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 35struct v4l2_ctrl_handler; 36 37struct 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 /* BKL replacement mutex. Temporary solution only. */ 55 struct mutex ioctl_lock; 56}; 57 58/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev. 59 dev may be NULL in rare cases (ISA devices). In that case you 60 must fill in the v4l2_dev->name field before calling this function. */ 61int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); 62 63/* Optional function to initialize the name field of struct v4l2_device using 64 the driver name and a driver-global atomic_t instance. 65 This function will increment the instance counter and returns the instance 66 value used in the name. 67 68 Example: 69 70 static atomic_t drv_instance = ATOMIC_INIT(0); 71 72 ... 73 74 instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance); 75 76 The first time this is called the name field will be set to foo0 and 77 this function returns 0. If the name ends with a digit (e.g. cx18), 78 then the name will be set to cx18-0 since cx180 looks really odd. */ 79int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, 80 atomic_t *instance); 81 82/* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects. 83 Since the parent disappears this ensures that v4l2_dev doesn't have an 84 invalid parent pointer. */ 85void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); 86 87/* Unregister all sub-devices and any other resources related to v4l2_dev. */ 88void v4l2_device_unregister(struct v4l2_device *v4l2_dev); 89 90/* Register a subdev with a v4l2 device. While registered the subdev module 91 is marked as in-use. An error is returned if the module is no longer 92 loaded when you attempt to register it. */ 93int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 94 struct v4l2_subdev *sd); 95/* Unregister a subdev with a v4l2 device. Can also be called if the subdev 96 wasn't registered. In that case it will do nothing. */ 97void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); 98 99/* Iterate over all subdevs. */ 100#define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 101 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 102 103/* Call the specified callback for all subdevs matching the condition. 104 Ignore any errors. Note that you cannot add or delete a subdev 105 while walking the subdevs list. */ 106#define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ 107 do { \ 108 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ 109 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 110 (sd)->ops->o->f((sd) , ##args); \ 111 } while (0) 112 113#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 114 do { \ 115 struct v4l2_subdev *__sd; \ 116 \ 117 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ 118 f , ##args); \ 119 } while (0) 120 121/* Call the specified callback for all subdevs matching the condition. 122 If the callback returns an error other than 0 or -ENOIOCTLCMD, then 123 return with that error code. Note that you cannot add or delete a 124 subdev while walking the subdevs list. */ 125#define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ 126({ \ 127 long __err = 0; \ 128 \ 129 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ 130 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 131 __err = (sd)->ops->o->f((sd) , ##args); \ 132 if (__err && __err != -ENOIOCTLCMD) \ 133 break; \ 134 } \ 135 (__err == -ENOIOCTLCMD) ? 0 : __err; \ 136}) 137 138#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 139({ \ 140 struct v4l2_subdev *__sd; \ 141 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ 142 f, args...); \ 143}) 144 145/* Call the specified callback for all subdevs matching grp_id (if 0, then 146 match them all). Ignore any errors. Note that you cannot add or delete 147 a subdev while walking the subdevs list. */ 148#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 149 do { \ 150 struct v4l2_subdev *__sd; \ 151 \ 152 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 153 !(grpid) || __sd->grp_id == (grpid), o, f , \ 154 ##args); \ 155 } while (0) 156 157/* Call the specified callback for all subdevs matching grp_id (if 0, then 158 match them all). If the callback returns an error other than 0 or 159 -ENOIOCTLCMD, then return with that error code. Note that you cannot 160 add or delete a subdev while walking the subdevs list. */ 161#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 162({ \ 163 struct v4l2_subdev *__sd; \ 164 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 165 !(grpid) || __sd->grp_id == (grpid), o, f , \ 166 ##args); \ 167}) 168 169#endif 170