[libcamera-devel] [PATCH v4 2/6] libcamera: V4L2Device: Support v4l2 menu control

[Hirokazu Honda]

This adds a support of v4l2 menu. The control info for v4l2 menu
contains indices without names and 64bit values of querymenu.

Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
---
 include/libcamera/internal/v4l2_device.h |  3 ++
 src/libcamera/v4l2_device.cpp            | 65 +++++++++++++++++++++---
 2 files changed, 61 insertions(+), 7 deletions(-)

diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h
index 087f07e7..c7a2539c 100644
--- a/include/libcamera/internal/v4l2_device.h
+++ b/include/libcamera/internal/v4l2_device.h
@@ -54,6 +54,9 @@ protected:
 	int fd() const { return fd_; }
 
 private:
+	bool createControlInfoForMenu(const v4l2_query_ext_ctrl &ctrl,
+				      ControlInfo &ctrlInfo);
+
 	void listControls();
 	void updateControls(ControlList *ctrls,
 			    Span<const v4l2_ext_control> v4l2Ctrls);
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 397029ac..7056c71a 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -452,6 +452,7 @@ int V4L2Device::ioctl(unsigned long request, void *argp)
 	return 0;
 }
 
+
 /**
  * \fn V4L2Device::deviceNode()
  * \brief Retrieve the device node path
@@ -459,10 +460,47 @@ int V4L2Device::ioctl(unsigned long request, void *argp)
  */
 
 /**
- * \fn V4L2Device::fd()
- * \brief Retrieve the V4L2 device file descriptor
- * \return The V4L2 device file descriptor, -1 if the device node is not open
+ * \brief Create ControlInfo for v4l2 menu ctrl.
+ * \param[in] ctrl The v4l2_query_ext_ctrl that represents a menu
+ * \param[out] ctrlInfo The created controlInfo
+ *
+ * The created ControlInfo contains not only values and also extra values, which
+ * are indices and name/value acquired by VIDIOC_QUERYMENU, respectively. The
+ * extra values contains std::string if the type of \a ctrl is
+ * V4L2_CTRL_TYPE_MENU or int64_t otherwise.
+ *
+ * \return True on success or false otherwise
  */
+bool V4L2Device::createControlInfoForMenu(const v4l2_query_ext_ctrl &ctrl,
+					  ControlInfo &ctrlInfo)
+{
+	ASSERT(ctrl.type == V4L2_CTRL_TYPE_MENU ||
+	       ctrl.type == V4L2_CTRL_TYPE_INTEGER_MENU);
+
+	std::vector<ControlValue> indices;
+	v4l2_querymenu menu;
+	memset(&menu, 0, sizeof(menu));
+	menu.id = ctrl.id;
+
+	for (menu.index = ctrl.minimum;
+	     static_cast<int>(menu.index) <= ctrl.maximum; menu.index++) {
+		if (ioctl(VIDIOC_QUERYMENU, &menu) != 0)
+			continue;
+
+		indices.emplace_back(static_cast<int32_t>(menu.index));
+	}
+
+	if (indices.empty()) {
+		LOG(V4L2, Error)
+			<< "No applicable value: " << utils::hex(ctrl.id);
+
+		return false;
+	}
+
+	ctrlInfo = ControlInfo(indices);
+
+	return true;
+}
 
 /*
  * \brief List and store information about all controls supported by the
@@ -473,7 +511,6 @@ void V4L2Device::listControls()
 	ControlInfoMap::Map ctrls;
 	struct v4l2_query_ext_ctrl ctrl = {};
 
-	/* \todo Add support for menu controls. */
 	while (1) {
 		ctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL |
 			   V4L2_CTRL_FLAG_NEXT_COMPOUND;
@@ -484,15 +521,22 @@ void V4L2Device::listControls()
 		    ctrl.flags & V4L2_CTRL_FLAG_DISABLED)
 			continue;
 
+		ControlInfo ctrlInfo;
 		switch (ctrl.type) {
 		case V4L2_CTRL_TYPE_INTEGER:
 		case V4L2_CTRL_TYPE_BOOLEAN:
-		case V4L2_CTRL_TYPE_MENU:
 		case V4L2_CTRL_TYPE_BUTTON:
 		case V4L2_CTRL_TYPE_INTEGER64:
 		case V4L2_CTRL_TYPE_BITMASK:
-		case V4L2_CTRL_TYPE_INTEGER_MENU:
 		case V4L2_CTRL_TYPE_U8:
+			ctrlInfo = V4L2ControlInfo(ctrl);
+			break;
+
+		case V4L2_CTRL_TYPE_INTEGER_MENU:
+		case V4L2_CTRL_TYPE_MENU:
+			if (!createControlInfoForMenu(ctrl, ctrlInfo))
+				continue;
+
 			break;
 		/* \todo Support other control types. */
 		default:
@@ -502,10 +546,13 @@ void V4L2Device::listControls()
 			continue;
 		}
 
+		LOG(V4L2, Debug) << "Control: " << ctrl.name
+				 << " (" << utils::hex(ctrl.id) << ")";
+
 		controlIds_.emplace_back(std::make_unique<V4L2ControlId>(ctrl));
 		controlInfo_.emplace(ctrl.id, ctrl);
 
-		ctrls.emplace(controlIds_.back().get(), V4L2ControlInfo(ctrl));
+		ctrls.emplace(controlIds_.back().get(), ctrlInfo);
 	}
 
 	controls_ = std::move(ctrls);
@@ -535,6 +582,10 @@ void V4L2Device::updateControls(ControlList *ctrls,
 			value.set<int64_t>(v4l2Ctrl->value64);
 			break;
 
+		case ControlTypeInteger32:
+			value.set<int32_t>(v4l2Ctrl->value);
+			break;
+
 		case ControlTypeByte:
 			/*
 			 * No action required, the VIDIOC_[GS]_EXT_CTRLS ioctl
-- 
2.31.1.607.g51e8a6a459-goog