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 if (WARN_ON(!v4l2_dev->name[0])) 48 return -EINVAL; 49 return 0; 50 } 51 52 /* Set name to driver name + device name if it is empty. */ 53 if (!v4l2_dev->name[0]) 54 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s", 55 dev->driver->name, dev_name(dev)); 56 if (!dev_get_drvdata(dev)) 57 dev_set_drvdata(dev, v4l2_dev); 58 return 0; 59 } 60 EXPORT_SYMBOL_GPL(v4l2_device_register); 61 62 static void v4l2_device_release(struct kref *ref) 63 { 64 struct v4l2_device *v4l2_dev = 65 container_of(ref, struct v4l2_device, ref); 66 67 if (v4l2_dev->release) 68 v4l2_dev->release(v4l2_dev); 69 } 70 71 int v4l2_device_put(struct v4l2_device *v4l2_dev) 72 { 73 return kref_put(&v4l2_dev->ref, v4l2_device_release); 74 } 75 EXPORT_SYMBOL_GPL(v4l2_device_put); 76 77 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, 78 atomic_t *instance) 79 { 80 int num = atomic_inc_return(instance) - 1; 81 int len = strlen(basename); 82 83 if (basename[len - 1] >= '0' && basename[len - 1] <= '9') 84 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), 85 "%s-%d", basename, num); 86 else 87 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), 88 "%s%d", basename, num); 89 return num; 90 } 91 EXPORT_SYMBOL_GPL(v4l2_device_set_name); 92 93 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev) 94 { 95 if (v4l2_dev->dev == NULL) 96 return; 97 98 if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev) 99 dev_set_drvdata(v4l2_dev->dev, NULL); 100 put_device(v4l2_dev->dev); 101 v4l2_dev->dev = NULL; 102 } 103 EXPORT_SYMBOL_GPL(v4l2_device_disconnect); 104 105 void v4l2_device_unregister(struct v4l2_device *v4l2_dev) 106 { 107 struct v4l2_subdev *sd, *next; 108 109 /* Just return if v4l2_dev is NULL or if it was already 110 * unregistered before. */ 111 if (v4l2_dev == NULL || !v4l2_dev->name[0]) 112 return; 113 v4l2_device_disconnect(v4l2_dev); 114 115 /* Unregister subdevs */ 116 list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) { 117 v4l2_device_unregister_subdev(sd); 118 #if IS_ENABLED(CONFIG_I2C) 119 if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) { 120 struct i2c_client *client = v4l2_get_subdevdata(sd); 121 122 /* We need to unregister the i2c client explicitly. 123 We cannot rely on i2c_del_adapter to always 124 unregister clients for us, since if the i2c bus 125 is a platform bus, then it is never deleted. */ 126 if (client) 127 i2c_unregister_device(client); 128 continue; 129 } 130 #endif 131 #if defined(CONFIG_SPI) 132 if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) { 133 struct spi_device *spi = v4l2_get_subdevdata(sd); 134 135 if (spi) 136 spi_unregister_device(spi); 137 continue; 138 } 139 #endif 140 } 141 /* Mark as unregistered, thus preventing duplicate unregistrations */ 142 v4l2_dev->name[0] = '\0'; 143 } 144 EXPORT_SYMBOL_GPL(v4l2_device_unregister); 145 146 int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 147 struct v4l2_subdev *sd) 148 { 149 #if defined(CONFIG_MEDIA_CONTROLLER) 150 struct media_entity *entity = &sd->entity; 151 #endif 152 int err; 153 154 /* Check for valid input */ 155 if (v4l2_dev == NULL || sd == NULL || !sd->name[0]) 156 return -EINVAL; 157 158 /* Warn if we apparently re-register a subdev */ 159 WARN_ON(sd->v4l2_dev != NULL); 160 161 if (!try_module_get(sd->owner)) 162 return -ENODEV; 163 164 sd->v4l2_dev = v4l2_dev; 165 if (sd->internal_ops && sd->internal_ops->registered) { 166 err = sd->internal_ops->registered(sd); 167 if (err) 168 goto error_module; 169 } 170 171 /* This just returns 0 if either of the two args is NULL */ 172 err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL); 173 if (err) 174 goto error_unregister; 175 176 #if defined(CONFIG_MEDIA_CONTROLLER) 177 /* Register the entity. */ 178 if (v4l2_dev->mdev) { 179 err = media_device_register_entity(v4l2_dev->mdev, entity); 180 if (err < 0) 181 goto error_unregister; 182 } 183 #endif 184 185 spin_lock(&v4l2_dev->lock); 186 list_add_tail(&sd->list, &v4l2_dev->subdevs); 187 spin_unlock(&v4l2_dev->lock); 188 189 return 0; 190 191 error_unregister: 192 if (sd->internal_ops && sd->internal_ops->unregistered) 193 sd->internal_ops->unregistered(sd); 194 error_module: 195 module_put(sd->owner); 196 sd->v4l2_dev = NULL; 197 return err; 198 } 199 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev); 200 201 static void v4l2_device_release_subdev_node(struct video_device *vdev) 202 { 203 struct v4l2_subdev *sd = video_get_drvdata(vdev); 204 sd->devnode = NULL; 205 kfree(vdev); 206 } 207 208 int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) 209 { 210 struct video_device *vdev; 211 struct v4l2_subdev *sd; 212 int err; 213 214 /* Register a device node for every subdev marked with the 215 * V4L2_SUBDEV_FL_HAS_DEVNODE flag. 216 */ 217 list_for_each_entry(sd, &v4l2_dev->subdevs, list) { 218 if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE)) 219 continue; 220 221 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); 222 if (!vdev) { 223 err = -ENOMEM; 224 goto clean_up; 225 } 226 227 video_set_drvdata(vdev, sd); 228 strlcpy(vdev->name, sd->name, sizeof(vdev->name)); 229 vdev->v4l2_dev = v4l2_dev; 230 vdev->fops = &v4l2_subdev_fops; 231 vdev->release = v4l2_device_release_subdev_node; 232 vdev->ctrl_handler = sd->ctrl_handler; 233 err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1, 234 sd->owner); 235 if (err < 0) { 236 kfree(vdev); 237 goto clean_up; 238 } 239 #if defined(CONFIG_MEDIA_CONTROLLER) 240 sd->entity.info.v4l.major = VIDEO_MAJOR; 241 sd->entity.info.v4l.minor = vdev->minor; 242 #endif 243 sd->devnode = vdev; 244 } 245 return 0; 246 247 clean_up: 248 list_for_each_entry(sd, &v4l2_dev->subdevs, list) { 249 if (!sd->devnode) 250 break; 251 video_unregister_device(sd->devnode); 252 } 253 254 return err; 255 } 256 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes); 257 258 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd) 259 { 260 struct v4l2_device *v4l2_dev; 261 262 /* return if it isn't registered */ 263 if (sd == NULL || sd->v4l2_dev == NULL) 264 return; 265 266 v4l2_dev = sd->v4l2_dev; 267 268 spin_lock(&v4l2_dev->lock); 269 list_del(&sd->list); 270 spin_unlock(&v4l2_dev->lock); 271 272 if (sd->internal_ops && sd->internal_ops->unregistered) 273 sd->internal_ops->unregistered(sd); 274 sd->v4l2_dev = NULL; 275 276 #if defined(CONFIG_MEDIA_CONTROLLER) 277 if (v4l2_dev->mdev) { 278 media_entity_remove_links(&sd->entity); 279 media_device_unregister_entity(&sd->entity); 280 } 281 #endif 282 video_unregister_device(sd->devnode); 283 module_put(sd->owner); 284 } 285 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev); 286