[PATCH v2 1/3] dt-bindings: media: Add bindings for THine THP7312 ISP

[Krzysztof Kozlowski]

On 12/10/2023 15:05, Laurent Pinchart wrote:

>>> +
>>> +  clocks:
>>> +    maxItems: 1
>>> +    description: CLKI clock input
>>> +
>>> +  thine,boot-mode:
>>> +    $ref: /schemas/types.yaml#/definitions/uint32
>>> +    description:
>>> +      Boot mode of the THP7312. 0 is for standard streaming mode, for the
>>> +      THP7312 to be used as an ISP. 1 is for firmware flashing mode.
>>
>> Why, for a given board, would you always boot device in one specific
>> mode but not the other? This does not look like property of DT.
> 
> The device has two boot mode pins, and it operates differently depending
> on its boot mode. The pins are typically hardwired, on development
> boards you commonly have DIP switches, and on production systems test
> pads that allow modifying the boot mode on the production line. The
> driver needs to know the boot mode to interact with the device
> appropriately. I haven't found a good way to interogate the device at
> runtime to figure out the boot mode, but I'm still trying. If that
> doesn't succeed, we need to convey it through the device tree.

Hm, that's okay then, but please describe that it is expected
bootstrapped boot mode of a device, because now it sounds like
configuring some boot mode in the device.

Best regards,
Krzysztof