Re: [PATCH v2 3/6] pinctrl: sh-pfc: r8a7790: Add separate functions for SDHI 1.8V operation

[Ben Hutchings <ben.hutchings@codethink.co.uk>]

On Fri, 2015-06-12 at 22:07 +0300, Laurent Pinchart wrote:
> Hi Ben,
> 
> On Friday 12 June 2015 14:23:55 Ben Hutchings wrote:
> > On Fri, 2015-06-12 at 10:18 +0300, Laurent Pinchart wrote:
> > > Hi Ben,
> > > 
> > > (CC'ing Linus Walleij)
> > > 
> > > Thank you for the patch.
> > > 
> > > On Wednesday 10 June 2015 00:23:31 Ben Hutchings wrote:
> > > > All the SHDIs can operate with either 3.3V or 1.8V signals, depending
> > > > on negotiation with the card.
> > > > 
> > > > Add separate functions for the 1.8V mode, and implement the set_mux
> > > > operation on all SDHI functions to configure the voltage for each
> > > > group of pins.
> > > 
> > > I don't think duplicating all functions for 1.8V and 3.3V is the right way
> > > to go. Can't we use the pinconf API instead, and in particular the
> > > PIN_CONFIG_POWER_SOURCE configuration ?
> > 
> > [...]
> > 
> > So far as I could see, you can't use the pinconf API with pinmux groups.
> 
> Can't you ? Both Documentation/devicetree/bindings/pinctrl/pinctrl-
> bindings.txt and Documentation/devicetree/bindings/pinctrl/renesas,pfc-
> pinctrl.txt document the usage of pinconf with groups (see for instance 
> example 3 in the latter).

Sorry, I should say you can't use them with pinmux *functions*.  You can
either bind a group to a function *or* set the various pinconf
properties for the group, but not both.  Unless I'm very much mistaken.

Ben.