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2020-06-24i2c: add newly exported functions to the header, tooWolfram Sang
commit 550113d4e9f5c7b62be760fc01178c9e0139c1f4 upstream. Nobody (including me) noticed that these functions were exported but not added to the header :/ Fixes: 7159dbdae3c5 ("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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-06-08i2c: fix missing pm_runtime_put_sync in i2c_device_probeAlain Volmat
commit 3c3dd56f760da056e821ac177e3ad0de4209a435 upstream. In case of the I2C client exposes the flag I2C_CLIENT_HOST_NOTIFY, pm_runtime_get_sync is called in order to always keep active the adapter. However later on, pm_runtime_put_sync is never called within the function in case of an error. This commit add this error handling. Fixes: 72bfcee11cf8 ("i2c: Prevent runtime suspend of adapter when Host Notify is required") Signed-off-by: Alain Volmat <alain.volmat@st.com> Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-03-30i2c: fix bus recovery stop mode timingRussell King
commit cf8ce8b80f8bf9669f6ec4e71e16668430febdac upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157Thomas Gleixner
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>
2019-05-17i2c: core: add device-managed version of i2c_new_dummyHeiner Kallweit
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>
2019-05-17i2c: core: improve return value handling of i2c_new_device and i2c_new_dummyHeiner Kallweit
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>
2019-05-09Merge branch 'i2c/for-5.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 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 ...
2019-05-03Merge branch 'i2c/for-current-fixed' of ↵Linus Torvalds
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux 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
2019-05-03i2c: core: apply 'is_suspended' check for SMBus, tooWolfram Sang
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 <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>
2019-05-03i2c: core: ratelimit 'transfer when suspended' errorsWolfram Sang
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: 9ac6cb5fbb17 ("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+
2019-05-02i2c: Prevent runtime suspend of adapter when Host Notify is requiredJarkko Nikula
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 c5eb1190074c ("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: c5eb1190074c ("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>
2019-05-01gcc-9: don't warn about uninitialized variableLinus Torvalds
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>
2019-04-16i2c: core: introduce callbacks for atomic transfersWolfram Sang
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>
2019-04-16i2c: core: use I2C locking behaviour also for SMBUSWolfram Sang
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>
2019-04-16i2c: core: remove use of in_atomic()Wolfram Sang
Commit cea443a81c9c ("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 b7a3670131c7 ("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>
2019-03-13i2c: add extra check to safe DMA buffer helperWolfram Sang
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: e94bc5d18be0 ("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>
2019-02-24i2c: Allow recovery of the initial IRQ by an I2C client device.Jim Broadus
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: 6f108dd70d30 ("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>
2019-01-08i2c: add suspended flag and accessors for i2c adaptersWolfram Sang
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>
2018-10-31i2c: Clear client->irq in i2c_device_removeCharles Keepax
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>
2018-10-31i2c: Remove unnecessary call to irq_find_mappingCharles Keepax
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>
2018-10-29Merge branch 'i2c/for-4.20' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 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 ...
2018-10-11i2c: Fix kerneldoc for renamed i2c dma put functionStephen Boyd
This function was renamed in commit 82fe39a6bc7b ("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: 82fe39a6bc7b ("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>
2018-10-05i2c: core: remove level of indentation in i2c_transferWolfram Sang
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>
2018-10-05i2c: core: remove outdated DEBUG outputWolfram Sang
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>
2018-08-30i2c: refactor function to release a DMA safe bufferWolfram Sang
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>
2018-08-24i2c: remove deprecated attach_adapter callbackWolfram Sang
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>
2018-08-21Merge branch 'i2c/for-4.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 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 ...
