kernel.git/drivers/video/backlight/gpio_backlight.c, branch linux-4.18.y

backlight: gpio_backlight: Delete pdata inversion

2017-08-07T16:11:28Z

The option to invert the output of the GPIO (active low) is not used by the only platform still using platform data to set up a GPIO backlight (one SH board). Delete the option as we do not expect to expand the use of board files for this driver, and GPIO descriptors intrinsically keep track of any signal inversion. Signed-off-by: Linus Walleij Acked-by: Daniel Thompson Reviewed-by: Laurent Pinchart Signed-off-by: Lee Jones

backlight: gpio_backlight: Convert to use GPIO descriptor

2017-08-07T16:04:32Z

This driver is predominantly used by device tree systems, all of which can deal with modern GPIO descriptors. The legacy GPIO API is only used by one SH board so make the GPIO descriptor the default way to deal with it. As an intended side effect we do not need to look around in the device tree for the inversion flag since the GPIO descriptors will intrinsically deal with this. Signed-off-by: Linus Walleij Acked-by: Daniel Thompson Reviewed-by: Laurent Pinchart Signed-off-by: Lee Jones

backlight: gpio-backlight: Use default-on on GPIO request

2016-01-11T07:58:35Z

There are situations where the backlight should be on at boot time (e.g. if the boot loader already turned the display on). The DT bindings specify the "default-on" property for that purpose. Currently, the initial state of the GPIO at request time is always set to logical off (high or low depending on whether it is an active high or low GPIO). Since the GPIO is requested as an output, the GPIO will be driven low for a short period of time, which leads to a flickering display in the above use-case. Initialize the GPIO depending on the default-on property to be logical on or off. Signed-off-by: Stefan Agner Signed-off-by: Lee Jones

gpio-backlight: Discover driver during boot time

2015-06-23T14:28:46Z

The gpio-backlight driver seems to be missing the MODULE_DEVICE_TABLE line which is preventing it from being modprobed during boot time even if the gpio-backlight device exists. This seems to be a bug and this patch attempts to fix that. Signed-off-by: Arun Bharadwaj Signed-off-by: Ash Charles Signed-off-by: Lee Jones

backlight: Remove .owner field for drivers using module_platform_driver

2014-08-28T13:09:48Z

This patch removes the superflous .owner field for drivers which use the module_platform_driver or platform_driver_register api, as this is overriden in __platform_driver_register. Signed-off-by: Peter Griffin Signed-off-by: Lee Jones

backlight: Remove trivial get_brightness implementations

2014-06-23T12:24:22Z

Since backlight core returns props.brightness in case get_brightness is not implemented trivial implementations are not needed anymore. Acked-by: Jingoo Han Signed-off-by: Andrzej Hajda Signed-off-by: Lee Jones

backlight: gpio-backlight: Fix warning when the GPIO is on a I2C chip

2014-06-05T09:00:53Z

If the GPIO for the backlight is on an I2C chip, we currently get nasty warnings like this during the boot: WARNING: CPU: 0 PID: 6 at drivers/gpio/gpiolib.c:2364 gpiod_set_raw_value+0x40/0x4c() Modules linked in: CPU: 0 PID: 6 Comm: kworker/u2:0 Not tainted 3.15.0-rc4-12393-gcde9f4e #400 Workqueue: deferwq deferred_probe_work_func [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0x80/0x9c) [] (dump_stack) from [] (warn_slowpath_common+0x68/0x8c) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24) [] (warn_slowpath_null) from [] (gpiod_set_raw_value+0x40/0x4c) [] (gpiod_set_raw_value) from [] (gpio_backlight_update_status+0x4c/0x74) [] (gpio_backlight_update_status) from [] (gpio_backlight_probe+0x168/0x254) [] (gpio_backlight_probe) from [] (platform_drv_probe+0x18/0x48) [] (platform_drv_probe) from [] (driver_probe_device+0x10c/0x238) [] (driver_probe_device) from [] (bus_for_each_drv+0x44/0x8c) [] (bus_for_each_drv) from [] (device_attach+0x74/0x8c) [] (device_attach) from [] (bus_probe_device+0x88/0xb0) [] (bus_probe_device) from [] (deferred_probe_work_func+0x64/0x94) [] (deferred_probe_work_func) from [] (process_one_work+0x1b4/0x4bc) [] (process_one_work) from [] (worker_thread+0x11c/0x398) [] (worker_thread) from [] (kthread+0xc8/0xe4) [] (kthread) from [] (ret_from_fork+0x14/0x2c) Fix this by using gpio_set_value_cansleep() as suggested in drivers/gpio/gpiolib.c:2364. This is what the other backlight drivers are also doing. Signed-off-by: Tony Lindgren Acked-by: Jingoo Han Signed-off-by: Lee Jones

backlight: gpio-backlight: Add DT support

2014-04-08T12:20:40Z

Signed-off-by: Denis Carikli Acked-by: Jingoo Han Signed-off-by: Lee Jones

backlight: gpio_backlight: use devm_backlight_device_register()

2013-11-13T03:09:17Z

Use devm_backlight_device_register() to make cleanup paths simpler, and remove unnecessary remove(). Signed-off-by: Jingoo Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

backlight: use dev_get_platdata()

2013-11-13T03:09:16Z

Use the wrapper function for retrieving the platform data instead of accessing dev->platform_data directly. This is a cosmetic change to make the code simpler and enhance the readability. Signed-off-by: Jingoo Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds