[PATCH] v4l2: v4l2_camera_proxy: Fix VIDIOC_[GS]_PARM support

[Paul Elder]

On Mon, Nov 04, 2024 at 05:38:25PM +0200, Laurent Pinchart wrote:
> v4l2-compliance reports an error due to VIDIOC_S_PARM being supported
> without VIDIOC_G_PARM. Fix it by implementing VIDIOC_G_PARM. To satisfy
> all compliance tests, VIDIOC_S_PARM also needs to be updated to properly
> zero reserved fields.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Looks good to me.

Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>

> ---
>  src/v4l2/v4l2_camera.h         |  1 +
>  src/v4l2/v4l2_camera_proxy.cpp | 63 ++++++++++++++++++++++++++++++++--
>  src/v4l2/v4l2_camera_proxy.h   |  2 ++
>  3 files changed, 64 insertions(+), 2 deletions(-)
> 
> diff --git a/src/v4l2/v4l2_camera.h b/src/v4l2/v4l2_camera.h
> index e54371fb4e00..9bd161b909de 100644
> --- a/src/v4l2/v4l2_camera.h
> +++ b/src/v4l2/v4l2_camera.h
> @@ -52,6 +52,7 @@ public:
>  				  libcamera::StreamConfiguration *streamConfigOut);
>  
>  	libcamera::ControlList &controls() { return controls_; }
> +	const libcamera::ControlInfoMap &controlInfo() { return camera_->controls(); }
>  
>  	int allocBuffers(unsigned int count);
>  	void freeBuffers();
> diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
> index 5ac8df4cffef..559ffc6170b1 100644
> --- a/src/v4l2/v4l2_camera_proxy.cpp
> +++ b/src/v4l2/v4l2_camera_proxy.cpp
> @@ -195,6 +195,29 @@ void V4L2CameraProxy::setFmtFromConfig(const StreamConfiguration &streamConfig)
>  	v4l2PixFormat_.xfer_func    = V4L2_XFER_FUNC_DEFAULT;
>  
>  	sizeimage_ = streamConfig.frameSize;
> +
> +	const ControlInfoMap &controls = vcam_->controlInfo();
> +	const auto &it = controls.find(&controls::FrameDurationLimits);
> +
> +	if (it != controls.end()) {
> +		const int64_t duration = it->second.def().get<int64_t>();
> +
> +		v4l2TimePerFrame_.numerator = duration;
> +		v4l2TimePerFrame_.denominator = 1000000;
> +	} else {
> +		/*
> +		 * Default to 30fps if the camera doesn't expose the
> +		 * FrameDurationLimits control.
> +		 *
> +		 * \todo Remove this once all pipeline handlers implement the
> +		 * control
> +		 */
> +		LOG(V4L2Compat, Warning)
> +			<< "Camera does not support FrameDurationLimits";
> +
> +		v4l2TimePerFrame_.numerator = 333333;
> +		v4l2TimePerFrame_.denominator = 1000000;
> +	}
>  }
>  
>  void V4L2CameraProxy::querycap(std::shared_ptr<Camera> camera)
> @@ -758,6 +781,22 @@ int V4L2CameraProxy::vidioc_streamoff(V4L2CameraFile *file, int *arg)
>  	return ret;
>  }
>  
> +int V4L2CameraProxy::vidioc_g_parm(V4L2CameraFile *file, struct v4l2_streamparm *arg)
> +{
> +	LOG(V4L2Compat, Debug)
> +		<< "[" << file->description() << "] " << __func__ << "()";
> +
> +	if (!validateBufferType(arg->type))
> +		return -EINVAL;
> +
> +	memset(&arg->parm, 0, sizeof(arg->parm));
> +
> +	arg->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
> +	arg->parm.capture.timeperframe = v4l2TimePerFrame_;
