1 /* 2 * Media device 3 * 4 * Copyright (C) 2010 Nokia Corporation 5 * 6 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com> 7 * Sakari Ailus <sakari.ailus@iki.fi> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 */ 18 19 #ifndef _MEDIA_DEVICE_H 20 #define _MEDIA_DEVICE_H 21 22 #include <linux/list.h> 23 #include <linux/mutex.h> 24 25 #include <media/media-devnode.h> 26 #include <media/media-entity.h> 27 28 struct ida; 29 struct device; 30 struct media_device; 31 32 /** 33 * struct media_entity_notify - Media Entity Notify 34 * 35 * @list: List head 36 * @notify_data: Input data to invoke the callback 37 * @notify: Callback function pointer 38 * 39 * Drivers may register a callback to take action when new entities get 40 * registered with the media device. This handler is intended for creating 41 * links between existing entities and should not create entities and register 42 * them. 43 */ 44 struct media_entity_notify { 45 struct list_head list; 46 void *notify_data; 47 void (*notify)(struct media_entity *entity, void *notify_data); 48 }; 49 50 /** 51 * struct media_device_ops - Media device operations 52 * @link_notify: Link state change notification callback. This callback is 53 * called with the graph_mutex held. 54 * @req_alloc: Allocate a request. Set this if you need to allocate a struct 55 * larger then struct media_request. @req_alloc and @req_free must 56 * either both be set or both be NULL. 57 * @req_free: Free a request. Set this if @req_alloc was set as well, leave 58 * to NULL otherwise. 59 * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex 60 * lock is held when this op is called. 61 * @req_queue: Queue a validated request, cannot fail. If something goes 62 * wrong when queueing this request then it should be marked 63 * as such internally in the driver and any related buffers 64 * must eventually return to vb2 with state VB2_BUF_STATE_ERROR. 65 * The req_queue_mutex lock is held when this op is called. 66 * It is important that vb2 buffer objects are queued last after 67 * all other object types are queued: queueing a buffer kickstarts 68 * the request processing, so all other objects related to the 69 * request (and thus the buffer) must be available to the driver. 70 * And once a buffer is queued, then the driver can complete 71 * or delete objects from the request before req_queue exits. 72 */ 73 struct media_device_ops { 74 int (*link_notify)(struct media_link *link, u32 flags, 75 unsigned int notification); 76 struct media_request *(*req_alloc)(struct media_device *mdev); 77 void (*req_free)(struct media_request *req); 78 int (*req_validate)(struct media_request *req); 79 void (*req_queue)(struct media_request *req); 80 }; 81 82 /** 83 * struct media_device - Media device 84 * @dev: Parent device 85 * @devnode: Media device node 86 * @driver_name: Optional device driver name. If not set, calls to 87 * %MEDIA_IOC_DEVICE_INFO will return ``dev->driver->name``. 88 * This is needed for USB drivers for example, as otherwise 89 * they'll all appear as if the driver name was "usb". 90 * @model: Device model name 91 * @serial: Device serial number (optional) 92 * @bus_info: Unique and stable device location identifier 93 * @hw_revision: Hardware device revision 94 * @topology_version: Monotonic counter for storing the version of the graph 95 * topology. Should be incremented each time the topology changes. 96 * @id: Unique ID used on the last registered graph object 97 * @entity_internal_idx: Unique internal entity ID used by the graph traversal 98 * algorithms 99 * @entity_internal_idx_max: Allocated internal entity indices 100 * @entities: List of registered entities 101 * @interfaces: List of registered interfaces 102 * @pads: List of registered pads 103 * @links: List of registered links 104 * @entity_notify: List of registered entity_notify callbacks 105 * @graph_mutex: Protects access to struct media_device data 106 * @pm_count_walk: Graph walk for power state walk. Access serialised using 107 * graph_mutex. 108 * 109 * @source_priv: Driver Private data for enable/disable source handlers 110 * @enable_source: Enable Source Handler function pointer 111 * @disable_source: Disable Source Handler function pointer 112 * 113 * @ops: Operation handler callbacks 114 * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t. 115 * other operations that stop or start streaming. 116 * @request_id: Used to generate unique request IDs 117 * 118 * This structure represents an abstract high-level media device. It allows easy 119 * access to entities and provides basic media device-level support. The 120 * structure can be allocated directly or embedded in a larger structure. 