1 /* 2 * device.h - generic, centralized driver model 3 * 4 * Copyright (c) 2001-2003 Patrick Mochel <[email protected]> 5 * Copyright (c) 2004-2009 Greg Kroah-Hartman <[email protected]> 6 * Copyright (c) 2008-2009 Novell Inc. 7 * 8 * This file is released under the GPLv2 9 * 10 * See Documentation/driver-model/ for more information. 11 */ 12 13 #ifndef _DEVICE_H_ 14 #define _DEVICE_H_ 15 16 #include <linux/ioport.h> 17 #include <linux/kobject.h> 18 #include <linux/klist.h> 19 #include <linux/list.h> 20 #include <linux/lockdep.h> 21 #include <linux/compiler.h> 22 #include <linux/types.h> 23 #include <linux/mutex.h> 24 #include <linux/pm.h> 25 #include <linux/atomic.h> 26 #include <asm/device.h> 27 28 struct device; 29 struct device_private; 30 struct device_driver; 31 struct driver_private; 32 struct module; 33 struct class; 34 struct subsys_private; 35 struct bus_type; 36 struct device_node; 37 struct iommu_ops; 38 39 struct bus_attribute { 40 struct attribute attr; 41 ssize_t (*show)(struct bus_type *bus, char *buf); 42 ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count); 43 }; 44 45 #define BUS_ATTR(_name, _mode, _show, _store) \ 46 struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store) 47 48 extern int __must_check bus_create_file(struct bus_type *, 49 struct bus_attribute *); 50 extern void bus_remove_file(struct bus_type *, struct bus_attribute *); 51 52 /** 53 * struct bus_type - The bus type of the device 54 * 55 * @name: The name of the bus. 56 * @dev_name: Used for subsystems to enumerate devices like ("foo%u", dev->id). 57 * @dev_root: Default device to use as the parent. 58 * @bus_attrs: Default attributes of the bus. 59 * @dev_attrs: Default attributes of the devices on the bus. 60 * @drv_attrs: Default attributes of the device drivers on the bus. 61 * @match: Called, perhaps multiple times, whenever a new device or driver 62 * is added for this bus. It should return a nonzero value if the 63 * given device can be handled by the given driver. 64 * @uevent: Called when a device is added, removed, or a few other things 65 * that generate uevents to add the environment variables. 66 * @probe: Called when a new device or driver add to this bus, and callback 67 * the specific driver's probe to initial the matched device. 68 * @remove: Called when a device removed from this bus. 69 * @shutdown: Called at shut-down time to quiesce the device. 70 * @suspend: Called when a device on this bus wants to go to sleep mode. 71 * @resume: Called to bring a device on this bus out of sleep mode. 72 * @pm: Power management operations of this bus, callback the specific 73 * device driver's pm-ops. 74 * @iommu_ops: IOMMU specific operations for this bus, used to attach IOMMU 75 * driver implementations to a bus and allow the driver to do 76 * bus-specific setup 77 * @p: The private data of the driver core, only the driver core can 78 * touch this. 79 * 80 * A bus is a channel between the processor and one or more devices. For the 81 * purposes of the device model, all devices are connected via a bus, even if 82 * it is an internal, virtual, "platform" bus. Buses can plug into each other. 83 * A USB controller is usually a PCI device, for example. The device model 84 * represents the actual connections between buses and the devices they control. 85 * A bus is represented by the bus_type structure. It contains the name, the 86 * default attributes, the bus' methods, PM operations, and the driver core's 87 * private data. 88 */ 89 struct bus_type { 90 const char *name; 91 const char *dev_name; 92 struct device *dev_root; 93 struct bus_attribute *bus_attrs; 94 struct device_attribute *dev_attrs; 95 struct driver_attribute *drv_attrs; 96 97 int (*match)(struct device *dev, struct device_driver *drv); 98 int (*uevent)(struct device *dev, struct kobj_uevent_env *env); 99 int (*probe)(struct device *dev); 100 int (*remove)(struct device *dev); 101 void (*shutdown)(struct device *dev); 102 103 int (*suspend)(struct device *dev, pm_message_t state); 104 int (*resume)(struct device *dev); 105 106 const struct dev_pm_ops *pm; 107 108 struct iommu_ops *iommu_ops; 109 110 struct subsys_private *p; 111 }; 112 113 /* This is a #define to keep the compiler from merging different 114 * instances of the __key variable */ 115 #define bus_register(subsys) \ 116 ({ \ 117 static struct lock_class_key __key; \ 118 __bus_register(subsys, &__key); \ 119 }) 120 extern int __must_check __bus_register(struct bus_type *bus, 121 struct lock_class_key *key); 122 extern void bus_unregister(struct bus_type *bus); 123 124 extern int __must_check