[PATCH 1/2] dt-bindings: display: Add Sharp Memory LCD bindings

Krzysztof Kozlowski krzk at kernel.org
Sun Jul 28 14:43:42 UTC 2024


On 28/07/2024 14:56, Alex Lanzano wrote:
>>>>> +
>>>>> +  spi-cs-high: true
>>>>
>>>> You can drop it.
>>>>
>>>
>>> This is a required property in order for the display to function correctly.
>>> But I have no issues removing it if there's a better place to document it.
>>
>> The sharp LCD device or the board (e.g. via some inversion)?
>>
> 
> The sharp LCD device itself.
> 
> https://cdn.sparkfun.com/assets/d/e/8/9/7/LS013B7DH03_datasheet.pdf
> Page 16 of the PDF below shows the timing chart for it if interested

OK, so you enforce chip select as always high and then someone comes
with a board which has a inversion and expect the SoC to drive it low,
as usually? In such system this would not work, would it?

IOW, I think this is the first case where you require specific CS high
and this should make you think why...

Best regards,
Krzysztof



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