[PATCH v3 1/3] power: Add simple poweroff-gpio driver

[Andrew Lunn]

On Tue, Nov 20, 2012 at 10:11:18AM -0700, Stephen Warren wrote:
> On 11/20/2012 01:37 AM, Andrew Lunn wrote:
> > Hi Jason
> > 
> > These are good comments from Stephan that i want to address. However,
> > i also don't want to delay the pull-requests direction arm-soc, the
> > merge window is getting close. Both Linus and Anton have Acked the
> > current version, so please go with what you have and i will produce a
> > patch over the top. If its available before Arnd pulls, you can squash
> > it, otherwise send it upstream as a standalone patch.
> 
> I'm not sure I agree here; the comments I made re: the delays and
> pulse-vs-level may affect the definition of the DT binding, and that's
> something that should be correct from the start.

Hi Stephen

There should be no need to change the binding is a none-backwards
compatible way. The current delays work for all current users. If some
other user comes along which needs longer delays, they can add an
optional property which specified a longer delay.

The pulse-vs-level is needed for the potential PXA use case, which is
where i took this code from. When we first proposed this driver,
Russel King pointed to the PXA reset.c code and requested we create
something which PXA could use. The configuring the GPIO as an input
also come from PXA, which the current two uses user don't need.

I agree it need better documentation, but the current code covers all
bases. It will turn off a level based system, it will also turn off an
edge based system. There is no need to specify in the DT which is
needed, it will just work.

> The implementation of gpio_poweroff_do_poweroff() really doesn't seem to
> make sense; related to the above.
> 
> Also, probe deferral doesn't work, which will likely make this code
> completely ineffective.

This code has been tested by the two current users. It works. However,
i agree about your comment here, and i will fix it in the follow up
patch.

	Andrew