bus_rescan_devices(struct bus_type *bus); 125 126 /* iterator helpers for buses */ 127 struct subsys_dev_iter { 128 struct klist_iter ki; 129 const struct device_type *type; 130 }; 131 void subsys_dev_iter_init(struct subsys_dev_iter *iter, 132 struct bus_type *subsys, 133 struct device *start, 134 const struct device_type *type); 135 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter); 136 void subsys_dev_iter_exit(struct subsys_dev_iter *iter); 137 138 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data, 139 int (*fn)(struct device *dev, void *data)); 140 struct device *bus_find_device(struct bus_type *bus, struct device *start, 141 void *data, 142 int (*match)(struct device *dev, void *data)); 143 struct device *bus_find_device_by_name(struct bus_type *bus, 144 struct device *start, 145 const char *name); 146 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id, 147 struct device *hint); 148 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start, 149 void *data, int (*fn)(struct device_driver *, void *)); 150 void bus_sort_breadthfirst(struct bus_type *bus, 151 int (*compare)(const struct device *a, 152 const struct device *b)); 153 /* 154 * Bus notifiers: Get notified of addition/removal of devices 155 * and binding/unbinding of drivers to devices. 156 * In the long run, it should be a replacement for the platform 157 * notify hooks. 158 */ 159 struct notifier_block; 160 161 extern int bus_register_notifier(struct bus_type *bus, 162 struct notifier_block *nb); 163 extern int bus_unregister_notifier(struct bus_type *bus, 164 struct notifier_block *nb); 165 166 /* All 4 notifers below get called with the target struct device * 167 * as an argument. Note that those functions are likely to be called 168 * with the device lock held in the core, so be careful. 169 */ 170 #define BUS_NOTIFY_ADD_DEVICE 0x00000001 /* device added */ 171 #define BUS_NOTIFY_DEL_DEVICE 0x00000002 /* device removed */ 172 #define BUS_NOTIFY_BIND_DRIVER 0x00000003 /* driver about to be 173 bound */ 174 #define BUS_NOTIFY_BOUND_DRIVER 0x00000004 /* driver bound to device */ 175 #define BUS_NOTIFY_UNBIND_DRIVER 0x00000005 /* driver about to be 176 unbound */ 177 #define BUS_NOTIFY_UNBOUND_DRIVER 0x00000006 /* driver is unbound 178 from the device */ 179 180 extern struct kset *bus_get_kset(struct bus_type *bus); 181 extern struct klist *bus_get_device_klist(struct bus_type *bus); 182 183 /** 184 * struct device_driver - The basic device driver structure 185 * @name: Name of the device driver. 186 * @bus: The bus which the device of this driver belongs to. 187 * @owner: The module owner. 188 * @mod_name: Used for built-in modules. 189 * @suppress_bind_attrs: Disables bind/unbind via sysfs. 190 * @of_match_table: The open firmware table. 191 * @probe: Called to query the existence of a specific device, 192 * whether this driver can work with it, and bind the driver 193 * to a specific device. 194 * @remove: Called when the device is removed from the system to 195 * unbind a device from this driver. 196 * @shutdown: Called at shut-down time to quiesce the device. 197 * @suspend: Called to put the device to sleep mode. Usually to a 198 * low power state. 199 * @resume: Called to bring a device from sleep mode. 200 * @groups: Default attributes that get created by the driver core 201 * automatically. 202 * @pm: Power management operations of the device which matched 203 * this driver. 204 * @p: Driver core's private data, no one other than the driver 205 * core can touch this. 206 * 207 * The device driver-model tracks all of the drivers known to the system. 208 * The main reason for this tracking is to enable the driver core to match 209 * up drivers with new devices. Once drivers are known objects within the 210 * system, however, a number of other things become possible. Device drivers 211 * can export information and configuration variables that are independent 212 * of any specific device. 