clk: bcm2835: remove use of BCM2835_CLOCK_COUNT in driver
[linux/fpc-iii.git] / include / media / v4l2-fh.h
blob803516775162d184d4dbe8cf78e427ec3452e23c
1 /*
2 * v4l2-fh.h
4 * V4L2 file handle. Store per file handle data for the V4L2
5 * framework. Using file handles is optional for the drivers.
7 * Copyright (C) 2009--2010 Nokia Corporation.
9 * Contact: Sakari Ailus <sakari.ailus@iki.fi>
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * version 2 as published by the Free Software Foundation.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
23 * 02110-1301 USA
26 #ifndef V4L2_FH_H
27 #define V4L2_FH_H
29 #include <linux/fs.h>
30 #include <linux/list.h>
31 #include <linux/videodev2.h>
33 struct video_device;
34 struct v4l2_ctrl_handler;
36 struct v4l2_fh {
37 struct list_head list;
38 struct video_device *vdev;
39 struct v4l2_ctrl_handler *ctrl_handler;
40 enum v4l2_priority prio;
42 /* Events */
43 wait_queue_head_t wait;
44 struct list_head subscribed; /* Subscribed events */
45 struct list_head available; /* Dequeueable event */
46 unsigned int navailable;
47 u32 sequence;
49 #if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV)
50 struct v4l2_m2m_ctx *m2m_ctx;
51 #endif
55 * Initialise the file handle. Parts of the V4L2 framework using the
56 * file handles should be initialised in this function. Must be called
57 * from driver's v4l2_file_operations->open() handler if the driver
58 * uses v4l2_fh.
60 void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
62 * Add the fh to the list of file handles on a video_device. The file
63 * handle must be initialised first.
65 void v4l2_fh_add(struct v4l2_fh *fh);
67 * Can be used as the open() op of v4l2_file_operations.
68 * It allocates a v4l2_fh and inits and adds it to the video_device associated
69 * with the file pointer.
71 int v4l2_fh_open(struct file *filp);
73 * Remove file handle from the list of file handles. Must be called in
74 * v4l2_file_operations->release() handler if the driver uses v4l2_fh.
75 * On error filp->private_data will be NULL, otherwise it will point to
76 * the v4l2_fh struct.
78 void v4l2_fh_del(struct v4l2_fh *fh);
80 * Release resources related to a file handle. Parts of the V4L2
81 * framework using the v4l2_fh must release their resources here, too.
82 * Must be called in v4l2_file_operations->release() handler if the
83 * driver uses v4l2_fh.
85 void v4l2_fh_exit(struct v4l2_fh *fh);
87 * Can be used as the release() op of v4l2_file_operations.
88 * It deletes and exits the v4l2_fh associated with the file pointer and
89 * frees it. It will do nothing if filp->private_data (the pointer to the
90 * v4l2_fh struct) is NULL. This function always returns 0.
92 int v4l2_fh_release(struct file *filp);
94 * Returns 1 if this filehandle is the only filehandle opened for the
95 * associated video_device. If fh is NULL, then it returns 0.
97 int v4l2_fh_is_singular(struct v4l2_fh *fh);
99 * Helper function with struct file as argument. If filp->private_data is
100 * NULL, then it will return 0.
102 static inline int v4l2_fh_is_singular_file(struct file *filp)
104 return v4l2_fh_is_singular(filp->private_data);
107 #endif /* V4L2_EVENT_H */