include/media/v4l2-dev.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *
   4  *      V 4 L 2   D R I V E R   H E L P E R   A P I
   5  *
   6  * Moved from videodev2.h
   7  *
   8  *      Some commonly needed functions for drivers (v4l2-common.o module)
   9  */
  10 #ifndef _V4L2_DEV_H
  11 #define _V4L2_DEV_H
  12
  13 #include <linux/poll.h>
  14 #include <linux/fs.h>
  15 #include <linux/device.h>
  16 #include <linux/cdev.h>
  17 #include <linux/mutex.h>
  18 #include <linux/videodev2.h>
  19
  20 #include <media/media-entity.h>
  21
  22 #define VIDEO_MAJOR     81
  23
  24 /**
  25  * enum vfl_devnode_type - type of V4L2 device node
  26  *
  27  * @VFL_TYPE_GRABBER:   for video input/output devices
  28  * @VFL_TYPE_VBI:       for vertical blank data (i.e. closed captions, teletext)
  29  * @VFL_TYPE_RADIO:     for radio tuners
  30  * @VFL_TYPE_SUBDEV:    for V4L2 subdevices
  31  * @VFL_TYPE_SDR:       for Software Defined Radio tuners
  32  * @VFL_TYPE_TOUCH:     for touch sensors
  33  * @VFL_TYPE_MAX:       number of VFL types, must always be last in the enum
  34  */
  35 enum vfl_devnode_type {
  36         VFL_TYPE_GRABBER        = 0,
  37         VFL_TYPE_VBI,
  38         VFL_TYPE_RADIO,
  39         VFL_TYPE_SUBDEV,
  40         VFL_TYPE_SDR,
  41         VFL_TYPE_TOUCH,
  42         VFL_TYPE_MAX /* Shall be the last one */
  43 };
  44
  45 /**
  46  * enum  vfl_direction - Identifies if a &struct video_device corresponds
  47  *      to a receiver, a transmitter or a mem-to-mem device.
  48  *
  49  * @VFL_DIR_RX:         device is a receiver.
  50  * @VFL_DIR_TX:         device is a transmitter.
  51  * @VFL_DIR_M2M:        device is a memory to memory device.
  52  *
  53  * Note: Ignored if &enum vfl_devnode_type is %VFL_TYPE_SUBDEV.
  54  */
  55 enum vfl_devnode_direction {
  56         VFL_DIR_RX,
  57         VFL_DIR_TX,
  58         VFL_DIR_M2M,
  59 };
  60
  61 struct v4l2_ioctl_callbacks;
  62 struct video_device;
  63 struct v4l2_device;
  64 struct v4l2_ctrl_handler;
  65
  66 /**
  67  * enum v4l2_video_device_flags - Flags used by &struct video_device
  68  *
  69  * @V4L2_FL_REGISTERED:
  70  *      indicates that a &struct video_device is registered.
  71  *      Drivers can clear this flag if they want to block all future
  72  *      device access. It is cleared by video_unregister_device.
  73  * @V4L2_FL_USES_V4L2_FH:
  74  *      indicates that file->private_data points to &struct v4l2_fh.
  75  *      This flag is set by the core when v4l2_fh_init() is called.
  76  *      All new drivers should use it.
  77  * @V4L2_FL_QUIRK_INVERTED_CROP:
  78  *      some old M2M drivers use g/s_crop/cropcap incorrectly: crop and
  79  *      compose are swapped. If this flag is set, then the selection
  80  *      targets are swapped in the g/s_crop/cropcap functions in v4l2-ioctl.c.
  81  *      This allows those drivers to correctly implement the selection API,
  82  *      but the old crop API will still work as expected in order to preserve
  83  *      backwards compatibility.
  84  *      Never set this flag for new drivers.
