[libcamera-devel] [PATCH v4 4/9] libcamera: camera_sensor: Discover VCMs through ancillary links

[Daniel Scally]

Morning Laurent

On 03/02/2022 00:19, Laurent Pinchart wrote:
> Hi Dan,
>
> Thank you for the patch.
>
> On Mon, Jan 31, 2022 at 10:33:25PM +0000, Daniel Scally wrote:
>> Add a function to check for and initialise any VCMs linked to the
>> CameraSensor's entity by ancillary links. This should initialise
>> the lens_ member with the linked entity. Call the new function
>> during CameraSensor::init().
>>
>> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
>> Signed-off-by: Daniel Scally <djrscally at gmail.com>
>> ---
>> Changes in v4:
>>
>> 	- Fixed typo (Laurent)
>>
>> Changes in v3:
>>
>> 	- Fixed some style errors
>> 	- Replaced the flash case by printing the entity function in the 
>> 	default case.
>>
>>  include/libcamera/internal/camera_sensor.h |  1 +
>>  src/libcamera/camera_sensor.cpp            | 39 ++++++++++++++++++++++
>>  2 files changed, 40 insertions(+)
>>
>> diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h
>> index 2fa11567..7fb4eded 100644
>> --- a/include/libcamera/internal/camera_sensor.h
>> +++ b/include/libcamera/internal/camera_sensor.h
>> @@ -81,6 +81,7 @@ private:
>>  	void initTestPatternModes();
>>  	int initProperties();
>>  	int applyTestPatternMode(controls::draft::TestPatternModeEnum mode);
>> +	int discoverAncillaryDevices();
>>  
>>  	const MediaEntity *entity_;
>>  	std::unique_ptr<V4L2Subdevice> subdev_;
>> diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
>> index 64f7f12c..f00c0aca 100644
>> --- a/src/libcamera/camera_sensor.cpp
>> +++ b/src/libcamera/camera_sensor.cpp
>> @@ -172,6 +172,10 @@ int CameraSensor::init()
>>  	if (ret)
>>  		return ret;
>>  
>> +	ret = discoverAncillaryDevices();
>> +	if (ret)
>> +		return ret;
>> +
>>  	return applyTestPatternMode(controls::draft::TestPatternModeEnum::TestPatternModeOff);
>>  }
>>  
>> @@ -443,6 +447,41 @@ int CameraSensor::initProperties()
>>  	return 0;
>>  }
>>  
>> +/**
>> + * \brief Check for and initialise any ancillary devices
>> + *
>> + * Sensors sometimes have ancillary devices such as a Lens or Flash that could
>> + * be linked to their MediaEntity by the kernel. Search for and handle any
>> + * such device.
>> + *
>> + * \todo Handle MEDIA_ENT_F_FLASH too.
>> + */
>> +int CameraSensor::discoverAncillaryDevices()
>> +{
>> +	int ret;
>> +
>> +	for (MediaEntity *ancillary : entity_->ancillaryEntities()) {
>> +		switch (ancillary->function()) {
>> +		case MEDIA_ENT_F_LENS:
>> +			focusLens_ = std::make_unique<CameraLens>(ancillary);
>> +			ret = focusLens_->init();
>> +			if (ret) {
>> +				LOG(CameraSensor, Error)
>> +					<< "CameraLens initialisation failed";
>> +				return ret;
>> +			}
>> +			break;
>> +
>> +		default:
>> +			LOG(CameraSensor, Warning)
>> +				<< "Unsupported ancillary entity function "
>> +				<< ancillary->function();
> A break would be good here too, even if not strictly required.


Okedokey - I'll add it in v5. Thanks for the comments on the other
patches also :)

>
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>  /**
>>   * \fn CameraSensor::model()
>>   * \brief Retrieve the sensor model name