libcamera: v4l2_controls: Index V4L2ControlInfoMap by ControlId *

To bring the libcamera and V4L2 control info maps closer, index the
latter by ControlId * like the former. As V4L2ControlInfoMap is widely
indexed by V4L2 numerical IDs, add accessors based on numerical IDs.

This allows complete removal of the ControId pointer from the
V4L2ControlInfo, as the ControId is accessible as the key when iterating
over the map. A handful of users have to be modified to adapt to the
change.

The controlInfo argument from V4L2Device::updateControls() can also be
removed as it itsn't used anymore.

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

6 files changed, 93 insertions, 50 deletions

diff --git a/src/libcamera/include/v4l2_controls.h b/src/libcamera/include/v4l2_controls.h
index 4d7ac1a1..ca721750 100644
--- a/src/libcamera/include/v4l2_controls.h
+++ b/src/libcamera/include/v4l2_controls.h
@@ -28,31 +28,41 @@ public:
 class V4L2ControlInfo
 {
 public:
-	V4L2ControlInfo(const V4L2ControlId &id,
-			const struct v4l2_query_ext_ctrl &ctrl);
+	V4L2ControlInfo(const struct v4l2_query_ext_ctrl &ctrl);
 
-	const ControlId &id() const { return *id_; }
 	const ControlRange &range() const { return range_; }
 
 private:
-	const V4L2ControlId *id_;
 	ControlRange range_;
 };
 
-class V4L2ControlInfoMap : private std::map<unsigned int, V4L2ControlInfo>
+class V4L2ControlInfoMap : private std::map<const ControlId *, V4L2ControlInfo>
 {
 public:
-	V4L2ControlInfoMap &operator=(std::map<unsigned int, V4L2ControlInfo> &&info);
-
-	using std::map<unsigned int, V4L2ControlInfo>::begin;
-	using std::map<unsigned int, V4L2ControlInfo>::cbegin;
-	using std::map<unsigned int, V4L2ControlInfo>::end;
-	using std::map<unsigned int, V4L2ControlInfo>::cend;
-	using std::map<unsigned int, V4L2ControlInfo>::at;
-	using std::map<unsigned int, V4L2ControlInfo>::empty;
-	using std::map<unsigned int, V4L2ControlInfo>::size;
-	using std::map<unsigned int, V4L2ControlInfo>::count;
-	using std::map<unsigned int, V4L2ControlInfo>::find;
+	V4L2ControlInfoMap &operator=(std::map<const ControlId *, V4L2ControlInfo> &&info);
+
+	using std::map<const ControlId *, V4L2ControlInfo>::key_type;
+	using std::map<const ControlId *, V4L2ControlInfo>::mapped_type;
+	using std::map<const ControlId *, V4L2ControlInfo>::value_type;
+	using std::map<const ControlId *, V4L2ControlInfo>::size_type;
+	using std::map<const ControlId *, V4L2ControlInfo>::iterator;
+	using std::map<const ControlId *, V4L2ControlInfo>::const_iterator;
+
+	using std::map<const ControlId *, V4L2ControlInfo>::begin;
+	using std::map<const ControlId *, V4L2ControlInfo>::cbegin;
+	using std::map<const ControlId *, V4L2ControlInfo>::end;
+	using std::map<const ControlId *, V4L2ControlInfo>::cend;
+	using std::map<const ControlId *, V4L2ControlInfo>::at;
+	using std::map<const ControlId *, V4L2ControlInfo>::empty;
+	using std::map<const ControlId *, V4L2ControlInfo>::size;
+	using std::map<const ControlId *, V4L2ControlInfo>::count;
+	using std::map<const ControlId *, V4L2ControlInfo>::find;
+
+	mapped_type &at(unsigned int key);
+	const mapped_type &at(unsigned int key) const;
+	size_type count(unsigned int key) const;
+	iterator find(unsigned int key);
+	const_iterator find(unsigned int key) const;
 
 	const ControlIdMap &idmap() const { return idmap_; }
 
diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h
index 5a5b8582..f30b1c2c 100644
--- a/src/libcamera/include/v4l2_device.h
+++ b/src/libcamera/include/v4l2_device.h
@@ -45,7 +45,6 @@ protected:
 private:
 	void listControls();
 	void updateControls(ControlList *ctrls,
-			    const V4L2ControlInfo **controlInfo,
 			    const struct v4l2_ext_control *v4l2Ctrls,
 			    unsigned int count);
 
diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
index 547ad5ca..4d76b5fd 100644
--- a/src/libcamera/pipeline/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo.cpp
@@ -340,7 +340,7 @@ int UVCCameraData::init(MediaEntity *entity)
 		const V4L2ControlInfo &info = ctrl.second;
 		const ControlId *id;
 