213 */ 214 struct device_driver { 215 const char *name; 216 struct bus_type *bus; 217 218 struct module *owner; 219 const char *mod_name; /* used for built-in modules */ 220 221 bool suppress_bind_attrs; /* disables bind/unbind via sysfs */ 222 223 const struct of_device_id *of_match_table; 224 225 int (*probe) (struct device *dev); 226 int (*remove) (struct device *dev); 227 void (*shutdown) (struct device *dev); 228 int (*suspend) (struct device *dev, pm_message_t state); 229 int (*resume) (struct device *dev); 230 const struct attribute_group **groups; 231 232 const struct dev_pm_ops *pm; 233 234 struct driver_private *p; 235 }; 236 237 238 extern int __must_check driver_register(struct device_driver *drv); 239 extern void driver_unregister(struct device_driver *drv); 240 241 extern struct device_driver *get_driver(struct device_driver *drv); 242 extern void put_driver(struct device_driver *drv); 243 extern struct device_driver *driver_find(const char *name, 244 struct bus_type *bus); 245 extern int driver_probe_done(void); 246 extern void wait_for_device_probe(void); 247 248 249 /* sysfs interface for exporting driver attributes */ 250 251 struct driver_attribute { 252 struct attribute attr; 253 ssize_t (*show)(struct device_driver *driver, char *buf); 254 ssize_t (*store)(struct device_driver *driver, const char *buf, 255 size_t count); 256 }; 257 258 #define DRIVER_ATTR(_name, _mode, _show, _store) \ 259 struct driver_attribute driver_attr_##_name = \ 260 __ATTR(_name, _mode, _show, _store) 261 262 extern int __must_check driver_create_file(struct device_driver *driver, 263 const struct driver_attribute *attr); 264 extern void driver_remove_file(struct device_driver *driver, 265 const struct driver_attribute *attr); 266 267 extern int __must_check driver_for_each_device(struct device_driver *drv, 268 struct device *start, 269 void *data, 270 int (*fn)(struct device *dev, 271 void *)); 272 struct device *driver_find_device(struct device_driver *drv, 273 struct device *start, void *data, 274 int (*match)(struct device *dev, void *data)); 275 276 /** 277 * struct subsys_interface - interfaces to device functions 278 * @name: name of the device function 279 * @subsys: subsytem of the devices to attach to 280 * @node: the list of functions registered at the subsystem 281 * @add_dev: device hookup to device function handler 282 * @remove_dev: device hookup to device function handler 283 * 284 * Simple interfaces attached to a subsystem. Multiple interfaces can 285 * attach to a subsystem and its devices. Unlike drivers, they do not 286 * exclusively claim or control devices. Interfaces usually represent 287 * a specific functionality of a subsystem/class of devices. 288 */ 289 struct subsys_interface { 290 const char *name; 291 struct bus_type *subsys; 292 struct list_head node; 293 int (*add_dev)(struct device *dev, struct subsys_interface *sif); 294 int (*remove_dev)(struct device *dev, struct subsys_interface *sif); 295 }; 296 297 int subsys_interface_register(struct subsys_interface *sif); 298 void subsys_interface_unregister(struct subsys_interface *sif); 299 300 int subsys_system_register(struct bus_type *subsys, 301 const struct attribute_group **groups); 302 303 /** 304 * struct class - device classes 305 * @name: Name of the class. 306 * @owner: The module owner. 307 * @class_attrs: Default attributes of this class. 308 * @dev_attrs: Default attributes of the devices belong to the class. 309 * @dev_bin_attrs: Default binary attributes of the devices belong to the class. 310 * @dev_kobj: The kobject that represents this class and links it into the hierarchy. 311 * @dev_uevent: Called when a device is added, removed from this class, or a 312 * few other things that generate uevents to add the environment 313 * variables. 314 * @devnode: Callback to provide the devtmpfs. 315 * @class_release: Called to release this class. 316 * @dev_release: Called to release the device. 317 * @suspend: Used to put the device to sleep mode, usually to a low power 318 * state. 319 * @resume: Used to bring the device from the sleep mode. 320 * @ns_type: Callbacks so sysfs can detemine namespaces. 321 * @namespace: Namespace of the device belongs to this class. 322 * @pm: The default device power management operations of this class. 323 * @p: The private data of the driver core, no one other than the 324 * driver core can touch this. 325 * 326 * A class is a higher-level view of a device that abstracts out low-level 327 * implementation details. Drivers may see a SCSI disk or an ATA disk, but, 328 * at the class level, they are all simply disks. Classes allow user space 329 * to work with devices based on what they do, rather than how they are 330 * connected or how they work. 331 */ 332 struct class { 333 const char *name; 334 struct module *owner; 335 336 struct class_attribute *class_attrs; 337 struct device_attribute *dev_attrs; 338 struct bin_attribute *dev_bin_attrs; 339 struct kobject *dev_kobj; 340 341 int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env); 342 char *(*devnode)(struct device *dev, umode_t *mode); 343 344 void (*class_release)(struct class *class); 345 void (*dev_release)(struct device *dev); 346 347 int (*suspend)(struct device *dev, pm_message_t state); 