In all cases in which a struct acpi_driver is used for binding a driver
to an ACPI device object, a corresponding platform device is created by
the ACPI core and that device is regarded as a proper representation of
underlying hardware. Accordingly, a struct platform_driver should be
used by driver code to bind to that device. There are multiple reasons
why drivers should not bind directly to ACPI device objects [1].
Overall, it is better to bind drivers to platform devices than to their
ACPI companions, so convert the Apple Backlight ACPI driver to a
platform one.
While this is not expected to alter functionality, it changes sysfs
layout and so it will be visible to user space.
Link: https://lore.kernel.org/all/2396510.ElGaqSPkdT@rafael.j.wysocki/ [1]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
Link: https://patch.msgid.link/5084777.GXAFRqVoOG@rafael.j.wysocki
Signed-off-by: Lee Jones <lee@kernel.org>
The devm_gpiod_get_optional() function may return an ERR_PTR in case of
genuine GPIO acquisition errors, not just NULL which indicates the
legitimate absence of an optional GPIO.
Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On
error, return the error code to ensure proper failure handling rather
than proceeding with invalid pointers.
Fixes: e1915eec54 ("backlight: sky81452: Convert to GPIO descriptors")
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
Link: https://patch.msgid.link/20260203021625.578678-1-nichen@iscas.ac.cn
Signed-off-by: Lee Jones <lee@kernel.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
The driver uses GPIO descriptor API (devm_gpiod_get,
gpiod_set_value_cansleep, GPIOD_OUT_LOW) but includes the legacy
<linux/gpio.h> header instead of <linux/gpio/consumer.h>.
When CONFIG_GPIOLIB is not set, <linux/gpio.h> does not include
<linux/gpio/consumer.h>, causing build errors:
error: implicit declaration of function 'gpiod_set_value_cansleep'
error: implicit declaration of function 'devm_gpiod_get'
error: 'GPIOD_OUT_LOW' undeclared
Fix by including the correct header <linux/gpio/consumer.h>.
Fixes: 147b38a5ad ("backlight: aw99706: Add support for Awinic AW99706 backlight")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202512171631.uKXlYwqu-lkp@intel.com/
Signed-off-by: Junjie Cao <junjie.cao@intel.com>
Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
Link: https://patch.msgid.link/20260111130117.5041-1-junjie.cao@intel.com
Signed-off-by: Lee Jones <lee@kernel.org>
When building for a platform without CONFIG_PM_SLEEP, such as s390,
there are two unused function warnings:
drivers/video/backlight/aw99706.c:436:12: error: 'aw99706_resume' defined but not used [-Werror=unused-function]
436 | static int aw99706_resume(struct device *dev)
| ^~~~~~~~~~~~~~
drivers/video/backlight/aw99706.c:429:12: error: 'aw99706_suspend' defined but not used [-Werror=unused-function]
429 | static int aw99706_suspend(struct device *dev)
| ^~~~~~~~~~~~~~~
SET_SYSTEM_SLEEP_PM_OPS, used within SIMPLE_DEV_PM_OPS, expands to
nothing when CONFIG_PM_SLEEP is not set, so these functions are
completely unused in this configuration.
SIMPLE_DEV_PM_OPS is deprecated in favor of DEFINE_SIMPLE_DEV_PM_OPS,
which avoids this issue by using pm_sleep_ptr to make these callbacks
NULL when CONFIG_PM_SLEEP is unset while making the callback functions
always appear used to the compiler regardless of configuration. Switch
to DEFINE_SIMPLE_DEV_PM_OPS for aw99706_pm_ops to clear up the warning.
Additionally, wrap the pointer to aw99706_pm_ops in pm_ptr() in
aw99706_i2c_driver to ensure that the structure is completely eliminated
in configurations without CONFIG_PM.
Fixes: 88a8e9b49ee8 ("backlight: aw99706: Add support for Awinic AW99706 backlight")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20251120-backlight-aw99706-fix-unused-pm-functions-v1-1-8b9c17c4e783@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
LED Backlight is a consumer of one or multiple LED class devices, but
devlink is currently unable to create correct supplier-producer links when
the supplier is a class device. It creates instead a link where the
supplier is the parent of the expected device.
One consequence is that removal order is not correctly enforced.
Issues happen for example with the following sections in a device tree
overlay:
// An LED driver chip
pca9632@62 {
compatible = "nxp,pca9632";
reg = <0x62>;
// ...
addon_led_pwm: led-pwm@3 {
reg = <3>;
label = "addon:led:pwm";
};
};
backlight-addon {
compatible = "led-backlight";
leds = <&addon_led_pwm>;
brightness-levels = <255>;
default-brightness-level = <255>;
};
In this example, the devlink should be created between the backlight-addon
(consumer) and the pca9632@62 (supplier). Instead it is created between the
backlight-addon (consumer) and the parent of the pca9632@62, which is
typically the I2C bus adapter.
On removal of the above overlay, the LED driver can be removed before the
backlight device, resulting in:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
...
Call trace:
led_put+0xe0/0x140
devm_led_release+0x6c/0x98
Another way to reproduce the bug without any device tree overlays is
unbinding the LED class device (pca9632@62) before unbinding the consumer
(backlight-addon):
echo 11-0062 >/sys/bus/i2c/drivers/leds-pca963x/unbind
echo ...backlight-dock >/sys/bus/platform/drivers/led-backlight/unbind
Fix by adding a devlink between the consuming led-backlight device and the
supplying LED device, as other drivers and subsystems do as well.
Fixes: ae232e45ac ("backlight: add led-backlight driver")
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
Reviewed-by: Herve Codina <herve.codina@bootlin.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://patch.msgid.link/20250519-led-backlight-add-devlink-to-supplier-class-device-v6-1-845224aeb2ce@bootlin.com
Signed-off-by: Lee Jones <lee@kernel.org>