  85  */
  86 enum v4l2_video_device_flags {
  87         V4L2_FL_REGISTERED              = 0,
  88         V4L2_FL_USES_V4L2_FH            = 1,
  89         V4L2_FL_QUIRK_INVERTED_CROP     = 2,
  90 };
  91
  92 /* Priority helper functions */
  93
  94 /**
  95  * struct v4l2_prio_state - stores the priority states
  96  *
  97  * @prios: array with elements to store the array priorities
  98  *
  99  *
 100  * .. note::
 101  *    The size of @prios array matches the number of priority types defined
 102  *    by enum &v4l2_priority.
 103  */
 104 struct v4l2_prio_state {
 105         atomic_t prios[4];
 106 };
 107
 108 /**
 109  * v4l2_prio_init - initializes a struct v4l2_prio_state
 110  *
 111  * @global: pointer to &struct v4l2_prio_state
 112  */
 113 void v4l2_prio_init(struct v4l2_prio_state *global);
 114
 115 /**
 116  * v4l2_prio_change - changes the v4l2 file handler priority
 117  *
 118  * @global: pointer to the &struct v4l2_prio_state of the device node.
 119  * @local: pointer to the desired priority, as defined by enum &v4l2_priority
 120  * @new: Priority type requested, as defined by enum &v4l2_priority.
 121  *
 122  * .. note::
 123  *      This function should be used only by the V4L2 core.
 124  */
 125 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
 126                      enum v4l2_priority new);
 127
 128 /**
 129  * v4l2_prio_open - Implements the priority logic for a file handler open
 130  *
 131  * @global: pointer to the &struct v4l2_prio_state of the device node.
 132  * @local: pointer to the desired priority, as defined by enum &v4l2_priority
 133  *
 134  * .. note::
 135  *      This function should be used only by the V4L2 core.
 136  */
 137 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
 138
 139 /**
 140  * v4l2_prio_close - Implements the priority logic for a file handler close
 141  *
 142  * @global: pointer to the &struct v4l2_prio_state of the device node.
 143  * @local: priority to be released, as defined by enum &v4l2_priority
 144  *
 145  * .. note::
 146  *      This function should be used only by the V4L2 core.
 147  */
 148 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
 149
 150 /**
 151  * v4l2_prio_max - Return the maximum priority, as stored at the @global array.
 152  *
 153  * @global: pointer to the &struct v4l2_prio_state of the device node.
 154  *
 155  * .. note::
 156  *      This function should be used only by the V4L2 core.
 157  */
 158 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
 159
 160 /**
 161  * v4l2_prio_check - Implements the priority logic for a file handler close
 162  *
 163  * @global: pointer to the &struct v4l2_prio_state of the device node.
 164  * @local: desired priority, as defined by enum &v4l2_priority local
 165  *
 166  * .. note::
 167  *      This function should be used only by the V4L2 core.
 168  */
 169 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
 170
 171 /**
 172  * struct v4l2_file_operations - fs operations used by a V4L2 device
 173  *
 174  * @owner: pointer to struct module
 175  * @read: operations needed to implement the read() syscall
 176  * @write: operations needed to implement the write() syscall
 177  * @poll: operations needed to implement the poll() syscall
 178  * @unlocked_ioctl: operations needed to implement the ioctl() syscall
 179  * @compat_ioctl32: operations needed to implement the ioctl() syscall for
 180  *      the special case where the Kernel uses 64 bits instructions, but
 181  *      the userspace uses 32 bits.
 182  * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU
 183  * @mmap: operations needed to implement the mmap() syscall
 184  * @open: operations needed to implement the open() syscall
 185  * @release: operations needed to implement the release() syscall
 186  *
 187  * .. note::
 188  *
 189  *      Those operations are used to implemente the fs struct file_operations
 190  *      at the V4L2 drivers. The V4L2 core overrides the fs ops with some
 191  *      extra logic needed by the subsystem.
