[PATCH] media: stm32: dcmi: Register V4L2 subdev nodes

[Hugues FRUCHET]

Hi Marek,

As said by Laurent -thanks for answer Laurent- driver configures the 
subdevs internally and not expose subdev interface. This is done to keep 
legacy applications based on V4L2 interface up & running.

As said also, all the sensor controls are exposed on dcmi video node so 
you don't need subdev interface to get access on sensor controls.

Best regards,
Hugues.

On 6/19/22 02:43, Marek Vasut wrote:
> On 6/19/22 02:33, Laurent Pinchart wrote:
>> On Sun, Jun 19, 2022 at 02:28:55AM +0200, Marek Vasut wrote:
>>> On 6/19/22 01:20, Laurent Pinchart wrote:
>>>> Hi Marek,
>>>>
>>>> Thank you for the patch.
>>>>
>>>> On Sun, Jun 19, 2022 at 12:23:35AM +0200, Marek Vasut wrote:
>>>>> Unless the V4L2 device calls v4l2_device_register_subdev_nodes(),
>>>>> the /dev/v4l-subdev* sub-device nodes are not registered and thus
>>>>> not created. Add the missing call.
>>>>
>>>> This driver configures the subdevs internally. Exposing the subdev 
>>>> nodes
>>>> to userspace would conflict with driver operation.
>>>>
>>>> If you need the subdev nodes only to query subdev information, you can
>>>> use v4l2_device_register_ro_subdev_nodes(). Ideally I'd prefer this
>>>> driver to expose subdev nodes to userspace and stop propagating formats
>>>> internally, but that may break applications :-(
>>>
>>> I need those subdevs to configure e.g. test pattern on the sensor side.
>>
>> Doesn't the dcmi driver expose the sensor controls on the video node ?
> 
> Apparently it does, so, discard this patch.