On Mon, Oct 1, 2012 at 5:44 PM, Tony Lindgren [off-list ref] wrote:

quoted

OK that is typical pinctrl driver implementation work.
I hope Tony can advice on this?

I think we're best off to just stick to alternative named modes
passed from device tree. For example, for GPIO wake-ups you can
have named modes such as "default", "enabled" and "idle" where
"idle" muxes things for GPIO wake-ups for the duration of idle.

It seems that should also work for leds-gpio. And you can
define more named modes as needed.

This is what we're doing for ux500 and should be a good model.

You really don't want the client driver or the GPIO driver doing
things like pull-up/down automatically as that is board specific and
can also depend on things like externall pull resistors.

Nope. We've had instances of people getting bad leakage
because of pulling down a line where there is already a
pull-down resistor on the board :-(

quoted

OK so the threshold is that we need to get it right for the first
one and then the others will look good too.

It seems we want to keep leds-gpio, gpio framework and pinctrl
framework generic. It also seems you should be able to do
what you're describing using the pinctrl named modes.

I think so too.

Yours,
Linus Walleij