Re: [PATCH] ARM: dts: vf-colibri-eval-v3: Use enable-gpios for BL_ON

From: Stefan Agner
Date: Thu Jan 28 2016 - 17:31:22 EST


On 2016-01-28 00:39, Shawn Guo wrote:
> On Sat, Jan 09, 2016 at 12:29:53PM +0530, Bhuvanchandra DV wrote:
>> Use pwm-backlight driver 'enable-gpios' property for backlight on/off
>> control.
>>
>> Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@xxxxxxxxxxx>
>> ---
>> arch/arm/boot/dts/vf-colibri.dtsi | 9 +++++++++
>> 1 file changed, 9 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/vf-colibri.dtsi b/arch/arm/boot/dts/vf-colibri.dtsi
>> index e5949b9..1c0da05 100644
>> --- a/arch/arm/boot/dts/vf-colibri.dtsi
>> +++ b/arch/arm/boot/dts/vf-colibri.dtsi
>> @@ -10,7 +10,10 @@
>> / {
>> bl: backlight {
>> compatible = "pwm-backlight";
>> + pinctrl-names = "default";
>> + pinctrl-0 = <&pinctrl_gpio_bl_on>;
>> pwms = <&pwm0 0 5000000 0>;
>> + enable-gpios = <&gpio1 13 GPIO_ACTIVE_HIGH>;
>> status = "disabled";
>> };
>> };
>> @@ -169,6 +172,12 @@
>> >;
>> };
>>
>> + pinctrl_gpio_bl_on: gpio_bl_on {
>> + fsl,pins = <
>> + VF610_PAD_PTC0__GPIO_45 0x22ef
>> + >;
>> + };
>> +
>
> @Stefan,
>
> Do we need this? My understanding is that on Vybrid, when gpio is
> requested, the pinctrl will set it up automatically.

Yes this is required. The GPIO driver asks the pinctrl driver to enable
the GPIO, and the pinctrl driver requires a "valid" pinmux configuration
to be able to find the IOMUXC register at all.

Acked-by: Stefan Agner <stefan@xxxxxxxx>

--
Stefan