally

The I2C driver fails to probe if CONFIG_PM_SLEEP=n because runtime PM
doesn't depend on the PM sleep and in this case the runtime PM ops are
not included in the driver, resulting in I2C clock not being enabled.
It's much cleaner to simply allow compiler to remove the dead code
instead of messing with the #ifdefs.

This patch fixes such errors when CONFIG_PM_SLEEP=n:

tegra-i2c 7000c400.i2c: timeout waiting for fifo flush
tegra-i2c 7000c400.i2c: Failed to initialize i2c controller

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: remove BUG() macro

The usage of BUG() macro is generally discouraged in kernel, unless
it's a problem that results in a physical damage or loss of data.
This patch removes unnecessary BUG() macros and replaces the rest
with warning.

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Add suspend-resume support

Post suspend I2C registers have power on reset values. Before any
transfer initialize I2C registers to prevent I2C transfer timeout
and implement suspend and resume callbacks needed. Fix below errors
post suspend:

1) Tegra I2C transfer timeout during jetson tx2 resume:

[ 27.520613] pca953x 1-0074: calling pca953x_resume+0x0/0x1b0 @ 2939, parent: i2c-1
[ 27.633623] tegra-i2c 3160000.i2c: i2c transfer timed out
[ 27.639162] pca953x 1-0074: Unable to sync registers 0x3-0x5. -110
[ 27.645336] pca953x 1-0074: Failed to sync GPIO dir registers: -110
[ 27.651596] PM: dpm_run_callback(): pca953x_resume+0x0/0x1b0 returns -110
[ 27.658375] pca953x 1-0074: pca953x_resume+0x0/0x1b0 returned -110 after 127152 usecs
[ 27.666194] PM: Device 1-0074 failed to resume: error -110

2) Tegra I2C transfer timeout error on jetson Xavier post resume.

Remove i2c bus lock-unlock calls in resume callback as i2c_mark_adapter_*
(suspended-resumed) help ensure i2c core calls from client are not
executed before i2c-tegra resume.

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Avoid error message on deferred probe

If the driver defers probe because of a missing clock, avoid outputting
an error message. The clock will show up eventually.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: fix msleep warning

Fix checkpatch.pl WARNING for delay of approximately 1msec
in flush i2c FIFO polling loop by using usleep_range(1000, 2000):
WARNING: msleep < 20ms can sleep for up to 20ms; see ...
Documentation/timers/timers-howto.txt
+ msleep(1);

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: add spinlock definition comment

Fix checkpatch.pl CHECK as follows:
CHECK: spinlock_t definition without comment
+ spinlock_t xfer_lock;

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: fix alignment and spacing violations

Fix checkpatch.pl alignment and blank line check(s) in i2c-tegra.c

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: remove unnecessary variable init

Remove variable initializations in functions that
are followed by assignments before use

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: clean up macros

Clean up macros by:
1) removing unused macros
2) replace constants by macro BIT()

Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Only display error messages if DMA setup fails

Commit 86c92b9965ff ("i2c: tegra: Add DMA support") added DMA support
to the Tegra I2C driver for Tegra devices that support the APB DMA
controller. One side-effect of this change is that even for Tegra
devices that do not have an APB DMA controller and hence, cannot
support DMA tranfers for I2C transactions, the following error messages
are still displayed ...

ERR KERN tegra-i2c 31c0000.i2c: cannot use DMA: -19
ERR KERN tegra-i2c 31c0000.i2c: falling back to PIO

There is no point displaying the above messages for devices that do not
have an APB DMA controller and so fix this by returning from the
tegra_i2c_init_dma() function if 'has_apb_dma' is not true.

Furthermore, if CONFIG_TEGRA20_APB_DMA is not set, then rather than
printing an error message, print an debug message as for whatever reason
this could be intentional.

Fixes: 86c92b9965ff ("i2c: tegra: Add DMA support")
Signed-off-by: Jonathan Hunter <jonathanh@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: remove multi-master support

Multi-master support is defeatured on Tegra210 and Tegra186 due to
known bugs.

This patch removes multi-master support for Tegra210 and Tegra186
I2C HW feature.

Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: remove master fifo support on tegra186

Tegra186 does not have master FIFO control register and instead
uses FIFO control register like prior Tegra chipset.

This patch fixes this and prevents crashing during boot when
accessing FIFO control registers.

Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: change phrasing, "fallbacking" to "falling back"

The phrasing in two dev_err messages is using fallbacking which
os less understandable than "falling back", so fix this up.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: add i2c interface timing support

This patch adds I2C interface timing registers support for
proper bus rate configuration along with meeting the I2C spec
setup and hold times based on the tuning performed on Tegra210,
Tegra186 and Tegra194 platforms.

I2C_INTERFACE_TIMING_0 register contains TLOW and THIGH field
and Tegra I2C controller design uses them as a part of internal
clock divisor.

I2C_INTERFACE_TIMING_1 register contains the setup and hold times
for start and stop conditions.

Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: update transfer timeout

Tegra194 allows max of 64K bytes and Tegra186 and prior allows
max of 4K bytes of transfer per packet.

one sec timeout is not enough for transfers more than 10K bytes
at STD bus rate.

This patch updates I2C transfer timeout based on the transfer size
and I2C bus rate to allow enough time during max transfer size at
lower bus speed.

Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Add DMA support

This patch adds DMA support for Tegra I2C.

Tegra I2C TX and RX FIFO depth is 8 words. PIO mode is used for
transfer size of the max FIFO depth and DMA mode is used for
transfer size higher than max FIFO depth to save CPU overhead.

PIO mode needs full intervention of CPU to fill or empty FIFO's
and also need to service multiple data requests interrupt for the
same transaction. This adds delay between data bytes of the same
transfer when CPU is fully loaded and some slave devices has
internal timeout for no bus activity and stops transaction to
avoid bus hang. DMA mode is helpful in such cases.

DMA mode is also helpful for Large transfers during downloading or
uploading FW over I2C to some external devices.

Tegra210 and prior Tegra chips use APBDMA driver which is replaced
with GPCDMA on Tegra186 and Tegra194.
This patch uses has_apb_dma flag in hw_feature to differentiate
DMA driver change between Tegra chipset.

APBDMA driver is registered from module-init level and this patch
also has a change to register I2C driver at module-init level
rather than subsys-init to avoid deferring I2C probe till APBDMA
driver is registered.

Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: update maximum transfer size

Tegra194 supports maximum 64K bytes per packet including 12 bytes of
packet header irrespective of PIO or DMA mode transfer.

This patch updates Tegra194 max write length to account for packet
header size for transfers.

Cc: stable@vger.kernel.org # 4.20+

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: fix maximum transfer size

Tegra186 and prior supports maximum 4K bytes per packet transfer
including 12 bytes of packet header.

This patch fixes max write length limit to account packet header
size for transfers.

Cc: stable@vger.kernel.org # 4.4+

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: add bus clear Master Support

Bus clear feature of Tegra I2C controller helps to recover from
bus hang when I2C master loses the bus arbitration due to the
slave device holding SDA LOW continuously for some unknown reasons.

Per I2C specification, the device that held the bus LOW should
release it within 9 clock pulses.

During bus clear operation, Tegra I2C controller sends 9 clock
pulses and terminates the transaction with STOP condition.
Upon successful bus clear operation, bus goes to idle state and
driver retries the transaction.

Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: sort all the include headers alphabetically

This patch sorts all the include headers alphabetically for the
I2C Tegra driver.

Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Fix Maximum transfer size

Tegra194 supports maximum 64K Bytes transfer per packet.
Tegra186 and prior supports maximum 4K Bytes transfer per packet.

This patch fixes this payload difference between Tegra194 and prior
Tegra chipsets using separate i2c_adapter_quirks.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Add missing kerneldoc for some fields

Not all fields were properly documented. Add kerneldoc for the missing
fields to prevent the build from flagging them.

Reported-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Cleanup kerneldoc comments

Some of the kerneldoc uses a strange spelling for abbreviations. Turn
them into all-uppercase and clean up some whitespace issues while at it.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: replace spin_lock_irqsave with spin_lock in ISR

As you are already in ISR, it is unnecessary to call spin_lock_irqsave.

Signed-off-by: jun qian <hangdianqj@163.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: use core to detect 'no zero length' quirk

And don't reimplement in the driver.

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

i2c: tegra: Fix NACK error handling

On Tegra30 Cardhu the PCA9546 I2C mux is not ACK'ing I2C commands on
resume from suspend (which is caused by the reset signal for the I2C
mux not being configured correctl). However, this NACK is causing the
Tegra30 to hang on resuming from suspend which is not expected as we
detect NACKs and handle them. The hang observed appears to occur when
resetting the I2C controller to recover from the NACK.

