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 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 */ 22 23 #ifndef _MEDIA_DEVICE_H 24 #define _MEDIA_DEVICE_H 25 26 #include <linux/list.h> 27 #include <linux/mutex.h> 28 29 #include <media/media-devnode.h> 30 #include <media/media-entity.h> 31 32 struct ida; 33 struct device; 34 35 /** 36 * struct media_entity_notify - Media Entity Notify 37 * 38 * @list: List head 39 * @notify_data: Input data to invoke the callback 40 * @notify: Callback function pointer 41 * 42 * Drivers may register a callback to take action when new entities get 43 * registered with the media device. This handler is intended for creating 44 * links between existing entities and should not create entities and register 45 * them. 46 */ 47 struct media_entity_notify { 48 struct list_head list; 49 void *notify_data; 50 void (*notify)(struct media_entity *entity, void *notify_data); 51 }; 52 53 /** 54 * struct media_device_ops - Media device operations 55 * @link_notify: Link state change notification callback. This callback is 56 * called with the graph_mutex held. 57 */ 58 struct media_device_ops { 59 int (*link_notify)(struct media_link *link, u32 flags, 60 unsigned int notification); 61 }; 62 63 /** 64 * struct media_device - Media device 65 * @dev: Parent device 66 * @devnode: Media device node 67 * @driver_name: Optional device driver name. If not set, calls to 68 * %MEDIA_IOC_DEVICE_INFO will return ``dev->driver->name``. 69 * This is needed for USB drivers for example, as otherwise 70 * they'll all appear as if the driver name was "usb". 71 * @model: Device model name 72 * @serial: Device serial number (optional) 73 * @bus_info: Unique and stable device location identifier 74 * @hw_revision: Hardware device revision 75 * @driver_version: Device driver version 76 * @topology_version: Monotonic counter for storing the version of the graph 77 * topology. Should be incremented each time the topology changes. 78 * @id: Unique ID used on the last registered graph object 79 * @entity_internal_idx: Unique internal entity ID used by the graph traversal 80 * algorithms 81 * @entity_internal_idx_max: Allocated internal entity indices 82 * @entities: List of registered entities 83 * @interfaces: List of registered interfaces 84 * @pads: List of registered pads 85 * @links: List of registered links 86 * @entity_notify: List of registered entity_notify callbacks 87 * @graph_mutex: Protects access to struct media_device data 88 * @pm_count_walk: Graph walk for power state walk. Access serialised using 89 * graph_mutex. 90 * 91 * @source_priv: Driver Private data for enable/disable source handlers 92 * @enable_source: Enable Source Handler function pointer 93 * @disable_source: Disable Source Handler function pointer 94 * 95 * @ops: Operation handler callbacks 96 * 97 * This structure represents an abstract high-level media device. It allows easy 98 * access to entities and provides basic media device-level support. The 99 * structure can be allocated directly or embedded in a larger structure. 100 * 101 * The parent @dev is a physical device. It must be set before registering the 102 * media device. 103 * 104 * @model is a descriptive model name exported through sysfs. It doesn't have to 105 * be unique. 106 * 107 * @enable_source is a handler to find source entity for the 108 * sink entity and activate the link between them if source 109 * entity is free. Drivers should call this handler before 110 * accessing the source. 111 * 112 * @disable_source is a handler to find source entity for the 113 * sink entity and deactivate the link between them. Drivers 114 * should call this handler to release the source. 115 * 116 * Use-case: find tuner entity connected to the decoder 117 * entity and check if it is available, and activate the 118 * the link between them from @enable_source and deactivate 119 * from @disable_source. 120 * 121 * .. note:: 122 * 123 * Bridge driver is expected to implement and set the 124 * handler when &media_device is registered or when 125 * bridge driver finds the media_device during probe. 126 * Bridge driver sets source_priv with information 127 * necessary to run @enable_source and @disable_source handlers. 