Re: [PATCH 14/16] gpio: Add support for banked GPIO controllers

From: Tony Lindgren
Date: Thu Sep 14 2017 - 19:49:46 EST


* Tony Lindgren <tony@xxxxxxxxxxx> [170914 16:38]:
> * Linus Walleij <linus.walleij@xxxxxxxxxx> [170914 07:00]:
> > On Fri, Sep 1, 2017 at 8:57 PM, Thierry Reding <thierry.reding@xxxxxxxxx> wrote:
> >
> > > From: Thierry Reding <treding@xxxxxxxxxx>
> > >
> > > Some GPIO controllers are subdivided into multiple logical blocks called
> > > banks (or ports). This is often caused by the design assigning separate
> > > resources, such as register regions or interrupts, to each bank, or some
> > > set of banks.
> > >
> > > This commit adds support for describing controllers that have such a
> > > banked design and provides common code for dealing with them.
> > >
> > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> >
> > This patch makes me really happy.
> >
> > It pulls in a lot of weirdness to the OF core and creates a coherent
> > way of handling these "banked" GPIO chips.
> >
> > CC to Tony to make sure he checks that OMAP is ready to use this
> > too.
>
> Adding Grygorii to Cc as well, we'll take a look.
>
> Probably the runtime PM will be an issue here still. We must currently
> do runtime PM on per GPIO bank basis instead of per GPIO pin level as
> we constantly runtime_suspend/resume the whole GPIO bank for idle modes
> on the SoCs that support PM. So the usage count for the bank needs to
> be either 0 or 1 and cannot be the lines used in the bank.

And based on a quick look at this series it should not cause
problems there. For managing the banks in a generic way, I
like the idea too.

Regards,

Tony