1 files changed, 107 insertions, 0 deletions

diff --git a/kernel/include/media/v4l2-fh.h b/kernel/include/media/v4l2-fh.h
new file mode 100644
index 000000000..803516775
--- /dev/null
+++ b/kernel/include/media/v4l2-fh.h
@@ -0,0 +1,107 @@
+/*
+ * v4l2-fh.h
+ *
+ * V4L2 file handle. Store per file handle data for the V4L2
+ * framework. Using file handles is optional for the drivers.
+ *
+ * Copyright (C) 2009--2010 Nokia Corporation.
+ *
+ * Contact: Sakari Ailus <sakari.ailus@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef V4L2_FH_H
+#define V4L2_FH_H
+
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/videodev2.h>
+
+struct video_device;
+struct v4l2_ctrl_handler;
+
+struct v4l2_fh {
+	struct list_head	list;
+	struct video_device	*vdev;
+	struct v4l2_ctrl_handler *ctrl_handler;
+	enum v4l2_priority	prio;
+
+	/* Events */
+	wait_queue_head_t	wait;
+	struct list_head	subscribed; /* Subscribed events */
+	struct list_head	available; /* Dequeueable event */
+	unsigned int		navailable;
+	u32			sequence;
+
+#if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV)
+	struct v4l2_m2m_ctx	*m2m_ctx;
+#endif
+};
+
+/*
+ * Initialise the file handle. Parts of the V4L2 framework using the
+ * file handles should be initialised in this function. Must be called
+ * from driver's v4l2_file_operations->open() handler if the driver
+ * uses v4l2_fh.
+ */
+void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
+/*
+ * Add the fh to the list of file handles on a video_device. The file
+ * handle must be initialised first.
+ */
+void v4l2_fh_add(struct v4l2_fh *fh);
+/*
+ * Can be used as the open() op of v4l2_file_operations.
+ * It allocates a v4l2_fh and inits and adds it to the video_device associated
+ * with the file pointer.
+ */
+int v4l2_fh_open(struct file *filp);
+/*
+ * Remove file handle from the list of file handles. Must be called in
+ * v4l2_file_operations->release() handler if the driver uses v4l2_fh.
+ * On error filp->private_data will be NULL, otherwise it will point to
+ * the v4l2_fh struct.
+ */
+void v4l2_fh_del(struct v4l2_fh *fh);
+/*
+ * Release resources related to a file handle. Parts of the V4L2
+ * framework using the v4l2_fh must release their resources here, too.
+ * Must be called in v4l2_file_operations->release() handler if the
+ * driver uses v4l2_fh.
+ */
+void v4l2_fh_exit(struct v4l2_fh *fh);
+/*
+ * Can be used as the release() op of v4l2_file_operations.
+ * It deletes and exits the v4l2_fh associated with the file pointer and
+ * frees it. It will do nothing if filp->private_data (the pointer to the
+ * v4l2_fh struct) is NULL. This function always returns 0.
+ */
+int v4l2_fh_release(struct file *filp);
+/*
+ * Returns 1 if this filehandle is the only filehandle opened for the
+ * associated video_device. If fh is NULL, then it returns 0.
+ */
+int v4l2_fh_is_singular(struct v4l2_fh *fh);
+/*
+ * Helper function with struct file as argument. If filp->private_data is
+ * NULL, then it will return 0.
+ */
+static inline int v4l2_fh_is_singular_file(struct file *filp)
+{
+	return v4l2_fh_is_singular(filp->private_data);
+}
+
+#endif /* V4L2_EVENT_H */