kernel.git/include/linux/i2c.h, branch linux-6.10.y

i2c: core: Lock address during client device instantiation

2024-10-10T10:00:46Z

commit 8d3cefaf659265aa82b0373a563fdb9d16a2b947 upstream. 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: Greg Kroah-Hartman

i2c: Use IS_REACHABLE() for substituting empty ACPI functions

2024-09-08T05:56:41Z

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

2024-09-08T05:56:16Z

[ 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 nop fwnode operations

2024-06-21T11:33:17Z

Add nop variants of i2c_find_device_by_fwnode(), i2c_find_adapter_by_fwnode() and i2c_get_adapter_by_fwnode() for use without CONFIG_I2C. Signed-off-by: Sakari Ailus Signed-off-by: Wolfram Sang

i2c: Remove I2C_CLASS_SPD

2024-05-23T11:38:15Z

Remove this class after all users have been gone. Signed-off-by: Heiner Kallweit Signed-off-by: Andi Shyti

i2c: remove redundant condition

2024-03-07T08:36:08Z

I2C_M_RD is defined as and guaranteed to be 1 and 'flag & I2C_M_RD' is one or zero. No need for an additional condition to obtain the value. Signed-off-by: Hsin-Yu.Chen Reviewed-by: Andi Shyti [wsa: slightly updated commit message] Signed-off-by: Wolfram Sang

i2c: constify the struct device_type usage

2024-03-04T13:28:25Z

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver core can properly handle constant struct device_type. Move the i2c_adapter_type and i2c_client_type variables to be constant structures as well, placing it into read-only memory which can not be modified at runtime. Signed-off-by: Ricardo B. Marliere Signed-off-by: Wolfram Sang

i2c: make i2c_bus_type const

2024-01-18T20:10:43Z

Now that the driver core can properly handle constant struct bus_type, move the i2c_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Note, the sound/soc/rockchip/rk3399_gru_sound.c also needed tweaking as it decided to save off a pointer to a bus type for internal stuff, and it was using the i2c_bus_type as well. Signed-off-by: Greg Kroah-Hartman Acked-by: Mark Brown Signed-off-by: Wolfram Sang

i2c: create debugfs entry per adapter

2024-01-18T20:10:41Z

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

include/linux/i2c.h: remove I2C_CLASS_DDC support

2024-01-18T20:10:41Z

After removal of the legacy EEPROM driver and I2C_CLASS_DDC support in olpc_dcon there's no i2c client driver left supporting I2C_CLASS_DDC. Class-based device auto-detection is a legacy mechanism and shouldn't be used in new code. So we can remove this class completely now. Signed-off-by: Heiner Kallweit Signed-off-by: Wolfram Sang