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