Re: [PATCH] dt-bindings: input: Goodix SPI HID Touchscreen

[Krzysztof Kozlowski <krzk@kernel.org>]

On 19/10/2024 04:55, Charles Wang wrote:
> Hi Doug
> 
> On Fri, Oct 18, 2024 at 01:48:56PM -0700, Doug Anderson wrote:
>>
>> On Thu, Oct 17, 2024 at 7:09 PM Charles Wang <charles.goodix@gmail.com> wrote:
>>>
>>> The Goodix GT7986U touch controller report touch data according to the
>>> HID protocol through the SPI bus. However, it is incompatible with
>>> Microsoft's HID-over-SPI protocol.
>>>
>>> Signed-off-by: Charles Wang <charles.goodix@gmail.com>
>>> ---
>>>  .../bindings/input/goodix,gt7375p.yaml        | 68 ++++++++++++++++---
>>>  1 file changed, 58 insertions(+), 10 deletions(-)
>>
>> I'm happy to let device tree folks make the call here, but IMO it
>> would be much cleaner to just consider the I2C-connected GT7986U and
>> the SPI-connected GT7986U to be different things and just use a

Same device, you cannot have different compatibles. The way how the same
(literally same chip) device sits on the bus is not part of the binding,
thus no different compatibles.

>> different compatible string for them. So essentially go back to your
>> v7 patch from before [1] but change the compatible to
>> "goodix,gt7986u-spi". If, for instance, this device also had a USB
>> interface then I don't think we'd try to cram it into the same
>> bindings even though the same physical chip was present...
>>
> 
> Honestly, I agree with this approach, but Krzysztof seems to prefer
> extending the existing binding.

I prefer not to have warnings and that was the problem with original
patchset. I am fine with splitting different models between different
binding schemas/files, but not the same device in two files.

Best regards,
Krzysztof