2018-08-08i2c: core: Parse SDA hold time from firmwareAndy Shevchenko
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>
2018-08-04i2c: quirks: add zero length checksWolfram Sang
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>
2018-07-25i2c/mux, locking/core: Annotate the nested rt_mutex usagePeter Rosin
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>
2018-07-21i2c: recovery: make pin init look like STOPWolfram Sang
When we initialize the pins, make sure it looks like STOP by dividing the delay into halves. It shouldn't matter because SDA is expected to be held low by a device, but for super-safety, let's do it. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-17i2c: recovery: rename variable for easier understandingWolfram Sang
While refactoring the routine before, it occurred to me that this will make the code much easier to understand. 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>
2018-07-17i2c: recovery: add get_bus_free callbackWolfram Sang
Some IP cores have an internal 'bus free' logic which may be more advanced than just checking if SDA is high. Add a separate callback to get this status. Filling it is optional. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-17i2c: recovery: refactor recovery functionWolfram Sang
After exiting the while loop, we checked if recovery was successful and sent a STOP to the clients. Meanwhile however, we send a STOP after every pulse, so it is not needed after the loop. If we move the check for a free bus to the end of the while loop, we can shorten and simplify the logic. It is still ensured that at least one STOP will be sent to the wire even if SDA was not stuck low. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-17i2c: recovery: require either get_sda or set_sdaWolfram Sang
For bus recovery, we either need to bail out early if we can read SDA or we need to send STOP after every pulse. Otherwise recovery might be misinterpreted as an unwanted write. So, require one of those SDA handling functions to avoid this problem. 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>
2018-07-12i2c: recovery: if possible send STOP with recovery pulsesWolfram Sang
I2C clients may misunderstand recovery pulses if they can't read SDA to bail out early. In the worst case, as a write operation. To avoid that and if we can write SDA, try to send STOP to avoid the misinterpretation. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
2018-06-14Merge branch 'i2c/for-4.18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: - mainly feature additions to drivers (stm32f7, qup, xlp9xx, mlxcpld, ...) - conversion to use the i2c_8bit_addr_from_msg macro consistently - move includes to platform_data - core updates to allow the (still in review) I3C subsystem to connect - and the regular share of smaller driver updates * 'i2c/for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (68 commits) i2c: qup: fix building without CONFIG_ACPI i2c: tegra: Remove suspend-resume i2c: imx-lpi2c: Switch to SPDX identifier i2c: mxs: Switch to SPDX identifier i2c: busses: make use of i2c_8bit_addr_from_msg i2c: algos: make use of i2c_8bit_addr_from_msg i2c: rcar: document R8A77980 bindings i2c: qup: Add command-line parameter to override SCL frequency i2c: qup: Correct duty cycle for FM and FM+ i2c: qup: Add support for Fast Mode Plus i2c: qup: add probe path for Centriq ACPI devices i2c: robotfuzz-osif: drop pointless test i2c: robotfuzz-osif: remove pointless local variable i2c: rk3x: Don't print visible virtual mapping MMIO address i2c: opal: don't check number of messages in the driver i2c: ibm_iic: don't check number of messages in the driver i2c: imx: Switch to SPDX identifier i2c: mux: pca954x: merge calls to of_match_device and of_device_get_match_data i2c: mux: demux-pinctrl: use proper parent device for demux adapter i2c: mux: improve error message for failed symlink ...
2018-05-22i2c: Retain info->of_node in i2c_new_device()Boris Brezillon
Currently, of_i2c_register_devices() is responsible for retaining info->of_node, but we're about to expose a function to parse I2C board info without registering the I2C device. We could possibly let this function retain ->of_node, but this approach is prone to reference leak since people will have to remember to call of_node_put() if something goes wrong between the OF node parsing and the registration step. Let's just retain the ->of_node in i2c_new_register() instead. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-15i2c: Get rid of i2c_board_info->archdataBoris Brezillon
The only user of i2c_board_info->archdata is the OF parsing code and it just pass a zero-initialized object which has the same effect as leaving ->archdata to NULL since the client object is allocated with kzalloc(). Get rid of this useless field. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-14i2c: Respect all error codes from dev_pm_domain_attach()Ulf Hansson
The limitation of being able to check only for -EPROBE_DEFER from dev_pm_domain_attach() has been removed. Hence let's respect all error codes and bail out accordingly. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-11i2c: add param sanity check to i2c_transfer()Ard Biesheuvel
The API docs describe i2c_transfer() as taking a pointer to an array of i2c_msg containing at least 1 entry, but leaves it to the individual drivers to sanity check the msgs and num parameters. Let's do this in core code instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [wsa: changed '<= 0' to '< 1'] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-03i2c: Update i2c_trace_msg static key to modern apiDavidlohr Bueso
No changes in refcount semantics -- key init is false; replace static_key_slow_inc|dec with static_branch_inc|dec static_key_false with static_branch_unlikely Added a '_key' suffix to i2c_trace_msg, for better self documentation. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-03i2c: fix parameter of trace_i2c_resultAhbong Chang
According to the event i2c_result defined in include/trace/events/i2c.h, the second parameter should be the number of messages instead of the ended loop index. The value of ended loop index is the same as ret. Signed-off-by: Ahbong Chang <cwahbong@google.com> Reviewed-by: Todd Poynor <toddpoynor@google.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24i2c: make i2c_check_addr_validity() staticWolfram Sang
After previous refactoring, there is only one user in the same file left. Make the function static now. [wsa: added 'int' to bare 'unsigned'] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-17Merge branch 'i2c-mux/for-next' of https://github.com/peda-r/i2c-mux into ↵Wolfram Sang
i2c/for-4.17 "These patches verify the device id of the PCA984x mux chips using standardized (but rarely implemented) i2c device identification."