 192  */
 193 struct v4l2_file_operations {
 194         struct module *owner;
 195         ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
 196         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 197         __poll_t (*poll) (struct file *, struct poll_table_struct *);
 198         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 199 #ifdef CONFIG_COMPAT
 200         long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
 201 #endif
 202         unsigned long (*get_unmapped_area) (struct file *, unsigned long,
 203                                 unsigned long, unsigned long, unsigned long);
 204         int (*mmap) (struct file *, struct vm_area_struct *);
 205         int (*open) (struct file *);
 206         int (*release) (struct file *);
 207 };
 208
 209 /*
 210  * Newer version of video_device, handled by videodev2.c
 211  *      This version moves redundant code from video device code to
 212  *      the common handler
 213  */
 214
 215 /**
 216  * struct video_device - Structure used to create and manage the V4L2 device
 217  *      nodes.
 218  *
 219  * @entity: &struct media_entity
 220  * @intf_devnode: pointer to &struct media_intf_devnode
 221  * @pipe: &struct media_pipeline
 222  * @fops: pointer to &struct v4l2_file_operations for the video device
 223  * @device_caps: device capabilities as used in v4l2_capabilities
 224  * @dev: &struct device for the video device
 225  * @cdev: character device
 226  * @v4l2_dev: pointer to &struct v4l2_device parent
 227  * @dev_parent: pointer to &struct device parent
 228  * @ctrl_handler: Control handler associated with this device node.
 229  *       May be NULL.
 230  * @queue: &struct vb2_queue associated with this device node. May be NULL.
 231  * @prio: pointer to &struct v4l2_prio_state with device's Priority state.
 232  *       If NULL, then v4l2_dev->prio will be used.
 233  * @name: video device name
 234  * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type
 235  * @vfl_dir: V4L receiver, transmitter or m2m
 236  * @minor: device node 'minor'. It is set to -1 if the registration failed
 237  * @num: number of the video device node
 238  * @flags: video device flags. Use bitops to set/clear/test flags.
 239  *         Contains a set of &enum v4l2_video_device_flags.
 240  * @index: attribute to differentiate multiple indices on one physical device
 241  * @fh_lock: Lock for all v4l2_fhs
 242  * @fh_list: List of &struct v4l2_fh
 243  * @dev_debug: Internal device debug flags, not for use by drivers
 244  * @tvnorms: Supported tv norms
 245  *
 246  * @release: video device release() callback
 247  * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks
 248  *
 249  * @valid_ioctls: bitmap with the valid ioctls for this device
 250  * @lock: pointer to &struct mutex serialization lock
 251  *
 252  * .. note::
 253  *      Only set @dev_parent if that can't be deduced from @v4l2_dev.
 254  */
 255
 256 struct video_device
 257 {
 258 #if defined(CONFIG_MEDIA_CONTROLLER)
 259         struct media_entity entity;
 260         struct media_intf_devnode *intf_devnode;
 261         struct media_pipeline pipe;
 262 #endif
 263         const struct v4l2_file_operations *fops;
 264
 265         u32 device_caps;
 266
 267         /* sysfs */
 268         struct device dev;
 269         struct cdev *cdev;
 270
 271         struct v4l2_device *v4l2_dev;
 272         struct device *dev_parent;
 273
 274         struct v4l2_ctrl_handler *ctrl_handler;
 275
 276         struct vb2_queue *queue;
 277
 278         struct v4l2_prio_state *prio;
 279
 280         /* device info */
 281         char name[32];
 282         enum vfl_devnode_type vfl_type;
 283         enum vfl_devnode_direction vfl_dir;
 284         int minor;
 285         u16 num;
 286         unsigned long flags;
 287         int index;
 288
 289         /* V4L2 file handles */
 290         spinlock_t              fh_lock;
 291         struct list_head        fh_list;
 292
 293         int dev_debug;
 294
 295         v4l2_std_id tvnorms;
 296
 297         /* callbacks */
 298         void (*release)(struct video_device *vdev);
 299         const struct v4l2_ioctl_ops *ioctl_ops;
 300         DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
 301
 302         struct mutex *lock;
 303 };
 304
 305 /**
 306  * media_entity_to_video_device - Returns a &struct video_device from
 307  *      the &struct media_entity embedded on it.
