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 #include <linux/pci.h> 17 #include <linux/platform_device.h> 18 19 #include <media/media-devnode.h> 20 #include <media/media-entity.h> 21 22 struct ida; 23 struct media_device; 24 25 /** 26 * struct media_entity_notify - Media Entity Notify 27 * 28 * @list: List head 29 * @notify_data: Input data to invoke the callback 30 * @notify: Callback function pointer 31 * 32 * Drivers may register a callback to take action when new entities get 33 * registered with the media device. This handler is intended for creating 34 * links between existing entities and should not create entities and register 35 * them. 36 */ 37 struct media_entity_notify { 38 struct list_head list; 39 void *notify_data; 40 void (*notify)(struct media_entity *entity, void *notify_data); 41 }; 42 43 /** 44 * struct media_device_ops - Media device operations 45 * @link_notify: Link state change notification callback. This callback is 46 * called with the graph_mutex held. 47 * @req_alloc: Allocate a request. Set this if you need to allocate a struct 48 * larger then struct media_request. @req_alloc and @req_free must 49 * either both be set or both be NULL. 50 * @req_free: Free a request. Set this if @req_alloc was set as well, leave 51 * to NULL otherwise. 52 * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex 53 * lock is held when this op is called. 54 * @req_queue: Queue a validated request, cannot fail. If something goes 55 * wrong when queueing this request then it should be marked 56 * as such internally in the driver and any related buffers 57 * must eventually return to vb2 with state VB2_BUF_STATE_ERROR. 58 * The req_queue_mutex lock is held when this op is called. 59 * It is important that vb2 buffer objects are queued last after 60 * all other object types are queued: queueing a buffer kickstarts 61 * the request processing, so all other objects related to the 62 * request (and thus the buffer) must be available to the driver. 63 * And once a buffer is queued, then the driver can complete 64 * or delete objects from the request before req_queue exits. 65 */ 66 struct media_device_ops { 67 int (*link_notify)(struct media_link *link, u32 flags, 68 unsigned int notification); 69 struct media_request *(*req_alloc)(struct media_device *mdev); 70 void (*req_free)(struct media_request *req); 71 int (*req_validate)(struct media_request *req); 72 void (*req_queue)(struct media_request *req); 73 }; 74 75 /** 76 * struct media_device - Media device 77 * @dev: Parent device 78 * @devnode: Media device node 79 * @driver_name: Optional device driver name. If not set, calls to 80 * %MEDIA_IOC_DEVICE_INFO will return ``dev->driver->name``. 81 * This is needed for USB drivers for example, as otherwise 82 * they'll all appear as if the driver name was "usb". 83 * @model: Device model name 84 * @serial: Device serial number (optional) 85 * @bus_info: Unique and stable device location identifier 86 * @hw_revision: Hardware device revision 87 * @topology_version: Monotonic counter for storing the version of the graph 88 * topology. Should be incremented each time the topology changes. 89 * @id: Unique ID used on the last registered graph object 90 * @entity_internal_idx: Unique internal entity ID used by the graph traversal 91 * algorithms 92 * @entity_internal_idx_max: Allocated internal entity indices 93 * @entities: List of registered entities 94 * @interfaces: List of registered interfaces 95 * @pads: List of registered pads 96 * @links: List of registered links 97 * @entity_notify: List of registered entity_notify callbacks 98 * @graph_mutex: Protects access to struct media_device data 99 * @pm_count_walk: Graph walk for power state walk. Access serialised using 100 * graph_mutex. 101 * 102 * @source_priv: Driver Private data for enable/disable source handlers 103 * @enable_source: Enable Source Handler function pointer 104 * @disable_source: Disable Source Handler function pointer 105 * 106 * @ops: Operation handler callbacks 107 * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t. 108 * other operations that stop or start streaming. 109 * @request_id: Used to generate unique request IDs 110 * 111 * This structure represents an abstract high-level media device. It allows easy 112 * access to entities and provides basic media device-level support. The 113 * structure can be allocated directly or embedded in a larger structure. 