Some drivers may allow to override properties with 0 value when defaults
are not in use, thus, replace memset() with corresponding per property
update.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There are few maximum bus frequencies being used in the I²C core code.
Provide generic definitions for bus frequencies and use them in the core.
The drivers may use predefined constants where it is appropriate.
Some of them are already using these under slightly different names.
We will convert them later to use newly introduced defines.
Note, the name of modes are chosen to follow well established naming
scheme [1].
These definitions will also help to avoid typos in the numbers that
may lead to subtle errors.
[1]: https://en.wikipedia.org/wiki/I%C2%B2C#Differences_between_modes
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Move away from the deprecated API and return the shiny new ERRPTR where
useful.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The I2C specification states that tsu:sto for standard mode timing must
be at minimum 4us. Pictographically, this is:
SCL: ____/~~~~~~~~~
SDA: _________/~~~~
->| |<- 4us minimum
We are currently waiting 2.5us between asserting SCL and SDA, which is
in violation of the standard. Adjust the timings to ensure that we meet
what is stipulated as the minimum timings to ensure that all devices
correctly interpret the STOP bus transition.
This is more important than trying to generate a square wave with even
duty cycle.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Convert the i2c core sysfs attributes from DEVICE_ATTR() to
DEVICE_ATTR_*(), to reduce boilerplate.
This requires renaming some functions.
Although no suitable macro exists for the delete_device attribute,
rename i2c_sysfs_delete_device() to delete_device_store() for
consistency.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
All in-kernel users have been converted to
{devm_}i2c_new_dummy_device(). Remove the old API.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In the general move to have i2c_new_*_device functions which return
ERR_PTR instead of NULL, this patch converts i2c_new_probed_device().
There are only few users, so this patch converts the I2C core and all
users in one go. The function gets renamed to i2c_new_scanned_device()
so out-of-tree users will get a build failure to understand they need to
adapt their error checking code.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Max Staudt <max@enpas.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There are no in-tree users of these helpers anymore, and there
shouldn't. Most use cases went away once the driver model started to
refcount for us. There have been users like the media subsystem, but
they all switched to better refcounting methods meanwhile. Media did
this in 2008. Last user (IPMI) left 2018. Remove this cruft.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
i2c-digital-filter-width-ns:
This optional timing property specifies the width of the spikes on the i2c
lines (in ns) that can be filtered out by built-in digital filters which are
embedded in some i2c controllers.
i2c-analog-filter-cutoff-frequency:
This optional timing property specifies the cutoff frequency of a low-pass
analog filter built-in i2c controllers. This low pass filter is used to filter
out high frequency noise on the i2c lines. Specified in Hz.
Include these properties in the timings structure and read them as integers.
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
- new driver for ICY, an Amiga Zorro card :)
- axxia driver gained slave mode support, NXP driver gained ACPI
- the slave EEPROM backend gained 16 bit address support
- and lots of regular driver updates and reworks
* 'i2c/for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (52 commits)
i2c: tegra: Move suspend handling to NOIRQ phase
i2c: imx: ACPI support for NXP i2c controller
i2c: uniphier(-f): remove all dev_dbg()
i2c: uniphier(-f): use devm_platform_ioremap_resource()
i2c: slave-eeprom: Add comment about address handling
i2c: exynos5: Remove IRQF_ONESHOT
i2c: stm32f7: Make structure stm32f7_i2c_algo constant
i2c: cht-wc: drop check because i2c_unregister_device() is NULL safe
i2c-eeprom_slave: Add support for more eeprom models
i2c: fsi: Add of_put_node() before break
i2c: synquacer: Make synquacer_i2c_ops constant
i2c: hix5hd2: Remove IRQF_ONESHOT
i2c: i801: Use iTCO version 6 in Cannon Lake PCH and beyond
watchdog: iTCO: Add support for Cannon Lake PCH iTCO
i2c: iproc: Make bcm_iproc_i2c_quirks constant
i2c: iproc: Add full name of devicetree node to adapter name
i2c: piix4: Add ACPI support
i2c: piix4: Fix probing of reserved ports on AMD Family 16h Model 30h
i2c: ocores: use request_any_context_irq() to register IRQ handler
i2c: designware: Fix optional reset error handling
...
RST conversion is happily mostly behind us.
- A new document on reproducible builds.
- We finally got around to zapping the documentation for hardware support
that was removed in 2004; one doesn't want to rush these things.
- The usual assortment of fixes, typo corrections, etc.
You'll still find a handful of annoying conflicts against other trees,
mostly tied to the last RST conversions; resolutions are straightforward
and the linux-next ones are good.
