linux-toradex.git/drivers/video/backlight, branch v6.19

backlight: aw99706: Fix unused function warnings from suspend/resume ops

2025-11-27T08:34:21+00:00

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 
Link: https://patch.msgid.link/20251120-backlight-aw99706-fix-unused-pm-functions-v1-1-8b9c17c4e783@kernel.org
Signed-off-by: Lee Jones

backlight: aw99706: Add support for Awinic AW99706 backlight

2025-11-25T12:54:14+00:00

Add support for Awinic AW99706 backlight, which can be found in
tablet and notebook backlight, one case is the Lenovo Legion Y700
Gen4. This driver refers to the official datasheets and android
driver, they can be found in [1].

[1] https://www.awinic.com/en/productDetail/AW99706QNR

Signed-off-by: Junjie Cao 
Tested-by: Pengyu Luo 
Signed-off-by: Pengyu Luo 
Reviewed-by: Daniel Thompson (RISCstar) 
Link: https://patch.msgid.link/20251109032240.3422503-3-caojunjie650@gmail.com
Signed-off-by: Lee Jones

backlight: led-bl: Add devlink to supplier LEDs

2025-11-25T12:54:10+00:00

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: ae232e45acf9 ("backlight: add led-backlight driver")
Signed-off-by: Luca Ceresoli 
Reviewed-by: Daniel Thompson (RISCstar) 
Reviewed-by: Herve Codina 
Tested-by: Alexander Sverdlin 
Link: https://patch.msgid.link/20250519-led-backlight-add-devlink-to-supplier-class-device-v6-1-845224aeb2ce@bootlin.com
Signed-off-by: Lee Jones

backlight: ktd2801: Depend on GPIOLIB

2025-11-06T16:56:01+00:00

The LEDS_EXPRESSWIRE library used by the driver requires GPIOLIB. Make
sure this dependency is not left unsatisfied.

Reported-by: Randy Dunlap 
Closes: https://lore.kernel.org/all/b6c481bb-e854-405e-a428-90301789fe20@infradead.org/
Signed-off-by: Duje Mihanović 
Reviewed-by: Daniel Thompson (RISCstar) 
Reviewed-by: Randy Dunlap 
Tested-by: Randy Dunlap 
Acked-by: Randy Dunlap 
Link: https://patch.msgid.link/20250729-expresswire-dep-fix-v1-2-635cd4cc746b@dujemihanovic.xyz
Signed-off-by: Lee Jones

backlight: rt4831: Include

2025-09-16T16:05:19+00:00

Include  to declare struct of_device_id.
Avoids dependency on backlight header to include it.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: "Daniel Thompson (RISCstar)" 
Link: https://lore.kernel.org/r/20250715122643.137027-15-tzimmermann@suse.de
Signed-off-by: Lee Jones

backlight: rave-sp: Include and

2025-09-16T16:05:19+00:00

Include  to declare struct device_node and include
 to declare struct of_device_id. Avoids
dependency on backlight header to include it.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: "Daniel Thompson (RISCstar)" 
Link: https://lore.kernel.org/r/20250715122643.137027-14-tzimmermann@suse.de
Signed-off-by: Lee Jones

backlight: led_bl: Include

2025-09-16T16:05:19+00:00

Include  to declare struct of_count_phandle_with_args().
Avoids dependency on backlight header to include it.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: "Daniel Thompson (RISCstar)" 
Link: https://lore.kernel.org/r/20250715122643.137027-13-tzimmermann@suse.de
Signed-off-by: Lee Jones

backlight: ktd2801: Include

2025-09-16T16:05:19+00:00

Include  to declare struct of_device_id.
Avoids dependency on backlight header to include it.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Nick Chan 
Reviewed-by: "Daniel Thompson (RISCstar)" 
Acked-by: Duje Mihanović 
Link: https://lore.kernel.org/r/20250715122643.137027-12-tzimmermann@suse.de
Signed-off-by: Lee Jones

backlight: jornada720: Include

2025-09-16T16:05:19+00:00

Include  to declare IOMEM(). Avoids dependency on
backlight header to include it.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: "Daniel Thompson (RISCstar)" 
Link: https://lore.kernel.org/r/20250715122643.137027-11-tzimmermann@suse.de
Signed-off-by: Lee Jones

backlight: da9052_bl: Include

2025-09-16T16:05:19+00:00

Include  to declare struct platform_device_id.
Avoids dependency on backlight header to include it.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: "Daniel Thompson (RISCstar)" 
Link: https://lore.kernel.org/r/20250715122643.137027-10-tzimmermann@suse.de
Signed-off-by: Lee Jones