On Thu, Dec 18, 2014 at 10:52 AM, Uwe Kleine-K?nig
[off-list ref] wrote:

Hello,

Hi Uwe,

[Cc += linusw, linux-gpio]

On Wed, Dec 17, 2014 at 10:04:24PM +0300, Vasily Khoruzhick wrote:

quoted

I'd like to port several s3c24xx to DT, and I'm stuck with s3c24xx LCD
controller and power drivers for H1940 and RX1950.

Please see [1]. I want to move this function into another LCD power
driver, but I'm not sure what to do with s3c_gpio_cfgpin(). I need to
change pin function in runtime, and as far as I understand it should
be handled via pinctrl driver somehow. But how?

You can pass >1 pinctrl setups to a node:

        somedevice {
                pinctrl-names = "default", "foo", "bar";
                pinctrl-0 = <&pinctrl_somedevice_default>;
                pinctrl-1 = <&pinctrl_somedevice_foo>;
                pinctrl-2 = <&pinctrl_somedevice_bar>;
                cfg-gpios = <&gpio4 12 3>, <&gpio2 7 5>;
        };

Then I think you can fiddle with pinctrl_select_state(). For the gpios
you can then use the standard gpiod_{request,direction_{in,out}put}
combo.

Thanks for you response!

Can I change pin function after gpio was requested? In low-power state
(i.e. when display is disabled) it's gpio driving some level,
and in active state it's some LCD controller pin (don't remember which
one exactly)

Regards,
Vasily

Best regards
Uwe

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Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |