Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 1 | /* |
| 2 | * v4l2-fh.h |
| 3 | * |
| 4 | * V4L2 file handle. Store per file handle data for the V4L2 |
| 5 | * framework. Using file handles is optional for the drivers. |
| 6 | * |
| 7 | * Copyright (C) 2009--2010 Nokia Corporation. |
| 8 | * |
Sakari Ailus | 8c5dff9 | 2012-10-28 06:44:17 -0300 | [diff] [blame] | 9 | * Contact: Sakari Ailus <sakari.ailus@iki.fi> |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 10 | * |
| 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. |
| 14 | * |
| 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. |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 19 | */ |
| 20 | |
| 21 | #ifndef V4L2_FH_H |
| 22 | #define V4L2_FH_H |
| 23 | |
Laurent Pinchart | 4f1af2a | 2013-10-03 18:55:52 -0300 | [diff] [blame] | 24 | #include <linux/fs.h> |
Alexandre Courbot | 14351d4 | 2018-02-04 21:33:04 -0500 | [diff] [blame] | 25 | #include <linux/kconfig.h> |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 26 | #include <linux/list.h> |
Laurent Pinchart | c8d185c | 2013-10-03 18:59:30 -0300 | [diff] [blame] | 27 | #include <linux/videodev2.h> |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 28 | |
| 29 | struct video_device; |
Hans Verkuil | 2d28b68 | 2011-03-12 08:54:43 -0300 | [diff] [blame] | 30 | struct v4l2_ctrl_handler; |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 31 | |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 32 | /** |
| 33 | * struct v4l2_fh - Describes a V4L2 file handler |
| 34 | * |
| 35 | * @list: list of file handlers |
| 36 | * @vdev: pointer to &struct video_device |
| 37 | * @ctrl_handler: pointer to &struct v4l2_ctrl_handler |
| 38 | * @prio: priority of the file handler, as defined by &enum v4l2_priority |
| 39 | * |
| 40 | * @wait: event' s wait queue |
Sakari Ailus | ad608fb | 2018-09-11 05:32:37 -0400 | [diff] [blame] | 41 | * @subscribe_lock: serialise changes to the subscribed list; guarantee that |
| 42 | * the add and del event callbacks are orderly called |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 43 | * @subscribed: list of subscribed events |
| 44 | * @available: list of events waiting to be dequeued |
| 45 | * @navailable: number of available events at @available list |
| 46 | * @sequence: event sequence number |
Sakari Ailus | ad608fb | 2018-09-11 05:32:37 -0400 | [diff] [blame] | 47 | * |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 48 | * @m2m_ctx: pointer to &struct v4l2_m2m_ctx |
| 49 | */ |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 50 | struct v4l2_fh { |
| 51 | struct list_head list; |
| 52 | struct video_device *vdev; |
Hans Verkuil | 2d28b68 | 2011-03-12 08:54:43 -0300 | [diff] [blame] | 53 | struct v4l2_ctrl_handler *ctrl_handler; |
Hans Verkuil | fc5602b | 2010-12-29 13:36:50 -0300 | [diff] [blame] | 54 | enum v4l2_priority prio; |
Hans Verkuil | 523f46d | 2011-06-13 17:44:42 -0300 | [diff] [blame] | 55 | |
| 56 | /* Events */ |
| 57 | wait_queue_head_t wait; |
Sakari Ailus | ad608fb | 2018-09-11 05:32:37 -0400 | [diff] [blame] | 58 | struct mutex subscribe_lock; |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 59 | struct list_head subscribed; |
| 60 | struct list_head available; |
Hans Verkuil | 523f46d | 2011-06-13 17:44:42 -0300 | [diff] [blame] | 61 | unsigned int navailable; |
Hans Verkuil | 523f46d | 2011-06-13 17:44:42 -0300 | [diff] [blame] | 62 | u32 sequence; |
Sylwester Nawrocki | 8e6e8f9 | 2013-09-14 18:39:04 -0300 | [diff] [blame] | 63 | |
| 64 | #if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV) |
| 65 | struct v4l2_m2m_ctx *m2m_ctx; |
| 66 | #endif |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 67 | }; |
| 68 | |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 69 | /** |
| 70 | * v4l2_fh_init - Initialise the file handle. |
| 71 | * |
| 72 | * @fh: pointer to &struct v4l2_fh |
| 73 | * @vdev: pointer to &struct video_device |
| 74 | * |
| 75 | * Parts of the V4L2 framework using the |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 76 | * file handles should be initialised in this function. Must be called |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 77 | * from driver's v4l2_file_operations->open\(\) handler if the driver |
| 78 | * uses &struct v4l2_fh. |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 79 | */ |
