1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Media device 4 * 5 * Copyright (C) 2010 Nokia Corporation 6 * 7 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com> 8 * Sakari Ailus <sakari.ailus@iki.fi> 9 */ 10 11 #ifndef _MEDIA_DEVICE_H 12 #define _MEDIA_DEVICE_H 13 14 #include <linux/list.h> 15 #include <linux/mutex.h> 16 17 #include <media/media-devnode.h> 18 #include <media/media-entity.h> 19 20 struct ida; 21 struct device; 22 struct media_device; 23 24 /** 25 * struct media_entity_notify - Media Entity Notify 26 * 27 * @list: List head 28 * @notify_data: Input data to invoke the callback 29 * @notify: Callback function pointer 30 * 31 * Drivers may register a callback to take action when new entities get 32 * registered with the media device. This handler is intended for creating 33 * links between existing entities and should not create entities and register 34 * them. 35 */ 36 struct media_entity_notify { 37 struct list_head list; 38 void *notify_data; 39 void (*notify)(struct media_entity *entity, void *notify_data); 40 }; 41 42 /** 43 * struct media_device_ops - Media device operations 44 * @link_notify: Link state change notification callback. This callback is 45 * called with the graph_mutex held. 46 * @req_alloc: Allocate a request. Set this if you need to allocate a struct 47 * larger then struct media_request. @req_alloc and @req_free must 48 * either both be set or both be NULL. 49 * @req_free: Free a request. Set this if @req_alloc was set as well, leave 50 * to NULL otherwise. 51 * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex 52 * lock is held when this op is called. 53 * @req_queue: Queue a validated request, cannot fail. If something goes 54 * wrong when queueing this request then it should be marked 55 * as such internally in the driver and any related buffers 56 * must eventually return to vb2 with state VB2_BUF_STATE_ERROR. 57 * The req_queue_mutex lock is held when this op is called. 58 * It is important that vb2 buffer objects are queued last after 59 * all other object types are queued: queueing a buffer kickstarts 60 * the request processing, so all other objects related to the 61 * request (and thus the buffer) must be available to the driver. 62 * And once a buffer is queued, then the driver can complete 63 * or delete objects from the request before req_queue exits. 64 */ 65 struct media_device_ops { 66 int (*link_notify)(struct media_link *link, u32 flags, 67 unsigned int notification); 68 struct media_request *(*req_alloc)(struct media_device *mdev); 69 void (*req_free)(struct media_request *req); 70 int (*req_validate)(struct media_request *req); 71 void (*req_queue)(struct media_request *req); 72 }; 73 74 /** 75 * struct media_device - Media device 76 * @dev: Parent device 77 * @devnode: Media device node 78 * @driver_name: Optional device driver name. If not set, calls to 79 * %MEDIA_IOC_DEVICE_INFO will return ``dev->driver->name``. 80 * This is needed for USB drivers for example, as otherwise 81 * they'll all appear as if the driver name was "usb". 82 * @model: Device model name 83 * @serial: Device serial number (optional) 84 * @bus_info: Unique and stable device location identifier 85 * @hw_revision: Hardware device revision 86 * @topology_version: Monotonic counter for storing the version of the graph 87 * topology. Should be incremented each time the topology changes. 88 * @id: Unique ID used on the last registered graph object 89 * @entity_internal_idx: Unique internal entity ID used by the graph traversal 90 * algorithms 91 * @entity_internal_idx_max: Allocated internal entity indices 92 * @entities: List of registered entities 93 * @interfaces: List of registered interfaces 94 * @pads: List of registered pads 95 * @links: List of registered links 96 * @entity_notify: List of registered entity_notify callbacks 97 * @graph_mutex: Protects access to struct media_device data 98 * @pm_count_walk: Graph walk for power state walk. Access serialised using 99 * graph_mutex. 100 * 101 * @source_priv: Driver Private data for enable/disable source handlers 102 * @enable_source: Enable Source Handler function pointer 103 * @disable_source: Disable Source Handler function pointer 104 * 105 * @ops: Operation handler callbacks 106 * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t. 107 * other operations that stop or start streaming. 108 * @request_id: Used to generate unique request IDs 109 * 110 * This structure represents an abstract high-level media device. It allows easy 111 * access to entities and provides basic media device-level support. The 112 * structure can be allocated directly or embedded in a larger structure. 