On Wed, Sep 10, 2014 at 10:55 AM, Laurent Pinchart
[off-list ref] wrote:

On Sunday 31 August 2014 22:08:52 Kuninori Morimoto wrote:

quoted

I know we can use "defalt" PFC settings on DT.
But, how to use "defalt" GPIO pin settings on DT ?

We would like to use GPIO 7-17 as Low output,
and do nothing after boot.

From a DT point of view I believe this is supposed to be done by specifying
the output-low or output-high properties in the pinctrl configuration node.
However, these properties are not supported by the PFC driver, and there's no
easy way for the PFC driver to configure GPIOs handled by a different driver
such as the gpio-rcar driver for instance.

Linus, do you have any hindsight on how this should be implemented ?

I have suggested adding GPIO hogs, so that a GPIO node can specify
that some GPIO's specified on the local ship be hogged high or
low at probe. Generic DT bindings and generic code in gpiolib.c.

gpios-hog-high = <....>;
gpios-hog-low = <....>;

Yours,
Linus Walleij