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