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Merge tag 'docs-5.4' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"It's a somewhat calmer cycle for docs this time, as the churn of the
mass RST conversion is happily mostly behind us.
- A new document on reproducible builds.
- We finally got around to zapping the documentation for hardware
support that was removed in 2004; one doesn't want to rush these
things.
- The usual assortment of fixes, typo corrections, etc"
* tag 'docs-5.4' of git://git.lwn.net/linux: (67 commits)
Documentation: kbuild: Add document about reproducible builds
docs: printk-formats: Stop encouraging use of unnecessary %h[xudi] and %hh[xudi]
Documentation: Add "earlycon=sbi" to the admin guide
doc🔒 remove reference to clever use of read-write lock
devices.txt: improve entry for comedi (char major 98)
docs: mtd: Update spi nor reference driver
doc: arm64: fix grammar dtb placed in no attributes region
Documentation: sysrq: don't recommend 'S' 'U' before 'B'
mailmap: Update email address for Quentin Perret
docs: ftrace: clarify when tracing is disabled by the trace file
docs: process: fix broken link
Documentation/arm/samsung-s3c24xx: Remove stray U+FEFF character to fix title
Documentation/arm/sa1100/assabet: Fix 'make assabet_defconfig' command
Documentation/arm/sa1100: Remove some obsolete documentation
docs/zh_CN: update Chinese howto.rst for latexdocs making
Documentation: virt: Fix broken reference to virt tree's index
docs: Fix typo on pull requests guide
kernel-doc: Allow anonymous enum
Documentation: sphinx: Don't parse socket() as identifier reference
Documentation: sphinx: Add missing comma to list of strings
...
We are moving towards returning ERR_PTRs when i2c_new_*_device() calls
fail. Make sure its counterpart for unregistering handles ERR_PTRs as
well.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In the general move to have i2c_new_*_device functions which return
ERR_PTR instead of NULL, this patch converts i2c_new_secondary_device().
There are only few users, so this patch converts the I2C core and all
users in one go. The function gets renamed to i2c_new_ancillary_device()
so out-of-tree users will get a build failure to understand they need to
adapt their error checking code.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> # adv748x
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> # adv7511 + adv7604
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # adv7604
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
of_find_property() will return NULL if of_node is NULL,
thus of_irq_get_by_name() returns -EINVAL which we ignore,
so no need to double check.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Convert each file at I2C subsystem, renaming them to .rst and
adding to the driver-api book.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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
...
Only set init_irq during i2c_device_new and only handle client->irq on
the probe/remove paths.
Suggested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
It makes sense to contain all the ACPI IRQ handling in a single helper
function.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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 <andriy.shevchenko@linux.intel.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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 <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Nobody (including me) noticed that these functions were exported but not
added to the header :/
Fixes: 7159dbdae3 ("i2c: core: improve return value handling of i2c_new_device and i2c_new_dummy")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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 <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c_new_dummy is typically called from the probe function of the
driver for the primary i2c client. It requires calls to
i2c_unregister_device in the error path of the probe function and
in the remove function.
This can be simplified by introducing a device-managed version.
Note the changed error case return value type: i2c_new_dummy returns
NULL whilst devm_i2c_new_dummy_device returns an ERR_PTR.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[wsa: rename new functions and fix minor kdoc issues]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Currently i2c_new_device and i2c_new_dummy return just NULL in error
case although they have more error details internally. Therefore move
the functionality into new functions returning detailed errors and
add wrappers for compatibility with the current API.
This allows to use these functions with detailed error codes within
the i2c core or for API extensions.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[wsa: rename new functions and fix minor kdoc issues]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
- API for late atomic transfers (e.g. to shut down via PMIC). We have a
seperate callback now which is called under clearly defined
conditions. In-kernel users are converted, too.
- new driver for the AMD PCIe MP2 I2C controller
- large refactoring for at91 and bcm-iproc (both gain slave support due
to this)
- and a good share of various driver improvements anf fixes
* 'i2c/for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (57 commits)
dt-bindings: i2c: riic: document r7s9210 support
i2c: imx-lpi2c: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
i2c-piix4: Add Hygon Dhyana SMBus support
i2c: core: apply 'is_suspended' check for SMBus, too
i2c: core: ratelimit 'transfer when suspended' errors
i2c: iproc: Change driver to use 'BIT' macro
i2c: riic: Add Runtime PM support
i2c: mux: demux-pinctrl: use struct_size() in devm_kzalloc()
i2c: mux: pca954x: allow management of device idle state via sysfs
i2c: mux: pca9541: remove support for unused platform data
i2c: mux: pca954x: remove support for unused platform data
dt-bindings: i2c: i2c-mtk: add support for MT8516
i2c: axxia: use auto cmd for last message
i2c: gpio: flag atomic capability if possible
i2c: algo: bit: add flag to whitelist atomic transfers
i2c: stu300: use xfer_atomic callback to bail out early
i2c: ocores: enable atomic xfers
i2c: ocores: refactor setup for polling
i2c: tegra-bpmp: convert to use new atomic callbacks
i2c: omap: Add the master_xfer_atomic hook
...