> +
> +	return 0;
> +}
> +
>  int V4L2CameraProxy::vidioc_s_parm(V4L2CameraFile *file, struct v4l2_streamparm *arg)
>  {
>  	LOG(V4L2Compat, Debug)
> @@ -766,9 +805,25 @@ int V4L2CameraProxy::vidioc_s_parm(V4L2CameraFile *file, struct v4l2_streamparm
>  	if (!validateBufferType(arg->type))
>  		return -EINVAL;
>  
> -	struct v4l2_fract *timeperframe = &arg->parm.capture.timeperframe;
> -	utils::Duration frameDuration = 1.0s * timeperframe->numerator / timeperframe->denominator;
> +	/*
> +	 * Store the frame duration if it is valid, otherwise keep the current
> +	 * value.
> +	 *
> +	 * \todo The provided value should be adjusted based on the camera
> +	 * capabilities.
> +	 */
> +	if (arg->parm.capture.timeperframe.numerator &&
> +	    arg->parm.capture.timeperframe.denominator)
> +		v4l2TimePerFrame_ = arg->parm.capture.timeperframe;
>  
> +	memset(&arg->parm, 0, sizeof(arg->parm));
> +
> +	arg->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
> +	arg->parm.capture.timeperframe = v4l2TimePerFrame_;
> +
> +	/* Apply the frame duration. */
> +	utils::Duration frameDuration = 1.0s * v4l2TimePerFrame_.numerator
> +				      / v4l2TimePerFrame_.denominator;
>  	int64_t uDuration = frameDuration.get<std::micro>();
>  	vcam_->controls().set(controls::FrameDurationLimits, { uDuration, uDuration });
>  
> @@ -795,6 +850,7 @@ const std::set<unsigned long> V4L2CameraProxy::supportedIoctls_ = {
>  	VIDIOC_EXPBUF,
>  	VIDIOC_STREAMON,
>  	VIDIOC_STREAMOFF,
> +	VIDIOC_G_PARM,
>  	VIDIOC_S_PARM,
>  };
>  
> @@ -883,6 +939,9 @@ int V4L2CameraProxy::ioctl(V4L2CameraFile *file, unsigned long longRequest, void
>  	case VIDIOC_STREAMOFF:
>  		ret = vidioc_streamoff(file, static_cast<int *>(arg));
>  		break;
> +	case VIDIOC_G_PARM:
> +		ret = vidioc_g_parm(file, static_cast<struct v4l2_streamparm *>(arg));
> +		break;
>  	case VIDIOC_S_PARM:
>  		ret = vidioc_s_parm(file, static_cast<struct v4l2_streamparm *>(arg));
>  		break;
> diff --git a/src/v4l2/v4l2_camera_proxy.h b/src/v4l2/v4l2_camera_proxy.h
> index c957db5349cc..5aa352c36f6a 100644
> --- a/src/v4l2/v4l2_camera_proxy.h
> +++ b/src/v4l2/v4l2_camera_proxy.h
> @@ -67,6 +67,7 @@ private:
>  	int vidioc_expbuf(V4L2CameraFile *file, struct v4l2_exportbuffer *arg);
>  	int vidioc_streamon(V4L2CameraFile *file, int *arg);
>  	int vidioc_streamoff(V4L2CameraFile *file, int *arg);
> +	int vidioc_g_parm(V4L2CameraFile *file, struct v4l2_streamparm *arg);
>  	int vidioc_s_parm(V4L2CameraFile *file, struct v4l2_streamparm *arg);
>  
>  	bool hasOwnership(V4L2CameraFile *file);
> @@ -85,6 +86,7 @@ private:
>  
>  	struct v4l2_capability capabilities_;
>  	struct v4l2_pix_format v4l2PixFormat_;
> +	struct v4l2_fract v4l2TimePerFrame_;
>  
>  	std::vector<struct v4l2_buffer> buffers_;
>  	std::map<void *, unsigned int> mmaps_;
> 
> base-commit: 58598f4dde9a3d4236ed52881da9b155443cbc50
> -- 
> Regards,
> 
> Laurent Pinchart
>