tree 6ce8c8b1d8a4fb58d85484555ea25b2a6d298796
parent 61a83932b8b3f1624d753e06aab2fdf0a119e100
author Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> 1294880360 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1294934586 -0800

leds: add output inversion option to backlight trigger

Extend the LED backlight tirgger driver with an option that allows for
inverting the trigger output polarity.

With the invertion option provided, I (ab)use the backlight trigger for
driving a LED that indicates LCD display blank condtition on my Amstrad
Delta videophone.  Since the machine has no dedicated power LED, it was
not possible to distinguish if the display was blanked, or the machine was
turned off, without touching it.

The invert sysfs control is patterned after a similiar function of the GPIO
trigger driver.

[akpm@linux-foundation.org: make output match input, tighten input checking]
[akpm@linux-foundation.org: make output match input, tighten input checking]
Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>