Pull i2c fixes from Wolfram Sang:
"I2C driver bugfixes and a MAINTAINERS update for you"
* 'i2c/for-current-fixed' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: Prevent runtime suspend of adapter when Host Notify is required
i2c: synquacer: fix enumeration of slave devices
MAINTAINERS: friendly takeover of i2c-gpio driver
i2c: designware: ratelimit 'transfer when suspended' errors
i2c: imx: correct the method of getting private data in notifier_call
We checked I2C calls, but not SMBus. Refactor the helper to an inline
function and use it for both, I2C and SMBus.
Fixes: 9ac6cb5fbb ("i2c: add suspended flag and accessors for i2c adapters")
Reported-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There are two problems with WARN_ON() here. One: It is not ratelimited.
Two: We don't see which adapter was used when trying to transfer
something when already suspended. Implement a custom ratelimit once per
adapter and use dev_WARN there. This fixes both issues. Drawback is that
we don't see if multiple drivers are trying to transfer with the same
adapter while suspended. They need to be discovered one after the other
now. This is better than a high CPU load because a really broken driver
might try to resend endlessly.
Fixes: 9ac6cb5fbb ("i2c: add suspended flag and accessors for i2c adapters")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org # v5.1+
Multiple users have reported their Synaptics touchpad has stopped
working between v4.20.1 and v4.20.2 when using SMBus interface.
The culprit for this appeared to be commit c5eb119007 ("PCI / PM: Allow
runtime PM without callback functions") that fixed the runtime PM for
i2c-i801 SMBus adapter. Those Synaptics touchpad are using i2c-i801
for SMBus communication and testing showed they are able to get back
working by preventing the runtime suspend of adapter.
Normally when i2c-i801 SMBus adapter transmits with the client it resumes
before operation and autosuspends after.
However, if client requires SMBus Host Notify protocol, what those
Synaptics touchpads do, then the host adapter must not go to runtime
suspend since then it cannot process incoming SMBus Host Notify commands
the client may send.
Fix this by keeping I2C/SMBus adapter active in case client requires
Host Notify.
Reported-by: Keijo Vaara <ferdasyn@rocketmail.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203297
Fixes: c5eb119007 ("PCI / PM: Allow runtime PM without callback functions")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Keijo Vaara <ferdasyn@rocketmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
I'm not sure what made gcc warn about this code now. The 'ret' variable
does end up initialized in all cases, but it's definitely not obvious,
so the compiler is quite reasonable to warn about this.
So just add initialization to make it all much more obvious both to
compilers and to humans.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We had the request to access devices very late when interrupts are not
available anymore multiple times now. Mostly to prepare shutdown or
reboot. Allow adapters to specify a specific callback for this case.
Note that we fall back to the generic {master|smbus}_xfer callback if
this new atomic one is not present. This is intentional to preserve the
previous behaviour and avoid regressions. Because there are drivers not
using interrupts or because it might have worked "accidently" before.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Stefan Lengfeld <contact@stefanchrist.eu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If I2C transfers are executed in atomic contexts, trylock is used
instead of lock. This behaviour was missing for SMBUS, although a lot of
transfers are of SMBUS type, either emulated or direct. So, factor out
the locking routine into a helper and use it for I2C and SMBUS.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Commit cea443a81c ("i2c: Support i2c_transfer in atomic contexts")
added in_atomic() to the I2C core. However, the use of in_atomic()
outside of core kernel code is discouraged and was already[1] when this
code was added in early 2008. The above commit was a preparation for
commit b7a3670131 ("i2c-pxa: Add polling transfer"). Its commit
message says explicitly it was added "for cases where I2C transactions
have to occur at times interrup[t]s are disabled". So, the intention was
'disabled interrupts'. This matches the use cases for atomic I2C
transfers I have seen so far: very late communication (mostly to a PMIC)
to powerdown or reboot the system. For those cases, interrupts are
disabled then. It doesn't seem that in_atomic() adds value.
After a discussion with Peter Zijlstra[2], we came up with a better set
of conditionals to match the use case.