-		switch (info.id().id()) {
+		switch (ctrl.first->id()) {
 		case V4L2_CID_BRIGHTNESS:
 			id = &controls::Brightness;
 			break;
diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
index 53d00360..78c0fe5a 100644
--- a/src/libcamera/pipeline/vimc.cpp
+++ b/src/libcamera/pipeline/vimc.cpp
@@ -416,7 +416,7 @@ int VimcCameraData::init(MediaDevice *media)
 		const V4L2ControlInfo &info = ctrl.second;
 		const ControlId *id;
 
-		switch (info.id().id()) {
+		switch (ctrl.first->id()) {
 		case V4L2_CID_BRIGHTNESS:
 			id = &controls::Brightness;
 			break;
diff --git a/src/libcamera/v4l2_controls.cpp b/src/libcamera/v4l2_controls.cpp
index 12c4fb27..9a5e4830 100644
--- a/src/libcamera/v4l2_controls.cpp
+++ b/src/libcamera/v4l2_controls.cpp
@@ -122,12 +122,9 @@ V4L2ControlId::V4L2ControlId(const struct v4l2_query_ext_ctrl &ctrl)
 
 /**
  * \brief Construct a V4L2ControlInfo from a struct v4l2_query_ext_ctrl
- * \param[in] id The V4L2 control ID
  * \param[in] ctrl The struct v4l2_query_ext_ctrl as returned by the kernel
  */
-V4L2ControlInfo::V4L2ControlInfo(const V4L2ControlId &id,
-				 const struct v4l2_query_ext_ctrl &ctrl)
-	: id_(&id)
+V4L2ControlInfo::V4L2ControlInfo(const struct v4l2_query_ext_ctrl &ctrl)
 {
 	if (ctrl.type == V4L2_CTRL_TYPE_INTEGER64)
 		range_ = ControlRange(static_cast<int64_t>(ctrl.minimum),
@@ -138,12 +135,6 @@ V4L2ControlInfo::V4L2ControlInfo(const V4L2ControlId &id,
 }
 
 /**
- * \fn V4L2ControlInfo::id()
- * \brief Retrieve the control ID
- * \return The V4L2 control ID
- */
-
-/**
  * \fn V4L2ControlInfo::range()
  * \brief Retrieve the control value range
  * \return The V4L2 control value range
@@ -151,7 +142,7 @@ V4L2ControlInfo::V4L2ControlInfo(const V4L2ControlId &id,
 
 /**
  * \class V4L2ControlInfoMap
- * \brief A map of control ID to V4L2ControlInfo
+ * \brief A map of controlID to V4L2ControlInfo
  */
 
 /**
@@ -165,18 +156,70 @@ V4L2ControlInfo::V4L2ControlInfo(const V4L2ControlId &id,
  *
  * \return The populated V4L2ControlInfoMap
  */
-V4L2ControlInfoMap &V4L2ControlInfoMap::operator=(std::map<unsigned int, V4L2ControlInfo> &&info)
+V4L2ControlInfoMap &V4L2ControlInfoMap::operator=(std::map<const ControlId *, V4L2ControlInfo> &&info)
 {
-	std::map<unsigned int, V4L2ControlInfo>::operator=(std::move(info));
+	std::map<const ControlId *, V4L2ControlInfo>::operator=(std::move(info));
 
 	idmap_.clear();
 	for (const auto &ctrl : *this)
-		idmap_[ctrl.first] = &ctrl.second.id();
+		idmap_[ctrl.first->id()] = ctrl.first;
 
 	return *this;
 }
 
 /**
+ * \brief Access specified element by numerical ID
+ * \param[in] id The numerical ID
+ * \return A reference to the element whose ID is equal to \a id
+ */
+V4L2ControlInfoMap::mapped_type &V4L2ControlInfoMap::at(unsigned int id)
+{
+	return at(idmap_.at(id));
+}
+
+/**
+ * \brief Access specified element by numerical ID
+ * \param[in] id The numerical ID
+ * \return A const reference to the element whose ID is equal to \a id
+ */
+const V4L2ControlInfoMap::mapped_type &V4L2ControlInfoMap::at(unsigned int id) const
+{
+	return at(idmap_.at(id));
+}
+
+/**
+ * \brief Count the number of elements matching a numerical ID
+ * \param[in] id The numerical ID
+ * \return The number of elements matching the numerical \a id
+ */
+V4L2ControlInfoMap::size_type V4L2ControlInfoMap::count(unsigned int id) const
+{
+	return count(idmap_.at(id));
+}
+
+/**
+ * \brief Find the element matching a numerical ID
+ * \param[in] id The numerical ID
+ * \return An iterator pointing to the element matching the numerical \a id, or
+ * end() if no such element exists
+ */
+V4L2ControlInfoMap::iterator V4L2ControlInfoMap::find(unsigned int id)
+{
+	return find(idmap_.at(id));
+}
+
+/**
+ * \brief Find the element matching a numerical ID
+ * \param[in] id The numerical ID
+ * \return A const iterator pointing to the element matching the numerical
+ * \a id, or end() if no such element exists
+ */
+V4L2ControlInfoMap::const_iterator V4L2ControlInfoMap::find(unsigned int id) const
+{
+	return find(idmap_.at(id));
+}
+
+/**
  * \fn const ControlIdMap &V4L2ControlInfoMap::idmap() const
  * \brief Retrieve the ControlId map
  *
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 144a60b4..4bb7d595 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -171,7 +171,6 @@ int V4L2Device::getControls(ControlList *ctrls)
 	if (count == 0)
 		return 0;
 
