Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 171 insertions, 0 deletions

diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h
new file mode 100644
index 000000000..8586cfb49
--- /dev/null
+++ b/include/media/v4l2-fh.h
@@ -0,0 +1,171 @@
+/*
+ * 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.
+ */
+
+#ifndef V4L2_FH_H
+#define V4L2_FH_H
+
+#include <linux/fs.h>
+#include <linux/kconfig.h>
+#include <linux/list.h>
+#include <linux/videodev2.h>
+
+struct video_device;
+struct v4l2_ctrl_handler;
+
+/**
+ * struct v4l2_fh - Describes a V4L2 file handler
+ *
+ * @list: list of file handlers
+ * @vdev: pointer to &struct video_device
+ * @ctrl_handler: pointer to &struct v4l2_ctrl_handler
+ * @prio: priority of the file handler, as defined by &enum v4l2_priority
+ *
+ * @wait: event' s wait queue
+ * @subscribe_lock: serialise changes to the subscribed list; guarantee that
+ *		    the add and del event callbacks are orderly called
+ * @subscribed: list of subscribed events
+ * @available: list of events waiting to be dequeued
+ * @navailable: number of available events at @available list
+ * @sequence: event sequence number
+ *
+ * @m2m_ctx: pointer to &struct v4l2_m2m_ctx
+ */
+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 mutex		subscribe_lock;
+	struct list_head	subscribed;
+	struct list_head	available;
+	unsigned int		navailable;
+	u32			sequence;
+
+#if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV)
+	struct v4l2_m2m_ctx	*m2m_ctx;
+#endif
+};
+
+/**
+ * v4l2_fh_init - Initialise the file handle.
+ *
+ * @fh: pointer to &struct v4l2_fh
+ * @vdev: pointer to &struct video_device
+ *
+ * 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 &struct v4l2_fh.
+ */
+void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
+
+/**
+ * v4l2_fh_add - Add the fh to the list of file handles on a video_device.
+ *
+ * @fh: pointer to &struct v4l2_fh
+ *
+ * .. note::
+ *    The @fh file handle must be initialised first.
+ */
+void v4l2_fh_add(struct v4l2_fh *fh);
+
+/**
+ * v4l2_fh_open - Ancillary routine that can be used as the open\(\) op
+ *	of v4l2_file_operations.
+ *
+ * @filp: pointer to struct file
+ *
+ * It allocates a v4l2_fh and inits and adds it to the &struct video_device
+ * associated with the file pointer.
+ */
+int v4l2_fh_open(struct file *filp);
+
+/**
+ * v4l2_fh_del - Remove file handle from the list of file handles.
+ *
+ * @fh: pointer to &struct v4l2_fh
+ *
+ * On error filp->private_data will be %NULL, otherwise it will point to
+ * the &struct v4l2_fh.
+ *
+ * .. note::
+ *    Must be called in v4l2_file_operations->release\(\) handler if the driver
+ *    uses &struct v4l2_fh.
+ */
+void v4l2_fh_del(struct v4l2_fh *fh);
+
+/**
+ * v4l2_fh_exit - Release resources related to a file handle.
+ *
+ * @fh: pointer to &struct v4l2_fh
+ *
+ * Parts of the V4L2 framework using the v4l2_fh must release their
+ * resources here, too.
+ *
+ * .. note::
+ *    Must be called in v4l2_file_operations->release\(\) handler if the
+ *    driver uses &struct v4l2_fh.
+ */
+void v4l2_fh_exit(struct v4l2_fh *fh);
+
+/**
+ * v4l2_fh_release - Ancillary routine that can be used as the release\(\) op
+ *	of v4l2_file_operations.
+ *
+ * @filp: pointer to struct file
+ *
+ * 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);
+
+/**
+ * v4l2_fh_is_singular - Returns 1 if this filehandle is the only filehandle
+ *	 opened for the associated video_device.
+ *
+ * @fh: pointer to &struct v4l2_fh
+ *
+ * If @fh is NULL, then it returns 0.
+ */
+int v4l2_fh_is_singular(struct v4l2_fh *fh);
+
+/**
+ * v4l2_fh_is_singular_file - Returns 1 if this filehandle is the only
+ *	filehandle opened for the associated video_device.
+ *
+ * @filp: pointer to struct file
+ *
+ * This is a helper function variant of v4l2_fh_is_singular() with uses
+ * 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 */