113 * 114 * The parent @dev is a physical device. It must be set before registering the 115 * media device. 116 * 117 * @model is a descriptive model name exported through sysfs. It doesn't have to 118 * be unique. 119 * 120 * @enable_source is a handler to find source entity for the 121 * sink entity and activate the link between them if source 122 * entity is free. Drivers should call this handler before 123 * accessing the source. 124 * 125 * @disable_source is a handler to find source entity for the 126 * sink entity and deactivate the link between them. Drivers 127 * should call this handler to release the source. 128 * 129 * Use-case: find tuner entity connected to the decoder 130 * entity and check if it is available, and activate the 131 * link between them from @enable_source and deactivate 132 * from @disable_source. 133 * 134 * .. note:: 135 * 136 * Bridge driver is expected to implement and set the 137 * handler when &media_device is registered or when 138 * bridge driver finds the media_device during probe. 139 * Bridge driver sets source_priv with information 140 * necessary to run @enable_source and @disable_source handlers. 141 * Callers should hold graph_mutex to access and call @enable_source 142 * and @disable_source handlers. 143 */ 144 struct media_device { 145 /* dev->driver_data points to this struct. */ 146 struct device *dev; 147 struct media_devnode *devnode; 148 149 char model[32]; 150 char driver_name[32]; 151 char serial[40]; 152 char bus_info[32]; 153 u32 hw_revision; 154 155 u64 topology_version; 156 157 u32 id; 158 struct ida entity_internal_idx; 159 int entity_internal_idx_max; 160 161 struct list_head entities; 162 struct list_head interfaces; 163 struct list_head pads; 164 struct list_head links; 165 166 /* notify callback list invoked when a new entity is registered */ 167 struct list_head entity_notify; 168 169 /* Serializes graph operations. */ 170 struct mutex graph_mutex; 171 struct media_graph pm_count_walk; 172 173 void *source_priv; 174 int (*enable_source)(struct media_entity *entity, 175 struct media_pipeline *pipe); 176 void (*disable_source)(struct media_entity *entity); 177 178 const struct media_device_ops *ops; 179 180 struct mutex req_queue_mutex; 181 atomic_t request_id; 182 }; 183 184 /* We don't need to include pci.h or usb.h here */ 185 struct pci_dev; 186 struct usb_device; 187 188 #ifdef CONFIG_MEDIA_CONTROLLER 189 190 /* Supported link_notify @notification values. */ 191 #define MEDIA_DEV_NOTIFY_PRE_LINK_CH 0 192 #define MEDIA_DEV_NOTIFY_POST_LINK_CH 1 193 194 /** 195 * media_entity_enum_init - Initialise an entity enumeration 196 * 197 * @ent_enum: Entity enumeration to be initialised 198 * @mdev: The related media device 199 * 200 * Return: zero on success or a negative error code. 201 */ 202 static inline __must_check int media_entity_enum_init( 203 struct media_entity_enum *ent_enum, struct media_device *mdev) 204 { 205 return __media_entity_enum_init(ent_enum, 206 mdev->entity_internal_idx_max + 1); 207 } 208 209 /** 210 * media_device_init() - Initializes a media device element 211 * 212 * @mdev: pointer to struct &media_device 213 * 214 * This function initializes the media device prior to its registration. 215 * The media device initialization and registration is split in two functions 216 * to avoid race conditions and make the media device available to user-space 217 * before the media graph has been completed. 218 * 219 * So drivers need to first initialize the media device, register any entity 220 * within the media device, create pad to pad links and then finally register 221 * the media device by calling media_device_register() as a final step. 222 */ 223 void media_device_init(struct media_device *mdev); 224 225 /** 226 * media_device_cleanup() - Cleanups a media device element 227 * 228 * @mdev: pointer to struct &media_device 229 * 230 * This function that will destroy the graph_mutex that is 231 * initialized in media_device_init(). 232 */ 233 void media_device_cleanup(struct media_device *mdev); 234 235 /** 236 * __media_device_register() - Registers a media device element 237 * 238 * @mdev: pointer to struct &media_device 239 * @owner: should be filled with %THIS_MODULE 240 * 241 * Users, should, instead, call the media_device_register() macro. 242 * 243 * The caller is responsible for initializing the &media_device structure 244 * before registration. The following fields of &media_device must be set: 245 * 246 * - &media_entity.dev must point to the parent device (usually a &pci_dev, 247 * &usb_interface or &platform_device instance). 