 308  *
 309  * @__entity: pointer to &struct media_entity
 310  */
 311 #define media_entity_to_video_device(__entity) \
 312         container_of(__entity, struct video_device, entity)
 313
 314 /**
 315  * to_video_device - Returns a &struct video_device from the
 316  *      &struct device embedded on it.
 317  *
 318  * @cd: pointer to &struct device
 319  */
 320 #define to_video_device(cd) container_of(cd, struct video_device, dev)
 321
 322 /**
 323  * __video_register_device - register video4linux devices
 324  *
 325  * @vdev: struct video_device to register
 326  * @type: type of device to register, as defined by &enum vfl_devnode_type
 327  * @nr:   which device node number is desired:
 328  *      (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
 329  * @warn_if_nr_in_use: warn if the desired device node number
 330  *        was already in use and another number was chosen instead.
 331  * @owner: module that owns the video device node
 332  *
 333  * The registration code assigns minor numbers and device node numbers
 334  * based on the requested type and registers the new device node with
 335  * the kernel.
 336  *
 337  * This function assumes that struct video_device was zeroed when it
 338  * was allocated and does not contain any stale date.
 339  *
 340  * An error is returned if no free minor or device node number could be
 341  * found, or if the registration of the device node failed.
 342  *
 343  * Returns 0 on success.
 344  *
 345  * .. note::
 346  *
 347  *      This function is meant to be used only inside the V4L2 core.
 348  *      Drivers should use video_register_device() or
 349  *      video_register_device_no_warn().
 350  */
 351 int __must_check __video_register_device(struct video_device *vdev,
 352                                          enum vfl_devnode_type type,
 353                                          int nr, int warn_if_nr_in_use,
 354                                          struct module *owner);
 355
 356 /**
 357  *  video_register_device - register video4linux devices
 358  *
 359  * @vdev: struct video_device to register
 360  * @type: type of device to register, as defined by &enum vfl_devnode_type
 361  * @nr:   which device node number is desired:
 362  *      (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
 363  *
 364  * Internally, it calls __video_register_device(). Please see its
 365  * documentation for more details.
 366  *
 367  * .. note::
 368  *      if video_register_device fails, the release() callback of
 369  *      &struct video_device structure is *not* called, so the caller
 370  *      is responsible for freeing any data. Usually that means that
 371  *      you video_device_release() should be called on failure.
 372  */
 373 static inline int __must_check video_register_device(struct video_device *vdev,
 374                                                      enum vfl_devnode_type type,
 375                                                      int nr)
 376 {
 377         return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
 378 }
 379
 380 /**
 381  *  video_register_device_no_warn - register video4linux devices
 382  *
 383  * @vdev: struct video_device to register
 384  * @type: type of device to register, as defined by &enum vfl_devnode_type
 385  * @nr:   which device node number is desired:
 386  *      (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
 387  *
 388  * This function is identical to video_register_device() except that no
 389  * warning is issued if the desired device node number was already in use.
 390  *
 391  * Internally, it calls __video_register_device(). Please see its
 392  * documentation for more details.
 393  *
 394  * .. note::
 395  *      if video_register_device fails, the release() callback of
 396  *      &struct video_device structure is *not* called, so the caller
 397  *      is responsible for freeing any data. Usually that means that
 398  *      you video_device_release() should be called on failure.
 399  */
 400 static inline int __must_check
 401 video_register_device_no_warn(struct video_device *vdev,
 402                               enum vfl_devnode_type type, int nr)
 403 {
 404         return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
 405 }
 406
 407 /**
 408  * video_unregister_device - Unregister video devices.