Commit 77821b4678f9 ("i2c: tegra: proper handling of error cases") added
additional error handling for some error cases including NACK, however,
it appears that this change conflicts with an early fix by commit
f70893d08338 ("i2c: tegra: Add delay before resetting the controller
after NACK"). After commit 77821b4678f9 was made we now disable 'packet
mode' before the delay from commit f70893d08338 happens. Testing shows
that moving the delay to before disabling 'packet mode' fixes the hang
observed on Tegra30. The delay was added to give the I2C controller
chance to send a stop condition and so it makes sense to move this to
before we disable packet mode. Please note that packet mode is always
enabled for Tegra.

Fixes: 77821b4678f9 ("i2c: tegra: proper handling of error cases")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org

i2c: tegra: Add support for Tegra194

In order to support advanced features, the I2C FIFO interface was
changed in the version of the Tegra I2C controller found in Tegra194.
The changes are backwards incompatible, so the driver needs to be
programmed in a slightly different way on new chips.

Add support for MST FIFO programming and add an OF match entry for
Tegra194. At the same time, mark all prior generations of this
controller as not having the MST FIFO interface.

Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Remove suspend-resume

Nothing prevents I2C clients to access I2C while Tegra's driver is being
suspended, this results in -EBUSY error returned to the clients and that
may have unfortunate consequences. In particular this causes problems
for the TPS6586x MFD driver which emits hundreds of "failed to read
interrupt status" error messages on resume from suspend. This happens if
TPS6586X is used to wake system from suspend by the expired RTC alarm
timer because TPS6586X is an I2C device driver and its IRQ handler reads
the status register while Tegra's I2C driver is suspended, i.e. just after
kernel enabled IRQ's during of resume-from-suspend process.

Note that the removed tegra_i2c_resume() invoked tegra_i2c_init() which
performs HW reset. That seems was also not entirely correct because moving
tegra_i2c_resume to an earlier stage of resume-from-suspend process causes
I2C transfer to fail in the case of TPS6586X. It is fine to remove the
HW-reinitialization for now because it should be only needed in a case of
using lowest power-mode during suspend, which upstream kernel doesn't
support.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: busses: make i2c_adapter_quirks const

Make these const as they are only stored as a reference in the quirks
field of an i2c_adapter structure, which is const. Done using
Coccinelle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: explicitly request exclusive reset control

Commit a53e35db70d1 ("reset: Ensure drivers are explicit when requesting
reset lines") started to transition the reset control request API calls
to explicitly state whether the driver needs exclusive or shared reset
control behavior. Convert all drivers requesting exclusive resets to the
explicit API call so the temporary transition helpers can be removed.

No functional changes.

Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-i2c@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Fix assignment of boolean variables

Fix the following warnings reported by coccinelle for the Tegra I2C
driver.

drivers/i2c/busses/i2c-tegra.c:513:2-23: WARNING: Assignment of bool to 0/1
drivers/i2c/busses/i2c-tegra.c:539:3-24: WARNING: Assignment of bool to 0/1

Reported-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: proper handling of error cases

To summarize the issue observed in error cases:

SW Flow: For i2c message transfer, packet header and data payload is
posted and then required error/packet completion interrupts are enabled
later.

HW flow: HW process the packet just after packet header is posted, if
ARB lost/NACK error occurs (SW will not handle immediately when error
happens as error interrupts are not enabled at this point). HW assumes
error is acknowledged and clears current data in FIFO, But SW here posts
the remaining data payload which still stays in FIFO as stale data
(data without packet header).

Now once the interrupts are enabled, SW handles ARB lost/NACK error by
clearing the ARB lost/NACK interrupt. Now HW assumes that SW attended
the error and will parse/process stale data (data without packet header)
present in FIFO which causes invalid NACK errors.

Fix: Enable the error interrupts before posting the packet into FIFO
which make sure HW to not clear the fifo. Also disable the packet mode
before acknowledging errors (ARB lost/NACK error) to not process any
stale data. As error interrupts are enabled before posting the packet
header use spinlock to avoid preempting.

Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: use atomic poll function during configuration

Use readl_poll_timeout_atomic() function as *wait_for_config_load()
function can be called from interrupt context.

Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: add separate function for config_load programing

Define separate function for configuration load register handling
to make it use by different functions later.

Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: If fifo flush fails return error

During i2c controller initialization, when fifo flush fails return error
instead of returning the error during exit.

Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: use readl_poll_timeout after config_load reg programmed

After CONFIG_LOAD register is programmed instead of explicitly waiting
for timeout, use readl_poll_timeout() to check for register value to get
updated or wait till timeout.

Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Add pinctrl support

On Tegra124/132 the pins for I2C6 are shared with the Display Port AUX
(DPAUX) channel and on Tegra210 the pins for I2C4 and I2C6 are shared
with DPAUX1 and DPAUX0, respectively. The multiplexing of the pins is
handled by a register in the DPAUX and so the Tegra DPAUX driver has
been updated to register a pinctrl device for managing these pins.

The pins for these particular I2C devices are bound to the I2C device
prior to probing. However, these I2C devices are in a different power
partition to the DPAUX devices that own the pins. Hence, it is desirable
to place the pins in the 'idle' state and allow the DPAUX power
partition to switch off, when these I2C devices is not in use.
Therefore, add calls to place the I2C pins in the 'default' and 'idle'
states when the I2C device is runtime resumed and suspended,
respectively.

Please note that the pinctrl functions that set the state of the pins
check to see if the devices has pins associated and will return zero
if they do not. Therefore, it is safe to call these pinctrl functions
even for I2C devices that do not have any pins associated.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Add runtime power-management support

Update the Tegra I2C driver to use runtime PM and move the code in the
tegra_i2c_clock_enable/disable() functions to the PM runtime resume and
suspend callbacks, respectively.

Note that given that CONFIG_PM is not mandatory for Tegra, if CONFIG_PM
is not enabled and so runtime PM is not enabled, ensure that the I2C
clocks are turned on during probe and kept on by calling the resume
callback directly.

In the function tegra_i2c_init(), the variable 'err' does not need to be
initialised to zero in tegra_i2c_init() because it is initialised when
pm_runtime_get_sync() is called. Furthermore, to ensure we only return 0
from tegra_i2c_init(), it is necessary to re-initialise 'err' to 0 after
a successful call to pm_runtime_get_sync() because it can return a
positive value on success. However, alternatively re-initialise 'err' by
using the return value of the function tegra_i2c_flush_fifos() because
it can only be 0 or -ETIMEDOUT.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Simplify I2C resume

The I2C adapter is unlocked regardless of whether the tegra_i2c_init()
called during the resume is successful or not. However, if the
tegra_i2c_init() is not successful, then ->is_suspended is not set to
false. Simplify the resume code by only setting ->is_suspended to false
if tegra_i2c_init() is successful and return the error code from
tegra_i2c_init().

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Use device name for adapter name

All Tegra I2C devices have the name "Tegra I2C adapter" which is not
very useful when viewing the I2C adapter names via the sysfs. Therefore,
use the device name, which is unique for each I2C device, instead.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Remove non device-tree support

Tegra has only supported device-tree for platform/board configuration
for quite some time now and so simplify the Tegra I2C driver by dropping
code for non device-tree platforms/boards.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Add missing new line characters

Add missing new line characters for the various error messages.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Fix missing blank lines after declarations

Checkpatch warns about missing blank lines after declarations in the
Tegra I2C driver and so fix these.

Note that the initialisation of 'val' to zero in tegra_dvc_init() is
unnecessary and so remove this.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Use BIT macro

Checkpatch warns about spacing around the '<<' operator in the Tegra I2C
driver and so fix these by converting the bit definitions that are using
this operator to use the BIT macro.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Fix lines over 80 characters

Checkpatch warns about some lines over 80 characters in the Tegra I2C
driver and so fix these.

While we are at it, prefix the second instance of "STOP condition" in
the comment with a "the".

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: don't print error when adding adapter fails

The core will do this for us now.

Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Correct error path in probe

Commit 497fbe24987b ("i2c: tegra: enable multi master mode for tegra210")
enables the Tegra I2C 'div_clk' for adapters using the multi-master mode
during the device probe. Although the probe error path was updated to
disable the clock on probe failure, there is one place after calling
tegra_i2c_init() where the clock will not be disabled on failure. Correct
the error path so that the 'div_clk' is disabled if calling
tegra_i2c_init() fails.

Fixes: 497fbe24987b ("i2c: tegra: enable multi master mode for tegra210")

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: disable clock before returning error

Disable clock before returning error in tegra_i2c_init() as its leaves
i2c clock ON in case of error and never turns off again as it will have
unbalanced clock enable/disable

Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: enable multi master mode for tegra210

Enable multi-master mode in I2C_CNFG reg based on hw features.
Using single/multi-master mode bit introduced for Tegra210,
whereas multi-master mode is enabled by default in HW for T124 and
earlier Tegra SOC. Enabling this bit doesn't explicitly start
treating the bus has having multiple masters, but will start
checking for arbitration lost and reporting when it occurs.

