[maemo-developers] [maemo-developers] n800 LED interface

[From: Larry Battraw]

  First off, kudos to the maemo team for making such a nifty and
easy-to-use interface for the keypad LED.  I spent a inordinate amount
of time just tinkering with the brightness, blinking period, and so
forth :-)  For those interested, the relevant sys entries are here:
/sys/class/leds/keypad
Should be self explanatory, particularly if you turn on the blinking
from the control panel so you can cat out the values it uses for
delay_off and delay_on, etc.
  My question is this: for the default trigger source (timer), is the
blinking just a hardware PWM built into the CPU or is the CPU involved
in counting timer interrupts to handle on/off periods and toggling the
LED?  I ask because there was some discussion on ITT about how someone
had their n800 run down overnight with the LED left on.  It seemed
unlikely but I wanted to make sure a bunch of CPU cycles weren't being
burned to run it.

Thanks-
Larry