| 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 | /* We need to unregister the i2c client explicitly. |
| 122 | We cannot rely on i2c_del_adapter to always |
| 123 | unregister clients for us, since if the i2c bus |
| 124 | is a platform bus, then it is never deleted. */ |
| 125 | if (client) |
| 126 | i2c_unregister_device(client); |
| 127 | continue; |
| 128 | } |
| 129 | #endif |
| 130 | #if defined(CONFIG_SPI) |
| 131 | if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) { |
| 132 | struct spi_device *spi = v4l2_get_subdevdata(sd); |
| 133 | |
| 134 | if (spi) |
| 135 | spi_unregister_device(spi); |
| 136 | continue; |
| 137 | } |
| 138 | #endif |
| 139 | } |
| 140 | /* Mark as unregistered, thus preventing duplicate unregistrations */ |
| 141 | v4l2_dev->name[0] = '\0'; |
| 142 | } |
| 143 | EXPORT_SYMBOL_GPL(v4l2_device_unregister); |
| 144 | |
| 145 | int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, |
| 146 | struct v4l2_subdev *sd) |
| 147 | { |
| 148 | #if defined(CONFIG_MEDIA_CONTROLLER) |
| 149 | struct media_entity *entity = &sd->entity; |
| 150 | #endif |
| 151 | int err; |
| 152 | |
| 153 | /* Check for valid input */ |
| 154 | if (v4l2_dev == NULL || sd == NULL || !sd->name[0]) |
| 155 | return -EINVAL; |
| 156 | |
| 157 | /* Warn if we apparently re-register a subdev */ |
| 158 | WARN_ON(sd->v4l2_dev != NULL); |
| 159 | |
| 160 | /* |
| 161 | * The reason to acquire the module here is to avoid unloading |
| 162 | * a module of sub-device which is registered to a media |
| 163 | * device. To make it possible to unload modules for media |
| 164 | * devices that also register sub-devices, do not |
| 165 | * try_module_get() such sub-device owners. |
| 166 | */ |
| 167 | sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver && |
| 168 | sd->owner == v4l2_dev->dev->driver->owner; |
| 169 | |
| 170 | if (!sd->owner_v4l2_dev && !try_module_get(sd->owner)) |
| 171 | return -ENODEV; |
| 172 | |
| 173 | sd->v4l2_dev = v4l2_dev; |
| 174 | if (sd->internal_ops && sd->internal_ops->registered) { |
| 175 | err = sd->internal_ops->registered(sd); |
| 176 | if (err) |
| 177 | goto error_module; |
| 178 | } |
| 179 | |
| 180 | /* This just returns 0 if either of the two args is NULL */ |
| 181 | err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL); |
| 182 | if (err) |
| 183 | goto error_unregister; |
| 184 | |
| 185 | #if defined(CONFIG_MEDIA_CONTROLLER) |
| 186 | /* Register the entity. */ |
| 187 | if (v4l2_dev->mdev) { |
| 188 | err = media_device_register_entity(v4l2_dev->mdev, entity); |
| 189 | if (err < 0) |
| 190 | goto error_unregister; |
| 191 | } |
| 192 | #endif |
| 193 | |
| 194 | spin_lock(&v4l2_dev->lock); |
| 195 | list_add_tail(&sd->list, &v4l2_dev->subdevs); |
| 196 | spin_unlock(&v4l2_dev->lock); |
| 197 | |
| 198 | return 0; |
| 199 | |
| 200 | error_unregister: |
| 201 | if (sd->internal_ops && sd->internal_ops->unregistered) |
| 202 | sd->internal_ops->unregistered(sd); |
| 203 | error_module: |
| 204 | if (!sd->owner_v4l2_dev) |
| 205 | module_put(sd->owner); |
| 206 | sd->v4l2_dev = NULL; |
| 207 | return err; |
| 208 | } |
| 209 | EXPORT_SYMBOL_GPL(v4l2_device_register_subdev); |
| 210 | |
| 211 | static void v4l2_device_release_subdev_node(struct video_device *vdev) |
| 212 | { |
| 213 | struct v4l2_subdev *sd = video_get_drvdata(vdev); |
| 214 | sd->devnode = NULL; |
| 215 | kfree(vdev); |
| 216 | } |
| 217 | |
| 218 | int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) |
| 219 | { |
| 220 | struct video_device *vdev; |
| 221 | struct v4l2_subdev *sd; |
| 222 | int err; |
| 223 | |
| 224 | /* Register a device node for every subdev marked with the |
| 225 | * V4L2_SUBDEV_FL_HAS_DEVNODE flag. |
| 226 | */ |
| 227 | list_for_each_entry(sd, &v4l2_dev->subdevs, list) { |
| 228 | if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE)) |
| 229 | continue; |
| 230 | |
| 231 | vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); |
| 232 | if (!vdev) { |
| 233 | err = -ENOMEM; |
| 234 | goto clean_up; |
| 235 | } |
| 236 | |
| 237 | video_set_drvdata(vdev, sd); |
| 238 | strlcpy(vdev->name, sd->name, sizeof(vdev->name)); |
| 239 | vdev->v4l2_dev = v4l2_dev; |
| 240 | vdev->fops = &v4l2_subdev_fops; |
| 241 | vdev->release = v4l2_device_release_subdev_node; |
| 242 | vdev->ctrl_handler = sd->ctrl_handler; |
| 243 | err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1, |
| 244 | sd->owner); |
| 245 | if (err < 0) { |
| 246 | kfree(vdev); |
| 247 | goto clean_up; |
| 248 | } |
| 249 | #if defined(CONFIG_MEDIA_CONTROLLER) |
| 250 | sd->entity.info.dev.major = VIDEO_MAJOR; |
| 251 | sd->entity.info.dev.minor = vdev->minor; |
| 252 | #endif |
| 253 | sd->devnode = vdev; |
| 254 | } |
| 255 | return 0; |
| 256 | |
| 257 | clean_up: |
| 258 | list_for_each_entry(sd, &v4l2_dev->subdevs, list) { |
| 259 | if (!sd->devnode) |
| 260 | break; |
| 261 | video_unregister_device(sd->devnode); |
| 262 | } |
| 263 | |
| 264 | return err; |
| 265 | } |
| 266 | EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes); |
| 267 | |
| 268 | void v4l2_device_unregister_subdev(struct v4l2_subdev *sd) |
| 269 | { |
| 270 | struct v4l2_device *v4l2_dev; |
| 271 | |
| 272 | /* return if it isn't registered */ |
| 273 | if (sd == NULL || sd->v4l2_dev == NULL) |
| 274 | return; |
| 275 | |
| 276 | v4l2_dev = sd->v4l2_dev; |
| 277 | |
| 278 | spin_lock(&v4l2_dev->lock); |
| 279 | list_del(&sd->list); |
| 280 | spin_unlock(&v4l2_dev->lock); |
| 281 | |
| 282 | if (sd->internal_ops && sd->internal_ops->unregistered) |
| 283 | sd->internal_ops->unregistered(sd); |
| 284 | sd->v4l2_dev = NULL; |
| 285 | |
| 286 | #if defined(CONFIG_MEDIA_CONTROLLER) |
| 287 | if (v4l2_dev->mdev) { |
| 288 | media_entity_remove_links(&sd->entity); |
| 289 | media_device_unregister_entity(&sd->entity); |
| 290 | } |
| 291 | #endif |
| 292 | video_unregister_device(sd->devnode); |
| 293 | if (!sd->owner_v4l2_dev) |
| 294 | module_put(sd->owner); |
| 295 | } |
| 296 | EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev); |