linux-stable.git/include/linux/i2c.h, branch v6.1.172 Linux kernel stable tree i2c: core: Lock address during client device instantiation 2024-10-17T13:22:04+00:00 Heiner Kallweit hkallweit1@gmail.com 2024-08-15T19:44:50+00:00 e2852a02469f4928023c280141312589d64506d5 [ Upstream commit 8d3cefaf659265aa82b0373a563fdb9d16a2b947 ] Krzysztof reported an issue [0] which is caused by parallel attempts to instantiate the same I2C client device. This can happen if driver supports auto-detection, but certain devices are also instantiated explicitly. The original change isn't actually wrong, it just revealed that I2C core isn't prepared yet to handle this scenario. Calls to i2c_new_client_device() can be nested, therefore we can't use a simple mutex here. Parallel instantiation of devices at different addresses is ok, so we just have to prevent parallel instantiation at the same address. We can use a bitmap with one bit per 7-bit I2C client address, and atomic bit operations to set/check/clear bits. Now a parallel attempt to instantiate a device at the same address will result in -EBUSY being returned, avoiding the "sysfs: cannot create duplicate filename" splash. Note: This patch version includes small cosmetic changes to the Tested-by version, only functional change is that address locking is supported for slave addresses too. [0] https://lore.kernel.org/linux-i2c/9479fe4e-eb0c-407e-84c0-bd60c15baf74@ans.pl/T/#m12706546e8e2414d8f1a0dc61c53393f731685cc Fixes: caba40ec3531 ("eeprom: at24: Probe for DDR3 thermal sensor in the SPD case") Cc: stable@vger.kernel.org Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8d3cefaf659265aa82b0373a563fdb9d16a2b947 ]

Krzysztof reported an issue [0] which is caused by parallel attempts to
instantiate the same I2C client device. This can happen if driver
supports auto-detection, but certain devices are also instantiated
explicitly.
The original change isn't actually wrong, it just revealed that I2C core
isn't prepared yet to handle this scenario.
Calls to i2c_new_client_device() can be nested, therefore we can't use a
simple mutex here. Parallel instantiation of devices at different addresses
is ok, so we just have to prevent parallel instantiation at the same address.
We can use a bitmap with one bit per 7-bit I2C client address, and atomic
bit operations to set/check/clear bits.
Now a parallel attempt to instantiate a device at the same address will
result in -EBUSY being returned, avoiding the "sysfs: cannot create duplicate
filename" splash.

Note: This patch version includes small cosmetic changes to the Tested-by
      version, only functional change is that address locking is supported
      for slave addresses too.

[0] https://lore.kernel.org/linux-i2c/9479fe4e-eb0c-407e-84c0-bd60c15baf74@ans.pl/T/#m12706546e8e2414d8f1a0dc61c53393f731685cc

Fixes: caba40ec3531 ("eeprom: at24: Probe for DDR3 thermal sensor in the SPD case")
Cc: stable@vger.kernel.org
Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: create debugfs entry per adapter 2024-10-17T13:22:03+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2023-11-12T22:54:41+00:00 e2a268b0f512fb18ae5961b1fdfaf610ed6bd661 [ Upstream commit 73febd775bdbdb98c81255ff85773ac410ded5c4 ] Two drivers already implement custom debugfs handling for their i2c_adapter and more will come. So, let the core create a debugfs directory per adapter and pass that to drivers for their debugfs files. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@kernel.org> Stable-dep-of: 8d3cefaf6592 ("i2c: core: Lock address during client device instantiation") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 73febd775bdbdb98c81255ff85773ac410ded5c4 ]

Two drivers already implement custom debugfs handling for their
i2c_adapter and more will come. So, let the core create a debugfs
directory per adapter and pass that to drivers for their debugfs files.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Stable-dep-of: 8d3cefaf6592 ("i2c: core: Lock address during client device instantiation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: Add i2c_get_match_data() 2024-10-17T13:20:48+00:00 Biju Das biju.das.jz@bp.renesas.com 2023-06-07T16:57:38+00:00 3ff59f75a9cb2034bd50989fa1c5124a6d945860 [ Upstream commit 564d73c4d9201526bd976b9379d2aaf1a7133e84 ] Add i2c_get_match_data() to get match data for I2C, ACPI and DT-based matching, so that we can optimize the driver code. Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> [wsa: simplified var initialization] Signed-off-by: Wolfram Sang <wsa@kernel.org> Stable-dep-of: 119abf7d1815 ("hwmon: (max16065) Fix alarm attributes") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 564d73c4d9201526bd976b9379d2aaf1a7133e84 ]

Add i2c_get_match_data() to get match data for I2C, ACPI and
DT-based matching, so that we can optimize the driver code.

Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
[wsa: simplified var initialization]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Stable-dep-of: 119abf7d1815 ("hwmon: (max16065) Fix alarm attributes")
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: Use IS_REACHABLE() for substituting empty ACPI functions 2024-09-08T05:53:13+00:00 Richard Fitzgerald rf@opensource.cirrus.com 2024-08-14T12:16:49+00:00 27b3111f450c6ce9957bce749063ca8c7aa88d8a commit 71833e79a42178d8a50b5081c98c78ace9325628 upstream. Replace IS_ENABLED() with IS_REACHABLE() to substitute empty stubs for: i2c_acpi_get_i2c_resource() i2c_acpi_client_count() i2c_acpi_find_bus_speed() i2c_acpi_new_device_by_fwnode() i2c_adapter *i2c_acpi_find_adapter_by_handle() i2c_acpi_waive_d0_probe() commit f17c06c6608a ("i2c: Fix conditional for substituting empty ACPI functions") partially fixed this conditional to depend on CONFIG_I2C, but used IS_ENABLED(), which is wrong since CONFIG_I2C is tristate. CONFIG_ACPI is boolean but let's also change it to use IS_REACHABLE() to future-proof it against becoming tristate. Somehow despite testing various combinations of CONFIG_I2C and CONFIG_ACPI we missed the combination CONFIG_I2C=m, CONFIG_ACPI=y. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Fixes: f17c06c6608a ("i2c: Fix conditional for substituting empty ACPI functions") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202408141333.gYnaitcV-lkp@intel.com/ Reviewed-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 71833e79a42178d8a50b5081c98c78ace9325628 upstream.

Replace IS_ENABLED() with IS_REACHABLE() to substitute empty stubs for:
    i2c_acpi_get_i2c_resource()
    i2c_acpi_client_count()
    i2c_acpi_find_bus_speed()
    i2c_acpi_new_device_by_fwnode()
    i2c_adapter *i2c_acpi_find_adapter_by_handle()
    i2c_acpi_waive_d0_probe()

commit f17c06c6608a ("i2c: Fix conditional for substituting empty ACPI
functions") partially fixed this conditional to depend on CONFIG_I2C,
but used IS_ENABLED(), which is wrong since CONFIG_I2C is tristate.

CONFIG_ACPI is boolean but let's also change it to use IS_REACHABLE()
to future-proof it against becoming tristate.

Somehow despite testing various combinations of CONFIG_I2C and CONFIG_ACPI
we missed the combination CONFIG_I2C=m, CONFIG_ACPI=y.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Fixes: f17c06c6608a ("i2c: Fix conditional for substituting empty ACPI functions")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202408141333.gYnaitcV-lkp@intel.com/
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: Fix conditional for substituting empty ACPI functions 2024-09-08T05:52:59+00:00 Richard Fitzgerald rf@opensource.cirrus.com 2024-08-02T15:22:14+00:00 689e48ab87cdc16523030832cdb22eae8d1bc4a8 [ Upstream commit f17c06c6608ad4ecd2ccf321753fb511812d821b ] Add IS_ENABLED(CONFIG_I2C) to the conditional around a bunch of ACPI functions. The conditional around these functions depended only on CONFIG_ACPI. But the functions are implemented in I2C core, so are only present if CONFIG_I2C is enabled. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f17c06c6608ad4ecd2ccf321753fb511812d821b ]

Add IS_ENABLED(CONFIG_I2C) to the conditional around a bunch of ACPI
functions.

The conditional around these functions depended only on CONFIG_ACPI.
But the functions are implemented in I2C core, so are only present if
CONFIG_I2C is enabled.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: add fwnode APIs 2024-06-21T12:35:40+00:00 Russell King (Oracle) rmk+kernel@armlinux.org.uk 2023-01-11T10:54:21+00:00 ef1e9b624d99b9dc48c33bf5404e4f046de3d9c9 [ Upstream commit 373c612d72461ddaea223592df31e62c934aae61 ] Add fwnode APIs for finding and getting I2C adapters, which will be used by the SFP code. These are passed the fwnode corresponding to the adapter, and return the I2C adapter. It is the responsibility of the caller to find the appropriate fwnode. We keep the DT and ACPI interfaces, but where appropriate, recode them to use the fwnode interfaces internally. Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Wolfram Sang <wsa@kernel.org> Stable-dep-of: 3f858bbf04db ("i2c: acpi: Unbind mux adapters before delete") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 373c612d72461ddaea223592df31e62c934aae61 ]

Add fwnode APIs for finding and getting I2C adapters, which will be
used by the SFP code. These are passed the fwnode corresponding to
the adapter, and return the I2C adapter. It is the responsibility of
the caller to find the appropriate fwnode.

