[libcamera-devel] [PATCH v7 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 |  2 +
 src/libcamera/v4l2_device.cpp            | 53 ++++++++++++++++++++++--
 2 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h
index b82e2a14..687be9b2 100644
--- a/include/libcamera/internal/v4l2_device.h
+++ b/include/libcamera/internal/v4l2_device.h
@@ -56,6 +56,8 @@ protected:
 	int fd() const { return fd_; }
 
 private:
+	ControlInfo v4l2MenuControlInfo(const v4l2_query_ext_ctrl &ctrl);
+
 	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 b39c6266..40e2c74c 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -524,6 +524,38 @@ int V4L2Device::ioctl(unsigned long request, void *argp)
  * \return The V4L2 device file descriptor, -1 if the device node is not open
  */
 
+/**
+ * \brief Create ControlInfo for a V4L2 menu ctrl
+ * \param[in] ctrl The v4l2_query_ext_ctrl that represents a menu
+ *
+ * The created ControlInfo contains indices acquired by VIDIOC_QUERYMENU.
+ *
+ * \return ControlInfo for a V4L2 menu ctrl.
+ */
+ControlInfo V4L2Device::v4l2MenuControlInfo(
+	const struct v4l2_query_ext_ctrl &ctrl)
+{
+	std::vector<ControlValue> indices;
+	struct v4l2_querymenu menu = {};
+	menu.id = ctrl.id;
+
+	if (ctrl.minimum < 0)
+		return ControlInfo();
+
+	ControlValue def = {};
+	for (int32_t index = ctrl.minimum; index <= ctrl.maximum; ++index) {
+		menu.index = index;
+		if (ioctl(VIDIOC_QUERYMENU, &menu) != 0)
+			continue;
+
+		indices.push_back(index);
+		if (index == ctrl.default_value)
+			def = ControlValue(index);
+	}
+
+	return ControlInfo(indices, def);
+}
+
 /*
  * \brief List and store information about all controls supported by the
  * V4L2 device
@@ -533,7 +565,6 @@ 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;
@@ -544,16 +575,23 @@ 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:
+			ctrlInfo = v4l2MenuControlInfo(ctrl);
 			break;
+
 		/* \todo Support other control types. */
 		default:
 			LOG(V4L2, Debug)
@@ -562,10 +600,13 @@ void V4L2Device::listControls()
 			continue;
 		}
 
+		LOG(V4L2, Debug) << "Control: " << ctrl.name
+				 << " (" << utils::hex(ctrl.id) << ")";
+
 		controlIds_.emplace_back(v4l2ControlId(ctrl));
 		controlInfo_.emplace(ctrl.id, ctrl);
 
-		ctrls.emplace(controlIds_.back().get(), v4l2ControlInfo(ctrl));
+		ctrls.emplace(controlIds_.back().get(), std::move(ctrlInfo));
 	}
 
 	controls_ = std::move(ctrls);
@@ -630,6 +671,10 @@ 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
-- 
2.32.0.rc1.229.g3e70b5a671-goog