DT on s3c24xx

Vasily Khoruzhick anarsoul at gmail.com
Thu Dec 18 00:34:15 PST 2014


On Thu, Dec 18, 2014 at 10:52 AM, Uwe Kleine-König
<u.kleine-koenig at pengutronix.de> wrote:
> Hello,

Hi Uwe,

> [Cc += linusw, linux-gpio]
>
> On Wed, Dec 17, 2014 at 10:04:24PM +0300, Vasily Khoruzhick wrote:
>> 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
>
> --
> Pengutronix e.K.                           | Uwe Kleine-König            |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |



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