| Jacek Anaszewski | f6ad395 | 2015-03-04 08:14:24 -0800 | [diff] [blame] | 1 | |
| 2 | Flash LED handling under Linux |
| 3 | ============================== |
| 4 | |
| 5 | Some LED devices provide two modes - torch and flash. In the LED subsystem |
| 6 | those modes are supported by LED class (see Documentation/leds/leds-class.txt) |
| 7 | and LED Flash class respectively. The torch mode related features are enabled |
| 8 | by default and the flash ones only if a driver declares it by setting |
| 9 | LED_DEV_CAP_FLASH flag. |
| 10 | |
| 11 | In order to enable the support for flash LEDs CONFIG_LEDS_CLASS_FLASH symbol |
| 12 | must be defined in the kernel config. A LED Flash class driver must be |
| 13 | registered in the LED subsystem with led_classdev_flash_register function. |
| 14 | |
| 15 | Following sysfs attributes are exposed for controlling flash LED devices: |
| 16 | (see Documentation/ABI/testing/sysfs-class-led-flash) |
| 17 | - flash_brightness |
| 18 | - max_flash_brightness |
| 19 | - flash_timeout |
| 20 | - max_flash_timeout |
| 21 | - flash_strobe |
| 22 | - flash_fault |