The I2C core will soon gain an extra callback into bus drivers
especially for atomic transfers to make them more generic. The code
deciding which transfer to use (atomic/non-atomic) should mimic the
behaviour which locking to use (trylock/lock). This is why we add a
helper for it.
[1] https://lwn.net/Articles/274695/
[2] http://patchwork.ozlabs.org/patch/1067437/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Stefan Lengfeld <contact@stefanchrist.eu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Make sure we report 'no buffer' for 0-length messages. This can only
happen if threshold is set to 0 which is kind of bogus but we should
still handle this situation. Update the docs and add a debug message
to educate callers of this function.
Reported-by: Hsin-Yi Wang <hsinyi@chromium.org>
Fixes: e94bc5d18b ("i2c: add helpers to ease DMA handling")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
A previous change allowed I2C client devices to discover new IRQs upon
reprobe by clearing the IRQ in i2c_device_remove. However, if an IRQ was
assigned in i2c_new_device, that information is lost.
For example, the touchscreen and trackpad devices on a Dell Inspiron laptop
are I2C devices whose IRQs are defined by ACPI extended IRQ types. The
client device structures are initialized during an ACPI walk. After
removing the i2c_hid device, modprobe fails.
This change caches the initial IRQ value in i2c_new_device and then resets
the client device IRQ to the initial value in i2c_device_remove.
Fixes: 6f108dd70d ("i2c: Clear client->irq in i2c_device_remove")
Signed-off-by: Jim Broadus <jbroadus@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
[wsa: this is an easy to backport fix for the regression. We will
refactor the code to handle irq assignments better in general.]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
A few drivers open code the handling of suspended adapters. It could be
handled by the core, though, to ensure generic handling. This patch adds
the flag and accessor functions. The usage of these helpers is optional,
though. See the kerneldoc in this patch. Using the new flag, we now
reject further transfers if the adapter is already marked suspended.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The IRQ will be mapped in i2c_device_probe only if client->irq is zero and
i2c_device_remove does not clear this. When rebinding an I2C device,
whos IRQ provider has also been rebound this means that an IRQ mapping
will never be created, causing the I2C device to fail to acquire its
IRQ. Fix this issue by clearing client->irq in i2c_device_remove,
forcing i2c_device_probe to lookup the mapping again.
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
irq_create_mapping calls irq_find_mapping internally and will use the
found mapping if one exists, so there is no need to manually call this
from i2c_smbus_host_notify_to_irq.
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
"I2C has not so much stuff this time. Mostly driver enablement for new
SoCs, some driver bugfixes, and some cleanups"
* 'i2c/for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (35 commits)
MAINTAINERS: add maintainer for Renesas RIIC driver
i2c: sh_mobile: Remove dummy runtime PM callbacks
i2c: uniphier-f: fix race condition when IRQ is cleared
i2c: uniphier-f: fix occasional timeout error
i2c: uniphier-f: make driver robust against concurrency
i2c: i2c-qcom-geni: Simplify irq handler
i2c: i2c-qcom-geni: Simplify tx/rx functions
i2c: designware: Set IRQF_NO_SUSPEND flag for all BYT and CHT controllers
i2c: mux: mlxcpld: simplify code to reach the adapter
i2c: mux: ltc4306: simplify code to reach the adapter
i2c: mux: pca954x: simplify code to reach the adapter
i2c: core: remove level of indentation in i2c_transfer
i2c: core: remove outdated DEBUG output
i2c: zx2967: use core to detect 'no zero length' quirk
i2c: tegra: use core to detect 'no zero length' quirk
i2c: qup: use core to detect 'no zero length' quirk
i2c: omap: use core to detect 'no zero length' quirk
i2c: Convert to using %pOFn instead of device_node.name
i2c: brcmstb: Allow enabling the driver on DSL SoCs
eeprom: at24: fix unexpected timeout under high load
...
This function was renamed in commit 82fe39a6bc ("i2c: refactor
function to release a DMA safe buffer") but this kernel doc wasn't
updated to point at the new function. Rename it.
Fixes: 82fe39a6bc ("i2c: refactor function to release a DMA safe buffer")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Using the common kernel pattern to bail out at the beginning if some
conditions are not met, we can save a level of indentation. No
functional change.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The usefulness of this debug output is questionable. It covers only
direct i2c_transfer calls and no SMBUS calls, neither direct nor
emulated ones. And the latter one is largely used in the kernel, so a
lot of stuff is missed. False positives are also generated in case the
locking later fails. Also, we have a proper tracing mechanism for all
these kinds of transfers in place for years now. Remove this old one.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
a) rename to 'put' instead of 'release' to match 'get' when obtaining
the buffer
b) change the argument order to have the buffer as first argument
c) add a new argument telling the function if the message was
transferred. This allows the function to be used also in cases
where setting up DMA failed, so the buffer needs to be freed without
syncing to the message buffer.
