According to the comments in arch/arm/special/empeg_power.c, and a couple
of old BBS posts, the empeg's power PIC can wake up the empeg at more or
less user-definable intervals. I've tried to play with this functionality, but
so far I'm not seeing what I expect. Here's what I'm doing:
Code:
int fd = open("/dev/empeg_power", O_RDONLY);
int time = 1;
if (fd < 1)
{
printf("couldn't open empeg_power\n");
exit(-1);
}
int rc = ioctl(fd, EMPEG_POWER_WAKETIME, &time);
sleep(1);
printf("goodbye, cruel world...\n");
rc = ioctl(fd, EMPEG_POWER_TURNOFF, NULL);
So, if I'm understanding the comments in empeg_power.c correctly, the above
code should be setting the power PIC's wakeup timer to wake up the empeg in
roughly 15 seconds, and then powering the empeg off. What I see is the empeg
does indeed power off, but doesn't wake up, or, rather, doesn't boot up.
Now, this part of the empeg_power.c comments is where I'm thinking I might
be losing:
Code:
* If there are no events pending when the system wakes up, it just powers
* itself off again. Generally, this brief flash of power lasts no more than
* 300ms (using 200mA - an average hourly drain of 16uAH).
What I don't understand is "if there are no events pending when the system wakes
up." What's a pending event in this context? Is my code fragment above actually
waking the empeg up, but it's going right back to sleep again? How can I get it to
actually wake itself up and boot into the player, for instance?
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