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authorJacopo Mondi <jacopo@jmondi.org>2019-06-12 17:30:21 +0200
committerJacopo Mondi <jacopo@jmondi.org>2019-06-25 14:01:35 +0200
commit030ce6491ed3d4c827a6ef4aa5c7e706867ded7b (patch)
tree247906891903410e3ec587329b330e27d4721700
parentbab8b01895bbbd2fd96af635cdfa8d62ae2d0e5f (diff)
libcamera: v4l2_device: List valid controls at open
Enumerate all the valid controls a device supports at open() time. A control is valid only if its type is supported. Store the control information in a map inside the device to save querying the control when setting or getting its value from the device and provide an operation to retrieve information by control ID. Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
-rw-r--r--src/libcamera/include/v4l2_device.h8
-rw-r--r--src/libcamera/v4l2_device.cpp57
2 files changed, 65 insertions, 0 deletions
diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h
index 75f23a05..55696046 100644
--- a/src/libcamera/include/v4l2_device.h
+++ b/src/libcamera/include/v4l2_device.h
@@ -7,18 +7,23 @@
#ifndef __LIBCAMERA_V4L2_DEVICE_H__
#define __LIBCAMERA_V4L2_DEVICE_H__
+#include <map>
#include <string>
#include "log.h"
namespace libcamera {
+class V4L2ControlInfo;
+
class V4L2Device : protected Loggable
{
public:
void close();
bool isOpen() const { return fd_ != -1; }
+ const V4L2ControlInfo *getControlInfo(unsigned int id) const;
+
const std::string &deviceNode() const { return deviceNode_; }
protected:
@@ -32,6 +37,9 @@ protected:
int fd() { return fd_; }
private:
+ void listControls();
+
+ std::map<unsigned int, V4L2ControlInfo> controls_;
std::string deviceNode_;
int fd_;
};
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 99621a72..51764b44 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -13,6 +13,7 @@
#include <unistd.h>
#include "log.h"
+#include "v4l2_controls.h"
/**
* \file v4l2_device.h
@@ -82,6 +83,8 @@ int V4L2Device::open(unsigned int flags)
fd_ = ret;
+ listControls();
+
return 0;
}
@@ -108,6 +111,21 @@ void V4L2Device::close()
*/
/**
+ * \brief Retrieve information about a control
+ * \param[in] id The control ID
+ * \return A pointer to the V4L2ControlInfo for control \a id, or nullptr
+ * if the device doesn't have such a control
+ */
+const V4L2ControlInfo *V4L2Device::getControlInfo(unsigned int id) const
+{
+ auto it = controls_.find(id);
+ if (it == controls_.end())
+ return nullptr;
+
+ return &it->second;
+}
+
+/**
* \brief Perform an IOCTL system call on the device node
* \param[in] request The IOCTL request code
* \param[in] argp A pointer to the IOCTL argument
@@ -137,4 +155,43 @@ int V4L2Device::ioctl(unsigned long request, void *argp)
* \return The V4L2 device file descriptor, -1 if the device node is not open
*/
+/*
+ * \brief List and store information about all controls supported by the
+ * V4L2 device
+ */
+void V4L2Device::listControls()
+{
+ struct v4l2_query_ext_ctrl ctrl = {};
+
+ /* \todo Add support for menu and compound controls. */
+ ctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
+ while (ioctl(VIDIOC_QUERY_EXT_CTRL, &ctrl) == 0) {
+ if (ctrl.type == V4L2_CTRL_TYPE_CTRL_CLASS ||
+ ctrl.flags & V4L2_CTRL_FLAG_DISABLED) {
+ ctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
+ continue;
+ }
+
+ V4L2ControlInfo info(ctrl);
+ switch (info.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:
+ break;
+ /* \todo Support compound controls. */
+ default:
+ LOG(V4L2, Error) << "Control type '" << info.type()
+ << "' not supported";
+ continue;
+ }
+
+ controls_.emplace(ctrl.id, info);
+ ctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
+ }
+}
+
} /* namespace libcamera */