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authorNémeth Márton <nm127@freemail.hu>2008-03-09 20:54:37 +0000
committerRichard Purdie <rpurdie@rpsys.net>2008-04-24 23:34:18 +0100
commit0013b23d66a2768f5babbb0ea9f03ab067a990d8 (patch)
tree14d60a50bb68e422767a268cd737f70ef4e6e19d /Documentation/leds-class.txt
parentb3ba31f84ea041c0945b5904d4c407ce14b2b72c (diff)
leds: disable triggers on brightness set
Disable any active triggers when the brightness attribute is set to zero. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Márton Németh <nm127@freemail.hu> Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Diffstat (limited to 'Documentation/leds-class.txt')
-rw-r--r--Documentation/leds-class.txt12
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.
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/<device>/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/<device>/trigger). Trigger specific
@@ -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