128 */ 129 struct media_device { 130 /* dev->driver_data points to this struct. */ 131 struct device *dev; 132 struct media_devnode *devnode; 133 134 char model[32]; 135 char driver_name[32]; 136 char serial[40]; 137 char bus_info[32]; 138 u32 hw_revision; 139 u32 driver_version; 140 141 u64 topology_version; 142 143 u32 id; 144 struct ida entity_internal_idx; 145 int entity_internal_idx_max; 146 147 struct list_head entities; 148 struct list_head interfaces; 149 struct list_head pads; 150 struct list_head links; 151 152 /* notify callback list invoked when a new entity is registered */ 153 struct list_head entity_notify; 154 155 /* Serializes graph operations. */ 156 struct mutex graph_mutex; 157 struct media_entity_graph pm_count_walk; 158 159 void *source_priv; 160 int (*enable_source)(struct media_entity *entity, 161 struct media_pipeline *pipe); 162 void (*disable_source)(struct media_entity *entity); 163 164 const struct media_device_ops *ops; 165 }; 166 167 /* We don't need to include pci.h or usb.h here */ 168 struct pci_dev; 169 struct usb_device; 170 171 #ifdef CONFIG_MEDIA_CONTROLLER 172 173 /* Supported link_notify @notification values. */ 174 #define MEDIA_DEV_NOTIFY_PRE_LINK_CH 0 175 #define MEDIA_DEV_NOTIFY_POST_LINK_CH 1 176 177 /** 178 * media_entity_enum_init - Initialise an entity enumeration 179 * 180 * @ent_enum: Entity enumeration to be initialised 181 * @mdev: The related media device 182 * 183 * Return: zero on success or a negative error code. 184 */ 185 static inline __must_check int media_entity_enum_init( 186 struct media_entity_enum *ent_enum, struct media_device *mdev) 187 { 188 return __media_entity_enum_init(ent_enum, 189 mdev->entity_internal_idx_max + 1); 190 } 191 192 /** 193 * media_device_init() - Initializes a media device element 194 * 195 * @mdev: pointer to struct &media_device 196 * 197 * This function initializes the media device prior to its registration. 198 * The media device initialization and registration is split in two functions 199 * to avoid race conditions and make the media device available to user-space 200 * before the media graph has been completed. 201 * 202 * So drivers need to first initialize the media device, register any entity 203 * within the media device, create pad to pad links and then finally register 204 * the media device by calling media_device_register() as a final step. 205 */ 206 void media_device_init(struct media_device *mdev); 207 208 /** 209 * media_device_cleanup() - Cleanups a media device element 210 * 211 * @mdev: pointer to struct &media_device 212 * 213 * This function that will destroy the graph_mutex that is 214 * initialized in media_device_init(). 215 */ 216 void media_device_cleanup(struct media_device *mdev); 217 218 /** 219 * __media_device_register() - Registers a media device element 220 * 221 * @mdev: pointer to struct &media_device 222 * @owner: should be filled with %THIS_MODULE 223 * 224 * Users, should, instead, call the media_device_register() macro. 225 * 226 * The caller is responsible for initializing the &media_device structure 227 * before registration. The following fields of &media_device must be set: 228 * 229 * - &media_entity.dev must point to the parent device (usually a &pci_dev, 230 * &usb_interface or &platform_device instance). 231 * 232 * - &media_entity.model must be filled with the device model name as a 233 * NUL-terminated UTF-8 string. The device/model revision must not be 234 * stored in this field. 235 * 236 * The following fields are optional: 237 * 238 * - &media_entity.serial is a unique serial number stored as a 239 * NUL-terminated ASCII string. The field is big enough to store a GUID 240 * in text form. If the hardware doesn't provide a unique serial number 241 * this field must be left empty. 242 * 243 * - &media_entity.bus_info represents the location of the device in the 244 * system as a NUL-terminated ASCII string. For PCI/PCIe devices 245 * &media_entity.bus_info must be set to "PCI:" (or "PCIe:") followed by 246 * the value of pci_name(). For USB devices,the usb_make_path() function 247 * must be used. This field is used by applications to distinguish between 248 * otherwise identical devices that don't provide a serial number. 