diff options
Diffstat (limited to 'Documentation/leds-class.txt')
-rw-r--r-- | Documentation/leds-class.txt | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/Documentation/leds-class.txt b/Documentation/leds-class.txt index 56757c751d6f..18860ad9935a 100644 --- a/Documentation/leds-class.txt +++ b/Documentation/leds-class.txt | |||
@@ -19,6 +19,12 @@ optimises away. | |||
19 | 19 | ||
20 | Complex triggers whilst available to all LEDs have LED specific | 20 | Complex triggers whilst available to all LEDs have LED specific |
21 | parameters and work on a per LED basis. The timer trigger is an example. | 21 | parameters and work on a per LED basis. The timer trigger is an example. |
22 | The timer trigger will periodically change the LED brightness between | ||
23 | LED_OFF and the current brightness setting. The "on" and "off" time can | ||
24 | be specified via /sys/class/leds/<device>/delay_{on,off} in milliseconds. | ||
25 | You can change the brightness value of a LED independently of the timer | ||
26 | trigger. However, if you set the brightness value to LED_OFF it will | ||
27 | also disable the timer trigger. | ||
22 | 28 | ||
23 | You can change triggers in a similar manner to the way an IO scheduler | 29 | You can change triggers in a similar manner to the way an IO scheduler |
24 | is chosen (via /sys/class/leds/<device>/trigger). Trigger specific | 30 | is chosen (via /sys/class/leds/<device>/trigger). Trigger specific |
@@ -63,9 +69,9 @@ value if it is called with *delay_on==0 && *delay_off==0 parameters. In | |||
63 | this case the driver should give back the chosen value through delay_on | 69 | this case the driver should give back the chosen value through delay_on |
64 | and delay_off parameters to the leds subsystem. | 70 | and delay_off parameters to the leds subsystem. |
65 | 71 | ||
66 | Any call to the brightness_set() callback function should cancel the | 72 | Setting the brightness to zero with brightness_set() callback function |
67 | previously programmed hardware blinking function so setting the brightness | 73 | should completely turn off the LED and cancel the previously programmed |
68 | to 0 can also cancel the blinking of the LED. | 74 | hardware blinking function, if any. |
69 | 75 | ||
70 | 76 | ||
71 | Known Issues | 77 | Known Issues |