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/v4l2-subdev.h> 25 26 /* Each instance of a V4L2 device should create the v4l2_device struct, 27 either stand-alone or embedded in a larger struct. 28 29 It allows easy access to sub-devices (see v4l2-subdev.h) and provides 30 basic V4L2 device-level support. 31 */ 32 33 #define V4L2_DEVICE_NAME_SIZE (20 + 16) 34 35 struct v4l2_ctrl_handler; 36 37 struct v4l2_device { 38 /* dev->driver_data points to this struct. 39 Note: dev might be NULL if there is no parent device 40 as is the case with e.g. ISA devices. */ 41 struct device *dev; 42 /* used to keep track of the registered subdevs */ 43 struct list_head subdevs; 44 /* lock this struct; can be used by the driver as well if this 45 struct is embedded into a larger struct. */ 46 spinlock_t lock; 47 /* unique device name, by default the driver name + bus ID */ 48 char name[V4L2_DEVICE_NAME_SIZE]; 49 /* notify callback called by some sub-devices. */ 50 void (*notify)(struct v4l2_subdev *sd, 51 unsigned int notification, void *arg); 52 /* The control handler. May be NULL. */ 53 struct v4l2_ctrl_handler *ctrl_handler; 54 }; 55 56 /* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev. 57 dev may be NULL in rare cases (ISA devices). In that case you 58 must fill in the v4l2_dev->name field before calling this function. */ 59 int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); 60 61 /* Optional function to initialize the name field of struct v4l2_device using 62 the driver name and a driver-global atomic_t instance. 63 This function will increment the instance counter and returns the instance 64 value used in the name. 65 66 Example: 67 68 static atomic_t drv_instance = ATOMIC_INIT(0); 69 70 ... 71 72 instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance); 73 74 The first time this is called the name field will be set to foo0 and 75 this function returns 0. If the name ends with a digit (e.g. cx18), 76 then the name will be set to cx18-0 since cx180 looks really odd. */ 77 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, 78 atomic_t *instance); 79 80 /* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects. 81 Since the parent disappears this ensures that v4l2_dev doesn't have an 82 invalid parent pointer. */ 83 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); 84 85 /* Unregister all sub-devices and any other resources related to v4l2_dev. */ 86 void v4l2_device_unregister(struct v4l2_device *v4l2_dev); 87 88 /* Register a subdev with a v4l2 device. While registered the subdev module 89 is marked as in-use. An error is returned if the module is no longer 90 loaded when you attempt to register it. */ 91 int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 92 struct v4l2_subdev *sd); 93 /* Unregister a subdev with a v4l2 device. Can also be called if the subdev 94 wasn't registered. In that case it will do nothing. */ 95 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); 96 97 /* Iterate over all subdevs. */ 98 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 99 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 100 101 /* Call the specified callback for all subdevs matching the condition. 102 Ignore any errors. Note that you cannot add or delete a subdev 103 while walking the subdevs list. */ 104 #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ 105 do { \ 106 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ 107 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 108 (sd)->ops->o->f((sd) , ##args); \ 109 } while (0) 110 111 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 112 do { \ 113 struct v4l2_subdev *__sd; \ 114 \ 115 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ 116 f , ##args); \ 117 } while (0) 118 119 /* Call the specified callback for all subdevs matching the condition. 120 If the callback returns an error other than 0 or -ENOIOCTLCMD, then 121 return with that error code. Note that you cannot add or delete a 122 subdev while walking the subdevs list. */ 123 #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ 124 ({ \ 125 long __err = 0; \ 126 \ 127 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ 128 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 129 __err = (sd)->ops->o->f((sd) , ##args); \ 130 if (__err && __err != -ENOIOCTLCMD) \ 131 break; \ 132 } \ 133 (__err == -ENOIOCTLCMD) ? 0 : __err; \ 134 }) 135 136 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 137 ({ \ 138 struct v4l2_subdev *__sd; \ 139 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ 140 f, args...); \ 141 }) 142 143 /* Call the specified callback for all subdevs matching grp_id (if 0, then 144 match them all). Ignore any errors. Note that you cannot add or delete 145 a subdev while walking the subdevs list. */ 146 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 147 do { \ 148 struct v4l2_subdev *__sd; \ 149 \ 150 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 151 !(grpid) || __sd->grp_id == (grpid), o, f , \ 152 ##args); \ 153 } while (0) 154 155 /* Call the specified callback for all subdevs matching grp_id (if 0, then 156 match them all). If the callback returns an error other than 0 or 157 -ENOIOCTLCMD, then return with that error code. Note that you cannot 158 add or delete a subdev while walking the subdevs list. */ 159 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 160 ({ \ 161 struct v4l2_subdev *__sd; \ 162 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 163 !(grpid) || __sd->grp_id == (grpid), o, f , \ 164 ##args); \ 165 }) 166 167 #endif 168