Hans Verkuil | 523f46d | 2011-06-13 17:44:42 -0300 | [diff] [blame] | 80 | void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev); |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 81 | |
| 82 | /** |
| 83 | * v4l2_fh_add - Add the fh to the list of file handles on a video_device. |
| 84 | * |
| 85 | * @fh: pointer to &struct v4l2_fh |
| 86 | * |
| 87 | * .. note:: |
| 88 | * The @fh file handle must be initialised first. |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 89 | */ |
| 90 | void v4l2_fh_add(struct v4l2_fh *fh); |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 91 | |
| 92 | /** |
| 93 | * v4l2_fh_open - Ancillary routine that can be used as the open\(\) op |
| 94 | * of v4l2_file_operations. |
| 95 | * |
| 96 | * @filp: pointer to struct file |
| 97 | * |
| 98 | * It allocates a v4l2_fh and inits and adds it to the &struct video_device |
| 99 | * associated with the file pointer. |
Hans Verkuil | 73cb420 | 2011-01-08 09:36:04 -0300 | [diff] [blame] | 100 | */ |
| 101 | int v4l2_fh_open(struct file *filp); |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 102 | |
| 103 | /** |
| 104 | * v4l2_fh_del - Remove file handle from the list of file handles. |
| 105 | * |
| 106 | * @fh: pointer to &struct v4l2_fh |
| 107 | * |
| 108 | * On error filp->private_data will be %NULL, otherwise it will point to |
| 109 | * the &struct v4l2_fh. |
| 110 | * |
| 111 | * .. note:: |
| 112 | * Must be called in v4l2_file_operations->release\(\) handler if the driver |
| 113 | * uses &struct v4l2_fh. |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 114 | */ |
| 115 | void v4l2_fh_del(struct v4l2_fh *fh); |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 116 | |
| 117 | /** |
| 118 | * v4l2_fh_exit - Release resources related to a file handle. |
| 119 | * |
| 120 | * @fh: pointer to &struct v4l2_fh |
| 121 | * |
| 122 | * Parts of the V4L2 framework using the v4l2_fh must release their |
| 123 | * resources here, too. |
| 124 | * |
| 125 | * .. note:: |
| 126 | * Must be called in v4l2_file_operations->release\(\) handler if the |
| 127 | * driver uses &struct v4l2_fh. |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 128 | */ |
| 129 | void v4l2_fh_exit(struct v4l2_fh *fh); |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 130 | |
| 131 | /** |
| 132 | * v4l2_fh_release - Ancillary routine that can be used as the release\(\) op |
| 133 | * of v4l2_file_operations. |
| 134 | * |
| 135 | * @filp: pointer to struct file |
| 136 | * |
Hans Verkuil | 73cb420 | 2011-01-08 09:36:04 -0300 | [diff] [blame] | 137 | * It deletes and exits the v4l2_fh associated with the file pointer and |
| 138 | * frees it. It will do nothing if filp->private_data (the pointer to the |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 139 | * v4l2_fh struct) is %NULL. |
| 140 | * |
| 141 | * This function always returns 0. |
Hans Verkuil | 73cb420 | 2011-01-08 09:36:04 -0300 | [diff] [blame] | 142 | */ |
| 143 | int v4l2_fh_release(struct file *filp); |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 144 | |
| 145 | /** |
| 146 | * v4l2_fh_is_singular - Returns 1 if this filehandle is the only filehandle |
| 147 | * opened for the associated video_device. |
| 148 | * |
| 149 | * @fh: pointer to &struct v4l2_fh |
| 150 | * |
| 151 | * If @fh is NULL, then it returns 0. |
Hans Verkuil | dfddb24 | 2011-01-08 09:38:02 -0300 | [diff] [blame] | 152 | */ |
| 153 | int v4l2_fh_is_singular(struct v4l2_fh *fh); |
Mauro Carvalho Chehab | 4ada120 | 2016-07-22 09:06:45 -0300 | [diff] [blame] | 154 | |
| 155 | /** |
| 156 | * v4l2_fh_is_singular_file - Returns 1 if this filehandle is the only |
| 157 | * filehandle opened for the associated video_device. |
| 158 | * |
| 159 | * @filp: pointer to struct file |
| 160 | * |
| 161 | * This is a helper function variant of v4l2_fh_is_singular() with uses |
| 162 | * struct file as argument. |
| 163 | * |
| 164 | * If filp->private_data is %NULL, then it will return 0. |
Hans Verkuil | dfddb24 | 2011-01-08 09:38:02 -0300 | [diff] [blame] | 165 | */ |
| 166 | static inline int v4l2_fh_is_singular_file(struct file *filp) |
| 167 | { |
| 168 | return v4l2_fh_is_singular(filp->private_data); |
| 169 | } |
Sakari Ailus | 1babcb4 | 2010-03-23 09:25:26 -0300 | [diff] [blame] | 170 | |
| 171 | #endif /* V4L2_EVENT_H */ |