[PATCH 5/8] ARM: PXA: Z2: Add poweroff function

[anarsoul@gmail.com (Vasily Khoruzhick)]

On Saturday 12 March 2011 13:06:13 Marek Vasut wrote:
 
> You have a problem with suspend then ? That'd need a different solution.

I'm still not sure if resume from deepsleep is possible on Zipit Z2, so using 
deepsleep as poweroff is the only solution we know for now.

> > Ok, I can clear PSPR before going to deepsleep, would it be enough?
> 
> As Eric pointed out, the wake-up scenario is bootloader-specific ... taking
> into acount only your own version of bootloader is a no-no

That will work with mainline u-boot, here's pseudocode:

1. PSPR = 0x0;
2. Put_PXA270_Into_DeepSleep();
.......
Wake-up
.......
3. Load RCSR to temporary var
4. Clear RCSR bits
5. If we resumed from suspend jump to location pointed by PSPR

Steps 3-5 are already implemented in u-boot, so it'll jump to 0x0 (NOR), to 
the u-boot entry point. RCSR bits are already cleared, so it just continues 
regular boot process.

Regards
Vasily