121 * 122 * The parent @dev is a physical device. It must be set before registering the 123 * media device. 124 * 125 * @model is a descriptive model name exported through sysfs. It doesn't have to 126 * be unique. 127 * 128 * @enable_source is a handler to find source entity for the 129 * sink entity and activate the link between them if source 130 * entity is free. Drivers should call this handler before 131 * accessing the source. 132 * 133 * @disable_source is a handler to find source entity for the 134 * sink entity and deactivate the link between them. Drivers 135 * should call this handler to release the source. 136 * 137 * Use-case: find tuner entity connected to the decoder 138 * entity and check if it is available, and activate the 139 * the link between them from @enable_source and deactivate 140 * from @disable_source. 141 * 142 * .. note:: 143 * 144 * Bridge driver is expected to implement and set the 145 * handler when &media_device is registered or when 146 * bridge driver finds the media_device during probe. 147 * Bridge driver sets source_priv with information 148 * necessary to run @enable_source and @disable_source handlers. 149 * Callers should hold graph_mutex to access and call @enable_source 150 * and @disable_source handlers. 151 */ 152 struct media_device { 153 /* dev->driver_data points to this struct. */ 154 struct device *dev; 155 struct media_devnode *devnode; 156 157 char model[32]; 158 char driver_name[32]; 159 char serial[40]; 160 char bus_info[32]; 161 u32 hw_revision; 162 163 u64 topology_version; 164 165 u32 id; 166 struct ida entity_internal_idx; 167 int entity_internal_idx_max; 168 169 struct list_head entities; 170 struct list_head interfaces; 171 struct list_head pads; 172 struct list_head links; 173 174 /* notify callback list invoked when a new entity is registered */ 175 struct list_head entity_notify; 176 177 /* Serializes graph operations. */ 178 struct mutex graph_mutex; 179 struct media_graph pm_count_walk; 180 181 void *source_priv; 182 int (*enable_source)(struct media_entity *entity, 183 struct media_pipeline *pipe); 184 void (*disable_source)(struct media_entity *entity); 185 186 const struct media_device_ops *ops; 187 188 struct mutex req_queue_mutex; 189 atomic_t request_id; 190 }; 191 192 /* We don't need to include pci.h or usb.h here */ 193 struct pci_dev; 194 struct usb_device; 195 196 #ifdef CONFIG_MEDIA_CONTROLLER 197 198 /* Supported link_notify @notification values. */ 199 #define MEDIA_DEV_NOTIFY_PRE_LINK_CH 0 200 #define MEDIA_DEV_NOTIFY_POST_LINK_CH 1 201 202 /** 203 * media_entity_enum_init - Initialise an entity enumeration 204 * 205 * @ent_enum: Entity enumeration to be initialised 206 * @mdev: The related media device 207 * 208 * Return: zero on success or a negative error code. 209 */ 210 static inline __must_check int media_entity_enum_init( 211 struct media_entity_enum *ent_enum, struct media_device *mdev) 212 { 213 return __media_entity_enum_init(ent_enum, 214 mdev->entity_internal_idx_max + 1); 215 } 216 217 /** 218 * media_device_init() - Initializes a media device element 219 * 220 * @mdev: pointer to struct &media_device 221 * 222 * This function initializes the media device prior to its registration. 223 * The media device initialization and registration is split in two functions 224 * to avoid race conditions and make the media device available to user-space 225 * before the media graph has been completed. 226 * 227 * So drivers need to first initialize the media device, register any entity 228 * within the media device, create pad to pad links and then finally register 229 * the media device by calling media_device_register() as a final step. 230 */ 231 void media_device_init(struct media_device *mdev); 232 233 /** 234 * media_device_cleanup() - Cleanups a media device element 235 * 236 * @mdev: pointer to struct &media_device 237 * 238 * This function that will destroy the graph_mutex that is 239 * initialized in media_device_init(). 240 */ 241 void media_device_cleanup(struct media_device *mdev); 242 243 /** 244 * __media_device_register() - Registers a media device element 245 * 246 * @mdev: pointer to struct &media_device 247 * @owner: should be filled with %THIS_MODULE 248 * 249 * Users, should, instead, call the media_device_register() macro. 250 * 251 * The caller is responsible for initializing the &media_device structure 252 * before registration. The following fields of &media_device must be set: 253 * 254 * - &media_entity.dev must point to the parent device (usually a &pci_dev, 255 * &usb_interface or &platform_device instance). 