248 * 249 * - &media_entity.model must be filled with the device model name as a 250 * NUL-terminated UTF-8 string. The device/model revision must not be 251 * stored in this field. 252 * 253 * The following fields are optional: 254 * 255 * - &media_entity.serial is a unique serial number stored as a 256 * NUL-terminated ASCII string. The field is big enough to store a GUID 257 * in text form. If the hardware doesn't provide a unique serial number 258 * this field must be left empty. 259 * 260 * - &media_entity.bus_info represents the location of the device in the 261 * system as a NUL-terminated ASCII string. For PCI/PCIe devices 262 * &media_entity.bus_info must be set to "PCI:" (or "PCIe:") followed by 263 * the value of pci_name(). For USB devices,the usb_make_path() function 264 * must be used. This field is used by applications to distinguish between 265 * otherwise identical devices that don't provide a serial number. 266 * 267 * - &media_entity.hw_revision is the hardware device revision in a 268 * driver-specific format. When possible the revision should be formatted 269 * with the KERNEL_VERSION() macro. 270 * 271 * .. note:: 272 * 273 * #) Upon successful registration a character device named media[0-9]+ is created. The device major and minor numbers are dynamic. The model name is exported as a sysfs attribute. 274 * 275 * #) Unregistering a media device that hasn't been registered is **NOT** safe. 276 * 277 * Return: returns zero on success or a negative error code. 278 */ 279 int __must_check __media_device_register(struct media_device *mdev, 280 struct module *owner); 281 282 283 /** 284 * media_device_register() - Registers a media device element 285 * 286 * @mdev: pointer to struct &media_device 287 * 288 * This macro calls __media_device_register() passing %THIS_MODULE as 289 * the __media_device_register() second argument (**owner**). 290 */ 291 #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE) 292 293 /** 294 * media_device_unregister() - Unregisters a media device element 295 * 296 * @mdev: pointer to struct &media_device 297 * 298 * It is safe to call this function on an unregistered (but initialised) 299 * media device. 300 */ 301 void media_device_unregister(struct media_device *mdev); 302 303 /** 304 * media_device_register_entity() - registers a media entity inside a 305 * previously registered media device. 306 * 307 * @mdev: pointer to struct &media_device 308 * @entity: pointer to struct &media_entity to be registered 309 * 310 * Entities are identified by a unique positive integer ID. The media 311 * controller framework will such ID automatically. IDs are not guaranteed 312 * to be contiguous, and the ID number can change on newer Kernel versions. 313 * So, neither the driver nor userspace should hardcode ID numbers to refer 314 * to the entities, but, instead, use the framework to find the ID, when 315 * needed. 316 * 317 * The media_entity name, type and flags fields should be initialized before 318 * calling media_device_register_entity(). Entities embedded in higher-level 319 * standard structures can have some of those fields set by the higher-level 320 * framework. 321 * 322 * If the device has pads, media_entity_pads_init() should be called before 323 * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads 324 * should be zeroed before calling this function. 325 * 326 * Entities have flags that describe the entity capabilities and state: 327 * 328 * %MEDIA_ENT_FL_DEFAULT 329 * indicates the default entity for a given type. 330 * This can be used to report the default audio and video devices or the 331 * default camera sensor. 332 * 333 * .. note:: 334 * 335 * Drivers should set the entity function before calling this function. 336 * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and 337 * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers. 338 */ 339 int __must_check media_device_register_entity(struct media_device *mdev, 340 struct media_entity *entity); 341 342 /** 343 * media_device_unregister_entity() - unregisters a media entity. 344 * 345 * @entity: pointer to struct &media_entity to be unregistered 346 * 347 * All links associated with the entity and all PADs are automatically 348 * unregistered from the media_device when this function is called. 349 * 350 * Unregistering an entity will not change the IDs of the other entities and 351 * the previoully used ID will never be reused for a newly registered entities. 