libcamera: Add V4L2 Device object

Provide a helper V4L2 device object capable of interacting with the V4L2 Linux Kernel APIs. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-01-17 21:55:21 +00:00
parent e399a0745b
commit e74f3eebb4
3 changed files with 248 additions and 0 deletions
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * v4l2_device.h - V4L2 Device
+ */
+#ifndef __LIBCAMERA_V4L2_DEVICE_H__
+#define __LIBCAMERA_V4L2_DEVICE_H__
+
+#include <string>
+
+#include <linux/videodev2.h>
+
+namespace libcamera {
+
+struct V4L2Capability final : v4l2_capability {
+	const char *driver() const
+	{
+		return reinterpret_cast<const char *>(v4l2_capability::driver);
+	}
+	const char *card() const
+	{
+		return reinterpret_cast<const char *>(v4l2_capability::card);
+	}
+	const char *bus_info() const
+	{
+		return reinterpret_cast<const char *>(v4l2_capability::bus_info);
+	}
+
+	bool isCapture() const { return capabilities & V4L2_CAP_VIDEO_CAPTURE; }
+	bool isOutput() const { return capabilities & V4L2_CAP_VIDEO_OUTPUT; }
+	bool hasStreaming() const { return capabilities & V4L2_CAP_STREAMING; }
+};
+
+class V4L2Device
+{
+public:
+	V4L2Device(const std::string &devnode);
+	V4L2Device(const V4L2Device &) = delete;
+	~V4L2Device();
+
+	void operator=(const V4L2Device &) = delete;
+
+	int open();
+	bool isOpen() const;
+	void close();
+
+	const char *driverName() const { return caps_.driver(); }
+	const char *deviceName() const { return caps_.card(); }
+	const char *busName() const { return caps_.bus_info(); }
+
+private:
+	std::string devnode_;
+	int fd_;
+	V4L2Capability caps_;
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_V4L2_DEVICE_H__ */