249 * 250 * - &media_entity.hw_revision is the hardware device revision in a 251 * driver-specific format. When possible the revision should be formatted 252 * with the KERNEL_VERSION() macro. 253 * 254 * - &media_entity.driver_version is formatted with the KERNEL_VERSION() 255 * macro. The version minor must be incremented when new features are added 256 * to the userspace API without breaking binary compatibility. The version 257 * major must be incremented when binary compatibility is broken. 258 * 259 * .. note:: 260 * 261 * #) 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. 262 * 263 * #) Unregistering a media device that hasn't been registered is **NOT** safe. 264 * 265 * Return: returns zero on success or a negative error code. 266 */ 267 int __must_check __media_device_register(struct media_device *mdev, 268 struct module *owner); 269 270 271 /** 272 * media_device_register() - Registers a media device element 273 * 274 * @mdev: pointer to struct &media_device 275 * 276 * This macro calls __media_device_register() passing %THIS_MODULE as 277 * the __media_device_register() second argument (**owner**). 278 */ 279 #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE) 280 281 /** 282 * media_device_unregister() - Unregisters a media device element 283 * 284 * @mdev: pointer to struct &media_device 285 * 286 * It is safe to call this function on an unregistered (but initialised) 287 * media device. 288 */ 289 void media_device_unregister(struct media_device *mdev); 290 291 /** 292 * media_device_register_entity() - registers a media entity inside a 293 * previously registered media device. 294 * 295 * @mdev: pointer to struct &media_device 296 * @entity: pointer to struct &media_entity to be registered 297 * 298 * Entities are identified by a unique positive integer ID. The media 299 * controller framework will such ID automatically. IDs are not guaranteed 300 * to be contiguous, and the ID number can change on newer Kernel versions. 301 * So, neither the driver nor userspace should hardcode ID numbers to refer 302 * to the entities, but, instead, use the framework to find the ID, when 303 * needed. 304 * 305 * The media_entity name, type and flags fields should be initialized before 306 * calling media_device_register_entity(). Entities embedded in higher-level 307 * standard structures can have some of those fields set by the higher-level 308 * framework. 309 * 310 * If the device has pads, media_entity_pads_init() should be called before 311 * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads 312 * should be zeroed before calling this function. 313 * 314 * Entities have flags that describe the entity capabilities and state: 315 * 316 * %MEDIA_ENT_FL_DEFAULT 317 * indicates the default entity for a given type. 318 * This can be used to report the default audio and video devices or the 319 * default camera sensor. 320 * 321 * .. note:: 322 * 323 * Drivers should set the entity function before calling this function. 324 * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and 325 * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers. 326 */ 327 int __must_check media_device_register_entity(struct media_device *mdev, 328 struct media_entity *entity); 329 330 /** 331 * media_device_unregister_entity() - unregisters a media entity. 332 * 333 * @entity: pointer to struct &media_entity to be unregistered 334 * 335 * All links associated with the entity and all PADs are automatically 336 * unregistered from the media_device when this function is called. 337 * 338 * Unregistering an entity will not change the IDs of the other entities and 339 * the previoully used ID will never be reused for a newly registered entities. 340 * 341 * When a media device is unregistered, all its entities are unregistered 342 * automatically. No manual entities unregistration is then required. 343 * 344 * .. note:: 345 * 346 * The media_entity instance itself must be freed explicitly by 347 * the driver if required. 