348 int (*resume)(struct device *dev); 349 350 const struct kobj_ns_type_operations *ns_type; 351 const void *(*namespace)(struct device *dev); 352 353 const struct dev_pm_ops *pm; 354 355 struct subsys_private *p; 356 }; 357 358 struct class_dev_iter { 359 struct klist_iter ki; 360 const struct device_type *type; 361 }; 362 363 extern struct kobject *sysfs_dev_block_kobj; 364 extern struct kobject *sysfs_dev_char_kobj; 365 extern int __must_check __class_register(struct class *class, 366 struct lock_class_key *key); 367 extern void class_unregister(struct class *class); 368 369 /* This is a #define to keep the compiler from merging different 370 * instances of the __key variable */ 371 #define class_register(class) \ 372 ({ \ 373 static struct lock_class_key __key; \ 374 __class_register(class, &__key); \ 375 }) 376 377 struct class_compat; 378 struct class_compat *class_compat_register(const char *name); 379 void class_compat_unregister(struct class_compat *cls); 380 int class_compat_create_link(struct class_compat *cls, struct device *dev, 381 struct device *device_link); 382 void class_compat_remove_link(struct class_compat *cls, struct device *dev, 383 struct device *device_link); 384 385 extern void class_dev_iter_init(struct class_dev_iter *iter, 386 struct class *class, 387 struct device *start, 388 const struct device_type *type); 389 extern struct device *class_dev_iter_next(struct class_dev_iter *iter); 390 extern void class_dev_iter_exit(struct class_dev_iter *iter); 391 392 extern int class_for_each_device(struct class *class, struct device *start, 393 void *data, 394 int (*fn)(struct device *dev, void *data)); 395 extern struct device *class_find_device(struct class *class, 396 struct device *start, void *data, 397 int (*match)(struct device *, void *)); 398 399 struct class_attribute { 400 struct attribute attr; 401 ssize_t (*show)(struct class *class, struct class_attribute *attr, 402 char *buf); 403 ssize_t (*store)(struct class *class, struct class_attribute *attr, 404 const char *buf, size_t count); 405 const void *(*namespace)(struct class *class, 406 const struct class_attribute *attr); 407 }; 408 409 #define CLASS_ATTR(_name, _mode, _show, _store) \ 410 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store) 411 412 extern int __must_check class_create_file(struct class *class, 413 const struct class_attribute *attr); 414 extern void class_remove_file(struct class *class, 415 const struct class_attribute *attr); 416 417 /* Simple class attribute that is just a static string */ 418 419 struct class_attribute_string { 420 struct class_attribute attr; 421 char *str; 422 }; 423 424 /* Currently read-only only */ 425 #define _CLASS_ATTR_STRING(_name, _mode, _str) \ 426 { __ATTR(_name, _mode, show_class_attr_string, NULL), _str } 427 #define CLASS_ATTR_STRING(_name, _mode, _str) \ 428 struct class_attribute_string class_attr_##_name = \ 429 _CLASS_ATTR_STRING(_name, _mode, _str) 430 431 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr, 432 char *buf); 433 434 struct class_interface { 435 struct list_head node; 436 struct class *class; 437 438 int (*add_dev) (struct device *, struct class_interface *); 439 void (*remove_dev) (struct device *, struct class_interface *); 440 }; 441 442 extern int __must_check class_interface_register(struct class_interface *); 443 extern void class_interface_unregister(struct class_interface *); 444 445 extern struct class * __must_check __class_create(struct module *owner, 446 const char *name, 447 struct lock_class_key *key); 448 extern void class_destroy(struct class *cls); 449 450 /* This is a #define to keep the compiler from merging different 451 * instances of the __key variable */ 452 #define class_create(owner, name) \ 453 ({ \ 454 static struct lock_class_key __key; \ 455 __class_create(owner, name, &__key); \ 456 }) 457 458 /* 459 * The type of device, "struct device" is embedded in. A class 460 * or bus can contain devices of different types 461 * like "partitions" and "disks", "mouse" and "event". 462 * This identifies the device type and carries type-specific 463 * information, equivalent to the kobj_type of a kobject. 464 * If "name" is specified, the uevent will contain it in 465 * the DEVTYPE variable. 