From f6ad395bad57dcd15c6423715d15d91363a62ae8 Mon Sep 17 00:00:00 2001 From: Jacek Anaszewski Date: Wed, 4 Mar 2015 08:14:24 -0800 Subject: [PATCH] Documentation: leds: Add description of LED Flash class extension The documentation being added contains overall description of the LED Flash Class and the related sysfs attributes. Signed-off-by: Jacek Anaszewski Acked-by: Kyungmin Park Cc: Richard Purdie Signed-off-by: Bryan Wu --- Documentation/leds/leds-class-flash.txt | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 Documentation/leds/leds-class-flash.txt diff --git a/Documentation/leds/leds-class-flash.txt b/Documentation/leds/leds-class-flash.txt new file mode 100644 index 000000000000..19bb67355424 --- /dev/null +++ b/Documentation/leds/leds-class-flash.txt @@ -0,0 +1,22 @@ + +Flash LED handling under Linux +============================== + +Some LED devices provide two modes - torch and flash. In the LED subsystem +those modes are supported by LED class (see Documentation/leds/leds-class.txt) +and LED Flash class respectively. The torch mode related features are enabled +by default and the flash ones only if a driver declares it by setting +LED_DEV_CAP_FLASH flag. + +In order to enable the support for flash LEDs CONFIG_LEDS_CLASS_FLASH symbol +must be defined in the kernel config. A LED Flash class driver must be +registered in the LED subsystem with led_classdev_flash_register function. + +Following sysfs attributes are exposed for controlling flash LED devices: +(see Documentation/ABI/testing/sysfs-class-led-flash) + - flash_brightness + - max_flash_brightness + - flash_timeout + - max_flash_timeout + - flash_strobe + - flash_fault -- 2.20.1