The Tegra210 I2C controller supports single/multi master mode.
Add chipdata for Tegra210 and its compatibility string so that
Tegra210 will select data that enables multi master mode correctly.

Do below prerequisites for multi-master bus if "multi-master"
dt property entry is added.
1. Enable 1st level clock always set.
2. Disable 2nd level clock gating (slcg which
is supported from T124 SOC and later chips)

Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: don't open code of_device_get_match_data()

This change will also make Coverity happy by avoiding a theoretical NULL
pointer dereference; yet another reason is to use the above helper function
to tighten the code and make it more readable.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Laxman Dewangan <ldewangan@nvidia.com>

i2c: tegra: drop duplicated code for assigning algo

This code is repeated in probe:
i2c_dev->adapter.algo = &tegra_i2c_algo;

Cc: Donglin Peng <pengdonglin137@163.com>
Signed-off-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: add support for fast plus (FM+) mode clock rate

Tegra I2C controller required to configure the clock divisor
register inside controller to different value based on the clock
speed. The recommended clock divisor for the I2C controller for
standard/fast mode is 0x19 and for fast-mode plus is 0x10.

Add support to configure clock divisor register of I2C controller
based on bus clock rate.

This clock divisor is supported form T114 onwards.

Signed-off-by: Chaitanya Bandi <bandik@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: update CONFIG_LOAD for new conifiguration

Once the new configuration is set on the conifg register of
I2C controller, it is require to update the CONFIG_LOAD register
to transfer the new SW configuration to actual HW internal
registers that would be used in the actual logic.

It is like, SW is programming only shadow registers through
regular configuration and when these load_config bit fields
are set to 1, it causes the regular/shadows registers
configuration transferred to the HW internal active registers.
So SW has to set these bit fields at the end of all regular
registers configuration. And these config_load bits are HW
auto-clear bits. HW clears these bit fields once the register
configuration is moved to HW internal active registers. So SW
has to wait until these bits are auto-cleared before going
for any further programming

This mechanism is supported on T124 and after this SoCs.

Signed-off-by: Chaitanya Bandi <bandik@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: apply size limit quirk

payload_size is a 12 bit field in the HW register, so add a limit for
this size. That way we gracefully reject the message beforehand instead
of generating an OOPS while transferring. Verified using some older
Tegra2 documentation and a more recent Jetson TK1 board.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>

i2c: tegra: don't advertise SMBUS_QUICK

This HW cannot send 0-byte-length messages and the driver discards them.
So, we should not advertise SMBUS_QUICK.

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

i2c: tegra: match return type of wait_for_completion_timeout

return type of wait_for_completion_timeout is unsigned long not int. As ret
was only used for wait_for_completion_timeout here it is renamed to time_left
the type changed to unsigned long and references fixed up.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: Maintain CPU endianness

Support CPU BE mode by adding endianness conversion for memcpy interactions.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: busses: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

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

i2c: tegra: Move clk_prepare/clk_set_rate to probe

Currently the i2c-tegra bus driver prepares, enables
and set_rates its clocks separately for each transfer.
This causes locking problems when doing I2C transfers
from clock notifiers; see
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-July/268653.html

This patch moves clk_prepare/unprepare and clk_set_rate calls to
the probe function, leaving only clk_enable/disable to be
done on each transfer. This solves the locking issue.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-tegra: Drop class based scanning to improve bootup time

This driver has been flagged to drop class based instantiation. The removal
improves boot-up time and is unneeded for embedded controllers. Users have been
warned to switch for some time now, so we can actually do the removal. Keep the
DEPRECATED flag, so the core can inform users that the behaviour finally
changed now. After another transition period, this flag can go, too.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Tested-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>

i2c: remove unnecessary OOM messages

The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message. For example,
k.alloc and v.alloc failures use dump_stack().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: i2c-tegra: deprecate class based instantiation

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Stephen Warren <swarren@nvidia.com>

i2c: tegra: use reset framework

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Thierry Reding <treding@nvidia.com>

tree-wide: use reinit_completion instead of INIT_COMPLETION

Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.

[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

i2c: move OF helpers into the core

I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.

