[libcamera-devel] [PATCH v5 4/6] libcamera: camera_sensor: Add V4L2 control operations

[Laurent Pinchart]

Hi Jacopo,

Thank you for the patch.

On Thu, Jun 20, 2019 at 05:31:42PM +0200, Jacopo Mondi wrote:
> Add operations to get and set control and to retrieve the informations
> on a V4L2 control. For simple camera sensors, the operations are
> directly called on the underlying V4L2 subdevice.
> 
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
>  src/libcamera/camera_sensor.cpp       | 65 +++++++++++++++++++++++++++
>  src/libcamera/include/camera_sensor.h |  6 +++
>  2 files changed, 71 insertions(+)
> 
> diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
> index a804a68c9d91..637f86b05701 100644
> --- a/src/libcamera/camera_sensor.cpp
> +++ b/src/libcamera/camera_sensor.cpp
> @@ -247,6 +247,71 @@ int CameraSensor::setFormat(V4L2SubdeviceFormat *format)
>  	return subdev_->setFormat(0, format);
>  }
>  
> +/**
> + * \brief Retrieve information about a control
> + * \param[in] id The control ID
> + * \return A pointer to the V4L2ControlInfo for control \a id, or nullptr
> + * if the sensor doesn't have such a control
> + */
> +const V4L2ControlInfo *CameraSensor::getControlInfo(unsigned int id) const
> +{
> +	return subdev_->getControlInfo(id);
> +}
> +
> +/**
> + * \brief Read controls from the sensor
> + * \param[inout] ctrls The list of controls to read
> + *
> + * Read the value of each control contained in \a ctrls, and store the
> + * value in the corresponding \a ctrls entry.
> + *
> + * If an integer number less than the requested number of controls is returned,
> + * only controls up to that index have been successfully read.
> + *
> + * Each V4L2Control instance in \a ctrls should be supported by the sensor and
> + * accessible (ie the V4L2_CTRL_FLAG_DISABLED flag should not be set), otherwise
> + * a negative error code (-EINVAL) is returned
> + *
> + * \sa V4L2Device::getControls()
> + *
> + * \return 0 on success or an error code otherwise
> + * \retval -EINVAL One of the control is not supported or not accessible
> + * \retval i The index of the control that failed
> + */

Let's copy the documentation for getControls() and setControls() from
patch 3/6 once we agree on it, and

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> +int CameraSensor::getControls(V4L2Controls *ctrls)
> +{
> +	return subdev_->getControls(ctrls);
> +}
> +
> +/**
> + * \brief Write controls to the sensor
> + * \param[in] ctrls The list of controls to write
> + *
> + * Write the value of each V4L2Control contained in \a ctrls. Each
> + * control should be initialized by the caller with a value, otherwise
> + * the result of the operation is undefined.
> + *
> + * The value of each control is updated to reflect what has been
> + * actually applied on the sensor.
> + *
> + * If an integer number less than the requested number of controls is returned,
> + * only controls up to that index have been successfully applied.
> + *
> + * Each V4L2Control instance in \a ctrls should be supported by the sensor and
> + * accessible (ie the V4L2_CTRL_FLAG_DISABLED flag should not be set), otherwise
> + * a negative error code (-EINVAL) is returned
> + *
> + * \sa V4L2Device::setControls()
> + *
> + * \return 0 on success or an error code otherwise
> + * \retval -EINVAL One of the control is not supported or not accessible
> + * \retval i The index of the control that failed
> + */
> +int CameraSensor::setControls(V4L2Controls *ctrls)
> +{
> +	return subdev_->setControls(ctrls);
> +}
> +
>  std::string CameraSensor::logPrefix() const
>  {
>  	return "'" + subdev_->entity()->name() + "'";
> diff --git a/src/libcamera/include/camera_sensor.h b/src/libcamera/include/camera_sensor.h
> index b823480241a7..b4f4b66e96c4 100644
> --- a/src/libcamera/include/camera_sensor.h
> +++ b/src/libcamera/include/camera_sensor.h
> @@ -17,6 +17,8 @@
>  namespace libcamera {
>  
>  class MediaEntity;
> +class V4L2ControlInfo;
> +class V4L2Controls;
>  class V4L2Subdevice;
>  
>  struct V4L2SubdeviceFormat;
> @@ -41,6 +43,10 @@ public:
>  				      const Size &size) const;
>  	int setFormat(V4L2SubdeviceFormat *format);
>  
> +	const V4L2ControlInfo *getControlInfo(unsigned int id) const;
> +	int getControls(V4L2Controls *ctrls);
> +	int setControls(V4L2Controls *ctrls);
> +
>  protected:
>  	std::string logPrefix() const;
>  

-- 
Regards,

Laurent Pinchart