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 v4l2_prio_init(&v4l2_dev->prio); 41 kref_init(&v4l2_dev->ref); 42 get_device(dev); 43 v4l2_dev->dev = dev; 44 if (dev == NULL) { 45 /* If dev == NULL, then name must be filled in by the caller */ 46 if (WARN_ON(!v4l2_dev->name[0])) 47 return -EINVAL; 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 /* Just return if v4l2_dev is NULL or if it was already 109 * unregistered before. */ 110 if (v4l2_dev == NULL || !v4l2_dev->name[0]) 111 return; 112 v4l2_device_disconnect(v4l2_dev); 113 114 /* Unregister subdevs */ 115 list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) { 116 v4l2_device_unregister_subdev(sd); 117 #if IS_ENABLED(CONFIG_I2C) 118 if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) { 119 struct i2c_client *client = v4l2_get_subdevdata(sd); 120 121 /* 122 * We need to unregister the i2c client 123 * explicitly. We cannot rely on 124 * i2c_del_adapter to always unregister 125 * clients for us, since if the i2c bus is a 126 * platform bus, then it is never deleted. 127 * 128 * Device tree or ACPI based devices must not 129 * be unregistered as they have not been 130 * registered by us, and would not be 131 * re-created by just probing the V4L2 driver. 132 */ 133 if (client && 134 !client->dev.of_node && !client->dev.fwnode) 135 i2c_unregister_device(client); 136 continue; 137 } 138 #endif 139 #if defined(CONFIG_SPI) 140 if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) { 141 struct spi_device *spi = v4l2_get_subdevdata(sd); 142 143 if (spi && !spi->dev.of_node && !spi->dev.fwnode) 144 spi_unregister_device(spi); 145 continue; 146 } 147 #endif 148 } 149 /* Mark as unregistered, thus preventing duplicate unregistrations */ 150 v4l2_dev->name[0] = '\0'; 151 } 152 EXPORT_SYMBOL_GPL(v4l2_device_unregister); 153 154 int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 155 struct v4l2_subdev *sd) 156 { 157 #if defined(CONFIG_MEDIA_CONTROLLER) 158 struct media_entity *entity = &sd->entity; 159 #endif 160 int err; 161 162 /* Check for valid input */ 163 if (v4l2_dev == NULL || sd == NULL || !sd->name[0]) 164 return -EINVAL; 165 166 /* Warn if we apparently re-register a subdev */ 167 WARN_ON(sd->v4l2_dev != NULL); 168 169 /* 170 * The reason to acquire the module here is to avoid unloading 171 * a module of sub-device which is registered to a media 172 * device. To make it possible to unload modules for media 173 * devices that also register sub-devices, do not 174 * try_module_get() such sub-device owners. 175 */ 176 sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver && 177 sd->owner == v4l2_dev->dev->driver->owner; 178 179 if (!sd->owner_v4l2_dev && !try_module_get(sd->owner)) 180 return -ENODEV; 181 182 sd->v4l2_dev = v4l2_dev; 183 if (sd->internal_ops && sd->internal_ops->registered) { 184 err = sd->internal_ops->registered(sd); 185 if (err) 186 goto error_module; 187 } 188 189 /* This just returns 0 if either of the two args is NULL */ 190 err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL); 191 if (err) 192 goto error_unregister; 193 194 #if defined(CONFIG_MEDIA_CONTROLLER) 195 /* Register the entity. */ 196 if (v4l2_dev->mdev) { 197 err = media_device_register_entity(v4l2_dev->mdev, entity); 198 if (err < 0) 199 goto error_unregister; 200 } 201 #endif 202 203 spin_lock(&v4l2_dev->lock); 204 list_add_tail(&sd->list, &v4l2_dev->subdevs); 205 spin_unlock(&v4l2_dev->lock); 206 207 return 0; 208 209 error_unregister: 210 if (sd->internal_ops && sd->internal_ops->unregistered) 211 sd->internal_ops->unregistered(sd); 212 error_module: 213 if (!sd->owner_v4l2_dev) 214 module_put(sd->owner); 215 sd->v4l2_dev = NULL; 216 return err; 217 } 218 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev); 219 220 static void v4l2_device_release_subdev_node(struct video_device *vdev) 221 { 222 struct v4l2_subdev *sd = video_get_drvdata(vdev); 223 sd->devnode = NULL; 224 kfree(vdev); 225 } 226 227 int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) 228 { 229 struct video_device *vdev; 230 struct v4l2_subdev *sd; 231 int err; 232 233 /* Register a device node for every subdev marked with the 234 * V4L2_SUBDEV_FL_HAS_DEVNODE flag. 235 */ 236 list_for_each_entry(sd, &v4l2_dev->subdevs, list) { 237 if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE)) 238 continue; 239 240 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); 241 if (!vdev) { 242 err = -ENOMEM; 243 goto clean_up; 244 } 245 246 video_set_drvdata(vdev, sd); 247 strlcpy(vdev->name, sd->name, sizeof(vdev->name)); 248 vdev->v4l2_dev = v4l2_dev; 249 vdev->fops = &v4l2_subdev_fops; 250 vdev->release = v4l2_device_release_subdev_node; 251 vdev->ctrl_handler = sd->ctrl_handler; 252 err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1, 253 sd->owner); 254 if (err < 0) { 255 kfree(vdev); 256 goto clean_up; 257 } 258 #if defined(CONFIG_MEDIA_CONTROLLER) 259 sd->entity.info.dev.major = VIDEO_MAJOR; 260 sd->entity.info.dev.minor = vdev->minor; 261 262 /* Interface is created by __video_register_device() */ 263 if (vdev->v4l2_dev->mdev) { 264 struct media_link *link; 265 266 link = media_create_intf_link(&sd->entity, 267 &vdev->intf_devnode->intf, 268 0); 269 if (!link) 270 goto clean_up; 271 } 272 #endif 273 sd->devnode = vdev; 274 } 275 return 0; 276 277 clean_up: 278 list_for_each_entry(sd, &v4l2_dev->subdevs, list) { 279 if (!sd->devnode) 280 break; 281 video_unregister_device(sd->devnode); 282 } 283 284 return err; 285 } 286 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes); 287 288 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd) 289 { 290 struct v4l2_device *v4l2_dev; 291 292 /* return if it isn't registered */ 293 if (sd == NULL || sd->v4l2_dev == NULL) 294 return; 295 296 v4l2_dev = sd->v4l2_dev; 297 298 spin_lock(&v4l2_dev->lock); 299 list_del(&sd->list); 300 spin_unlock(&v4l2_dev->lock); 301 302 if (sd->internal_ops && sd->internal_ops->unregistered) 303 sd->internal_ops->unregistered(sd); 304 sd->v4l2_dev = NULL; 305 306 #if defined(CONFIG_MEDIA_CONTROLLER) 307 if (v4l2_dev->mdev) { 308 /* 309 * No need to explicitly remove links, as both pads and 310 * links are removed by the function below, in the right order 311 */ 312 media_device_unregister_entity(&sd->entity); 313 } 314 #endif 315 video_unregister_device(sd->devnode); 316 if (!sd->owner_v4l2_dev) 317 module_put(sd->owner); 318 } 319 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev); 320