Power Managment Tips: Difference between revisions

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#REDIRECT [[Power_Management_Tips]]
= Power Management Tips and Tricks =

These are tips and tricks for saving power on the XO platform.

== Lid events ==

Starting with the B2 platform, we now have the capability to get events when the lid is closed and opened. The events can be collected along with the power button event from the geode_pm input device.
Here is a bit of pseudo code for doing that:

#include <linux/event.h>
struct input_event ev;
input_fd = open("/dev/input/event0", O_RDONLY);
read(input_fd, &event, sizeof(struct input_event));
if (ev.type == EV_SW && ev.code == SW_LID) {
if (ev.value == 1)
lid_down();
else
lid_up();
}

== DCON sleep ==

The DCON can be put to sleep (ie - blanked). This is useful for those times when the system should stay up, but the DCON is drawing too much power. To put it to sleep:

echo "1" > /sys/devices/platform/dcon/sleep

and to wake back up:

echo "0" > /sys/devices/platform/dcon/sleep

This is particularly useful when combined with the lid events (above).

Latest revision as of 16:11, 26 March 2007