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