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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/leds/ledtrig-oneshot.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/leds/ledtrig-oneshot.txt')
-rw-r--r-- | kernel/Documentation/leds/ledtrig-oneshot.txt | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/kernel/Documentation/leds/ledtrig-oneshot.txt b/kernel/Documentation/leds/ledtrig-oneshot.txt new file mode 100644 index 000000000..07cd1fa41 --- /dev/null +++ b/kernel/Documentation/leds/ledtrig-oneshot.txt @@ -0,0 +1,59 @@ +One-shot LED Trigger +==================== + +This is a LED trigger useful for signaling the user of an event where there are +no clear trap points to put standard led-on and led-off settings. Using this +trigger, the application needs only to signal the trigger when an event has +happened, than the trigger turns the LED on and than keeps it off for a +specified amount of time. + +This trigger is meant to be usable both for sporadic and dense events. In the +first case, the trigger produces a clear single controlled blink for each +event, while in the latter it keeps blinking at constant rate, as to signal +that the events are arriving continuously. + +A one-shot LED only stays in a constant state when there are no events. An +additional "invert" property specifies if the LED has to stay off (normal) or +on (inverted) when not rearmed. + +The trigger can be activated from user space on led class devices as shown +below: + + echo oneshot > trigger + +This adds the following sysfs attributes to the LED: + + delay_on - specifies for how many milliseconds the LED has to stay at + LED_FULL brightness after it has been armed. + Default to 100 ms. + + delay_off - specifies for how many milliseconds the LED has to stay at + LED_OFF brightness after it has been armed. + Default to 100 ms. + + invert - reverse the blink logic. If set to 0 (default) blink on for delay_on + ms, then blink off for delay_off ms, leaving the LED normally off. If + set to 1, blink off for delay_off ms, then blink on for delay_on ms, + leaving the LED normally on. + Setting this value also immediately change the LED state. + + shot - write any non-empty string to signal an events, this starts a blink + sequence if not already running. + +Example use-case: network devices, initialization: + + echo oneshot > trigger # set trigger for this led + echo 33 > delay_on # blink at 1 / (33 + 33) Hz on continuous traffic + echo 33 > delay_off + +interface goes up: + + echo 1 > invert # set led as normally-on, turn the led on + +packet received/transmitted: + + echo 1 > shot # led starts blinking, ignored if already blinking + +interface goes down + + echo 0 > invert # set led as normally-off, turn the led off |