Hi!

quoted

+        led.default_brightness = LED_OFF;
+        of_property_read_u32(child, "brightness",
+                     &led.default_brightness);

At first you would have to submit a patch for
Documentation/devicetree/bindings/leds/common.txt that would add
brightness property. The question is whether it is really needed?
You can set brightness from userspace via sysfs API.

By the way, I have a question to DT maintainers: is DT a proper
place for defining this type of configuration that can be set via
userspace scripts? Shouldn't DT describe only hardware properties and
constraints resulting from board configuration?

Well, if the hardware has label "half - power, full - transmitting" on
a LED, we might want kernel to turn it to half power on bootup.

If you have a "disk activity LED" on a PC, it is driven by
hardware. On arm notebook, it would be nice if "disk activity LED"
worked, too. Preferably even when running fsck in init=/bin/bash
mode. We already provide that, AFAICT, so having ability to set
constant brightness sounds sane to me.

									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html