348 */ 349 void media_device_unregister_entity(struct media_entity *entity); 350 351 /** 352 * media_device_register_entity_notify() - Registers a media entity_notify 353 * callback 354 * 355 * @mdev: The media device 356 * @nptr: The media_entity_notify 357 * 358 * .. note:: 359 * 360 * When a new entity is registered, all the registered 361 * media_entity_notify callbacks are invoked. 362 */ 363 364 int __must_check media_device_register_entity_notify(struct media_device *mdev, 365 struct media_entity_notify *nptr); 366 367 /** 368 * media_device_unregister_entity_notify() - Unregister a media entity notify 369 * callback 370 * 371 * @mdev: The media device 372 * @nptr: The media_entity_notify 373 * 374 */ 375 void media_device_unregister_entity_notify(struct media_device *mdev, 376 struct media_entity_notify *nptr); 377 378 /* Iterate over all entities. */ 379 #define media_device_for_each_entity(entity, mdev) \ 380 list_for_each_entry(entity, &(mdev)->entities, graph_obj.list) 381 382 /* Iterate over all interfaces. */ 383 #define media_device_for_each_intf(intf, mdev) \ 384 list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list) 385 386 /* Iterate over all pads. */ 387 #define media_device_for_each_pad(pad, mdev) \ 388 list_for_each_entry(pad, &(mdev)->pads, graph_obj.list) 389 390 /* Iterate over all links. */ 391 #define media_device_for_each_link(link, mdev) \ 392 list_for_each_entry(link, &(mdev)->links, graph_obj.list) 393 394 /** 395 * media_device_pci_init() - create and initialize a 396 * struct &media_device from a PCI device. 397 * 398 * @mdev: pointer to struct &media_device 399 * @pci_dev: pointer to struct pci_dev 400 * @name: media device name. If %NULL, the routine will use the default 401 * name for the pci device, given by pci_name() macro. 402 */ 403 void media_device_pci_init(struct media_device *mdev, 404 struct pci_dev *pci_dev, 405 const char *name); 406 /** 407 * __media_device_usb_init() - create and initialize a 408 * struct &media_device from a PCI device. 409 * 410 * @mdev: pointer to struct &media_device 411 * @udev: pointer to struct usb_device 412 * @board_name: media device name. If %NULL, the routine will use the usb 413 * product name, if available. 414 * @driver_name: name of the driver. if %NULL, the routine will use the name 415 * given by ``udev->dev->driver->name``, with is usually the wrong 416 * thing to do. 417 * 418 * .. note:: 419 * 420 * It is better to call media_device_usb_init() instead, as 421 * such macro fills driver_name with %KBUILD_MODNAME. 422 */ 423 void __media_device_usb_init(struct media_device *mdev, 424 struct usb_device *udev, 425 const char *board_name, 426 const char *driver_name); 427 428 #else 429 static inline int media_device_register(struct media_device *mdev) 430 { 431 return 0; 432 } 433 static inline void media_device_unregister(struct media_device *mdev) 434 { 435 } 436 static inline int media_device_register_entity(struct media_device *mdev, 437 struct media_entity *entity) 438 { 439 return 0; 440 } 441 static inline void media_device_unregister_entity(struct media_entity *entity) 442 { 443 } 444 static inline int media_device_register_entity_notify( 445 struct media_device *mdev, 446 struct media_entity_notify *nptr) 447 { 448 return 0; 449 } 450 static inline void media_device_unregister_entity_notify( 451 struct media_device *mdev, 452 struct media_entity_notify *nptr) 453 { 454 } 455 456 static inline void media_device_pci_init(struct media_device *mdev, 457 struct pci_dev *pci_dev, 458 char *name) 459 { 460 } 461 462 static inline void __media_device_usb_init(struct media_device *mdev, 463 struct usb_device *udev, 464 char *board_name, 465 char *driver_name) 466 { 467 } 468 469 #endif /* CONFIG_MEDIA_CONTROLLER */ 470 471 /** 472 * media_device_usb_init() - create and initialize a 473 * struct &media_device from a PCI device. 474 * 475 * @mdev: pointer to struct &media_device 476 * @udev: pointer to struct usb_device 477 * @name: media device name. If %NULL, the routine will use the usb 478 * product name, if available. 479 * 480 * This macro calls media_device_usb_init() passing the 481 * media_device_usb_init() **driver_name** parameter filled with 482 * %KBUILD_MODNAME. 483 */ 484 #define media_device_usb_init(mdev, udev, name) \ 485 __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME) 486 487 #endif 488