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

drivers/i2c/busses: don't check resource with devm_ioremap_resource

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Barry Song <Baohua.Song@csr.com>

i2c: tegra: assume CONFIG_OF, remove platform data

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: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: tegra: check the clk_prepare_enable() return value

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: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

i2c: tegra: remove warning dump if timeout happen in transfer

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>

ARM: tegra: migrate to new clock code

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: Prashant Gaikwad <pgaikwad@nvidia.com>
[swarren: use to_clk_periph_gate().]
Signed-off-by: Stephen Warren <swarren@nvidia.com>

i2c: tegra: add support for Tegra114 SoC

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>

i2c: Convert to devm_ioremap_resource()

Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.

devm_ioremap_resource() provides its own error messages so all explicit
error messages can be removed from the failure code paths.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

i2c: remove __dev* attributes from subsystem

CONFIG_HOTPLUG is going away as an option. As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> (for ocores and mux-gpio)
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com> (for i2c-gpio)
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> (for puf3)
Acked-by: Barry Song <baohua.song@csr.com> (for sirf)
Reviewed-by: Jean Delvare <khali@linux-fr.org>
[wsa: Fixed "foo* bar" flaws while we are here]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: set irq name as device name

When watching the irqs name of tegra i2c, all instances
irq name shows as tegra_i2c.

Passing the device name properly to have the irq names with
instance like tegra-i2c.0, tegra-i2c.1 etc.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: dynamically control fast clk

Tegra I2C driver enables the fast clock during initialization
and does not disable till driver removed.
Enable this clock before transfer and disable after transfer done.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

i2c: tegra: I2_M_NOSTART functionality not supported in Tegra20

Tegra20 i2c controller does not support the continue transfer
which implements the I2C_M_NOSTART functionality of i2c
protocol mangling.
Removing the I2C_M_NOSTART functionality support for Tegra20.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

i2c: tegra: pass proper name for getting clock

Tegra's i2c controller require two clock sources named as
div_clk and fast_clk.
This change make sure that driver pass the correct clock's
name when it acquires clock handle. Also change the
variable name to reflect the correct clock handles.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

i2c: tegra: protect suspend/resume callbacks with CONFIG_PM_SLEEP

The CONFIG_PM doesn't actually enable any of the PM callbacks, it
only allows to enable CONFIG_PM_SLEEP and CONFIG_PM_RUNTIME.
This means if CONFIG_PM is used to protect system sleep callbacks
then it may end up unreferenced if only runtime PM is enabled.
Hence protecting sleep callbacks with CONFIG_PM_SLEEP.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Revert "i2c: tegra: convert normal suspend/resume to *_noirq"

This reverts commit 7c86d44cda2e715bc95f525fd0eac4bd6a66998e.
Stephen says:

IIRC, I proposed it before solely to solve some suspend/resume ordering
issues, and Colin Cross NAKd it. These days, deferred probe should make
this change unnecessary.

Reported-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: convert normal suspend/resume to *_noirq

To provide the late suspend and early resume for i2c
driver, convert the suspend/resume as
suspend-> suspend_noirq
resume -> resume_noirq

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>

[wsa: fixed up to match previous pm_ops change]

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c-tegra: Use struct dev_pm_ops for power management

Make the Tegra I2C controller driver define its PM callbacks through
a struct dev_pm_ops object rather than by using legacy PM hooks
in struct platform_driver.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>

[wsa] adapt to of_match_ptr change

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: use of_match_ptr() for match_table initialization

In place of defining match_table for non-DT based as NULL,
use of_match_ptr() for initialzing the of_match_table.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: use clk_disable_unprepare in place of clk_disable

Use clk_disable_unprepare() inplace of clk_disable().
This was missed as part of moving clock enable/disable to
prepare/unprepare for using the common clock framework.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: remove unused member variable

Remove unused member variable "iomem" of the
i2c device structure.

This variable becomes unused when converted all allocation
to devm_* in following change:
i2c: tegra: make all resource allocation through devm_*

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: make all resource allocation through devm_*

Use the devm_* for the memory region allocation, interrupt request,
clock handler request.
By doing this, it does not require to explicitly free it and hence
saving some code.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: support for I2C_M_NOSTART functionality

Adding support for functionality I2C_M_NOSTART.
When multiple message transfer request made through i2c
and if any message is flagged with I2C_M_NOSTART then
it will not send the start/repeat-start and address of
that message i.e. sends data directly.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: add PROTOCOL_MANGLING as supported functionality.

