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    SubjectRe: [PATCH V3] led: Backlight trigger for led subsystem
    On Tue, Oct 07, 2008 at 03:54:20PM +0200, Pavel Machek wrote:
    > Hi!
    > > This patch set adds a new led trigger which emulates the backlight
    > > behaviour: the leds are turned off and on each time the display blanks
    > > and unblacks.
    > >
    > > Since backlights are usually implemented with leds this patch set is
    > > useful for those drivers whose manage leds controller used as
    > > backlight controller.
    > >
    > > The driver simply registers itself into the led subsystem and then the
    > > user may get backlight emulation by setting the "backlight"
    > > trigger. Moreover a driver, which usually manages more than one led,
    > > can use some leds as "led" and the others as "backlights" at user
    > > request.
    > We already have backlight subsystem, it can also handle display
    > brightness. Why not use that?

    Just to use a led as "led" or as "backlight" at user request. You can
    do it by using:

    echo none > /sys/class/leds/lcd/trigger
    echo backlight > /sys/class/leds/lcd/trigger

    and the led will work accordingly.

    Also a led used as "backlight" is just a normal led (you can set the
    brightness as a normal led) but it switchs off automatically when the
    LCD blanks.




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