466 */ 467 struct device_type { 468 const char *name; 469 const struct attribute_group **groups; 470 int (*uevent)(struct device *dev, struct kobj_uevent_env *env); 471 char *(*devnode)(struct device *dev, umode_t *mode); 472 void (*release)(struct device *dev); 473 474 const struct dev_pm_ops *pm; 475 }; 476 477 /* interface for exporting device attributes */ 478 struct device_attribute { 479 struct attribute attr; 480 ssize_t (*show)(struct device *dev, struct device_attribute *attr, 481 char *buf); 482 ssize_t (*store)(struct device *dev, struct device_attribute *attr, 483 const char *buf, size_t count); 484 }; 485 486 struct dev_ext_attribute { 487 struct device_attribute attr; 488 void *var; 489 }; 490 491 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr, 492 char *buf); 493 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr, 494 const char *buf, size_t count); 495 ssize_t device_show_int(struct device *dev, struct device_attribute *attr, 496 char *buf); 497 ssize_t device_store_int(struct device *dev, struct device_attribute *attr, 498 const char *buf, size_t count); 499 500 #define DEVICE_ATTR(_name, _mode, _show, _store) \ 501 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store) 502 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \ 503 struct dev_ext_attribute dev_attr_##_name = \ 504 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) } 505 #define DEVICE_INT_ATTR(_name, _mode, _var) \ 506 struct dev_ext_attribute dev_attr_##_name = \ 507 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) } 508 509 extern int device_create_file(struct device *device, 510 const struct device_attribute *entry); 511 extern void device_remove_file(struct device *dev, 512 const struct device_attribute *attr); 513 extern int __must_check device_create_bin_file(struct device *dev, 514 const struct bin_attribute *attr); 515 extern void device_remove_bin_file(struct device *dev, 516 const struct bin_attribute *attr); 517 extern int device_schedule_callback_owner(struct device *dev, 518 void (*func)(struct device *dev), struct module *owner); 519 520 /* This is a macro to avoid include problems with THIS_MODULE */ 521 #define device_schedule_callback(dev, func) \ 522 device_schedule_callback_owner(dev, func, THIS_MODULE) 523 524 /* device resource management */ 525 typedef void (*dr_release_t)(struct device *dev, void *res); 526 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data); 527 528 #ifdef CONFIG_DEBUG_DEVRES 529 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp, 530 const char *name); 531 #define devres_alloc(release, size, gfp) \ 532 __devres_alloc(release, size, gfp, #release) 533 #else 534 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp); 535 #endif 536 extern void devres_free(void *res); 537 extern void devres_add(struct device *dev, void *res); 538 extern void *devres_find(struct device *dev, dr_release_t release, 539 dr_match_t match, void *match_data); 540 extern void *devres_get(struct device *dev, void *new_res, 541 dr_match_t match, void *match_data); 542 extern void *devres_remove(struct device *dev, dr_release_t release, 543 dr_match_t match, void *match_data); 544 extern int devres_destroy(struct device *dev, dr_release_t release, 545 dr_match_t match, void *match_data); 546 547 /* devres group */ 548 extern void * __must_check devres_open_group(struct device *dev, void *id, 549 gfp_t gfp); 550 extern void devres_close_group(struct device *dev, void *id); 551 extern void devres_remove_group(struct device *dev, void *id); 552 extern int devres_release_group(struct device *dev, void *id); 553 554 /* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */ 555 extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp); 556 extern void devm_kfree(struct device *dev, void *p); 557 558 void __iomem *devm_request_and_ioremap(struct device *dev, 559 struct resource *res); 560 561 struct device_dma_parameters { 562 /* 563 * a low level driver may set these to teach IOMMU code about 564 * sg limitations. 565 */ 566 unsigned int max_segment_size; 567 unsigned long segment_boundary_mask; 568 }; 569 570 /** 571 * struct device - The basic device structure 572 * @parent: The device's "parent" device, the device to which it is attached. 573 * In most cases, a parent device is some sort of bus or host 574 * controller. If parent is NULL, the device, is a top-level device, 575 * which is not usually what you want. 576 * @p: Holds the private data of the driver core portions of the device. 577 * See the comment of the struct device_private for detail. 578 * @kobj: A top-level, abstract class from which other classes are derived. 579 * @init_name: Initial name of the device. 580 * @type: The type of device. 581 * This identifies the device type and carries type-specific 582 * information. 583 * @mutex: Mutex to synchronize calls to its driver. 584 * @bus: Type of bus device is on. 585 * @driver: Which driver has allocated this 586 * @platform_data: Platform data specific to the device. 