[libcamera-devel] [PATCH v8 2/8] libcamera: Allow access to v4l2_query_ext_ctrl structure for a V4L2 control

[David Plowman]

The V4L2Device::controlInfo 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>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.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..722fb72 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 *controlInfo(uint32_t id) const;
+
 	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..31d4dad 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 Retrieve the v4l2_query_ext_ctrl information for the given control
+ * \param[in] id 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
+ */
+const struct v4l2_query_ext_ctrl *V4L2Device::controlInfo(uint32_t id) const
+{
+	const auto it = controlInfo_.find(id);
+	if (it == controlInfo_.end())
+		return nullptr;
+
+	return &it->second;
+}
+
 /**
  * \brief Retrieve the device path in sysfs
  *
-- 
2.20.1