[libcamera-devel] [PATCH v5 2/8] libcamera: Allow access to v4l2_query_ext_ctrl structure for a V4L2 control

[Laurent Pinchart]

Hi David,

Thank you for the patch.

On Sat, Aug 29, 2020 at 12:54:23PM +0100, David Plowman wrote:
> The V4L2Device::queryCtrl method simply returns a pointer to the
> v4l2_query_ext_ctrl structure for the given control, which has already
> been retrieved and stored.
> 
> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> ---
>  include/libcamera/internal/v4l2_device.h |  2 ++
>  src/libcamera/v4l2_device.cpp            | 15 +++++++++++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h
> index 3b605aa..86dc05c 100644
> --- a/include/libcamera/internal/v4l2_device.h
> +++ b/include/libcamera/internal/v4l2_device.h
> @@ -29,6 +29,8 @@ public:
>  	ControlList getControls(const std::vector<uint32_t> &ids);
>  	int setControls(ControlList *ctrls);
>  
> +	const struct v4l2_query_ext_ctrl *queryControl(uint32_t id);
> +
>  	const std::string &deviceNode() const { return deviceNode_; }
>  	std::string devicePath() const;
>  
> diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
> index 65830d4..af48107 100644
> --- a/src/libcamera/v4l2_device.cpp
> +++ b/src/libcamera/v4l2_device.cpp
> @@ -353,6 +353,21 @@ int V4L2Device::setControls(ControlList *ctrls)
>  	return ret;
>  }
>  
> +/**
> + * \brief Return the v4l2_query_ext_ctrl information for the given control.

s/Return/Retrieve/

> + * \param[in] id The id number of the V4L2 control.

Maybe just "The V4L2 control ID" ?

> + * \return A pointer to the v4l2_query_ext_ctrl structure for the given
> + * control, or a null pointer if not found.

No need for trailing . at the end of one-line doxygen tags.

> + */
> +const struct v4l2_query_ext_ctrl *V4L2Device::queryControl(uint32_t id)

I'd name the function controlInfo() as queryControl() may be considered
as implying that it issues a query control ioctl.

With these small issues fixed,

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

> +{
> +	const auto it = controlInfo_.find(id);
> +	if (it == controlInfo_.end())
> +		return nullptr;
> +
> +	return &it->second;
> +}
> +
>  /**
>   * \brief Retrieve the device path in sysfs
>   *

-- 
Regards,

Laurent Pinchart