1 /* 2 V4L2 device support. 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 #include <linux/types.h> 22 #include <linux/ioctl.h> 23 #include <linux/module.h> 24 #include <linux/i2c.h> 25 #include <linux/slab.h> 26 #if defined(CONFIG_SPI) 27 #include <linux/spi/spi.h> 28 #endif 29 #include <linux/videodev2.h> 30 #include <media/v4l2-device.h> 31 #include <media/v4l2-ctrls.h> 32 33 int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev) 34 { 35 if (v4l2_dev == NULL) 36 return -EINVAL; 37 38 INIT_LIST_HEAD(&v4l2_dev->subdevs); 39 spin_lock_init(&v4l2_dev->lock); 40 mutex_init(&v4l2_dev->ioctl_lock); 41 v4l2_prio_init(&v4l2_dev->prio); 42 kref_init(&v4l2_dev->ref); 43 get_device(dev); 44 v4l2_dev->dev = dev; 45 if (dev == NULL) { 46 /* If dev == NULL, then name must be filled in by the caller */ 47 WARN_ON(!v4l2_dev->name[0]); 48 return 0; 49 } 50 51 /* Set name to driver name + device name if it is empty. */ 52 if (!v4l2_dev->name[0]) 53 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s", 54 dev->driver->name, dev_name(dev)); 55 if (!dev_get_drvdata(dev)) 56 dev_set_drvdata(dev, v4l2_dev); 57 return 0; 58 } 59 EXPORT_SYMBOL_GPL(v4l2_device_register); 60 61 static void v4l2_device_release(struct kref *ref) 62 { 63 struct v4l2_device *v4l2_dev = 64 container_of(ref, struct v4l2_device, ref); 65 66 if (v4l2_dev->release) 67 v4l2_dev->release(v4l2_dev); 68 } 69 70 int v4l2_device_put(struct v4l2_device *v4l2_dev) 71 { 72 return kref_put(&v4l2_dev->ref, v4l2_device_release); 73 } 74 EXPORT_SYMBOL_GPL(v4l2_device_put); 75 76 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, 77 atomic_t *instance) 78 { 79 int num = atomic_inc_return(instance) - 1; 80 int len = strlen(basename); 81 82 if (basename[len - 1] >= '0' && basename[len - 1] <= '9') 83 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), 84 "%s-%d", basename, num); 85 else 86 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), 87 "%s%d", basename, num); 88 return num; 89 } 90 EXPORT_SYMBOL_GPL(v4l2_device_set_name); 91 92 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev) 93 { 94 if (v4l2_dev->dev == NULL) 95 return; 96 97 if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev) 98 dev_set_drvdata(v4l2_dev->dev, NULL); 99 put_device(v4l2_dev->dev); 100 v4l2_dev->dev = NULL; 101 } 102 EXPORT_SYMBOL_GPL(v4l2_device_disconnect); 103 104 void v4l2_device_unregister(struct v4l2_device *v4l2_dev) 105 { 106 struct v4l2_subdev *sd, *next; 107 108 if (v4l2_dev == NULL) 109 return; 110 v4l2_device_disconnect(v4l2_dev); 111 112 /* Unregister subdevs */ 113 list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) { 114 v4l2_device_unregister_subdev(sd); 115 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE)) 116 if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) { 117 struct i2c_client *client = v4l2_get_subdevdata(sd); 118 119 /* We need to unregister the i2c client explicitly. 120 We cannot rely on i2c_del_adapter to always 121 unregister clients for us, since if the i2c bus 122 is a platform bus, then it is never deleted. */ 123 if (client) 124 i2c_unregister_device(client); 125 continue; 126 } 127 #endif 128 #if defined(CONFIG_SPI) 129 if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) { 130 struct spi_device *spi = v4l2_get_subdevdata(sd); 131 132 if (spi) 133 spi_unregister_device(spi); 134 continue; 135 } 136 #endif 137 } 138 } 139 EXPORT_SYMBOL_GPL(v4l2_device_unregister); 140 141 int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 142 struct v4l2_subdev *sd) 143 { 144 #if defined(CONFIG_MEDIA_CONTROLLER) 145 struct media_entity *entity = &sd->entity; 146 #endif 147 int err; 148 149 /* Check for valid input */ 150 if (v4l2_dev == NULL || sd == NULL || !sd->name[0]) 151 return -EINVAL; 152 153 /* Warn if we apparently re-register a subdev */ 154 WARN_ON(sd->v4l2_dev != NULL); 155 156 if (!try_module_get(sd->owner)) 157 return -ENODEV; 158 159 sd->v4l2_dev = v4l2_dev; 160 if (sd->internal_ops && sd->internal_ops->registered) { 161 err = sd->internal_ops->registered(sd); 162 if (err) { 163 module_put(sd->owner); 164 return err; 165 } 166 } 167 168 /* This just returns 0 if either of the two args is NULL */ 169 err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL); 170 if (err) { 171 if (sd->internal_ops && sd->internal_ops->unregistered) 172 sd->internal_ops->unregistered(sd); 173 module_put(sd->owner); 174 return err; 175 } 176 177 #if defined(CONFIG_MEDIA_CONTROLLER) 178 /* Register the entity. */ 179 if (v4l2_dev->mdev) { 180 err = media_device_register_entity(v4l2_dev->mdev, entity); 181 if (err < 0) { 182 if (sd->internal_ops && sd->internal_ops->unregistered) 183 sd->internal_ops->unregistered(sd); 184 module_put(sd->owner); 185 return err; 186 } 187 } 188 #endif 189 190 spin_lock(&v4l2_dev->lock); 191 list_add_tail(&sd->list, &v4l2_dev->subdevs); 192 spin_unlock(&v4l2_dev->lock); 193 194 return 0; 195 } 196 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev); 197 198 static void v4l2_device_release_subdev_node(struct video_device *vdev) 199 { 200 struct v4l2_subdev *sd = video_get_drvdata(vdev); 201 sd->devnode = NULL; 202 kfree(vdev); 203 } 204 205 int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) 206 { 207 struct video_device *vdev; 208 struct v4l2_subdev *sd; 209 int err; 210 211 /* Register a device node for every subdev marked with the 212 * V4L2_SUBDEV_FL_HAS_DEVNODE flag. 213 */ 214 list_for_each_entry(sd, &v4l2_dev->subdevs, list) { 215 if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE)) 216 continue; 217 218 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); 219 if (!vdev) { 220 err = -ENOMEM; 221 goto clean_up; 222 } 223 224 video_set_drvdata(vdev, sd); 225 strlcpy(vdev->name, sd->name, sizeof(vdev->name)); 226 vdev->v4l2_dev = v4l2_dev; 227 vdev->fops = &v4l2_subdev_fops; 228 vdev->release = v4l2_device_release_subdev_node; 229 vdev->ctrl_handler = sd->ctrl_handler; 230 err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1, 231 sd->owner); 232 if (err < 0) { 233 kfree(vdev); 234 goto clean_up; 235 } 236 #if defined(CONFIG_MEDIA_CONTROLLER) 237 sd->entity.info.v4l.major = VIDEO_MAJOR; 238 sd->entity.info.v4l.minor = vdev->minor; 239 #endif 240 sd->devnode = vdev; 241 } 242 return 0; 243 244 clean_up: 245 list_for_each_entry(sd, &v4l2_dev->subdevs, list) { 246 if (!sd->devnode) 247 break; 248 video_unregister_device(sd->devnode); 249 } 250 251 return err; 252 } 253 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes); 254 255 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd) 256 { 257 struct v4l2_device *v4l2_dev; 258 259 /* return if it isn't registered */ 260 if (sd == NULL || sd->v4l2_dev == NULL) 261 return; 262 263 v4l2_dev = sd->v4l2_dev; 264 265 spin_lock(&v4l2_dev->lock); 266 list_del(&sd->list); 267 spin_unlock(&v4l2_dev->lock); 268 269 if (sd->internal_ops && sd->internal_ops->unregistered) 270 sd->internal_ops->unregistered(sd); 271 sd->v4l2_dev = NULL; 272 273 #if defined(CONFIG_MEDIA_CONTROLLER) 274 if (v4l2_dev->mdev) 275 media_device_unregister_entity(&sd->entity); 276 #endif 277 video_unregister_device(sd->devnode); 278 module_put(sd->owner); 279 } 280 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev); 281