libcamera: v4l2_controls: Add min and max to V4L2ControlInfo

Add min() and max() methods to V4L2ControlInfo to report the control's
minimum and maximum value respectively.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

src/libcamera/v4l2_controls.cpp

@@ -74,6 +74,8 @@ V4L2ControlInfo::V4L2ControlInfo(const struct v4l2_query_ext_ctrl &ctrl)
 	type_ = ctrl.type;
 	name_ = static_cast<const char *>(ctrl.name);
 	size_ = ctrl.elem_size * ctrl.elems;
+	min_ = ctrl.minimum;
+	max_ = ctrl.maximum;
 }
 
 /**
@@ -100,6 +102,18 @@ V4L2ControlInfo::V4L2ControlInfo(const struct v4l2_query_ext_ctrl &ctrl)
  * \return The V4L2 control user readable name
  */
 
+/**
+ * \fn V4L2ControlInfo::min()
+ * \brief Retrieve the control minimum value
+ * \return The V4L2 control minimum value
+ */
+
+/**
+ * \fn V4L2ControlInfo::max()
+ * \brief Retrieve the control maximum value
+ * \return The V4L2 control maximum value
+ */
+
 /**
  * \class V4L2Control
  * \brief A V4L2 control value