We keep the DT and ACPI interfaces, but where appropriate, recode them
to use the fwnode interfaces internally.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Stable-dep-of: 3f858bbf04db ("i2c: acpi: Unbind mux adapters before delete")
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: Make remove callback return void 2022-08-16T10:46:26+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2022-08-15T08:02:30+00:00 ed5c2f5fd10dda07263f79f338a512c0f49f76f5 The value returned by an i2c driver's remove function is mostly ignored. (Only an error message is printed if the value is non-zero that the error is ignored.) So change the prototype of the remove function to return no value. This way driver authors are not tempted to assume that passing an error to the upper layer is a good idea. All drivers are adapted accordingly. There is no intended change of behaviour, all callbacks were prepared to return 0 before. Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com> Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au> Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Crt Mori <cmo@melexis.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013 Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/* Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5 Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860 Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power Acked-by: Krzysztof Hałasa <khalasa@piap.pl> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Wolfram Sang <wsa@kernel.org> 
The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
i2c: extend documentation about retvals of master_xfer functions 2022-07-26T21:13:36+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2022-07-24T18:46:28+00:00 a11821495fd4d9b5c97945db929e02c473b7a5d9 It was stated how the error codes should be. It was not stated what the regular case should return. Add this. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@kernel.org> 
It was stated how the error codes should be. It was not stated what the
regular case should return. Add this.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
i2c: add tracepoints for I2C slave events 2022-03-19T23:11:05+00:00 Jae Hyun Yoo quic_jaehyoo@quicinc.com 2022-03-18T20:41:33+00:00 d714fb25e755ad96b699993fac47f48c4d6cebe9 I2C slave events tracepoints can be enabled by: echo 1 > /sys/kernel/tracing/events/i2c_slave/enable and logs in /sys/kernel/tracing/trace will look like: ... i2c_slave: i2c-0 a=010 ret=0 WR_REQ [] ... i2c_slave: i2c-0 a=010 ret=0 WR_RCV [02] ... i2c_slave: i2c-0 a=010 ret=0 WR_RCV [0c] ... i2c_slave: i2c-0 a=010 ret=0 STOP [] ... i2c_slave: i2c-0 a=010 ret=0 RD_REQ [04] ... i2c_slave: i2c-0 a=010 ret=0 RD_PRO [b4] ... i2c_slave: i2c-0 a=010 ret=0 STOP [] formatted as: i2c-<adapter_nr> a=<addr> ret=<ret> <- callback return value <event> [<data>] trace printings can be selected by adding a filter like: echo adapter_nr==1 >/sys/kernel/tracing/events/i2c_slave/filter Signed-off-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com> Signed-off-by: Wolfram Sang <wsa@kernel.org> 
I2C slave events tracepoints can be enabled by:

	echo 1 > /sys/kernel/tracing/events/i2c_slave/enable

and logs in /sys/kernel/tracing/trace will look like:

	... i2c_slave: i2c-0 a=010 ret=0 WR_REQ []
	... i2c_slave: i2c-0 a=010 ret=0 WR_RCV [02]
	... i2c_slave: i2c-0 a=010 ret=0 WR_RCV [0c]
	... i2c_slave: i2c-0 a=010 ret=0   STOP []
	... i2c_slave: i2c-0 a=010 ret=0 RD_REQ [04]
	... i2c_slave: i2c-0 a=010 ret=0 RD_PRO [b4]
	... i2c_slave: i2c-0 a=010 ret=0  STOP []

formatted as:

	i2c-<adapter_nr>
	a=<addr>
	ret=<ret>	<- callback return value
	<event>
	[<data>]

trace printings can be selected by adding a filter like:

	echo adapter_nr==1 >/sys/kernel/tracing/events/i2c_slave/filter

Signed-off-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
i2c: acpi: Add i2c_acpi_new_device_by_fwnode() function 2021-12-13T10:44:47+00:00 Hans de Goede hdegoede@redhat.com 2021-12-03T10:28:46+00:00 c537be0bfad6337f2afd618fe252c03217191405 Change i2c_acpi_new_device() into i2c_acpi_new_device_by_fwnode() and add a static inline wrapper providing the old i2c_acpi_new_device() behavior. This is necessary because in some cases we may only have access to the fwnode / acpi_device and not to the matching physical-node struct device *. Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20211203102857.44539-4-hdegoede@redhat.com 
Change i2c_acpi_new_device() into i2c_acpi_new_device_by_fwnode() and
add a static inline wrapper providing the old i2c_acpi_new_device()
behavior.

This is necessary because in some cases we may only have access
to the fwnode / acpi_device and not to the matching physical-node
struct device *.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211203102857.44539-4-hdegoede@redhat.com