Re: [PATCH v2 1/2] spi: dt-bindings: amlogic, meson-gx-spicc: Add pinctrl names for SPI signal states

From: Krzysztof Kozlowski
Date: Fri Oct 07 2022 - 03:04:37 EST


On 06/10/2022 17:48, Neil Armstrong wrote:
> On 06/10/2022 16:11, Krzysztof Kozlowski wrote:
>> On 06/10/2022 12:57, Amjad Ouled-Ameur wrote:
>>> Hi Krzysztof,
>>>
>>> Thank you for the review.
>>>
>>> On 10/5/22 10:14, Krzysztof Kozlowski wrote:
>>>> On 04/10/2022 13:10, Amjad Ouled-Ameur wrote:
>>>>> SPI pins of the SPICC Controller in Meson-GX needs to be controlled by
>>>>> pin biais when idle. Therefore define three pinctrl names:
>>>>> - default: SPI pins are controlled by spi function.
>>>>> - idle-high: SCLK pin is pulled-up, but MOSI/MISO are still controlled
>>>>> by spi function.
>>>>> - idle-low: SCLK pin is pulled-down, but MOSI/MISO are still controlled
>>>>> by spi function.
>>>>>
>>>>> Reported-by: Da Xue <da@libre.computer>
>>>>> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
>>>>> Signed-off-by: Amjad Ouled-Ameur <aouledameur@xxxxxxxxxxxx>
>>>>> ---
>>>>> .../devicetree/bindings/spi/amlogic,meson-gx-spicc.yaml | 15 +++++++++++++++
>>>>> 1 file changed, 15 insertions(+)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/spi/amlogic,meson-gx-spicc.yaml b/Documentation/devicetree/bindings/spi/amlogic,meson-gx-spicc.yaml
>>>>> index 0c10f7678178..53013e27f507 100644
>>>>> --- a/Documentation/devicetree/bindings/spi/amlogic,meson-gx-spicc.yaml
>>>>> +++ b/Documentation/devicetree/bindings/spi/amlogic,meson-gx-spicc.yaml
>>>>> @@ -43,6 +43,14 @@ properties:
>>>>> minItems: 1
>>>>> maxItems: 2
>>>>>
>>>>> + pinctrl-0:
>>>>> + minItems: 1
>>>> maxItems?
>>>>
>>> Will fill it in next version.
>>>>> +
>>>>> + pinctrl-1:
>>>>> + maxItems: 1
>>>>> +
>>>>> + pinctrl-names: true
>>>> Why do you need all these in the bindings?
>>>
>>> SPI clock bias needs to change at runtime depending on SPI mode, here is an example of
>>>
>>> how this is supposed to be used ("spi_idle_low_pins" and "spi_idle_low_pins" are defined
>>>
>>> in the second patch of this series):
>>
>> I know what it the point in general of pinctrl configuration... But the
>> question is why do you need to specify them in the bindings? Core
>> handles that. IOW, do you require them and missing/incomplete pinctrl
>> should be reported?
>
> Looking at other bindings, when specific pinctrl state names were requires, they were
> documented.

Yes, the required and/or necessary entries were added to few other
bindings. Since Amjad did not make them required, why adding them? So I
repeat the question for the third time - why do you need to add them to
the bindings?

> There's some bindings with pinctrl-names for specific states like rockchip/rockchip,dw-hdmi.yaml,
> mediatek/mediatek,dpi.yaml, mmc/mtk-sd.yaml or mmc/fsl-imx-esdhc.yaml

And? Just because someone did something is not itself an argument. They
might have their reasons. If their reasons are applicable here, please
state them.

Best regards,
Krzysztof