linux-toradex.git/drivers/i2c/i2c-core.h, branch v6.7-rc7

i2c: core: Run atomic i2c xfer when !preemptible

2023-07-28T10:33:02+00:00

Since bae1d3a05a8b, i2c transfers are non-atomic if preemption is
disabled. However, non-atomic i2c transfers require preemption (e.g. in
wait_for_completion() while waiting for the DMA).

panic() calls preempt_disable_notrace() before calling
emergency_restart(). Therefore, if an i2c device is used for the
restart, the xfer should be atomic. This avoids warnings like:

[   12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0
[   12.676926] Voluntary context switch within RCU read-side critical section!
...
[   12.742376]  schedule_timeout from wait_for_completion_timeout+0x90/0x114
[   12.749179]  wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70
...
[   12.994527]  atomic_notifier_call_chain from machine_restart+0x34/0x58
[   13.001050]  machine_restart from panic+0x2a8/0x32c

Use !preemptible() instead, which is basically the same check as
pre-v5.2.

Fixes: bae1d3a05a8b ("i2c: core: remove use of in_atomic()")
Cc: stable@vger.kernel.org # v5.2+
Suggested-by: Dmitry Osipenko 
Acked-by: Wolfram Sang 
Reviewed-by: Dmitry Osipenko 
Tested-by: Nishanth Menon 
Signed-off-by: Benjamin Bara 
Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-2-18699d5dcd76@skidata.com
Signed-off-by: Lee Jones

i2c: acpi: Use ACPI wake capability bit to set wake_irq

2022-10-04T13:41:12+00:00

Device tree already has a mechanism to pass the wake_irq. It does this
by looking for the wakeup-source property and setting the
I2C_CLIENT_WAKE flag. This CL adds the ACPI equivalent. It uses the
ACPI interrupt wake flag to determine if the interrupt can be used to
wake the system. Previously the i2c drivers had to make assumptions and
blindly enable the wake IRQ. This can cause spurious wake events. e.g.,
If there is a device with an Active Low interrupt and the device gets
powered off while suspending, the interrupt line will go low since it's
no longer powered and wakes the system. For this reason we should
respect the board designers wishes and honor the wake bit defined on the
interrupt.

Signed-off-by: Raul E Rangel 
Reviewed-by: Mika Westerberg 
Reviewed-by: Andy Shevchenko 
Acked-by: Wolfram Sang 
Signed-off-by: Rafael J. Wysocki

i2c: don't expose function which is only used internally

2022-02-15T08:58:57+00:00

i2c_setup_smbus_alert() is only needed within the I2C core, so no need
to expose it to other modules.

Signed-off-by: Wolfram Sang 
Reviewed-by: Niklas Söderlund 
Signed-off-by: Wolfram Sang

i2c: acpi: Remove dead code, i.e. i2c_acpi_match_device()

2020-08-25T07:22:09+00:00

We have no users of i2c_acpi_match_device() anymore and seems
will not have them in the future, thus remove dead code.

Signed-off-by: Andy Shevchenko 
Reviewed-by: Mika Westerberg 
Signed-off-by: Wolfram Sang

i2c: reword explanation about atomic transfers

2020-05-20T13:25:55+00:00

Atomic transfers are not only about sending messages like the original
wording suggested. Speak of 'accessing' now like in i2c.h.

Reported-by: Michał Mirosław 
Signed-off-by: Wolfram Sang 
Signed-off-by: Wolfram Sang

Merge branch 'i2c/for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

2019-07-16T04:10:39+00:00

Pull i2c updates from Wolfram Sang:
 "New stuff from the I2C world:

   - in the core, getting irqs from ACPI is now similar to OF

   - new driver for MediaTek MT7621/7628/7688 SoCs

   - bcm2835, i801, and tegra drivers got some more attention

   - GPIO API cleanups

   - cleanups in the core headers

   - lots of usual driver updates"

* 'i2c/for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (74 commits)
  i2c: mt7621: Fix platform_no_drv_owner.cocci warnings
  i2c: cpm: remove casting dma_alloc
  dt-bindings: i2c: sun6i-p2wi: Fix the binding example
  dt-bindings: i2c: mv64xxx: Fix the example compatible
  i2c: i801: Documentation update
  i2c: i801: Add support for Intel Tiger Lake
  i2c: i801: Fix PCI ID sorting
  dt-bindings: i2c-stm32: document optional dmas
  i2c: i2c-stm32f7: Add I2C_SMBUS_I2C_BLOCK_DATA support
  i2c: core: Tidy up handling of init_irq
  i2c: core: Move ACPI gpio IRQ handling into i2c_acpi_get_irq
  i2c: core: Move ACPI IRQ handling to probe time
  i2c: acpi: Factor out getting the IRQ from ACPI
  i2c: acpi: Use available IRQ helper functions
  i2c: core: Allow whole core to use i2c_dev_irq_from_resources
  eeprom: at24: modify a comment referring to platform data
  dt-bindings: i2c: omap: Add new compatible for J721E SoCs
  dt-bindings: i2c: mv64xxx: Add YAML schemas
  dt-bindings: i2c: sun6i-p2wi: Add YAML schemas
  i2c: mt7621: Add MediaTek MT7621/7628/7688 I2C driver
  ...

i2c: core: Move ACPI IRQ handling to probe time

2019-06-29T11:17:44+00:00

Bring the ACPI path in sync with the device tree path and handle all the
IRQ fetching at probe time. This leaves the only IRQ handling at device
registration time being that which is passed directly through the board
info as either a resource or an actual IRQ number.

Reviewed-by: Andy Shevchenko 
Signed-off-by: Charles Keepax 
Reviewed-by: Mika Westerberg 
Signed-off-by: Wolfram Sang

i2c: core: Allow whole core to use i2c_dev_irq_from_resources

2019-06-29T11:17:17+00:00

Remove the static from i2c_dev_irq_from _resources so that other parts
of the core code can use this helper function.

Reviewed-by: Mika Westerberg 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Charles Keepax 
Signed-off-by: Wolfram Sang

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157

2019-05-30T18:26:37+00:00

Based on 3 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Reviewed-by: Kate Stewart 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman

i2c: core: apply 'is_suspended' check for SMBus, too

2019-05-03T14:44:51+00:00

We checked I2C calls, but not SMBus. Refactor the helper to an inline
function and use it for both, I2C and SMBus.

Fixes: 9ac6cb5fbb17 ("i2c: add suspended flag and accessors for i2c adapters")
Reported-by: Peter Rosin 
Signed-off-by: Wolfram Sang 
Reviewed-by: Simon Horman 
Signed-off-by: Wolfram Sang