Documentation of sysfs interface should be in ABI in the first place.
This moves relevant part of documentation and mentions where to look for
it.
Fix trivial typos whilst we are at it.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

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>

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>