587 * Example: For devices on custom boards, as typical of embedded 588 * and SOC based hardware, Linux often uses platform_data to point 589 * to board-specific structures describing devices and how they 590 * are wired. That can include what ports are available, chip 591 * variants, which GPIO pins act in what additional roles, and so 592 * on. This shrinks the "Board Support Packages" (BSPs) and 593 * minimizes board-specific #ifdefs in drivers. 594 * @power: For device power management. 595 * See Documentation/power/devices.txt for details. 596 * @pm_domain: Provide callbacks that are executed during system suspend, 597 * hibernation, system resume and during runtime PM transitions 598 * along with subsystem-level and driver-level callbacks. 599 * @numa_node: NUMA node this device is close to. 600 * @dma_mask: Dma mask (if dma'ble device). 601 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all 602 * hardware supports 64-bit addresses for consistent allocations 603 * such descriptors. 604 * @dma_parms: A low level driver may set these to teach IOMMU code about 605 * segment limitations. 606 * @dma_pools: Dma pools (if dma'ble device). 607 * @dma_mem: Internal for coherent mem override. 608 * @archdata: For arch-specific additions. 609 * @of_node: Associated device tree node. 610 * @devt: For creating the sysfs "dev". 611 * @id: device instance 612 * @devres_lock: Spinlock to protect the resource of the device. 613 * @devres_head: The resources list of the device. 614 * @knode_class: The node used to add the device to the class list. 615 * @class: The class of the device. 616 * @groups: Optional attribute groups. 617 * @release: Callback to free the device after all references have 618 * gone away. This should be set by the allocator of the 619 * device (i.e. the bus driver that discovered the device). 620 * 621 * At the lowest level, every device in a Linux system is represented by an 622 * instance of struct device. The device structure contains the information 623 * that the device model core needs to model the system. Most subsystems, 624 * however, track additional information about the devices they host. As a 625 * result, it is rare for devices to be represented by bare device structures; 626 * instead, that structure, like kobject structures, is usually embedded within 627 * a higher-level representation of the device. 628 */ 629 struct device { 630 struct device *parent; 631 632 struct device_private *p; 633 634 struct kobject kobj; 635 const char *init_name; /* initial name of the device */ 636 const struct device_type *type; 637 638 struct mutex mutex; /* mutex to synchronize calls to 639 * its driver. 640 */ 641 642 struct bus_type *bus; /* type of bus device is on */ 643 struct device_driver *driver; /* which driver has allocated this 644 device */ 645 void *platform_data; /* Platform specific data, device 646 core doesn't touch it */ 647 struct dev_pm_info power; 648 struct dev_pm_domain *pm_domain; 649 650 #ifdef CONFIG_NUMA 651 int numa_node; /* NUMA node this device is close to */ 652 #endif 653 u64 *dma_mask; /* dma mask (if dma'able device) */ 654 u64 coherent_dma_mask;/* Like dma_mask, but for 655 alloc_coherent mappings as 656 not all hardware supports 657 64 bit addresses for consistent 658 allocations such descriptors. */ 659 660 struct device_dma_parameters *dma_parms; 661 662 struct list_head dma_pools; /* dma pools (if dma'ble) */ 663 664 struct dma_coherent_mem *dma_mem; /* internal for coherent mem 665 override */ 666 /* arch specific additions */ 667 struct dev_archdata archdata; 668 669 struct device_node *of_node; /* associated device tree node */ 670 671 dev_t devt; /* dev_t, creates the sysfs "dev" */ 672 u32 id; /* device instance */ 673 674 spinlock_t devres_lock; 675 struct list_head devres_head; 676 677 struct klist_node knode_class; 678 struct class *class; 679 const struct attribute_group **groups; /* optional groups */ 680 681 void (*release)(struct device *dev); 682 }; 683 684 /* Get the wakeup routines, which depend on struct device */ 685 #include <linux/pm_wakeup.h> 686 687 static inline const char *dev_name(const struct device *dev) 688 { 689 /* Use the init name until the kobject becomes available */ 690 if (dev->init_name) 691 return dev->init_name; 692 693 return kobject_name(&dev->kobj); 694 } 695 696 extern __printf(2, 3) 697 int dev_set_name(struct device *dev, const char *name, ...); 698 699 #ifdef CONFIG_NUMA 700 static inline int dev_to_node(struct device *dev) 701 { 702 return dev->numa_node; 703 } 704 static inline void