The driver's interrupt handler checks whether a message is currently
being handled with the curr_msg pointer. When it is NULL, the interrupt
is considered to be unexpected. Similarly, the i2c_start_transfer
routine checks for the remaining number of messages to handle in
num_msgs.

However, these values are never cleared and always keep the message and
number relevant to the latest transfer (which might be done already and
the underlying message memory might have been freed).

When an unexpected interrupt hits with the DONE bit set, the isr will
then try to access the flags field of the curr_msg structure, leading
to a fatal page fault.

The msg_buf and msg_buf_remaining fields are also never cleared at the
end of the transfer, which can lead to similar pitfalls.

Fix these issues by introducing a cleanup function and always calling
it after a transfer is finished.

Fixes: e2474541032d ("i2c: bcm2835: Fix hang for writing messages larger than 16 bytes")
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

In case the hold bit is not needed we are carrying the old values.
Fix the same by resetting the bit when not needed.

Fixes the sporadic i2c bus lockups on National Instruments
Zynq-based devices.

Fixes: df8eb5691c48 ("i2c: Add driver for Cadence I2C controller")
Reported-by: Kyle Roeschley <kyle.roeschley@ni.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Tested-by: Kyle Roeschley <kyle.roeschley@ni.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

We currently get the following error with pixcir_ts driver during a
suspend resume cycle:

omap_i2c 4802a000.i2c: controller timed out
pixcir_ts 1-005c: pixcir_int_enable: can't read reg 0x34 : -110
pixcir_ts 1-005c: Failed to disable interrupt generation: -110
pixcir_ts 1-005c: Failed to stop
dpm_run_callback(): pixcir_i2c_ts_resume+0x0/0x98
[pixcir_i2c_ts] returns -110
PM: Device 1-005c failed to resume: error -110

And at least am437x based devices with pixcir_ts will fail to resume
to a touchscreen that is configured as the wakeup-source in device
tree for these devices.

This is because pixcir_ts tries to reconfigure it's registers for
noirq suspend which fails. This also leaves i2c-omap in enabled state
for suspend.

Let's fix the pixcir_ts issue and make sure i2c-omap is suspended by
adding SET_NOIRQ_SYSTEM_SLEEP_PM_OPS.

Let's also get rid of some ifdefs while at it and replace them with
__maybe_unused as SET_RUNTIME_PM_OPS and SET_NOIRQ_SYSTEM_SLEEP_PM_OPS
already deal with the various PM Kconfig options.

Reported-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

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>

Pull i2c updates from Wolfram Sang:
 "I2C has only driver updates for you this time.

  Mostly new IDs/DT compatibles, also SPDX conversions, small cleanups.
  STM32F7 got FastMode+ and PM support, Axxia some reliabilty
  improvements"

* 'i2c/for-5.0' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (26 commits)
  i2c: Add Actions Semiconductor Owl family S700 I2C support
  dt-bindings: i2c: Add S700 support for Actions Semi Soc's
  i2c: ismt: Add support for Intel Cedar Fork
  i2c: tegra: Switch to SPDX identifier
  i2c: tegra: Add missing kerneldoc for some fields
  i2c: tegra: Cleanup kerneldoc comments
  i2c: axxia: support sequence command mode
  dt-bindings: i2c: rcar: Add r8a774c0 support
  dt-bindings: i2c: sh_mobile: Add r8a774c0 support
  i2c: sh_mobile: Add support for r8a774c0 (RZ/G2E)
  i2c: i2c-cros-ec-tunnel: Switch to SPDX identifier.
  i2c: powermac: Use of_node_name_eq for node name comparisons
  i2c-axxia: check for error conditions first
  i2c-axxia: dedicated function to set client addr
  dt-bindings: i2c: Use correct vendor prefix for Atmel
  i2c: tegra: replace spin_lock_irqsave with spin_lock in ISR
  eeprom: at24: add support for 24c2048
  dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string
  i2c: i2c-stm32f7: add PM Runtime support
  i2c: sh_mobile: add support for r8a77990 (R-Car E3)
  ...

Add S700 to the list of devices supported by Owl I2C driver.

Add Actions Semiconductor Owl family S700 I2C driver.

Signed-off-by: Parthiban Nallathambi <pn@denx.de>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add PCI ID for the Intel Cedar Fork iSMT SMBus controller.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
[wsa: kept sorting]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

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>

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>

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>