kernel/linux.git/drivers/nvmem/core.c, branch v7.3-rc1

Merge tag 'char-misc-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2026-08-25T16:38:50+00:00

Pull char/misc/IIO/etc driver updates from Greg KH: "Here is the big set of char, misc, iio, counter, fpga, and other small driver subsystems for 7.3-rc1. Overall, due to some driver removals we only added a bit more code than removed, which was a nice change. Highlights in this merge request are: - Loads of IIO driver updates and additions - binder driver updates (more on that below...) - Removal of the SGI XP and GRU drivers as they are not used anymore and turn out to be pretty insecure overall - Removal of the obsolete ibmasm driver as it's not being used anymore - Coresight driver updates and additions - Mei driver udpates - Counter driver updates - FPGA driver updates - ICC driver updates - lots and lots of other tiny driver updates to resolve reported issues All of these have been in linux-next for a while" * tag 'char-misc-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (513 commits) iio: chemical: atlas-sensor: use iio_trigger_poll_nested() to fix remove UAF iio: adc: pac1921: fix wrong channel used in trigger handler read iio: light: gp2ap002: re-enable irq if runtime suspend fails iio: light: gp2ap002: Fix unbalanced runtime PM on repeated event writes iio: light: apds9306: fix PM reference leak in apds9306_read_data() iio: gyro: mpu3050: fix sign of raw angular velocity readings iio: srf04: fix pm_runtime handling on probe error path iio: adc: ad4080: configure backend data size iio: adc: adi-axi-adc: add data size support for AD408X backend iio: chemical: atlas-sensor: fix PM reference leak in buffer postenable iio: dac: ad5446: fix OF module device table iio: light: opt4001: Fix reversed GENMASK() arguments in fault count mask iio: light: opt4001: Reject integration times with a non-zero seconds part iio: light: opt4001: Fix incompatible pointer type passed to div_u64_rem() iio: light: opt4001: Fix power down clearing bits of the wrong register iio: light: opt4060: Fix incorrect register name in threshold read error message iio: light: opt4060: Fix pointer type passed to div_u64_rem() iio: light: opt4060: Reject integration times with a non-zero seconds part iio: light: ltrf216a: fix runtime PM reference leak in error path iio: pressure: dps310: fix NULL pointer dereference on ACPI probe ...

nvmem: simplify nvmem_sysfs_remove_compat()

2026-07-31T12:15:53+00:00

There's no need for the config argument in nvmem_sysfs_remove_compat(). Once the compat attribute is registered, that information is carried in nvmem_device::flags. Rework the code to always query that field and drop the second argument. Signed-off-by: Bartosz Golaszewski Tested-by: Loic Poulain Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260729094647.111468-8-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

nvmem: split out the reg_read/write() callbacks out of struct nvmem_device

2026-07-31T12:15:53+00:00

The reg_read/write() fields of struct nvmem_device point to memory owned by the nvmem provider. They must not be dereferenced after the provider is unregistered. Ahead of protecting against accesses to invalid memory with SRCU, move the callbacks into a separate structure the address of which is stored in nvmem_device. Signed-off-by: Bartosz Golaszewski Tested-by: Loic Poulain Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260729094647.111468-7-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

nvmem: remove unneeded __nvmem_device_put()

2026-07-31T12:15:53+00:00

__nvmem_device_put() is wrapped by nvmem_device_put() but there's no extra functionality offered by the latter so just fold one into the other. There's still the corresponding __nvmem_device_get() so in order to keep things symmetrical: rename it to nvmem_device_match() to better reflect its functionality and not confuse users by its presence in the absence of the similarly prefixed put() counterpart. Signed-off-by: Bartosz Golaszewski Tested-by: Loic Poulain Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260729094647.111468-6-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

nvmem: simplify locking with guard()

2026-07-31T12:15:53+00:00

Use lock guards from cleanup.h to simplify locking. While at it: add the missing mutex.h include. Signed-off-by: Bartosz Golaszewski Tested-by: Loic Poulain Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260729094647.111468-5-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

nvmem: check the return value of gpiod_set_value_cansleep()