The Tegra i2c driver supports the I2C_M_IGNORE_NAK and hence
returning I2C_FUNC_PROTOCOL_MANGLING as supported functionality.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: make sure register writes completes

The Tegra PPSB (an peripheral bus) queues writes transactions.
In order to guarantee that writes have completed before a
certain time, a read transaction to a register on the same
bus must be executed.
This is necessary in situations such as when clearing an
interrupt status or enable, so that when returning from an
interrupt handler, the HW has already de-asserted its
interrupt status output, which will avoid spurious interrupts.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: Add clk_prepare/clk_unprepare

Use clk_prepare/clk_unprepare as required by the generic clk framework.

Cc: w.sang@pengutronix.de
Cc: linux-i2c@vger.kernel.org
Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

i2c: tegra: notify transfer-complete after clearing status.

The notification of the transfer complete by calling complete()
should be done after clearing all interrupt status.
This avoids the race condition of misconfigure the i2c controller
in multi-core environment.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: stable@kernel.org

i2c: tegra: fix 10bit address configuration

The slave address of device to be configured in packet
header as follows:
7 bit address: PacketHeader3[7:1]
10 bit address: PacketHeader3[9:0]

Fixing the code to make packet header3 properly.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: Add delay before resetting the controller after NACK

NACK interrupt is generated before I2C controller generates the STOP
condition on bus. Because of this reset of controller is happening
before I2C controller could complete STOP condition. So wait for some
time before resetting the controller so that STOP condition has
delivered properly on bus.

Added delay of 2 clock period before resetting the controller in case of
NACK error.

Signed-off-by: Alok Chauhan <alokc@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>

[wsa: Reworded the commit msg and code comment a bit]

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: Remove unnecessary write to INT_STATUS

The write is not necessary and may cause the I2C controller to misbehave.
With this fix, I2C on Tegra30 works (at least, running i2cdump repeatedly
on the WM8903 on Cardhu's I2C5/DVC bus).

Signed-off-by: Alok Chauhan <alokc@nvidia.com>
[swarren: Reworded commit description]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

i2c: tegra: Add devexit_p() for remove

It was originally missed in the __devinit/__devexit annotations.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

i2c: tegra: Support DVC controller in device tree

One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
block. This block is identical to the rest of the I2C blocks, except that
it only supports master mode, it has registers moved around, and it needs
some extra init to get it into I2C mode. The register moves are handled
by i2c_readl and i2c_writel

This patch adds a new compatible value for controllers of this "DVC"
type; I figured that this approach was reasonable, as opposed to adding
an is-dvc property under the existing compatible value, since the HW
truly is different.

v2: Call of_device_is_compatible() to determine is_dvc, instead of storing
the flag in tegra_i2c_of_match[]'s .data field.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

i2c: tegra: Add __devinit/exit to probe/remove

This fixes some section mismatch build warnings.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

i2c: Add module.h to modular files prev. implicitly getting it

These files use interfaces from linux/module.h, so they must
include that file to avoid build errors when the implicit
presence of module.h is removed.

[with i2c-pxa-pci.c fix from Randy Dunlap <rdunlap@xenotime.net>]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

i2c-tegra: __iomem annotation fix

drivers/i2c/busses/i2c-tegra.c:585:7: warning: incorrect type in assignment (different address spaces)
drivers/i2c/busses/i2c-tegra.c:585:7: expected void *base
drivers/i2c/busses/i2c-tegra.c:585:7: got void [noderef] <asn:2>*
drivers/i2c/busses/i2c-tegra.c:619:16: warning: incorrect type in assignment (different address spaces)
drivers/i2c/busses/i2c-tegra.c:619:16: expected void [noderef] <asn:2>*base
drivers/i2c/busses/i2c-tegra.c:619:16: got void *base
drivers/i2c/busses/i2c-tegra.c:689:10: warning: incorrect type in argument 1 (different address spaces)
drivers/i2c/busses/i2c-tegra.c:689:10: expected void volatile [noderef] <asn:2>*addr
drivers/i2c/busses/i2c-tegra.c:689:10: got void *base

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by; Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-tegra: fix possible race condition after tx

In tegra_i2c_fill_tx_fifo, once we have finished pushing all the bytes
to the I2C hardware controller, the interrupt might happen before we
have updated i2c_dev->msg_buf_remaining at the end of the function.
Then, in tegra_i2c_isr, we will call again tegra_i2c_fill_tx_fifo
triggering weird behaviour. This has been shown to happen under real
conditions.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Acked-by: Rhyland Klein <rklein@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-tegra: add I2C_FUNC_SMBUS_EMUL

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c-tegra: Add of_match_table

This patch was intended to be part of 7ca2d1a105a239e300b937e9c41a10a4bd08f569
"i2c: Tegra: Add DeviceTree support". However, an early version of that patch,
which was missing a chunk, was applied to next-i2c. This change is that
missing chunk.

