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authorCorentin Chary <corentincj@iksaif.net>2009-08-28 12:56:45 +0000
committerLen Brown <len.brown@intel.com>2009-08-28 15:21:12 -0400
commit5f634c6527249275df4199a294ee9cec2f3ff3b1 (patch)
tree44c2d69f6e28823a6c1c66683440d7ba2e3890a4 /Documentation/leds-class.txt
parent243ca3e401bc62e704785d215931f1a51fd53bd7 (diff)
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led: document sysfs interface
Also fix Documentation/led-class.txt, the acceptable range of values for brightness is 0-max_brightness, not 0-255. Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Corentin Chary <corentincj@iksaif.net> Signed-off-by: Len Brown <len.brown@intel.com>
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LED handling under Linux
========================
@@ -5,10 +6,10 @@ If you're reading this and thinking about keyboard leds, these are
handled by the input subsystem and the led class is *not* needed.
In its simplest form, the LED class just allows control of LEDs from
-userspace. LEDs appear in /sys/class/leds/. The brightness file will
-set the brightness of the LED (taking a value 0-255). Most LEDs don't
-have hardware brightness support so will just be turned on for non-zero
-brightness settings.
+userspace. LEDs appear in /sys/class/leds/. The maximum brightness of the
+LED is defined in max_brightness file. The brightness file will set the brightness
+of the LED (taking a value 0-max_brightness). Most LEDs don't have hardware
+brightness support so will just be turned on for non-zero brightness settings.
The class also introduces the optional concept of an LED trigger. A trigger
is a kernel based source of led events. Triggers can either be simple or
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