1 /* 2 V4L2 device support header. 3 4 Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl> 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 */ 20 21 #ifndef _V4L2_DEVICE_H 22 #define _V4L2_DEVICE_H 23 24 #include <media/media-device.h> 25 #include <media/v4l2-subdev.h> 26 #include <media/v4l2-dev.h> 27 28 /* Each instance of a V4L2 device should create the v4l2_device struct, 29 either stand-alone or embedded in a larger struct. 30 31 It allows easy access to sub-devices (see v4l2-subdev.h) and provides 32 basic V4L2 device-level support. 33 */ 34 35 #define V4L2_DEVICE_NAME_SIZE (20 + 16) 36 37 struct v4l2_ctrl_handler; 38 39 struct v4l2_device { 40 /* dev->driver_data points to this struct. 41 Note: dev might be NULL if there is no parent device 42 as is the case with e.g. ISA devices. */ 43 struct device *dev; 44 #if defined(CONFIG_MEDIA_CONTROLLER) 45 struct media_device *mdev; 46 #endif 47 /* used to keep track of the registered subdevs */ 48 struct list_head subdevs; 49 /* lock this struct; can be used by the driver as well if this 50 struct is embedded into a larger struct. */ 51 spinlock_t lock; 52 /* unique device name, by default the driver name + bus ID */ 53 char name[V4L2_DEVICE_NAME_SIZE]; 54 /* notify callback called by some sub-devices. */ 55 void (*notify)(struct v4l2_subdev *sd, 56 unsigned int notification, void *arg); 57 /* The control handler. May be NULL. */ 58 struct v4l2_ctrl_handler *ctrl_handler; 59 /* Device's priority state */ 60 struct v4l2_prio_state prio; 61 /* Keep track of the references to this struct. */ 62 struct kref ref; 63 /* Release function that is called when the ref count goes to 0. */ 64 void (*release)(struct v4l2_device *v4l2_dev); 65 }; 66 67 static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) 68 { 69 kref_get(&v4l2_dev->ref); 70 } 71 72 int v4l2_device_put(struct v4l2_device *v4l2_dev); 73 74 /* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev. 75 dev may be NULL in rare cases (ISA devices). In that case you 76 must fill in the v4l2_dev->name field before calling this function. */ 77 int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); 78 79 /* Optional function to initialize the name field of struct v4l2_device using 80 the driver name and a driver-global atomic_t instance. 81 This function will increment the instance counter and returns the instance 82 value used in the name. 83 84 Example: 85 86 static atomic_t drv_instance = ATOMIC_INIT(0); 87 88 ... 89 90 instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance); 91 92 The first time this is called the name field will be set to foo0 and 93 this function returns 0. If the name ends with a digit (e.g. cx18), 94 then the name will be set to cx18-0 since cx180 looks really odd. */ 95 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, 96 atomic_t *instance); 97 98 /* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects. 99 Since the parent disappears this ensures that v4l2_dev doesn't have an 100 invalid parent pointer. */ 101 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); 102 103 /* Unregister all sub-devices and any other resources related to v4l2_dev. */ 104 void v4l2_device_unregister(struct v4l2_device *v4l2_dev); 105 106 /* Register a subdev with a v4l2 device. While registered the subdev module 107 is marked as in-use. An error is returned if the module is no longer 108 loaded when you attempt to register it. */ 109 int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 110 struct v4l2_subdev *sd); 111 /* Unregister a subdev with a v4l2 device. Can also be called if the subdev 112 wasn't registered. In that case it will do nothing. */ 113 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); 114 115 /* Register device nodes for all subdev of the v4l2 device that are marked with 116 * the V4L2_SUBDEV_FL_HAS_DEVNODE flag. 117 */ 118 int __must_check 119 v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); 120 121 /* Send a notification to v4l2_device. */ 122 static inline void v4l2_subdev_notify(struct v4l2_subdev *sd, 123 unsigned int notification, void *arg) 124 { 125 if (sd && sd->v4l2_dev && sd->v4l2_dev->notify) 126 sd->v4l2_dev->notify(sd, notification, arg); 127 } 128 129 /* Iterate over all subdevs. */ 130 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 131 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 132 133 /* Call the specified callback for all subdevs matching the condition. 134 Ignore any errors. Note that you cannot add or delete a subdev 135 while walking the subdevs list. */ 136 #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ 137 do { \ 138 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ 139 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 140 (sd)->ops->o->f((sd) , ##args); \ 141 } while (0) 142 143 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 144 do { \ 145 struct v4l2_subdev *__sd; \ 146 \ 147 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ 148 f , ##args); \ 149 } while (0) 150 151 /* Call the specified callback for all subdevs matching the condition. 152 If the callback returns an error other than 0 or -ENOIOCTLCMD, then 153 return with that error code. Note that you cannot add or delete a 154 subdev while walking the subdevs list. */ 155 #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ 156 ({ \ 157 long __err = 0; \ 158 \ 159 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ 160 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 161 __err = (sd)->ops->o->f((sd) , ##args); \ 162 if (__err && __err != -ENOIOCTLCMD) \ 163 break; \ 164 } \ 165 (__err == -ENOIOCTLCMD) ? 0 : __err; \ 166 }) 167 168 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 169 ({ \ 170 struct v4l2_subdev *__sd; \ 171 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ 172 f , ##args); \ 173 }) 174 175 /* Call the specified callback for all subdevs matching grp_id (if 0, then 176 match them all). Ignore any errors. Note that you cannot add or delete 177 a subdev while walking the subdevs list. */ 178 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 179 do { \ 180 struct v4l2_subdev *__sd; \ 181 \ 182 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 183 !(grpid) || __sd->grp_id == (grpid), o, f , \ 184 ##args); \ 185 } while (0) 186 187 /* Call the specified callback for all subdevs matching grp_id (if 0, then 188 match them all). If the callback returns an error other than 0 or 189 -ENOIOCTLCMD, then return with that error code. Note that you cannot 190 add or delete a subdev while walking the subdevs list. */ 191 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 192 ({ \ 193 struct v4l2_subdev *__sd; \ 194 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 195 !(grpid) || __sd->grp_id == (grpid), o, f , \ 196 ##args); \ 197 }) 198 199 #define v4l2_device_has_op(v4l2_dev, o, f) \ 200 ({ \ 201 struct v4l2_subdev *__sd; \ 202 bool __result = false; \ 203 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 204 if (v4l2_subdev_has_op(__sd, o, f)) { \ 205 __result = true; \ 206 break; \ 207 } \ 208 } \ 209 __result; \ 210 }) 211 212 #endif 213