Signed-off-by: John Bonesio <bones@secretlab.ca>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: Tegra: Add DeviceTree support

This patch modifies the tegra i2c driver so that it can be initiailized
using the device tree along with the devices connected to the i2c bus.

Signed-off-by: John Bonesio <bones@secretlab.ca>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: OIof Johansson <olof@lixom.net>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: tegra: Assign unused slave address

On Tegra, we should always use the "new" I2C slave controller, to avoid
issues with the old controller. This was implemented in commit 65a1a0a
"i2c: tegra: Enable new slave mode."

There is currently no driver for the Tegra I2C slave controller upstream.
Additionally, the controller cannot be completely disabled. Instead, we
need to:

a) Set I2C_SL_CNFG_NACK to make the controller automatically NACK any
incoming transactions.

b) The controller's definition of NACK isn't identical to the I2C
protocol's definition. Specifically, it will perform a standard NACK, but
*also* continue to hold the clock line low in expectation of receiving
more data. This can hang the bus, or at least cause transaction timeouts,
if something starts a transaction that matches the controller's slave
address. Since the default address is 0x00, the general call address,
this does occur in practice.

To avoid this, we explicitly program a slave address that is reserved for
future expansion. For current boards, this guarantees the address will
never be used. If a future board ever needs to use this address, we can
add platform data to determine a board-specific safe address. 0xfc is
picked by this patch.

This patch is based on a change previously posted by: Wei Ni <wni@nvidia.com>
http://www.spinics.net/lists/linux-i2c/msg05437.html
In turned based on internal changes by: Bharat Nihalani <bnihalani@nvidia.com>

A semantically equivalent change has been contained in the various
ChromeOS kernels for a while.

I tested this change on top of 3.0-rc2 on Harmony, and interacted with
the WM8903 I2C-based audio codec.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: tegra: Add de-bounce cycles.

This enables debouncing of the I2C lines. The debounce period is
2 * the debounce register field value, in terms of the I2C block's main
clock. The Tegra TRM indicates that a setting yielding >50nS is
desirable. Hence, a setting of 2 => 4 clocks @ 72MHz => ~55nS.

Signed-off-by: Ken Radtke <kradtke@nvidia.com>
[swarren: Added commit description body,
Fixed 80-column limit, Reverted file permission change]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: tegra: fix repeated start handling

A repeated start should be used for all but the last msg in an xfer. The
NOSTART flag is for skipping the START frame (addr/rw)

Signed-off-by: Erik Gilling <konkers@android.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: tegra: recover from spurious interrupt storm

Re-init the I2C controller when an IRQ arrives with no
I2C_INT_STATUS bits set to indicate why the interrupt was sent.
Storms of such mystery interrupts are infrequently seen.

Dump some more status when these interrupts arrive. Set an error
for the current request and wake up the requester (rather than
timing out the request or possibly silently ignoring the interrupts).

If the I2C block is inside the DVC, also ACK the DVC I2C transfer
done interrupt in the ISR error return path, as is done for the
normal return path.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
[swarren: Fix minor checkpatch whitespace issue, commit tag]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

i2c: tegra: Enable new slave mode.

For Tegra i2c controller to function properly new slave mode must be
enabled.

swarren notes:

In particular, I found this was needed when working on enabling the
Tegra audio driver on the Seaboard board. There are two different PCB
layouts for this board; a "clamshell" version, which works just fine
without this change, and the original non-clamshell version, which needs
this change in order for I2C to operate correctly. Without it, I2C
probing fails for some devices, e.g. with:

wm8903 0-001a: Device with ID register 0 is not a WM8903
wm8903 0-001a: asoc: failed to probe CODEC wm8903.0-001a: -19
asoc: failed to instantiate card tegra-wm8903: -19
ALSA device list:
No soundcards found.

Signed-off-by: Rakesh Iyer <riyer@nvidia.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

i2c: tegra: Add i2c support

Adds I2C bus driver for nVidia Tegra SoCs. Tegra includes 4 I2C
controllers, one of which is inside the Dynamic Voltage Controller
and has a slightly different register map.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>