set_dev_node(struct device *dev, int node) 705 { 706 dev->numa_node = node; 707 } 708 #else 709 static inline int dev_to_node(struct device *dev) 710 { 711 return -1; 712 } 713 static inline void set_dev_node(struct device *dev, int node) 714 { 715 } 716 #endif 717 718 static inline struct pm_subsys_data *dev_to_psd(struct device *dev) 719 { 720 return dev ? dev->power.subsys_data : NULL; 721 } 722 723 static inline unsigned int dev_get_uevent_suppress(const struct device *dev) 724 { 725 return dev->kobj.uevent_suppress; 726 } 727 728 static inline void dev_set_uevent_suppress(struct device *dev, int val) 729 { 730 dev->kobj.uevent_suppress = val; 731 } 732 733 static inline int device_is_registered(struct device *dev) 734 { 735 return dev->kobj.state_in_sysfs; 736 } 737 738 static inline void device_enable_async_suspend(struct device *dev) 739 { 740 if (!dev->power.is_prepared) 741 dev->power.async_suspend = true; 742 } 743 744 static inline void device_disable_async_suspend(struct device *dev) 745 { 746 if (!dev->power.is_prepared) 747 dev->power.async_suspend = false; 748 } 749 750 static inline bool device_async_suspend_enabled(struct device *dev) 751 { 752 return !!dev->power.async_suspend; 753 } 754 755 static inline void pm_suspend_ignore_children(struct device *dev, bool enable) 756 { 757 dev->power.ignore_children = enable; 758 } 759 760 static inline void device_lock(struct device *dev) 761 { 762 mutex_lock(&dev->mutex); 763 } 764 765 static inline int device_trylock(struct device *dev) 766 { 767 return mutex_trylock(&dev->mutex); 768 } 769 770 static inline void device_unlock(struct device *dev) 771 { 772 mutex_unlock(&dev->mutex); 773 } 774 775 void driver_init(void); 776 777 /* 778 * High level routines for use by the bus drivers 779 */ 780 extern int __must_check device_register(struct device *dev); 781 extern void device_unregister(struct device *dev); 782 extern void device_initialize(struct device *dev); 783 extern int __must_check device_add(struct device *dev); 784 extern void device_del(struct device *dev); 785 extern int device_for_each_child(struct device *dev, void *data, 786 int (*fn)(struct device *dev, void *data)); 787 extern struct device *device_find_child(struct device *dev, void *data, 788 int (*match)(struct device *dev, void *data)); 789 extern int device_rename(struct device *dev, const char *new_name); 790 extern int device_move(struct device *dev, struct device *new_parent, 791 enum dpm_order dpm_order); 792 extern const char *device_get_devnode(struct device *dev, 793 umode_t *mode, const char **tmp); 794 extern void *dev_get_drvdata(const struct device *dev); 795 extern int dev_set_drvdata(struct device *dev, void *data); 796 797 /* 798 * Root device objects for grouping under /sys/devices 799 */ 800 extern struct device *__root_device_register(const char *name, 801 struct module *owner); 802 803 /* 804 * This is a macro to avoid include problems with THIS_MODULE, 805 * just as per what is done for device_schedule_callback() above. 806 */ 807 #define root_device_register(name) \ 808 __root_device_register(name, THIS_MODULE) 809 810 extern void root_device_unregister(struct device *root); 811 812 static inline void *dev_get_platdata(const struct device *dev) 813 { 814 return dev->platform_data; 815 } 816 817 /* 818 * Manual binding of a device to driver. See drivers/base/bus.c 819 * for information on use. 820 */ 821 extern int __must_check device_bind_driver(struct device *dev); 822 extern void device_release_driver(struct device *dev); 823 extern int __must_check device_attach(struct device *dev); 824 extern int __must_check driver_attach(struct device_driver *drv); 825 extern int __must_check device_reprobe(struct device *dev); 826 827 /* 828 * Easy functions for dynamically creating devices on the fly 829 */ 830 extern struct device *device_create_vargs(struct class *cls, 831 struct device *parent, 832 dev_t devt, 833 void *drvdata, 834 const char *fmt, 835 va_list vargs); 836 extern __printf(5, 6) 837 struct device *device_create(struct class *cls, struct device *parent, 838 dev_t devt, void *drvdata, 839 const char *fmt, ...); 840 extern void device_destroy(struct class *cls, dev_t devt); 841 842 /* 843 * Platform "fixup" functions - allow the platform to have their say 844 * about devices and actions that the general device layer doesn't 845 * know about. 846 */ 847 /* Notify platform of device discovery */ 848 extern int (*platform_notify)(struct device *dev); 849 850 extern int (*platform_notify_remove)(struct device *dev); 851 852 853 /* 854 * get_device - atomically increment the reference count for the device. 