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#define V4L2_DEVICE_NAME_SIZE (20 + 16) 29 30struct v4l2_ctrl_handler; 31 32/** 33 * struct v4l2_device - main struct to for V4L2 device drivers 34 * 35 * @dev: pointer to struct device. 36 * @mdev: pointer to struct media_device 37 * @subdevs: used to keep track of the registered subdevs 38 * @lock: lock this struct; can be used by the driver as well 39 * if this struct is embedded into a larger struct. 40 * @name: unique device name, by default the driver name + bus ID 41 * @notify: notify callback called by some sub-devices. 42 * @ctrl_handler: The control handler. May be %NULL. 43 * @prio: Device's priority state 44 * @ref: Keep track of the references to this struct. 45 * @release: Release function that is called when the ref count 46 * goes to 0. 47 * 48 * Each instance of a V4L2 device should create the v4l2_device struct, 49 * either stand-alone or embedded in a larger struct. 50 * 51 * It allows easy access to sub-devices (see v4l2-subdev.h) and provides 52 * basic V4L2 device-level support. 53 * 54 * .. note:: 55 * 56 * #) @dev->driver_data points to this struct. 57 * #) @dev might be %NULL if there is no parent device 58 */ 59 60struct v4l2_device { 61 struct device *dev; 62#if defined(CONFIG_MEDIA_CONTROLLER) 63 struct media_device *mdev; 64#endif 65 struct list_head subdevs; 66 spinlock_t lock; 67 char name[V4L2_DEVICE_NAME_SIZE]; 68 void (*notify)(struct v4l2_subdev *sd, 69 unsigned int notification, void *arg); 70 struct v4l2_ctrl_handler *ctrl_handler; 71 struct v4l2_prio_state prio; 72 struct kref ref; 73 void (*release)(struct v4l2_device *v4l2_dev); 74}; 75 76/** 77 * v4l2_device_get - gets a V4L2 device reference 78 * 79 * @v4l2_dev: pointer to struct &v4l2_device 80 * 81 * This is an ancillary routine meant to increment the usage for the 82 * struct &v4l2_device pointed by @v4l2_dev. 83 */ 84static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) 85{ 86 kref_get(&v4l2_dev->ref); 87} 88 89/** 90 * v4l2_device_put - putss a V4L2 device reference 91 * 92 * @v4l2_dev: pointer to struct &v4l2_device 93 * 94 * This is an ancillary routine meant to decrement the usage for the 95 * struct &v4l2_device pointed by @v4l2_dev. 96 */ 97int v4l2_device_put(struct v4l2_device *v4l2_dev); 98 99/** 100 * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data 101 * point to @v4l2_dev. 102 * 103 * @dev: pointer to struct &device 104 * @v4l2_dev: pointer to struct &v4l2_device 105 * 106 * .. note:: 107 * @dev may be %NULL in rare cases (ISA devices). 108 * In such case the caller must fill in the @v4l2_dev->name field 109 * before calling this function. 110 */ 111int __must_check v4l2_device_register(struct device *dev, 112 struct v4l2_device *v4l2_dev); 113 114/** 115 * v4l2_device_set_name - Optional function to initialize the 116 * name field of struct &v4l2_device 117 * 118 * @v4l2_dev: pointer to struct &v4l2_device 119 * @basename: base name for the device name 120 * @instance: pointer to a static atomic_t var with the instance usage for 121 * the device driver. 122 * 123 * v4l2_device_set_name() initializes the name field of struct &v4l2_device 124 * using the driver name and a driver-global atomic_t instance. 125 * 126 * This function will increment the instance counter and returns the 127 * instance value used in the name. 128 * 129 * Example: 130 * 131 * static atomic_t drv_instance = ATOMIC_INIT(0); 132 * 133 * ... 134 * 135 * instance = v4l2_device_set_name(&\ v4l2_dev, "foo", &\ drv_instance); 136 * 137 * The first time this is called the name field will be set to foo0 and 138 * this function returns 0. If the name ends with a digit (e.g. cx18), 139 * then the name will be set to cx18-0 since cx180 would look really odd. 140 */ 141int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, 142 atomic_t *instance); 143 144/** 145 * v4l2_device_disconnect - Change V4L2 device state to disconnected. 146 * 147 * @v4l2_dev: pointer to struct v4l2_device 148 * 149 * Should be called when the USB parent disconnects. 150 * Since the parent disappears, this ensures that @v4l2_dev doesn't have 151 * an invalid parent pointer. 152 * 153 * .. note:: This function sets @v4l2_dev->dev to NULL. 154 */ 155void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); 156 157/** 158 * v4l2_device_unregister - Unregister all sub-devices and any other 159 * resources related to @v4l2_dev. 160 * 161 * @v4l2_dev: pointer to struct v4l2_device 162 */ 163void v4l2_device_unregister(struct v4l2_device *v4l2_dev); 164 165/** 166 * v4l2_device_register_subdev - Registers a subdev with a v4l2 device. 167 * 168 * @v4l2_dev: pointer to struct &v4l2_device 169 * @sd: pointer to struct &v4l2_subdev 170 * 171 * While registered, the subdev module is marked as in-use. 172 * 173 * An error is returned if the module is no longer loaded on any attempts 174 * to register it. 175 */ 176int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 177 struct v4l2_subdev *sd); 178 179/** 180 * v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device. 181 * 182 * @sd: pointer to struct &v4l2_subdev 183 * 184 * .. note :: 185 * 186 * Can also be called if the subdev wasn't registered. In such 187 * case, it will do nothing. 188 */ 189void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); 190 191/** 192 * v4l2_device_register_subdev_nodes - Registers device nodes for all subdevs 193 * of the v4l2 device that are marked with 194 * the %V4L2_SUBDEV_FL_HAS_DEVNODE flag. 195 * 196 * @v4l2_dev: pointer to struct v4l2_device 197 */ 198int __must_check 199v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); 200 201/** 202 * v4l2_subdev_notify - Sends a notification to v4l2_device. 203 * 204 * @sd: pointer to struct &v4l2_subdev 205 * @notification: type of notification. Please notice that the notification 206 * type is driver-specific. 207 * @arg: arguments for the notification. Those are specific to each 208 * notification type. 209 */ 210static inline void v4l2_subdev_notify(struct v4l2_subdev *sd, 211 unsigned int notification, void *arg) 212{ 213 if (sd && sd->v4l2_dev && sd->v4l2_dev->notify) 214 sd->v4l2_dev->notify(sd, notification, arg); 215} 216 217/* Iterate over all subdevs. */ 218#define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 219 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 220 221/* Call the specified callback for all subdevs matching the condition. 222 Ignore any errors. Note that you cannot add or delete a subdev 223 while walking the subdevs list. */ 224#define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ 225 do { \ 226 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ 227 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 228 (sd)->ops->o->f((sd) , ##args); \ 229 } while (0) 230 231#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 232 do { \ 233 struct v4l2_subdev *__sd; \ 234 \ 235 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ 236 f , ##args); \ 237 } while (0) 238 239/* Call the specified callback for all subdevs matching the condition. 240 If the callback returns an error other than 0 or -ENOIOCTLCMD, then 241 return with that error code. Note that you cannot add or delete a 242 subdev while walking the subdevs list. */ 243#define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ 244({ \ 245 long __err = 0; \ 246 \ 247 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ 248 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 249 __err = (sd)->ops->o->f((sd) , ##args); \ 250 if (__err && __err != -ENOIOCTLCMD) \ 251 break; \ 252 } \ 253 (__err == -ENOIOCTLCMD) ? 0 : __err; \ 254}) 255 256#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 257({ \ 258 struct v4l2_subdev *__sd; \ 259 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ 260 f , ##args); \ 261}) 262 263/* Call the specified callback for all subdevs matching grp_id (if 0, then 264 match them all). Ignore any errors. Note that you cannot add or delete 265 a subdev while walking the subdevs list. */ 266#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 267 do { \ 268 struct v4l2_subdev *__sd; \ 269 \ 270 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 271 !(grpid) || __sd->grp_id == (grpid), o, f , \ 272 ##args); \ 273 } while (0) 274 275/* Call the specified callback for all subdevs matching grp_id (if 0, then 276 match them all). If the callback returns an error other than 0 or 277 -ENOIOCTLCMD, then return with that error code. Note that you cannot 278 add or delete a subdev while walking the subdevs list. */ 279#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 280({ \ 281 struct v4l2_subdev *__sd; \ 282 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 283 !(grpid) || __sd->grp_id == (grpid), o, f , \ 284 ##args); \ 285}) 286 287/* 288 * Call the specified callback for all subdevs where grp_id & grpmsk != 0 289 * (if grpmsk == `0, then match them all). Ignore any errors. Note that you 290 * cannot add or delete a subdev while walking the subdevs list. 291 */ 292#define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \ 293 do { \ 294 struct v4l2_subdev *__sd; \ 295 \ 296 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 297 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ 298 ##args); \ 299 } while (0) 300 301/* 302 * Call the specified callback for all subdevs where grp_id & grpmsk != 0 303 * (if grpmsk == 0, then match them all). If the callback returns an error 304 * other than 0 or %-ENOIOCTLCMD, then return with that error code. Note that 305 * you cannot add or delete a subdev while walking the subdevs list. 306 */ 307#define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \ 308({ \ 309 struct v4l2_subdev *__sd; \ 310 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 311 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ 312 ##args); \ 313}) 314 315/* 316 * Does any subdev with matching grpid (or all if grpid == 0) has the given 317 * op? 318 */ 319#define v4l2_device_has_op(v4l2_dev, grpid, o, f) \ 320({ \ 321 struct v4l2_subdev *__sd; \ 322 bool __result = false; \ 323 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 324 if ((grpid) && __sd->grp_id != (grpid)) \ 325 continue; \ 326 if (v4l2_subdev_has_op(__sd, o, f)) { \ 327 __result = true; \ 328 break; \ 329 } \ 330 } \ 331 __result; \ 332}) 333 334/* 335 * Does any subdev with matching grpmsk (or all if grpmsk == 0) has the given 336 * op? 337 */ 338#define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \ 339({ \ 340 struct v4l2_subdev *__sd; \ 341 bool __result = false; \ 342 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 343 if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \ 344 continue; \ 345 if (v4l2_subdev_has_op(__sd, o, f)) { \ 346 __result = true; \ 347 break; \ 348 } \ 349 } \ 350 __result; \ 351}) 352 353#endif 354