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 /* BKL replacement mutex. Temporary solution only. */ 62 struct mutex ioctl_lock; 63 /* Keep track of the references to this struct. */ 64 struct kref ref; 65 /* Release function that is called when the ref count goes to 0. */ 66 void (*release)(struct v4l2_device *v4l2_dev); 67 }; 68 69 static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) 70 { 71 kref_get(&v4l2_dev->ref); 72 } 73 74 int v4l2_device_put(struct v4l2_device *v4l2_dev); 75 76 /* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev. 77 dev may be NULL in rare cases (ISA devices). In that case you 78 must fill in the v4l2_dev->name field before calling this function. */ 79 int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); 80 81 /* Optional function to initialize the name field of struct v4l2_device using 82 the driver name and a driver-global atomic_t instance. 83 This function will increment the instance counter and returns the instance 84 value used in the name. 85 86 Example: 87 88 static atomic_t drv_instance = ATOMIC_INIT(0); 89 90 ... 91 92 instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance); 93 94 The first time this is called the name field will be set to foo0 and 95 this function returns 0. If the name ends with a digit (e.g. cx18), 96 then the name will be set to cx18-0 since cx180 looks really odd. */ 97 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, 98 atomic_t *instance); 99 100 /* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects. 101 Since the parent disappears this ensures that v4l2_dev doesn't have an 102 invalid parent pointer. */ 103 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); 104 105 /* Unregister all sub-devices and any other resources related to v4l2_dev. */ 106 void v4l2_device_unregister(struct v4l2_device *v4l2_dev); 107 108 /* Register a subdev with a v4l2 device. While registered the subdev module 109 is marked as in-use. An error is returned if the module is no longer 110 loaded when you attempt to register it. */ 111 int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 112 struct v4l2_subdev *sd); 113 /* Unregister a subdev with a v4l2 device. Can also be called if the subdev 114 wasn't registered. In that case it will do nothing. */ 115 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); 116 117 /* Register device nodes for all subdev of the v4l2 device that are marked with 118 * the V4L2_SUBDEV_FL_HAS_DEVNODE flag. 119 */ 120 int __must_check 121 v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); 122 123 /* Send a notification to v4l2_device. */ 124 static inline void v4l2_subdev_notify(struct v4l2_subdev *sd, 125 unsigned int notification, void *arg) 126 { 127 if (sd && sd->v4l2_dev && sd->v4l2_dev->notify) 128 sd->v4l2_dev->notify(sd, notification, arg); 129 } 130 131 /* Iterate over all subdevs. */ 132 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 133 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 134 135 /* Call the specified callback for all subdevs matching the condition. 136 Ignore any errors. Note that you cannot add or delete a subdev 137 while walking the subdevs list. */ 138 #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ 139 do { \ 140 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ 141 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 142 (sd)->ops->o->f((sd) , ##args); \ 143 } while (0) 144 145 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 146 do { \ 147 struct v4l2_subdev *__sd; \ 148 \ 149 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ 150 f , ##args); \ 151 } while (0) 152 153 /* Call the specified callback for all subdevs matching the condition. 154 If the callback returns an error other than 0 or -ENOIOCTLCMD, then 155 return with that error code. Note that you cannot add or delete a 156 subdev while walking the subdevs list. */ 157 #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ 158 ({ \ 159 long __err = 0; \ 160 \ 161 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ 162 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 163 __err = (sd)->ops->o->f((sd) , ##args); \ 164 if (__err && __err != -ENOIOCTLCMD) \ 165 break; \ 166 } \ 167 (__err == -ENOIOCTLCMD) ? 0 : __err; \ 168 }) 169 170 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 171 ({ \ 172 struct v4l2_subdev *__sd; \ 173 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ 174 f , ##args); \ 175 }) 176 177 /* Call the specified callback for all subdevs matching grp_id (if 0, then 178 match them all). Ignore any errors. Note that you cannot add or delete 179 a subdev while walking the subdevs list. */ 180 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 181 do { \ 182 struct v4l2_subdev *__sd; \ 183 \ 184 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 185 !(grpid) || __sd->grp_id == (grpid), o, f , \ 186 ##args); \ 187 } while (0) 188 189 /* Call the specified callback for all subdevs matching grp_id (if 0, then 190 match them all). If the callback returns an error other than 0 or 191 -ENOIOCTLCMD, then return with that error code. Note that you cannot 192 add or delete a subdev while walking the subdevs list. */ 193 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 194 ({ \ 195 struct v4l2_subdev *__sd; \ 196 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 197 !(grpid) || __sd->grp_id == (grpid), o, f , \ 198 ##args); \ 199 }) 200 201 #define v4l2_device_has_op(v4l2_dev, o, f) \ 202 ({ \ 203 struct v4l2_subdev *__sd; \ 204 bool __result = false; \ 205 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 206 if (v4l2_subdev_has_op(__sd, o, f)) { \ 207 __result = true; \ 208 break; \ 209 } \ 210 } \ 211 __result; \ 212 }) 213 214 #endif 215