[libcamera-devel] [PATCH v2 6/6] [HACK] ipu3: Set and get a few sensor controls

[Kieran Bingham]

Hi Jacopo,

On 10/06/2019 17:40, Jacopo Mondi wrote:
> Not to merge patch to demonstrate how to set controls on the image
> sensor device.
> 
> Not-Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
>  src/libcamera/pipeline/ipu3/ipu3.cpp | 80 ++++++++++++++++++++++++++++
>  1 file changed, 80 insertions(+)
> 
> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> index b3e7fb0e9c64..59c1fe3c56fd 100644
> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> @@ -688,6 +688,86 @@ int PipelineHandlerIPU3::start(Camera *camera)
>  	ImgUDevice *imgu = data->imgu_;
>  	int ret;
>  
> +	/* --- Get control values --- */
> +	std::vector<unsigned int> controlIds = {
> +		V4L2_CID_EXPOSURE, V4L2_CID_ANALOGUE_GAIN,
> +	};
> +	V4L2Controls controls;
> +	ret = cio2->sensor_->dev()->getControls(controlIds, &controls);
> +	if (ret) {
> +		LOG(Error) << "Failed to get control values";
> +		return -EINVAL;
> +	}
> +

Moving some logic for printing the values (or working out how to use
ControlValue class in a V4L2Control) would simplify any debug prints
greatly:

for (V4L2Control *ctrl : controls) {
	LOG(Error) << "Control : " << id
		   << " - value: " << ctrl->value();
}


> +	for (V4L2Control *ctrl : controls) {
> +		unsigned int id = ctrl->id();
> +
> +		switch(ctrl->type()) {
> +		case V4L2_CTRL_TYPE_INTEGER:
> +		case V4L2_CTRL_TYPE_BOOLEAN:
> +		{
> +			uint32_t val = controls.getInt(id);
> +			LOG(Error) << "Control : " << id
> +				   << " - value: " << val;
> +		}
> +			break;
> +		case V4L2_CTRL_TYPE_INTEGER64:
> +		{
> +			uint64_t val = controls.getInt64(id);
> +			LOG(Error) << "Control : " << id
> +				   << " - value: " << val;
> +		}
> +			break;
> +		default:
> +			LOG(Error) << "Unsupported type: " << ctrl->type();
> +			return -EINVAL;
> +		}
> +	}
> +



> +	/* --- Set control values --- */
> +	V4L2Controls setControls;
> +	setControls.set(V4L2_CID_EXPOSURE, 2046);
> +	setControls.set(V4L2_CID_ANALOGUE_GAIN, 1024);
> +
> +	ret = cio2->sensor_->dev()->setControls(setControls);
> +	if (ret) {
> +		LOG(IPU3, Error) << "Failed to set controls";
> +		return ret;
> +	}
> +
> +	/* --- Get control values back again and verify they have changed --- */
> +	V4L2Controls newcontrols;
> +	ret = cio2->sensor_->dev()->getControls(controlIds, &newcontrols);
> +	if (ret) {
> +		LOG(Error) << "Failed to get control values";
> +		return -EINVAL;
> +	}
> +
> +	for (V4L2Control *ctrl : newcontrols) {
> +		unsigned int id = ctrl->id();
> +
> +		switch(ctrl->type()) {
> +		case V4L2_CTRL_TYPE_INTEGER:
> +		case V4L2_CTRL_TYPE_BOOLEAN:
> +		{
> +			uint32_t val = newcontrols.getInt(id);

Eeep, Here we are iterating new controls to print them (I get that this
is just a print) - but we are then 'getting' the int from the list
container instead of the V4L2Control, which is involving 'finding' the
control again, and iterating the 'newcontrols' container for each print?

Iterating the list twice seems painful to me... but perhaps that's just
because of this particular demo use case, and it might not be such an
issue in real usage.


> +			LOG(Error) << "Control : " << id
> +				   << " - value: " << val;
> +		}
> +			break;
> +		case V4L2_CTRL_TYPE_INTEGER64:
> +		{
> +			uint64_t val = newcontrols.getInt64(id);
> +			LOG(Error) << "Control : " << id
> +				   << " - value: " << val;
> +		}
> +			break;
> +		default:
> +			LOG(Error) << "Unsupported type: " << ctrl->type();
> +			return -EINVAL;
> +		}
> +	}
> +
>  	/*
>  	 * Start the ImgU video devices, buffers will be queued to the
>  	 * ImgU output and viewfinder when requests will be queued.
> 

-- 
Regards
--
Kieran