Also convert the only user.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There aren't any users left. Remove this callback from the 2.4 times.
Phew, finally, that took years to reach...
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
- the core has now a lockless variant of i2c_smbus_xfer. Some open
coded versions of this got removed in drivers. This also enables
proper SCCB support in regmap.
- locking got a more precise naming. i2c_{un}lock_adapter() had to go,
and we know use i2c_lock_bus() consistently with flags like
I2C_LOCK_ROOT_ADAPTER and I2C_LOCK_SEGMENT to avoid ambiguity.
- the gpio fault injector got a new delicate testcase
- the bus recovery procedure got fixed to handle the new testcase
correctly
- a new quirk flag for controllers not able to handle zero length
messages together with driver updates to use it
- new drivers: FSI bus attached I2C masters, GENI I2C controller, Owl
family S900
- and a good set of driver improvements and bugfixes
* 'i2c/for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (77 commits)
i2c: rcar: implement STOP and REP_START according to docs
i2c: rcar: refactor private flags
i2c: core: ACPI: Make acpi_gsb_i2c_read_bytes() check i2c_transfer return value
i2c: core: ACPI: Properly set status byte to 0 for multi-byte writes
dt-bindings: i2c: rcar: Add r8a774a1 support
dt-bindings: i2c: sh_mobile: Add r8a774a1 support
i2c: imx: Simplify stopped state tracking
i2c: imx: Fix race condition in dma read
i2c: pasemi: remove hardcoded bus numbers on smbus
i2c: designware: Add SPDX license tag
i2c: designware: Convert to use struct i2c_timings
i2c: core: Parse SDA hold time from firmware
i2c: designware-pcidrv: Mark expected switch fall-through
i2c: amd8111: Mark expected switch fall-through
i2c: sh_mobile: use core to detect 'no zero length read' quirk
i2c: xlr: use core to detect 'no zero length' quirk
i2c: rcar: use core to detect 'no zero length' quirk
i2c: stu300: use core to detect 'no zero length' quirk
i2c: pmcmsp: use core to detect 'no zero length' quirk
i2c: mxs: use core to detect 'no zero length' quirk
...
There are two drivers already using the SDA hold time setting.
It might be more in the future, thus, make I2C core to parse the setting
for us if provided by firmware.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Some adapters do not support a message length of 0. Add this as a quirk
so drivers don't have to open code it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If an i2c topology has instances of nested muxes, then a lockdep splat
is produced when when i2c_parent_lock_bus() is called. Here is an
example:
============================================
WARNING: possible recursive locking detected
--------------------------------------------
insmod/68159 is trying to acquire lock:
(i2c_register_adapter#2){+.+.}, at: i2c_parent_lock_bus+0x32/0x50 [i2c_mux]
but task is already holding lock:
(i2c_register_adapter#2){+.+.}, at: i2c_parent_lock_bus+0x32/0x50 [i2c_mux]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(i2c_register_adapter#2);
lock(i2c_register_adapter#2);
*** DEADLOCK ***
May be due to missing lock nesting notation
1 lock held by insmod/68159:
#0: (i2c_register_adapter#2){+.+.}, at: i2c_parent_lock_bus+0x32/0x50 [i2c_mux]
stack backtrace:
CPU: 13 PID: 68159 Comm: insmod Tainted: G O
Call Trace:
dump_stack+0x67/0x98
__lock_acquire+0x162e/0x1780
lock_acquire+0xba/0x200
rt_mutex_lock+0x44/0x60
i2c_parent_lock_bus+0x32/0x50 [i2c_mux]
i2c_parent_lock_bus+0x3e/0x50 [i2c_mux]
i2c_smbus_xfer+0xf0/0x700
i2c_smbus_read_byte+0x42/0x70
my2c_init+0xa2/0x1000 [my2c]
do_one_initcall+0x51/0x192
do_init_module+0x62/0x216
load_module+0x20f9/0x2b50
SYSC_init_module+0x19a/0x1c0
SyS_init_module+0xe/0x10
do_syscall_64+0x6c/0x1a0
entry_SYSCALL_64_after_hwframe+0x42/0xb7
Reported-by: John Sperbeck <jsperbeck@google.com>
Tested-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Deepa Dinamani <deepadinamani@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Chang <dpf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Link: http://lkml.kernel.org/r/20180720083914.1950-3-peda@axentia.se
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Shevchenko