[PATCH] ARM: dts: st: add buswidth property to stm32f429-disco

[PATCH] ARM: dts: st: add buswidth property to stm32f429-disco

[Raphael Gallais-Pou]

The ili9341 is left without a mandatory buswidth to properly communicate
between the SI bus and the display. Add the device-tree property.

Signed-off-by: Raphael Gallais-Pou <rgallaispou@gmail.com>
---
 arch/arm/boot/dts/stm32f429-disco.dts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/stm32f429-disco.dts b/arch/arm/boot/dts/stm32f429-disco.dts
index 3b81228d46a2..5eaf95afc8c7 100644
--- a/arch/arm/boot/dts/stm32f429-disco.dts
+++ b/arch/arm/boot/dts/stm32f429-disco.dts
@@ -197,6 +197,7 @@ display: display@1{
 		spi-3wire;
 		spi-max-frequency = <10000000>;
 		dc-gpios = <&gpiod 13 0>;
+		buswidth = <8>;
 		port {
 			panel_in_rgb: endpoint {
 			remote-endpoint = <&ltdc_out_rgb>;
-- 
2.41.0

Re: [PATCH] ARM: dts: st: add buswidth property to stm32f429-disco

[Krzysztof Kozlowski]

On 02/07/2023 12:35, Raphael Gallais-Pou wrote:
> The ili9341 is left without a mandatory buswidth to properly communicate
> between the SI bus and the display. Add the device-tree property.
> 
> Signed-off-by: Raphael Gallais-Pou <rgallaispou@gmail.com>
> ---
>  arch/arm/boot/dts/stm32f429-disco.dts | 1 +

There is no such file. Please rebase on recent Linux.

>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/boot/dts/stm32f429-disco.dts b/arch/arm/boot/dts/stm32f429-disco.dts
> index 3b81228d46a2..5eaf95afc8c7 100644
> --- a/arch/arm/boot/dts/stm32f429-disco.dts
> +++ b/arch/arm/boot/dts/stm32f429-disco.dts
> @@ -197,6 +197,7 @@ display: display@1{
>  		spi-3wire;
>  		spi-max-frequency = <10000000>;
>  		dc-gpios = <&gpiod 13 0>;
> +		buswidth = <8>;

There is no such spi property.

Best regards,
Krzysztof

Re: [PATCH] ARM: dts: st: add buswidth property to stm32f429-disco

[Raphaël Gallais-Pou]

Hi,

Le 02/07/2023 à 22:14, Krzysztof Kozlowski a écrit :
> On 02/07/2023 12:35, Raphael Gallais-Pou wrote:
>> The ili9341 is left without a mandatory buswidth to properly communicate
>> between the SI bus and the display. Add the device-tree property.
>>
>> Signed-off-by: Raphael Gallais-Pou <rgallaispou@gmail.com>
>> ---
>>   arch/arm/boot/dts/stm32f429-disco.dts | 1 +
> 
> There is no such file. Please rebase on recent Linux.

Yes, indeed. I forgot to pull, I'm sorry.

> 
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm/boot/dts/stm32f429-disco.dts b/arch/arm/boot/dts/stm32f429-disco.dts
>> index 3b81228d46a2..5eaf95afc8c7 100644
>> --- a/arch/arm/boot/dts/stm32f429-disco.dts
>> +++ b/arch/arm/boot/dts/stm32f429-disco.dts
>> @@ -197,6 +197,7 @@ display: display@1{
>>   		spi-3wire;
>>   		spi-max-frequency = <10000000>;
>>   		dc-gpios = <&gpiod 13 0>;
>> +		buswidth = <8>;
> 
> There is no such spi property.

While I agree with you, I saw in staging drivers that this property was 
fetch in the device-tree by the fbtft core.

Should I document those in or try to do it another way ?

> 
> Best regards,
> Krzysztof
> 

Thanks,
Raphaël

Re: [PATCH] ARM: dts: st: add buswidth property to stm32f429-disco

[Krzysztof Kozlowski]

On Mon, 3 Jul 2023 at 05:21, Raphaël Gallais-Pou <rgallaispou@gmail.com> wrote:
> >>              spi-3wire;
> >>              spi-max-frequency = <10000000>;
> >>              dc-gpios = <&gpiod 13 0>;
> >> +            buswidth = <8>;
> >
> > There is no such spi property.
>
> While I agree with you, I saw in staging drivers that this property was
> fetch in the device-tree by the fbtft core.
>
> Should I document those in or try to do it another way ?

You cannot use undocumented properties. Whether this should be used at
all, depends what's this, why other properties cannot be used etc.