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 (BUS_ID_SIZE + 16) 34 35 struct v4l2_device { 36 /* dev->driver_data points to this struct. 37 Note: dev might be NULL if there is no parent device 38 as is the case with e.g. ISA devices. */ 39 struct device *dev; 40 /* used to keep track of the registered subdevs */ 41 struct list_head subdevs; 42 /* lock this struct; can be used by the driver as well if this 43 struct is embedded into a larger struct. */ 44 spinlock_t lock; 45 /* unique device name, by default the driver name + bus ID */ 46 char name[V4L2_DEVICE_NAME_SIZE]; 47 /* notify callback called by some sub-devices. */ 48 void (*notify)(struct v4l2_subdev *sd, 49 unsigned int notification, void *arg); 50 }; 51 52 /* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev. 53 dev may be NULL in rare cases (ISA devices). In that case you 54 must fill in the v4l2_dev->name field before calling this function. */ 55 int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); 56 /* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects. 57 Since the parent disappears this ensures that v4l2_dev doesn't have an 58 invalid parent pointer. */ 59 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); 60 /* Unregister all sub-devices and any other resources related to v4l2_dev. */ 61 void v4l2_device_unregister(struct v4l2_device *v4l2_dev); 62 63 /* Register a subdev with a v4l2 device. While registered the subdev module 64 is marked as in-use. An error is returned if the module is no longer 65 loaded when you attempt to register it. */ 66 int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 67 struct v4l2_subdev *sd); 68 /* Unregister a subdev with a v4l2 device. Can also be called if the subdev 69 wasn't registered. In that case it will do nothing. */ 70 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); 71 72 /* Iterate over all subdevs. */ 73 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 74 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 75 76 /* Call the specified callback for all subdevs matching the condition. 77 Ignore any errors. Note that you cannot add or delete a subdev 78 while walking the subdevs list. */ 79 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 80 do { \ 81 struct v4l2_subdev *sd; \ 82 \ 83 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) \ 84 if ((cond) && sd->ops->o && sd->ops->o->f) \ 85 sd->ops->o->f(sd , ##args); \ 86 } while (0) 87 88 /* Call the specified callback for all subdevs matching the condition. 89 If the callback returns an error other than 0 or -ENOIOCTLCMD, then 90 return with that error code. Note that you cannot add or delete a 91 subdev while walking the subdevs list. */ 92 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 93 ({ \ 94 struct v4l2_subdev *sd; \ 95 long err = 0; \ 96 \ 97 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) { \ 98 if ((cond) && sd->ops->o && sd->ops->o->f) \ 99 err = sd->ops->o->f(sd , ##args); \ 100 if (err && err != -ENOIOCTLCMD) \ 101 break; \ 102 } \ 103 (err == -ENOIOCTLCMD) ? 0 : err; \ 104 }) 105 106 /* Call the specified callback for all subdevs matching grp_id (if 0, then 107 match them all). Ignore any errors. Note that you cannot add or delete 108 a subdev while walking the subdevs list. */ 109 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 110 __v4l2_device_call_subdevs(v4l2_dev, \ 111 !(grpid) || sd->grp_id == (grpid), o, f , ##args) 112 113 /* Call the specified callback for all subdevs matching grp_id (if 0, then 114 match them all). If the callback returns an error other than 0 or 115 -ENOIOCTLCMD, then return with that error code. Note that you cannot 116 add or delete a subdev while walking the subdevs list. */ 117 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 118 __v4l2_device_call_subdevs_until_err(v4l2_dev, \ 119 !(grpid) || sd->grp_id == (grpid), o, f , ##args) 120 121 #endif 122