RFC: representing sdio devices oob interrupt, clks, etc. in device tree

[Ulf Hansson]

On 4 June 2014 17:55, Mark Brown <broonie at kernel.org> wrote:
> On Tue, Jun 03, 2014 at 12:57:52PM +0200, Ulf Hansson wrote:
>> On 28 May 2014 13:03, Mark Brown <broonie at kernel.org> wrote:
>
>> > No, runtime PM isn't really fine grained - I'm talking about things
>> > like starting and stopping individual resources or configuring them.
>
>> Are you saying that you have several levels of quiescent mode of your
>> external chip?
>
> Partly, but also there can be active modes that don't use all
> functionality and hence can leave some of the inputs powered down (for
> example if a reference clock is used for some feature that isn't used
> all the time then that reference clock may be able to be powered down
> when the function is not in use).  The device isn't suspended but it can
> do without some of the resources it has.
>
>> I am a bit puzzled of how such library should look like, but I suppose
>> we need to be able to go to different power states through it.
>> Typically the library may be invoked both from the mmc core to do
>> power up/off and from the sdio func driver to handle power save.
>
>> Does it make sense to you as well?
>
> Yes, certainly for the power up/down and runtime PM type operations.

For your information; I have started implementing a library to handle
power sequences. I intend to have this separated from mmc, to let
other subsystems re-use the same code.

It will not require a compatible string, but instead use something
like 'power-method = blah' property.

I intend to post this as an RFC in couple of days.

Kind regards
Uffe