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 37struct v4l2_ctrl_handler; 38 39struct 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 69static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) 70{ 71 kref_get(&v4l2_dev->ref); 72} 73 74int 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. */ 79int __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. */ 97int 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. */ 103void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); 104 105/* Unregister all sub-devices and any other resources related to v4l2_dev. */ 106void 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. */ 111int __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. */ 115void 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 */ 120int __must_check 121v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); 122 123/* Iterate over all subdevs. */ 124#define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 125 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 126 127/* Call the specified callback for all subdevs matching the condition. 128 Ignore any errors. Note that you cannot add or delete a subdev 129 while walking the subdevs list. */ 130#define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ 131 do { \ 132 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ 133 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 134 (sd)->ops->o->f((sd) , ##args); \ 135 } while (0) 136 137#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 138 do { \ 139 struct v4l2_subdev *__sd; \ 140 \ 141 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ 142 f , ##args); \ 143 } while (0) 144 145/* Call the specified callback for all subdevs matching the condition. 146 If the callback returns an error other than 0 or -ENOIOCTLCMD, then 147 return with that error code. Note that you cannot add or delete a 148 subdev while walking the subdevs list. */ 149#define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ 150({ \ 151 long __err = 0; \ 152 \ 153 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ 154 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 155 __err = (sd)->ops->o->f((sd) , ##args); \ 156 if (__err && __err != -ENOIOCTLCMD) \ 157 break; \ 158 } \ 159 (__err == -ENOIOCTLCMD) ? 0 : __err; \ 160}) 161 162#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 163({ \ 164 struct v4l2_subdev *__sd; \ 165 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ 166 f , ##args); \ 167}) 168 169/* Call the specified callback for all subdevs matching grp_id (if 0, then 170 match them all). Ignore any errors. Note that you cannot add or delete 171 a subdev while walking the subdevs list. */ 172#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 173 do { \ 174 struct v4l2_subdev *__sd; \ 175 \ 176 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 177 !(grpid) || __sd->grp_id == (grpid), o, f , \ 178 ##args); \ 179 } while (0) 180 181/* Call the specified callback for all subdevs matching grp_id (if 0, then 182 match them all). If the callback returns an error other than 0 or 183 -ENOIOCTLCMD, then return with that error code. Note that you cannot 184 add or delete a subdev while walking the subdevs list. */ 185#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 186({ \ 187 struct v4l2_subdev *__sd; \ 188 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 189 !(grpid) || __sd->grp_id == (grpid), o, f , \ 190 ##args); \ 191}) 192 193#endif 194