2026-07-31T12:15:53+00:00

GPIO setters now return integer values and can indicate failures in lower abstraction layers. Check the return values of gpiod_set_value_cansleep() calls in nvmem core. Reviewed-by: Johan Hovold Signed-off-by: Bartosz Golaszewski Tested-by: Loic Poulain Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260729094647.111468-4-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

nvmem: return -EOPNOTSUPP to in-kernel users on missing callbacks

2026-07-31T12:15:53+00:00

__nvmem_reg_read/write() currently return -EINVAL if the relevant callback is not present. User-space helpers again check the presence of the callbacks to see if they should return -EPERM. Ahead of adding SRCU synchronization: change the error code returned to in-kernel users to -EOPNOTSUPP which is more indicative of the actual reason for the failure. Remove the checks from the sysfs attribute callbacks as these are not visible without the required callbacks. Signed-off-by: Bartosz Golaszewski Tested-by: Loic Poulain Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260729094647.111468-3-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

nvmem: layouts: Add fixed-layout driver

2026-07-31T09:00:13+00:00

Current implementation isn't working well when device tree nodes have a phandle on a fixed-layout nvmem node. As the fixed layout is handled in nvmem core, no driver is ever associated with the layout, and the device consumer driver probe is deferred indefinitely. Remove the specific handling of fixed-layout and add a layout driver. This makes the fixed-layout similar to all other layouts, fixing the whole issue. Fixes: fc29fd821d9a ("nvmem: core: Rework layouts to become regular devices") Cc: stable@vger.kernel.org Reviewed-by: Miquel Raynal Signed-off-by: Mathieu Dubois-Briand Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260724223404.629248-3-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: Default to read-only if wp-gpios present

2026-07-17T12:55:27+00:00

In case the nvmem DT node contains "wp-gpios" DT property, the device currently defaults to read-write and the force_ro sysfs attribute reads 0. Switch to the default read-only, which is both safer, and aligned with eMMC HW BOOT partition force_ro sysfs attribute behavior, which also defaults to read-only. The adjustment of nvmem->read_only value to read-only in case wp-gpios DT property is present must be done only after the device_add() got called because device_add() does internally call nvmem_bin_attr_get_umode(), which configures the permissions of 'nvmem' bin attr based on the value of nvmem->read_only that is only parsed from DT property 'read-only', without any adjustment. This way, if DT property 'read-only' is present, the 'nvmem' attribute is always read-only. Otherwise, if the device is writeable, then 'nvmem' attribute is writeable, and nvmem->read_only defaults to read-only, but can be switched to read-write at runtime via the 'force_ro' attribute. The updated behavior can be tested as follows: Current content: " $ cat /sys/bus/nvmem/devices/logging7/force_ro 1 $ hexdump -C /sys/bus/nvmem/devices/logging7/nvmem 00000000 66 6f 6f 0a ff ff ff ff " Write into default-read-only device: " $ echo bar > /sys/bus/nvmem/devices/logging7/nvmem bash: echo: write error: Operation not permitted $ cat /sys/bus/nvmem/devices/logging7/force_ro 1 " Unlock and write into device: " $ echo 0 > /sys/bus/nvmem/devices/logging7/force_ro $ cat /sys/bus/nvmem/devices/logging7/force_ro 0 $ echo bar > /sys/bus/nvmem/devices/logging7/nvmem $ hexdump -C /sys/bus/nvmem/devices/logging7/nvmem 00000000 62 61 72 0a ff ff ff ff " Relock and write into device, fails because device is read-only again: " $ echo 1 > /sys/bus/nvmem/devices/logging7/force_ro $ echo baz > /sys/bus/nvmem/devices/logging7/nvmem bash: echo: write error: Operation not permitted $ hexdump -C /sys/bus/nvmem/devices/logging7/nvmem 00000000 62 61 72 0a ff ff ff ff " Reviewed-by: Bartosz Golaszewski Signed-off-by: Marek Vasut Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260530205333.117458-4-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: fix use-after-free bugs in error paths

2026-06-05T15:18:58+00:00

Fix several instances of error paths in which we call __nvmem_device_put() - which may end up freeing the underlying memory and other resources - and then keep on using the nvmem structure. Always put the reference to the nvmem device as the last step before returning the error code. Cc: stable@vger.kernel.org Fixes: 7ae6478b304b ("nvmem: core: rework nvmem cell instance creation") Fixes: e888d445ac33 ("nvmem: resolve cells from DT at registration time") Signed-off-by: Bartosz Golaszewski Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260530204340.116743-3-srini@kernel.org Signed-off-by: Greg Kroah-Hartman