114 * 115 * The parent @dev is a physical device. It must be set before registering the 116 * media device. 117 * 118 * @model is a descriptive model name exported through sysfs. It doesn't have to 119 * be unique. 120 * 121 * @enable_source is a handler to find source entity for the 122 * sink entity and activate the link between them if source 123 * entity is free. Drivers should call this handler before 124 * accessing the source. 125 * 126 * @disable_source is a handler to find source entity for the 127 * sink entity and deactivate the link between them. Drivers 128 * should call this handler to release the source. 129 * 130 * Use-case: find tuner entity connected to the decoder 131 * entity and check if it is available, and activate the 132 * link between them from @enable_source and deactivate 133 * from @disable_source. 134 * 135 * .. note:: 136 * 137 * Bridge driver is expected to implement and set the 138 * handler when &media_device is registered or when 139 * bridge driver finds the media_device during probe. 140 * Bridge driver sets source_priv with information 141 * necessary to run @enable_source and @disable_source handlers. 142 * Callers should hold graph_mutex to access and call @enable_source 143 * and @disable_source handlers. 144 */ 145 struct media_device { 146 /* dev->driver_data points to this struct. */ 147 struct device *dev; 148 struct media_devnode *devnode; 149 150 char model[32]; 151 char driver_name[32]; 152 char serial[40]; 153 char bus_info[32]; 154 u32 hw_revision; 155 156 u64 topology_version; 157 158 u32 id; 159 struct ida entity_internal_idx; 160 int entity_internal_idx_max; 161 162 struct list_head entities; 163 struct list_head interfaces; 164 struct list_head pads; 165 struct list_head links; 166 167 /* notify callback list invoked when a new entity is registered */ 168 struct list_head entity_notify; 169 170 /* Serializes graph operations. */ 171 struct mutex graph_mutex; 172 struct media_graph pm_count_walk; 173 174 void *source_priv; 175 int (*enable_source)(struct media_entity *entity, 176 struct media_pipeline *pipe); 177 void (*disable_source)(struct media_entity *entity); 178 179 const struct media_device_ops *ops; 180 181 struct mutex req_queue_mutex; 182 atomic_t request_id; 183 }; 184 185 /* We don't need to include usb.h here */ 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 * The caller is responsible for initializing the media device before 224 * registration. The following fields must be set: 225 * 226 * - dev must point to the parent device 227 * - model must be filled with the device model name 228 * 229 * The bus_info field is set by media_device_init() for PCI and platform devices 230 * if the field begins with '\0'. 231 */ 232 void media_device_init(struct media_device *mdev); 233 234 /** 235 * media_device_cleanup() - Cleanups a media device element 236 * 237 * @mdev: pointer to struct &media_device 238 * 239 * This function that will destroy the graph_mutex that is 240 * initialized in media_device_init(). 241 */ 242 void media_device_cleanup(struct media_device *mdev); 243 244 /** 245 * __media_device_register() - Registers a media device element 246 * 247 * @mdev: pointer to struct &media_device 248 * @owner: should be filled with %THIS_MODULE 249 * 250 * Users, should, instead, call the media_device_register() macro. 251 * 252 * The caller is responsible for initializing the &media_device structure 253 * before registration. The following fields of &media_device must be set: 254 * 255 * - &media_device.model must be filled with the device model name as a 256 * NUL-terminated UTF-8 string. The device/model revision must not be 257 * stored in this field. 258 * 259 * The following fields are optional: 260 * 261 * - &media_device.serial is a unique serial number stored as a 262 * NUL-terminated ASCII string. The field is big enough to store a GUID 263 * in text form. If the hardware doesn't provide a unique serial number 264 * this field must be left empty. 265 * 266 * - &media_device.bus_info represents the location of the device in the 267 * system as a NUL-terminated ASCII string. For PCI/PCIe devices 268 * &media_device.bus_info must be set to "PCI:" (or "PCIe:") followed by 269 * the value of pci_name(). For USB devices,the usb_make_path() function 270 * must be used. This field is used by applications to distinguish between 271 * otherwise identical devices that don't provide a serial number. 272 * 273 * - &media_device.hw_revision is the hardware device revision in a 274 * driver-specific format. When possible the revision should be formatted 275 * with the KERNEL_VERSION() macro. 276 * 277 * .. note:: 278 * 279 * #) 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. 280 * 281 * #) Unregistering a media device that hasn't been registered is **NOT** safe. 282 * 283 * Return: returns zero on success or a negative error code. 284 */ 285 int __must_check __media_device_register(struct media_device *mdev, 286 struct module *owner); 287 288 289 /** 290 * media_device_register() - Registers a media device element 291 * 292 * @mdev: pointer to struct &media_device 293 * 294 * This macro calls __media_device_register() passing %THIS_MODULE as 295 * the __media_device_register() second argument (**owner**). 296 */ 297 #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE) 298 299 /** 300 * media_device_unregister() - Unregisters a media device element 301 * 302 * @mdev: pointer to struct &media_device 303 * 304 * It is safe to call this function on an unregistered (but initialised) 305 * media device. 306 */ 307 void media_device_unregister(struct media_device *mdev); 308 309 /** 310 * media_device_register_entity() - registers a media entity inside a 311 * previously registered media device. 312 * 313 * @mdev: pointer to struct &media_device 314 * @entity: pointer to struct &media_entity to be registered 315 * 316 * Entities are identified by a unique positive integer ID. The media 317 * controller framework will such ID automatically. IDs are not guaranteed 318 * to be contiguous, and the ID number can change on newer Kernel versions. 319 * So, neither the driver nor userspace should hardcode ID numbers to refer 320 * to the entities, but, instead, use the framework to find the ID, when 321 * needed. 322 * 323 * The media_entity name, type and flags fields should be initialized before 324 * calling media_device_register_entity(). Entities embedded in higher-level 325 * standard structures can have some of those fields set by the higher-level 326 * framework. 327 * 328 * If the device has pads, media_entity_pads_init() should be called before 329 * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads 330 * should be zeroed before calling this function. 331 * 332 * Entities have flags that describe the entity capabilities and state: 333 * 334 * %MEDIA_ENT_FL_DEFAULT 335 * indicates the default entity for a given type. 336 * This can be used to report the default audio and video devices or the 337 * default camera sensor. 338 * 339 * .. note:: 340 * 341 * Drivers should set the entity function before calling this function. 342 * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and 343 * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers. 344 */ 345 int __must_check media_device_register_entity(struct media_device *mdev, 346 struct media_entity *entity); 347 348 /** 349 * media_device_unregister_entity() - unregisters a media entity. 350 * 351 * @entity: pointer to struct &media_entity to be unregistered 352 * 353 * All links associated with the entity and all PADs are automatically 354 * unregistered from the media_device when this function is called. 355 * 356 * Unregistering an entity will not change the IDs of the other entities and 357 * the previoully used ID will never be reused for a newly registered entities. 358 * 359 * When a media device is unregistered, all its entities are unregistered 360 * automatically. No manual entities unregistration is then required. 361 * 362 * .. note:: 363 * 364 * The media_entity instance itself must be freed explicitly by 365 * the driver if required. 366 */ 367 void media_device_unregister_entity(struct media_entity *entity); 368 369 /** 370 * media_device_register_entity_notify() - Registers a media entity_notify 371 * callback 372 * 373 * @mdev: The media device 374 * @nptr: The media_entity_notify 375 * 376 * .. note:: 377 * 378 * When a new entity is registered, all the registered 379 * media_entity_notify callbacks are invoked. 