 409  *
 410  * @vdev: &struct video_device to register
 411  *
 412  * Does nothing if vdev == NULL or if video_is_registered() returns false.
 413  */
 414 void video_unregister_device(struct video_device *vdev);
 415
 416 /**
 417  * video_device_alloc - helper function to alloc &struct video_device
 418  *
 419  * Returns NULL if %-ENOMEM or a &struct video_device on success.
 420  */
 421 struct video_device * __must_check video_device_alloc(void);
 422
 423 /**
 424  * video_device_release - helper function to release &struct video_device
 425  *
 426  * @vdev: pointer to &struct video_device
 427  *
 428  * Can also be used for video_device->release\(\).
 429  */
 430 void video_device_release(struct video_device *vdev);
 431
 432 /**
 433  * video_device_release_empty - helper function to implement the
 434  *      video_device->release\(\) callback.
 435  *
 436  * @vdev: pointer to &struct video_device
 437  *
 438  * This release function does nothing.
 439  *
 440  * It should be used when the video_device is a static global struct.
 441  *
 442  * .. note::
 443  *      Having a static video_device is a dubious construction at best.
 444  */
 445 void video_device_release_empty(struct video_device *vdev);
 446
 447 /**
 448  * v4l2_disable_ioctl- mark that a given command isn't implemented.
 449  *      shouldn't use core locking
 450  *
 451  * @vdev: pointer to &struct video_device
 452  * @cmd: ioctl command
 453  *
 454  * This function allows drivers to provide just one v4l2_ioctl_ops struct, but
 455  * disable ioctls based on the specific card that is actually found.
 456  *
 457  * .. note::
 458  *
 459  *    This must be called before video_register_device.
 460  *    See also the comments for determine_valid_ioctls().
 461  */
 462 static inline void v4l2_disable_ioctl(struct video_device *vdev,
 463                                       unsigned int cmd)
 464 {
 465         if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 466                 set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
 467 }
 468
 469 /**
 470  * video_get_drvdata - gets private data from &struct video_device.
 471  *
 472  * @vdev: pointer to &struct video_device
 473  *
 474  * returns a pointer to the private data
 475  */
 476 static inline void *video_get_drvdata(struct video_device *vdev)
 477 {
 478         return dev_get_drvdata(&vdev->dev);
 479 }
 480
 481 /**
 482  * video_set_drvdata - sets private data from &struct video_device.
 483  *
 484  * @vdev: pointer to &struct video_device
 485  * @data: private data pointer
 486  */
 487 static inline void video_set_drvdata(struct video_device *vdev, void *data)
 488 {
 489         dev_set_drvdata(&vdev->dev, data);
 490 }
 491
 492 /**
 493  * video_devdata - gets &struct video_device from struct file.
 494  *
 495  * @file: pointer to struct file
 496  */
 497 struct video_device *video_devdata(struct file *file);
 498
 499 /**
 500  * video_drvdata - gets private data from &struct video_device using the
 501  *      struct file.
 502  *
 503  * @file: pointer to struct file
 504  *
 505  * This is function combines both video_get_drvdata() and video_devdata()
 506  * as this is used very often.
 507  */
 508 static inline void *video_drvdata(struct file *file)
 509 {
 510         return video_get_drvdata(video_devdata(file));
 511 }
 512
 513 /**
 514  * video_device_node_name - returns the video device name
 515  *
 516  * @vdev: pointer to &struct video_device
 517  *
 518  * Returns the device name string
 519  */
 520 static inline const char *video_device_node_name(struct video_device *vdev)
 521 {
 522         return dev_name(&vdev->dev);
 523 }
 524
 525 /**
 526  * video_is_registered - returns true if the &struct video_device is registered.
 527  *
 528  *
 529  * @vdev: pointer to &struct video_device
 530  */
 531 static inline int video_is_registered(struct video_device *vdev)
 532 {
 533         return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 534 }
 535
 536 #endif /* _V4L2_DEV_H */