X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Documentation%2Fleds-class.txt;h=6399557cdab3d6542a0feea0c0cd2c6b2af5ffad;hb=4f62f6cb93a58f77056daed73a7700fe467f7eb3;hp=56757c751d6fc5611b181f6d79302a195b3fe8c7;hpb=ab1ecbabb1c7b1599b1eb70c291407c557ea4ef3;p=pandora-kernel.git diff --git a/Documentation/leds-class.txt b/Documentation/leds-class.txt index 56757c751d6f..6399557cdab3 100644 --- a/Documentation/leds-class.txt +++ b/Documentation/leds-class.txt @@ -19,6 +19,12 @@ optimises away. Complex triggers whilst available to all LEDs have LED specific parameters and work on a per LED basis. The timer trigger is an example. +The timer trigger will periodically change the LED brightness between +LED_OFF and the current brightness setting. The "on" and "off" time can +be specified via /sys/class/leds//delay_{on,off} in milliseconds. +You can change the brightness value of a LED independently of the timer +trigger. However, if you set the brightness value to LED_OFF it will +also disable the timer trigger. You can change triggers in a similar manner to the way an IO scheduler is chosen (via /sys/class/leds//trigger). Trigger specific @@ -53,7 +59,7 @@ Hardware accelerated blink of LEDs Some LEDs can be programmed to blink without any CPU interaction. To support this feature, a LED driver can optionally implement the -blink_set() function (see ). If implemeted, triggers can +blink_set() function (see ). If implemented, triggers can attempt to use it before falling back to software timers. The blink_set() function should return 0 if the blink setting is supported, or -EINVAL otherwise, which means that LED blinking will be handled by software. @@ -63,9 +69,9 @@ value if it is called with *delay_on==0 && *delay_off==0 parameters. In this case the driver should give back the chosen value through delay_on and delay_off parameters to the leds subsystem. -Any call to the brightness_set() callback function should cancel the -previously programmed hardware blinking function so setting the brightness -to 0 can also cancel the blinking of the LED. +Setting the brightness to zero with brightness_set() callback function +should completely turn off the LED and cancel the previously programmed +hardware blinking function, if any. Known Issues