256 * 257 * - &media_entity.model must be filled with the device model name as a 258 * NUL-terminated UTF-8 string. The device/model revision must not be 259 * stored in this field. 260 * 261 * The following fields are optional: 262 * 263 * - &media_entity.serial is a unique serial number stored as a 264 * NUL-terminated ASCII string. The field is big enough to store a GUID 265 * in text form. If the hardware doesn't provide a unique serial number 266 * this field must be left empty. 267 * 268 * - &media_entity.bus_info represents the location of the device in the 269 * system as a NUL-terminated ASCII string. For PCI/PCIe devices 270 * &media_entity.bus_info must be set to "PCI:" (or "PCIe:") followed by 271 * the value of pci_name(). For USB devices,the usb_make_path() function 272 * must be used. This field is used by applications to distinguish between 273 * otherwise identical devices that don't provide a serial number. 274 * 275 * - &media_entity.hw_revision is the hardware device revision in a 276 * driver-specific format. When possible the revision should be formatted 277 * with the KERNEL_VERSION() macro. 278 * 279 * .. note:: 280 * 281 * #) 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. 282 * 283 * #) Unregistering a media device that hasn't been registered is **NOT** safe. 284 * 285 * Return: returns zero on success or a negative error code. 286 */ 287 int __must_check __media_device_register(struct media_device *mdev, 288 struct module *owner); 289 290 291 /** 292 * media_device_register() - Registers a media device element 293 * 294 * @mdev: pointer to struct &media_device 295 * 296 * This macro calls __media_device_register() passing %THIS_MODULE as 297 * the __media_device_register() second argument (**owner**). 298 */ 299 #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE) 300 301 /** 302 * media_device_unregister() - Unregisters a media device element 303 * 304 * @mdev: pointer to struct &media_device 305 * 306 * It is safe to call this function on an unregistered (but initialised) 307 * media device. 308 */ 309 void media_device_unregister(struct media_device *mdev); 310 311 /** 312 * media_device_register_entity() - registers a media entity inside a 313 * previously registered media device. 314 * 315 * @mdev: pointer to struct &media_device 316 * @entity: pointer to struct &media_entity to be registered 317 * 318 * Entities are identified by a unique positive integer ID. The media 319 * controller framework will such ID automatically. IDs are not guaranteed 320 * to be contiguous, and the ID number can change on newer Kernel versions. 321 * So, neither the driver nor userspace should hardcode ID numbers to refer 322 * to the entities, but, instead, use the framework to find the ID, when 323 * needed. 324 * 325 * The media_entity name, type and flags fields should be initialized before 326 * calling media_device_register_entity(). Entities embedded in higher-level 327 * standard structures can have some of those fields set by the higher-level 328 * framework. 329 * 330 * If the device has pads, media_entity_pads_init() should be called before 331 * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads 332 * should be zeroed before calling this function. 333 * 334 * Entities have flags that describe the entity capabilities and state: 335 * 336 * %MEDIA_ENT_FL_DEFAULT 337 * indicates the default entity for a given type. 338 * This can be used to report the default audio and video devices or the 339 * default camera sensor. 340 * 341 * .. note:: 342 * 343 * Drivers should set the entity function before calling this function. 344 * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and 345 * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers. 346 */ 347 int __must_check media_device_register_entity(struct media_device *mdev, 348 struct media_entity *entity); 349 350 /** 351 * media_device_unregister_entity() - unregisters a media entity. 352 * 353 * @entity: pointer to struct &media_entity to be unregistered 354 * 355 * All links associated with the entity and all PADs are automatically 356 * unregistered from the media_device when this function is called. 357 * 358 * Unregistering an entity will not change the IDs of the other entities and 359 * the previoully used ID will never be reused for a newly registered entities. 360 * 361 * When a media device is unregistered, all its entities are unregistered 362 * automatically. No manual entities unregistration is then required. 