380 */ 381 382 int __must_check media_device_register_entity_notify(struct media_device *mdev, 383 struct media_entity_notify *nptr); 384 385 /** 386 * media_device_unregister_entity_notify() - Unregister a media entity notify 387 * callback 388 * 389 * @mdev: The media device 390 * @nptr: The media_entity_notify 391 * 392 */ 393 void media_device_unregister_entity_notify(struct media_device *mdev, 394 struct media_entity_notify *nptr); 395 396 /* Iterate over all entities. */ 397 #define media_device_for_each_entity(entity, mdev) \ 398 list_for_each_entry(entity, &(mdev)->entities, graph_obj.list) 399 400 /* Iterate over all interfaces. */ 401 #define media_device_for_each_intf(intf, mdev) \ 402 list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list) 403 404 /* Iterate over all pads. */ 405 #define media_device_for_each_pad(pad, mdev) \ 406 list_for_each_entry(pad, &(mdev)->pads, graph_obj.list) 407 408 /* Iterate over all links. */ 409 #define media_device_for_each_link(link, mdev) \ 410 list_for_each_entry(link, &(mdev)->links, graph_obj.list) 411 412 /** 413 * media_device_pci_init() - create and initialize a 414 * struct &media_device from a PCI device. 415 * 416 * @mdev: pointer to struct &media_device 417 * @pci_dev: pointer to struct pci_dev 418 * @name: media device name. If %NULL, the routine will use the default 419 * name for the pci device, given by pci_name() macro. 420 */ 421 void media_device_pci_init(struct media_device *mdev, 422 struct pci_dev *pci_dev, 423 const char *name); 424 /** 425 * __media_device_usb_init() - create and initialize a 426 * struct &media_device from a PCI device. 427 * 428 * @mdev: pointer to struct &media_device 429 * @udev: pointer to struct usb_device 430 * @board_name: media device name. If %NULL, the routine will use the usb 431 * product name, if available. 432 * @driver_name: name of the driver. if %NULL, the routine will use the name 433 * given by ``udev->dev->driver->name``, with is usually the wrong 434 * thing to do. 435 * 436 * .. note:: 437 * 438 * It is better to call media_device_usb_init() instead, as 439 * such macro fills driver_name with %KBUILD_MODNAME. 440 */ 441 void __media_device_usb_init(struct media_device *mdev, 442 struct usb_device *udev, 443 const char *board_name, 444 const char *driver_name); 445 446 #else 447 static inline int media_device_register(struct media_device *mdev) 448 { 449 return 0; 450 } 451 static inline void media_device_unregister(struct media_device *mdev) 452 { 453 } 454 static inline int media_device_register_entity(struct media_device *mdev, 455 struct media_entity *entity) 456 { 457 return 0; 458 } 459 static inline void media_device_unregister_entity(struct media_entity *entity) 460 { 461 } 462 static inline int media_device_register_entity_notify( 463 struct media_device *mdev, 464 struct media_entity_notify *nptr) 465 { 466 return 0; 467 } 468 static inline void media_device_unregister_entity_notify( 469 struct media_device *mdev, 470 struct media_entity_notify *nptr) 471 { 472 } 473 474 static inline void media_device_pci_init(struct media_device *mdev, 475 struct pci_dev *pci_dev, 476 char *name) 477 { 478 } 479 480 static inline void __media_device_usb_init(struct media_device *mdev, 481 struct usb_device *udev, 482 char *board_name, 483 char *driver_name) 484 { 485 } 486 487 #endif /* CONFIG_MEDIA_CONTROLLER */ 488 489 /** 490 * media_device_usb_init() - create and initialize a 491 * struct &media_device from a PCI device. 492 * 493 * @mdev: pointer to struct &media_device 494 * @udev: pointer to struct usb_device 495 * @name: media device name. If %NULL, the routine will use the usb 496 * product name, if available. 497 * 498 * This macro calls media_device_usb_init() passing the 499 * media_device_usb_init() **driver_name** parameter filled with 500 * %KBUILD_MODNAME. 501 */ 502 #define media_device_usb_init(mdev, udev, name) \ 503 __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME) 504 505 /** 506 * media_set_bus_info() - Set bus_info field 507 * 508 * @bus_info: Variable where to write the bus info (char array) 509 * @bus_info_size: Length of the bus_info 510 * @dev: Related struct device 511 * 512 * Sets bus information based on &dev. This is currently done for PCI and 513 * platform devices. dev is required to be non-NULL for this to happen. 514 * 515 * This function is not meant to be called from drivers. 516 */ 517 static inline void 518 media_set_bus_info(char *bus_info, size_t bus_info_size, struct device *dev) 519 { 520 if (!dev) 521 strscpy(bus_info, "no bus info", bus_info_size); 522 else if (dev_is_platform(dev)) 523 snprintf(bus_info, bus_info_size, "platform:%s", dev_name(dev)); 524 else if (dev_is_pci(dev)) 525 snprintf(bus_info, bus_info_size, "PCI:%s", dev_name(dev)); 526 } 527 528 #endif 529