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_device_init() - Initializes a media device element 196 * 197 * @mdev: pointer to struct &media_device 198 * 199 * This function initializes the media device prior to its registration. 200 * The media device initialization and registration is split in two functions 201 * to avoid race conditions and make the media device available to user-space 202 * before the media graph has been completed. 203 * 204 * So drivers need to first initialize the media device, register any entity 205 * within the media device, create pad to pad links and then finally register 206 * the media device by calling media_device_register() as a final step. 207 * 208 * The caller is responsible for initializing the media device before 209 * registration. The following fields must be set: 210 * 211 * - dev must point to the parent device 212 * - model must be filled with the device model name 213 * 214 * The bus_info field is set by media_device_init() for PCI and platform devices 215 * if the field begins with '\0'. 216 */ 217 void media_device_init(struct media_device *mdev); 218 219 /** 220 * media_device_cleanup() - Cleanups a media device element 221 * 222 * @mdev: pointer to struct &media_device 223 * 224 * This function that will destroy the graph_mutex that is 225 * initialized in media_device_init(). 226 */ 227 void media_device_cleanup(struct media_device *mdev); 228 229 /** 230 * __media_device_register() - Registers a media device element 231 * 232 * @mdev: pointer to struct &media_device 233 * @owner: should be filled with %THIS_MODULE 234 * 235 * Users, should, instead, call the media_device_register() macro. 236 * 237 * The caller is responsible for initializing the &media_device structure 238 * before registration. The following fields of &media_device must be set: 239 * 240 * - &media_device.model must be filled with the device model name as a 241 * NUL-terminated UTF-8 string. The device/model revision must not be 242 * stored in this field. 243 * 244 * The following fields are optional: 245 * 246 * - &media_device.serial is a unique serial number stored as a 247 * NUL-terminated ASCII string. The field is big enough to store a GUID 248 * in text form. If the hardware doesn't provide a unique serial number 249 * this field must be left empty. 250 * 251 * - &media_device.bus_info represents the location of the device in the 252 * system as a NUL-terminated ASCII string. For PCI/PCIe devices 253 * &media_device.bus_info must be set to "PCI:" (or "PCIe:") followed by 254 * the value of pci_name(). For USB devices,the usb_make_path() function 255 * must be used. This field is used by applications to distinguish between 256 * otherwise identical devices that don't provide a serial number. 257 * 258 * - &media_device.hw_revision is the hardware device revision in a 259 * driver-specific format. When possible the revision should be formatted 260 * with the KERNEL_VERSION() macro. 261 * 262 * .. note:: 263 * 264 * #) 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. 265 * 266 * #) Unregistering a media device that hasn't been registered is **NOT** safe. 267 * 268 * Return: returns zero on success or a negative error code. 269 */ 270 int __must_check __media_device_register(struct media_device *mdev, 271 struct module *owner); 272 273 274 /** 275 * media_device_register() - Registers a media device element 276 * 277 * @mdev: pointer to struct &media_device 278 * 279 * This macro calls __media_device_register() passing %THIS_MODULE as 280 * the __media_device_register() second argument (**owner**). 281 */ 282 #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE) 283 284 /** 285 * media_device_unregister() - Unregisters a media device element 286 * 287 * @mdev: pointer to struct &media_device 288 * 289 * It is safe to call this function on an unregistered (but initialised) 290 * media device. 291 */ 292 void media_device_unregister(struct media_device *mdev); 293 294 /** 295 * media_device_register_entity() - registers a media entity inside a 296 * previously registered media device. 297 * 298 * @mdev: pointer to struct &media_device 299 * @entity: pointer to struct &media_entity to be registered 300 * 301 * Entities are identified by a unique positive integer ID. The media 302 * controller framework will such ID automatically. IDs are not guaranteed 303 * to be contiguous, and the ID number can change on newer Kernel versions. 304 * So, neither the driver nor userspace should hardcode ID numbers to refer 305 * to the entities, but, instead, use the framework to find the ID, when 306 * needed. 307 * 308 * The media_entity name, type and flags fields should be initialized before 309 * calling media_device_register_entity(). Entities embedded in higher-level 310 * standard structures can have some of those fields set by the higher-level 311 * framework. 312 * 313 * If the device has pads, media_entity_pads_init() should be called before 314 * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads 315 * should be zeroed before calling this function. 316 * 317 * Entities have flags that describe the entity capabilities and state: 318 * 319 * %MEDIA_ENT_FL_DEFAULT 320 * indicates the default entity for a given type. 321 * This can be used to report the default audio and video devices or the 322 * default camera sensor. 323 * 324 * .. note:: 325 * 326 * Drivers should set the entity function before calling this function. 327 * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and 328 * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers. 329 */ 330 int __must_check media_device_register_entity(struct media_device *mdev, 331 struct media_entity *entity); 332 333 /** 334 * media_device_unregister_entity() - unregisters a media entity. 