how to tell when kindle sleeps/wakes up

[fbdev]

does anyone know a way to programmatically determine when the kindle goes to sleep and wakes up?

i was looking at /dev/luigibutton but it is a bit difficult to decipher the ioctls for the device.
has anyone solved this problem?

[mark03]

Once the Kindle goes to sleep, won't your program be sleeping too?

Or do you mean to "register" your app somehow so it gets notified during the going-to-sleep process?

Keyword searches in the kernel source might turn up something useful. I don't have the link handy, but there is a complete set of mainline->amazon kernel diffs for the K3 posted somewhere. The only hitch is that they have many versions of their custom hardware drivers in the bundle, for each Kindle version and also for some internal dev platforms. Looking for "luigi" is a good rule of thumb, but it can still be tricky to know you're looking at the right code.

[mark03]

Here's the link I was thinking of:

http://blog.rlove.org/2010/10/kindle-3-kernel.html

I found this quite useful in understanding the hardware. Still a bunch of unanswered questions, like where is the third SD-card interface the kernel claims is there? etc...

Anyway, you should at least be able to look up the luigibutton stuff and figure out the ioctls.

[mobad]

The command "lipc-get-prop com.lab126.powerd state" will give you the power state of the device.

"lipc-probe -av" for more interesting stuff.

[fbdev]

that was very helpful.

[mark03]

Please forgive my ignorance, but how is it possible that that command will ever return an answer other than "device is not sleeping"? I mean, if the device is asleep, surely you can't run the command in the first place? What am I missing here?

[mobad]

The Kindle doesn't sleep for about a minute after you turn it off.

[fbdev]

you can run any command programmatically from a system application; 'sleep' just means the hardware is in a low-power state, i.e., the usb subsystem is powered off, the soundcard is powered off (this part is VERY annoying), the display is powered off, the radio transmitters are off, and the processor is in its lowest power state. software may be (and is!) still running in main memory. in theory, the device could be in a standby to memory or standby to disk state, but i don't think the kindle uses these features of the linux kernel (they're high latency).

[fbdev]

i did some investigating and found that the kindle does enter into standby (to memory) after 2 minutes in screensaver mode. logging the output of lipc:
Fri Aug 5 12:05:33 EDT 2011
active
Fri Aug 5 12:06:03 EDT 2011
screenSaver
Fri Aug 5 12:06:33 EDT 2011
screenSaver
Fri Aug 5 12:07:03 EDT 2011
readyToSuspend

some powerd properties you can control with lipc:
w Int wakeUp
rw Int preventScreenSaver [0]
rw Str logMask [0xffff0000]
w Int suspendGrace
w Int deferSuspend
rw Str logLevel [Current log level=info
(Possible levels: all, perf, debug[9-0], info, warn, error, crit, none)]
w Int touchScreenSaverTimeout
r Str state [active]
w Int abortSuspend
r Int isCharging [1]
r Int battLevel [100]
w Int rtcWakeup

for instance, if you want to wakeup the device using this command:
lipc-set-prop com.lab126.powerd wakeUp 1

[mark03]

Cool.

Does anyone know what lipc actually is, or where it came from? I googled for it a while back and didn't find anything. It looks sort of like dbus in concept. Is it an Amazon-proprietary thing, or based off of some open-source project?