363 * 364 * .. note:: 365 * 366 * The media_entity instance itself must be freed explicitly by 367 * the driver if required. 368 */ 369 void media_device_unregister_entity(struct media_entity *entity); 370 371 /** 372 * media_device_register_entity_notify() - Registers a media entity_notify 373 * callback 374 * 375 * @mdev: The media device 376 * @nptr: The media_entity_notify 377 * 378 * .. note:: 379 * 380 * When a new entity is registered, all the registered 381 * media_entity_notify callbacks are invoked. 382 */ 383 384 int __must_check media_device_register_entity_notify(struct media_device *mdev, 385 struct media_entity_notify *nptr); 386 387 /** 388 * media_device_unregister_entity_notify() - Unregister a media entity notify 389 * callback 390 * 391 * @mdev: The media device 392 * @nptr: The media_entity_notify 393 * 394 */ 395 void media_device_unregister_entity_notify(struct media_device *mdev, 396 struct media_entity_notify *nptr); 397 398 /* Iterate over all entities. */ 399 #define media_device_for_each_entity(entity, mdev) \ 400 list_for_each_entry(entity, &(mdev)->entities, graph_obj.list) 401 402 /* Iterate over all interfaces. */ 403 #define media_device_for_each_intf(intf, mdev) \ 404 list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list) 405 406 /* Iterate over all pads. */ 407 #define media_device_for_each_pad(pad, mdev) \ 408 list_for_each_entry(pad, &(mdev)->pads, graph_obj.list) 409 410 /* Iterate over all links. */ 411 #define media_device_for_each_link(link, mdev) \ 412 list_for_each_entry(link, &(mdev)->links, graph_obj.list) 413 414 /** 415 * media_device_pci_init() - create and initialize a 416 * struct &media_device from a PCI device. 417 * 418 * @mdev: pointer to struct &media_device 419 * @pci_dev: pointer to struct pci_dev 420 * @name: media device name. If %NULL, the routine will use the default 421 * name for the pci device, given by pci_name() macro. 422 */ 423 void media_device_pci_init(struct media_device *mdev, 424 struct pci_dev *pci_dev, 425 const char *name); 426 /** 427 * __media_device_usb_init() - create and initialize a 428 * struct &media_device from a PCI device. 429 * 430 * @mdev: pointer to struct &media_device 431 * @udev: pointer to struct usb_device 432 * @board_name: media device name. If %NULL, the routine will use the usb 433 * product name, if available. 434 * @driver_name: name of the driver. if %NULL, the routine will use the name 435 * given by ``udev->dev->driver->name``, with is usually the wrong 436 * thing to do. 437 * 438 * .. note:: 439 * 440 * It is better to call media_device_usb_init() instead, as 441 * such macro fills driver_name with %KBUILD_MODNAME. 442 */ 443 void __media_device_usb_init(struct media_device *mdev, 444 struct usb_device *udev, 445 const char *board_name, 446 const char *driver_name); 447 448 #else 449 static inline int media_device_register(struct media_device *mdev) 450 { 451 return 0; 452 } 453 static inline void media_device_unregister(struct media_device *mdev) 454 { 455 } 456 static inline int media_device_register_entity(struct media_device *mdev, 457 struct media_entity *entity) 458 { 459 return 0; 460 } 461 static inline void media_device_unregister_entity(struct media_entity *entity) 462 { 463 } 464 static inline int media_device_register_entity_notify( 465 struct media_device *mdev, 466 struct media_entity_notify *nptr) 467 { 468 return 0; 469 } 470 static inline void media_device_unregister_entity_notify( 471 struct media_device *mdev, 472 struct media_entity_notify *nptr) 473 { 474 } 475 476 static inline void media_device_pci_init(struct media_device *mdev, 477 struct pci_dev *pci_dev, 478 char *name) 479 { 480 } 481 482 static inline void __media_device_usb_init(struct media_device *mdev, 483 struct usb_device *udev, 484 char *board_name, 485 char *driver_name) 486 { 487 } 488 489 #endif /* CONFIG_MEDIA_CONTROLLER */ 490 491 /** 492 * media_device_usb_init() - create and initialize a 493 * struct &media_device from a PCI device. 494 * 495 * @mdev: pointer to struct &media_device 496 * @udev: pointer to struct usb_device 497 * @name: media device name. If %NULL, the routine will use the usb 498 * product name, if available. 499 * 500 * This macro calls media_device_usb_init() passing the 501 * media_device_usb_init() **driver_name** parameter filled with 502 * %KBUILD_MODNAME. 503 */ 504 #define media_device_usb_init(mdev, udev, name) \ 505 __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME) 506 507 #endif 508