335 * 336 * @entity: pointer to struct &media_entity to be unregistered 337 * 338 * All links associated with the entity and all PADs are automatically 339 * unregistered from the media_device when this function is called. 340 * 341 * Unregistering an entity will not change the IDs of the other entities and 342 * the previoully used ID will never be reused for a newly registered entities. 343 * 344 * When a media device is unregistered, all its entities are unregistered 345 * automatically. No manual entities unregistration is then required. 346 * 347 * .. note:: 348 * 349 * The media_entity instance itself must be freed explicitly by 350 * the driver if required. 351 */ 352 void media_device_unregister_entity(struct media_entity *entity); 353 354 /** 355 * media_device_register_entity_notify() - Registers a media entity_notify 356 * callback 357 * 358 * @mdev: The media device 359 * @nptr: The media_entity_notify 360 * 361 * .. note:: 362 * 363 * When a new entity is registered, all the registered 364 * media_entity_notify callbacks are invoked. 365 */ 366 367 void media_device_register_entity_notify(struct media_device *mdev, 368 struct media_entity_notify *nptr); 369 370 /** 371 * media_device_unregister_entity_notify() - Unregister a media entity notify 372 * callback 373 * 374 * @mdev: The media device 375 * @nptr: The media_entity_notify 376 * 377 */ 378 void media_device_unregister_entity_notify(struct media_device *mdev, 379 struct media_entity_notify *nptr); 380 381 /* Iterate over all entities. */ 382 #define media_device_for_each_entity(entity, mdev) \ 383 list_for_each_entry(entity, &(mdev)->entities, graph_obj.list) 384 385 /* Iterate over all interfaces. */ 386 #define media_device_for_each_intf(intf, mdev) \ 387 list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list) 388 389 /* Iterate over all pads. */ 390 #define media_device_for_each_pad(pad, mdev) \ 391 list_for_each_entry(pad, &(mdev)->pads, graph_obj.list) 392 393 /* Iterate over all links. */ 394 #define media_device_for_each_link(link, mdev) \ 395 list_for_each_entry(link, &(mdev)->links, graph_obj.list) 396 397 /** 398 * media_device_pci_init() - create and initialize a 399 * struct &media_device from a PCI device. 400 * 401 * @mdev: pointer to struct &media_device 402 * @pci_dev: pointer to struct pci_dev 403 * @name: media device name. If %NULL, the routine will use the default 404 * name for the pci device, given by pci_name() macro. 405 */ 406 void media_device_pci_init(struct media_device *mdev, 407 struct pci_dev *pci_dev, 408 const char *name); 409 /** 410 * __media_device_usb_init() - create and initialize a 411 * struct &media_device from a PCI device. 412 * 413 * @mdev: pointer to struct &media_device 414 * @udev: pointer to struct usb_device 415 * @board_name: media device name. If %NULL, the routine will use the usb 416 * product name, if available. 417 * @driver_name: name of the driver. if %NULL, the routine will use the name 418 * given by ``udev->dev->driver->name``, with is usually the wrong 419 * thing to do. 420 * 421 * .. note:: 422 * 423 * It is better to call media_device_usb_init() instead, as 424 * such macro fills driver_name with %KBUILD_MODNAME. 425 */ 426 void __media_device_usb_init(struct media_device *mdev, 427 struct usb_device *udev, 428 const char *board_name, 429 const char *driver_name); 430 431 #else 432 static inline int media_device_register(struct media_device *mdev) 433 { 434 return 0; 435 } 436 static inline void media_device_unregister(struct media_device *mdev) 437 { 438 } 439 static inline int media_device_register_entity(struct media_device *mdev, 440 struct media_entity *entity) 441 { 442 return 0; 443 } 444 static inline void media_device_unregister_entity(struct media_entity *entity) 445 { 446 } 447 static inline void media_device_register_entity_notify( 448 struct media_device *mdev, 449 struct media_entity_notify *nptr) 450 { 451 } 452 static inline void media_device_unregister_entity_notify( 453 struct media_device *mdev, 454 struct media_entity_notify *nptr) 455 { 456 } 457 458 static inline void media_device_pci_init(struct media_device *mdev, 459 struct pci_dev *pci_dev, 460 char *name) 461 { 462 } 463 464 static inline void __media_device_usb_init(struct media_device *mdev, 465 struct usb_device *udev, 466 char *board_name, 467 char *driver_name) 468 { 469 } 470 471 #endif /* CONFIG_MEDIA_CONTROLLER */ 472 473 /** 474 * media_device_usb_init() - create and initialize a 475 * struct &media_device from a PCI device. 476 * 477 * @mdev: pointer to struct &media_device 478 * @udev: pointer to struct usb_device 479 * @name: media device name. If %NULL, the routine will use the usb 480 * product name, if available. 481 * 482 * This macro calls media_device_usb_init() passing the 483 * media_device_usb_init() **driver_name** parameter filled with 484 * %KBUILD_MODNAME. 485 */ 486 #define media_device_usb_init(mdev, udev, name) \ 487 __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME) 488 489 /** 490 * media_set_bus_info() - Set bus_info field 491 * 492 * @bus_info: Variable where to write the bus info (char array) 493 * @bus_info_size: Length of the bus_info 494 * @dev: Related struct device 495 * 496 * Sets bus information based on &dev. This is currently done for PCI and 497 * platform devices. dev is required to be non-NULL for this to happen. 498 * 499 * This function is not meant to be called from drivers. 500 */ 501 static inline void 502 media_set_bus_info(char *bus_info, size_t bus_info_size, struct device *dev) 503 { 504 if (!dev) 505 strscpy(bus_info, "no bus info", bus_info_size); 506 else if (dev_is_platform(dev)) 507 snprintf(bus_info, bus_info_size, "platform:%s", dev_name(dev)); 508 else if (dev_is_pci(dev)) 509 snprintf(bus_info, bus_info_size, "PCI:%s", dev_name(dev)); 510 } 511 512 #endif 513