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