linux-stable.git/include/linux/i2c.h, branch v5.15.208

i2c: core: Lock address during client device instantiation

2024-10-17T13:11:43+00:00

[ 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 
Signed-off-by: Heiner Kallweit 
Signed-off-by: Wolfram Sang 
Signed-off-by: Sasha Levin

i2c: create debugfs entry per adapter

2024-10-17T13:11:43+00:00

[ 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 
Signed-off-by: Wolfram Sang 
Stable-dep-of: 8d3cefaf6592 ("i2c: core: Lock address during client device instantiation")
Signed-off-by: Sasha Levin

i2c: Add i2c_get_match_data()

2024-10-17T13:10:49+00:00

[ 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 
Signed-off-by: Biju Das 
[wsa: simplified var initialization]
Signed-off-by: Wolfram Sang 
Stable-dep-of: 119abf7d1815 ("hwmon: (max16065) Fix alarm attributes")
Signed-off-by: Sasha Levin

i2c: Use IS_REACHABLE() for substituting empty ACPI functions

2024-09-12T09:07:42+00:00

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 
Fixes: f17c06c6608a ("i2c: Fix conditional for substituting empty ACPI functions")
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202408141333.gYnaitcV-lkp@intel.com/
Reviewed-by: Takashi Iwai 
Signed-off-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman

i2c: Fix conditional for substituting empty ACPI functions

2024-09-12T09:07:38+00:00

[ 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 
Signed-off-by: Wolfram Sang 
Signed-off-by: Sasha Levin

i2c: add fwnode APIs

2024-07-05T07:14:12+00:00

[ 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 
Signed-off-by: Russell King (Oracle) 
Signed-off-by: Wolfram Sang 
Stable-dep-of: 3f858bbf04db ("i2c: acpi: Unbind mux adapters before delete")
Signed-off-by: Sasha Levin

i2c: acpi: Add an i2c_acpi_client_count() helper function

2021-08-12T15:26:24+00:00

We have 3 files now which have the need to count the number of
I2cSerialBus resources in an ACPI-device's resource-list.

Currently all implement their own helper function for this,
add a generic helper function to replace the 3 implementations.

Signed-off-by: Hans de Goede 
Link: https://lore.kernel.org/r/20210803160044.158802-2-hdegoede@redhat.com
Acked-by: Mika Westerberg 
Acked-by: Wolfram Sang

Merge tag 'staging-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

2021-07-05T21:01:53+00:00

Pull staging / IIO driver updates from Greg KH:
 "Here is the big set of IIO and staging driver patches for 5.14-rc1.

  Loads of IIO driver updates and additions in here, the shortlog has
  the full details.

  For the staging side, we moved a few drivers out of staging, and
  deleted the kpc2000 drivers as the original developer asked us to
  because no one was working on them anymore.

  Also in here are loads of coding style cleanups due to different
  intern projects focusing on the staging tree to try to get experience
  doing kernel development.

  All of these have been in the linux-next tree for a while with no
  reported problems"

* tag 'staging-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (744 commits)
  staging: hi6421-spmi-pmic: cleanup some macros
  staging: hi6421-spmi-pmic: change identation of a table
  staging: hi6421-spmi-pmic: change a return code
  staging: hi6421-spmi-pmic: better name IRQs
  staging: hi6421-spmi-pmic: use devm_request_threaded_irq()
  staging: hisilicon,hi6421-spmi-pmic.yaml: cleanup descriptions
  spmi: hisi-spmi-controller: move driver from staging
  phy: phy-hi3670-usb3: move driver from staging into phy
  staging: rtl8188eu: remove include/rtw_debug.h header
  staging: rtl8188eu: remove GlobalDebugLevel variable
  staging: rtl8188eu: remove DRIVER_PREFIX preprocessor definition
  staging: rtl8188eu: remove RT_TRACE macro
  staging: rtl8188eu: remove all RT_TRACE calls from hal/rtl8188eu_recv.c
  staging: rtl8188eu: remove all RT_TRACE calls from hal/hal_intf.c
  staging: rtl8188eu: remove all RT_TRACE calls from hal/rtl8188eu_xmit.c
  staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_xmit.c
  staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_pwrctrl.c
  staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_recv.c
  staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_ioctl_set.c
  staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_ieee80211.c
  ...

i2c: core-smbus: Expose PEC calculate function for generic use

2021-06-25T15:09:34+00:00

Expose the PEC calculation i2c_smbus_pec() for generic use.

Signed-off-by: Quan Nguyen 
Acked-by: Matt Johnston 
Signed-off-by: Wolfram Sang

i2c: core: Add stub for i2c_verify_client() if !CONFIG_I2C

2021-06-07T08:19:21+00:00

If I2C is not compiled, there is no way we should see a call to
i2c_verify_client() on a device that is an i2c client. As such,
provide a stub to return NULL to resolve an associated build failure.

The build is failing with this link error
ld: fxls8962af-core.o: in function `fxls8962af_fifo_transfer':
fxls8962af-core.c: undefined reference to `i2c_verify_client'

Reported-by: Tom Rix 
Signed-off-by: Jonathan Cameron 
Fixes: af959b7b96b8 ("iio: accel: fxls8962af: fix errata bug E3 - I2C burst reads")
Reviewed-by: Sean Nyekjaer 
Acked-by: Wolfram Sang 
Link: https://lore.kernel.org/r/20210603165835.3594557-1-jic23@kernel.org