Re: [PATCH v9 0/2] [media] atmel-isc: add driver for Atmel ISC

["Wu, Songjun" <Songjun.Wu@microchip.com>]

On 8/15/2016 15:15, Hans Verkuil wrote:
> On 08/15/2016 08:09 AM, Wu, Songjun wrote:
>>
>>
>> On 8/12/2016 15:32, Hans Verkuil wrote:
>>> One quick question:
>>>
>>> On 08/11/2016 09:06 AM, Songjun Wu wrote:
>>>> The Image Sensor Controller driver includes two parts.
>>>> 1) Driver code to implement the ISC function.
>>>> 2) Device tree binding documentation, it describes how
>>>>    to add the ISC in device tree.
>>>>
>>>> Test result with v4l-utils.
>>>> # v4l2-compliance -f
>>>> v4l2-compliance SHA   : not available
>>>>
>>>> Driver Info:
>>>>         Driver name   : atmel_isc
>>>>         Card type     : Atmel Image Sensor Controller
>>>>         Bus info      : platform:atmel_isc f0008000.isc
>>>>         Driver version: 4.7.0
>>>>         Capabilities  : 0x84200001
>>>>                 Video Capture
>>>>                 Streaming
>>>>                 Extended Pix Format
>>>>                 Device Capabilities
>>>>         Device Caps   : 0x04200001
>>>>                 Video Capture
>>>>                 Streaming
>>>>                 Extended Pix Format
>>>>
>>>> Compliance test for device /dev/video0 (not using libv4l2):
>>>>
>>>> Required ioctls:
>>>>         test VIDIOC_QUERYCAP: OK
>>>>
>>>> Allow for multiple opens:
>>>>         test second video open: OK
>>>>         test VIDIOC_QUERYCAP: OK
>>>>         test VIDIOC_G/S_PRIORITY: OK
>>>>         test for unlimited opens: OK
>>>>
>>>> Debug ioctls:
>>>>         test VIDIOC_DBG_G/S_REGISTER: OK (Not Supported)
>>>>         test VIDIOC_LOG_STATUS: OK (Not Supported)
>>>>
>>>> Input ioctls:
>>>>         test VIDIOC_G/S_TUNER/ENUM_FREQ_BANDS: OK (Not Supported)
>>>>         test VIDIOC_G/S_FREQUENCY: OK (Not Supported)
>>>>         test VIDIOC_S_HW_FREQ_SEEK: OK (Not Supported)
>>>>         test VIDIOC_ENUMAUDIO: OK (Not Supported)
>>>>         test VIDIOC_G/S/ENUMINPUT: OK
>>>>         test VIDIOC_G/S_AUDIO: OK (Not Supported)
>>>>         Inputs: 1 Audio Inputs: 0 Tuners: 0
>>>>
>>>> Output ioctls:
>>>>         test VIDIOC_G/S_MODULATOR: OK (Not Supported)
>>>>         test VIDIOC_G/S_FREQUENCY: OK (Not Supported)
>>>>         test VIDIOC_ENUMAUDOUT: OK (Not Supported)
>>>>         test VIDIOC_G/S/ENUMOUTPUT: OK (Not Supported)
>>>>         test VIDIOC_G/S_AUDOUT: OK (Not Supported)
>>>>         Outputs: 0 Audio Outputs: 0 Modulators: 0
>>>>
>>>> Input/Output configuration ioctls:
>>>>         test VIDIOC_ENUM/G/S/QUERY_STD: OK (Not Supported)
>>>>         test VIDIOC_ENUM/G/S/QUERY_DV_TIMINGS: OK (Not Supported)
>>>>         test VIDIOC_DV_TIMINGS_CAP: OK (Not Supported)
>>>>         test VIDIOC_G/S_EDID: OK (Not Supported)
>>>>
>>>> Test input 0:
>>>>
>>>>         Control ioctls:
>>>>                 test VIDIOC_QUERY_EXT_CTRL/QUERYMENU: OK (Not Supported)
>>>>                 test VIDIOC_QUERYCTRL: OK (Not Supported)
>>>>                 test VIDIOC_G/S_CTRL: OK (Not Supported)
>>>>                 test VIDIOC_G/S/TRY_EXT_CTRLS: OK (Not Supported)
>>>>                 test VIDIOC_(UN)SUBSCRIBE_EVENT/DQEVENT: OK (Not Supported)
>>>>                 test VIDIOC_G/S_JPEGCOMP: OK (Not Supported)
>>>>                 Standard Controls: 0 Private Controls: 0
>>>
>>> Can you confirm that the sensor subdevice you are using does not have any controls?
>>> I ask since that is fairly unusual, so I want to make sure that controls are really
>>> not supported in this setup.
>>>
>> Sorry for the late reply.
>> The subdevice I use supports controls, but I did not develop the v4l2
>> controls in the sensor driver.
>
> So you mean the sensor hardware has controls, but the sensor driver doesn't implement
> them? Do I understand you correctly?
>
Yes, your understanding is correct.

>> Should I add the v4l2 controls and test again?
>
> If the sensor driver does not implement controls (i.e. has a struct v4l2_ctrl_handler),
> then everything is fine and the v4l2-compliance output is correct.
>
> Please confirm this. I just want to be 100% certain about this before I make the pull
> request.
>
I can confirm this. I use the sensor ov7740, and the driver is developed 
by myself, I did not add the v4l2 controls into the sensor driver for now.

> Thanks,
>
> 	Hans
>