-	const V4L2ControlInfo *controlInfo[count];
 	struct v4l2_ext_control v4l2Ctrls[count];
 	memset(v4l2Ctrls, 0, sizeof(v4l2Ctrls));
 
@@ -185,10 +184,7 @@ int V4L2Device::getControls(ControlList *ctrls)
 			return -EINVAL;
 		}
 
-		const V4L2ControlInfo *info = &iter->second;
-		controlInfo[i] = info;
 		v4l2Ctrls[i].id = id->id();
-
 		i++;
 	}
 
@@ -215,7 +211,7 @@ int V4L2Device::getControls(ControlList *ctrls)
 		ret = errorIdx;
 	}
 
-	updateControls(ctrls, controlInfo, v4l2Ctrls, count);
+	updateControls(ctrls, v4l2Ctrls, count);
 
 	return ret;
 }
@@ -249,7 +245,6 @@ int V4L2Device::setControls(ControlList *ctrls)
 	if (count == 0)
 		return 0;
 
-	const V4L2ControlInfo *controlInfo[count];
 	struct v4l2_ext_control v4l2Ctrls[count];
 	memset(v4l2Ctrls, 0, sizeof(v4l2Ctrls));
 
@@ -263,13 +258,11 @@ int V4L2Device::setControls(ControlList *ctrls)
 			return -EINVAL;
 		}
 
-		const V4L2ControlInfo *info = &iter->second;
-		controlInfo[i] = info;
 		v4l2Ctrls[i].id = id->id();
 
 		/* Set the v4l2_ext_control value for the write operation. */
 		const ControlValue &value = ctrl.second;
-		switch (info->id().type()) {
+		switch (id->type()) {
 		case ControlTypeInteger64:
 			v4l2Ctrls[i].value64 = value.get<int64_t>();
 			break;
@@ -308,7 +301,7 @@ int V4L2Device::setControls(ControlList *ctrls)
 		ret = errorIdx;
 	}
 
-	updateControls(ctrls, controlInfo, v4l2Ctrls, count);
+	updateControls(ctrls, v4l2Ctrls, count);
 
 	return ret;
 }
@@ -349,7 +342,7 @@ int V4L2Device::ioctl(unsigned long request, void *argp)
  */
 void V4L2Device::listControls()
 {
-	std::map<unsigned int, V4L2ControlInfo> ctrls;
+	std::map<const ControlId *, V4L2ControlInfo> ctrls;
 	struct v4l2_query_ext_ctrl ctrl = {};
 
 	/* \todo Add support for menu and compound controls. */
@@ -388,8 +381,8 @@ void V4L2Device::listControls()
 
 		controlIds_.emplace_back(utils::make_unique<V4L2ControlId>(ctrl));
 		ctrls.emplace(std::piecewise_construct,
-			      std::forward_as_tuple(ctrl.id),
-			      std::forward_as_tuple(*controlIds_.back().get(), ctrl));
+			      std::forward_as_tuple(controlIds_.back().get()),
+			      std::forward_as_tuple(ctrl));
 	}
 
 	controls_ = std::move(ctrls);
@@ -399,12 +392,10 @@ void V4L2Device::listControls()
  * \brief Update the value of the first \a count V4L2 controls in \a ctrls using
  * values in \a v4l2Ctrls
  * \param[inout] ctrls List of V4L2 controls to update
- * \param[in] controlInfo List of V4L2 control information
  * \param[in] v4l2Ctrls List of V4L2 extended controls as returned by the driver
  * \param[in] count The number of controls to update
  */
 void V4L2Device::updateControls(ControlList *ctrls,
-				const V4L2ControlInfo **controlInfo,
 				const struct v4l2_ext_control *v4l2Ctrls,
 				unsigned int count)
 {
@@ -414,10 +405,10 @@ void V4L2Device::updateControls(ControlList *ctrls,
 			break;
 
 		const struct v4l2_ext_control *v4l2Ctrl = &v4l2Ctrls[i];
-		const V4L2ControlInfo *info = controlInfo[i];
+		const ControlId *id = ctrl.first;
 		ControlValue &value = ctrl.second;
 
-		switch (info->id().type()) {
+		switch (id->type()) {
 		case ControlTypeInteger64:
 			value.set<int64_t>(v4l2Ctrl->value64);
 			break;