352 * 353 * When a media device is unregistered, all its entities are unregistered 354 * automatically. No manual entities unregistration is then required. 355 * 356 * .. note:: 357 * 358 * The media_entity instance itself must be freed explicitly by 359 * the driver if required. 360 */ 361 void media_device_unregister_entity(struct media_entity *entity); 362 363 /** 364 * media_device_register_entity_notify() - Registers a media entity_notify 365 * callback 366 * 367 * @mdev: The media device 368 * @nptr: The media_entity_notify 369 * 370 * .. note:: 371 * 372 * When a new entity is registered, all the registered 373 * media_entity_notify callbacks are invoked. 374 */ 375 376 int __must_check media_device_register_entity_notify(struct media_device *mdev, 377 struct media_entity_notify *nptr); 378 379 /** 380 * media_device_unregister_entity_notify() - Unregister a media entity notify 381 * callback 382 * 383 * @mdev: The media device 384 * @nptr: The media_entity_notify 385 * 386 */ 387 void media_device_unregister_entity_notify(struct media_device *mdev, 388 struct media_entity_notify *nptr); 389 390 /* Iterate over all entities. */ 391 #define media_device_for_each_entity(entity, mdev) \ 392 list_for_each_entry(entity, &(mdev)->entities, graph_obj.list) 393 394 /* Iterate over all interfaces. */ 395 #define media_device_for_each_intf(intf, mdev) \ 396 list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list) 397 398 /* Iterate over all pads. */ 399 #define media_device_for_each_pad(pad, mdev) \ 400 list_for_each_entry(pad, &(mdev)->pads, graph_obj.list) 401 402 /* Iterate over all links. */ 403 #define media_device_for_each_link(link, mdev) \ 404 list_for_each_entry(link, &(mdev)->links, graph_obj.list) 405 406 /** 407 * media_device_pci_init() - create and initialize a 408 * struct &media_device from a PCI device. 409 * 410 * @mdev: pointer to struct &media_device 411 * @pci_dev: pointer to struct pci_dev 412 * @name: media device name. If %NULL, the routine will use the default 413 * name for the pci device, given by pci_name() macro. 414 */ 415 void media_device_pci_init(struct media_device *mdev, 416 struct pci_dev *pci_dev, 417 const char *name); 418 /** 419 * __media_device_usb_init() - create and initialize a 420 * struct &media_device from a PCI device. 421 * 422 * @mdev: pointer to struct &media_device 423 * @udev: pointer to struct usb_device 424 * @board_name: media device name. If %NULL, the routine will use the usb 425 * product name, if available. 426 * @driver_name: name of the driver. if %NULL, the routine will use the name 427 * given by ``udev->dev->driver->name``, with is usually the wrong 428 * thing to do. 429 * 430 * .. note:: 431 * 432 * It is better to call media_device_usb_init() instead, as 433 * such macro fills driver_name with %KBUILD_MODNAME. 434 */ 435 void __media_device_usb_init(struct media_device *mdev, 436 struct usb_device *udev, 437 const char *board_name, 438 const char *driver_name); 439 440 #else 441 static inline int media_device_register(struct media_device *mdev) 442 { 443 return 0; 444 } 445 static inline void media_device_unregister(struct media_device *mdev) 446 { 447 } 448 static inline int media_device_register_entity(struct media_device *mdev, 449 struct media_entity *entity) 450 { 451 return 0; 452 } 453 static inline void media_device_unregister_entity(struct media_entity *entity) 454 { 455 } 456 static inline int media_device_register_entity_notify( 457 struct media_device *mdev, 458 struct media_entity_notify *nptr) 459 { 460 return 0; 461 } 462 static inline void media_device_unregister_entity_notify( 463 struct media_device *mdev, 464 struct media_entity_notify *nptr) 465 { 466 } 467 468 static inline void media_device_pci_init(struct media_device *mdev, 469 struct pci_dev *pci_dev, 470 char *name) 471 { 472 } 473 474 static inline void __media_device_usb_init(struct media_device *mdev, 475 struct usb_device *udev, 476 char *board_name, 477 char *driver_name) 478 { 479 } 480 481 #endif /* CONFIG_MEDIA_CONTROLLER */ 482 483 /** 484 * media_device_usb_init() - create and initialize a 485 * struct &media_device from a PCI device. 486 * 487 * @mdev: pointer to struct &media_device 488 * @udev: pointer to struct usb_device 489 * @name: media device name. If %NULL, the routine will use the usb 490 * product name, if available. 491 * 492 * This macro calls media_device_usb_init() passing the 493 * media_device_usb_init() **driver_name** parameter filled with 494 * %KBUILD_MODNAME. 495 */ 496 #define media_device_usb_init(mdev, udev, name) \ 497 __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME) 498 499 #endif 500