2018-03-06i2c: add i2c_get_device_id() to get the standard i2c device idPeter Rosin
Can be used during probe to double check that the probed device is what is expected. Loosely based on code from Adrian Fiergolski <adrian.fiergolski@cern.ch>. Tested-by: Adrian Fiergolski <adrian.fiergolski@cern.ch> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Peter Rosin <peda@axentia.se>
2018-03-05i2c: core: report OF style module alias for devices registered via OFJavier Martinez Canillas
The buses should honor the firmware interface used to register the device, but the I2C core reports a MODALIAS of the form i2c:<device> even for I2C devices registered via OF. This means that user-space will never get an OF stype uevent MODALIAS even when the drivers modules contain aliases exported from both the I2C and OF device ID tables. For example, an Atmel maXTouch Touchscreen registered by a DT node with compatible "atmel,maxtouch" has the following module alias: $ cat /sys/class/i2c-adapter/i2c-8/8-004b/modalias i2c:maxtouch So udev won't be able to auto-load a module for an OF-only device driver. Many OF-only drivers duplicate the OF device ID table entries in an I2C ID table only has a workaround for how the I2C core reports the module alias. This patch changes the I2C core to report an OF related MODALIAS uevent if the device was registered via OF. So for the previous example, after this patch, the reported MODALIAS for the Atmel maXTouch will be the following: $ cat /sys/class/i2c-adapter/i2c-8/8-004b/modalias of:NtrackpadT<NULL>Catmel,maxtouch NOTE: This patch may break out-of-tree drivers that were relying on this behavior, and only had an I2C device ID table even when the device was registered via OF. There are no remaining drivers in mainline that do this, but out-of-tree drivers have to be fixed and define a proper OF device ID table to have module auto-loading working. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Tested-by: Dmitry Mastykin <mastichi@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-02-04Merge branch 'i2c/for-4.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "I2C has the following changes for you: - new flag to mark DMA safe buffers in i2c_msg. Also, some infrastructure around it. And docs. - huge refactoring of the at24 driver led by the new maintainer Bartosz - update I2C bus recovery to send STOP after recovery - conversion from gpio to gpiod for I2C bus recovery - adding a fault-injector to the i2c-gpio driver - lots of small driver improvements, and bigger ones to i2c-sh_mobile" * 'i2c/for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (99 commits) i2c: mv64xxx: Add myself as maintainer for this driver i2c: mv64xxx: Fix clock resource by adding an optional bus clock i2c: mv64xxx: Remove useless test before clk_disable_unprepare i2c: mxs: use true and false for boolean values i2c: meson: update doc description to fix build warnings i2c: meson: add configurable divider factors dt-bindings: i2c: update documentation for the Meson-AXG i2c: imx-lpi2c: add runtime pm support i2c: rcar: fix some trivial typos in comments i2c: davinci: fix the cpufreq transition i2c: rk3x: add proper kerneldoc header i2c: rk3x: account for const type of of_device_id.data i2c: acorn: remove outdated path from file header i2c: acorn: add MODULE_LICENSE tag i2c: rcar: implement bus recovery i2c: send STOP after successful bus recovery i2c: ensure SDA is released in recovery if SDA is controllable i2c: add 'set_sda' to bus_recovery_info i2c: add identifier in declarations for i2c_bus_recovery i2c: make kerneldoc about bus recovery more precise ...
2018-01-17i2c: core: decrease reference count of device node in i2c_unregister_deviceLixin Wang
Reference count of device node was increased in of_i2c_register_device, but without decreasing it in i2c_unregister_device. Then the added device node will never be released. Fix this by adding the of_node_put. Signed-off-by: Lixin Wang <alan.1.wang@nokia-sbell.com> Tested-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
2018-01-16i2c: send STOP after successful bus recoveryWolfram Sang
If we managed to get a client release SDA again, send a STOP afterwards to make sure we have a consistent state on the bus again. Tested-by: Phil Reid <preid@electromag.com.au> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>