855 * 856 */ 857 extern struct device *get_device(struct device *dev); 858 extern void put_device(struct device *dev); 859 860 extern void wait_for_device_probe(void); 861 862 #ifdef CONFIG_DEVTMPFS 863 extern int devtmpfs_create_node(struct device *dev); 864 extern int devtmpfs_delete_node(struct device *dev); 865 extern int devtmpfs_mount(const char *mntdir); 866 #else 867 static inline int devtmpfs_create_node(struct device *dev) { return 0; } 868 static inline int devtmpfs_delete_node(struct device *dev) { return 0; } 869 static inline int devtmpfs_mount(const char *mountpoint) { return 0; } 870 #endif 871 872 /* drivers/base/power/shutdown.c */ 873 extern void device_shutdown(void); 874 875 /* debugging and troubleshooting/diagnostic helpers. */ 876 extern const char *dev_driver_string(const struct device *dev); 877 878 879 #ifdef CONFIG_PRINTK 880 881 extern int __dev_printk(const char *level, const struct device *dev, 882 struct va_format *vaf); 883 extern __printf(3, 4) 884 int dev_printk(const char *level, const struct device *dev, 885 const char *fmt, ...) 886 ; 887 extern __printf(2, 3) 888 int dev_emerg(const struct device *dev, const char *fmt, ...); 889 extern __printf(2, 3) 890 int dev_alert(const struct device *dev, const char *fmt, ...); 891 extern __printf(2, 3) 892 int dev_crit(const struct device *dev, const char *fmt, ...); 893 extern __printf(2, 3) 894 int dev_err(const struct device *dev, const char *fmt, ...); 895 extern __printf(2, 3) 896 int dev_warn(const struct device *dev, const char *fmt, ...); 897 extern __printf(2, 3) 898 int dev_notice(const struct device *dev, const char *fmt, ...); 899 extern __printf(2, 3) 900 int _dev_info(const struct device *dev, const char *fmt, ...); 901 902 #else 903 904 static inline int __dev_printk(const char *level, const struct device *dev, 905 struct va_format *vaf) 906 { return 0; } 907 static inline __printf(3, 4) 908 int dev_printk(const char *level, const struct device *dev, 909 const char *fmt, ...) 910 { return 0; } 911 912 static inline __printf(2, 3) 913 int dev_emerg(const struct device *dev, const char *fmt, ...) 914 { return 0; } 915 static inline __printf(2, 3) 916 int dev_crit(const struct device *dev, const char *fmt, ...) 917 { return 0; } 918 static inline __printf(2, 3) 919 int dev_alert(const struct device *dev, const char *fmt, ...) 920 { return 0; } 921 static inline __printf(2, 3) 922 int dev_err(const struct device *dev, const char *fmt, ...) 923 { return 0; } 924 static inline __printf(2, 3) 925 int dev_warn(const struct device *dev, const char *fmt, ...) 926 { return 0; } 927 static inline __printf(2, 3) 928 int dev_notice(const struct device *dev, const char *fmt, ...) 929 { return 0; } 930 static inline __printf(2, 3) 931 int _dev_info(const struct device *dev, const char *fmt, ...) 932 { return 0; } 933 934 #endif 935 936 /* 937 * Stupid hackaround for existing uses of non-printk uses dev_info 938 * 939 * Note that the definition of dev_info below is actually _dev_info 940 * and a macro is used to avoid redefining dev_info 941 */ 942 943 #define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg) 944 945 #if defined(DEBUG) 946 #define dev_dbg(dev, format, arg...) \ 947 dev_printk(KERN_DEBUG, dev, format, ##arg) 948 #elif defined(CONFIG_DYNAMIC_DEBUG) 949 #define dev_dbg(dev, format, ...) \ 950 do { \ 951 dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \ 952 } while (0) 953 #else 954 #define dev_dbg(dev, format, arg...) \ 955 ({ \ 956 if (0) \ 957 dev_printk(KERN_DEBUG, dev, format, ##arg); \ 958 0; \ 959 }) 960 #endif 961 962 #ifdef VERBOSE_DEBUG 963 #define dev_vdbg dev_dbg 964 #else 965 #define dev_vdbg(dev, format, arg...) \ 966 ({ \ 967 if (0) \ 968 dev_printk(KERN_DEBUG, dev, format, ##arg); \ 969 0; \ 970 }) 971 #endif 972 973 /* 974 * dev_WARN*() acts like dev_printk(), but with the key difference 975 * of using a WARN/WARN_ON to get the message out, including the 976 * file/line information and a backtrace. 977 */ 978 #define dev_WARN(dev, format, arg...) \ 979 WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg); 980 981 #define dev_WARN_ONCE(dev, condition, format, arg...) \ 982 WARN_ONCE(condition, "Device %s\n" format, \ 983 dev_driver_string(dev), ## arg) 984 985 /* Create alias, so I can be autoloaded. */ 986 #define MODULE_ALIAS_CHARDEV(major,minor) \ 987 MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor)) 988 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \ 989 MODULE_ALIAS("char-major-" __stringify(major) "-*") 990 991 #ifdef CONFIG_SYSFS_DEPRECATED 992 extern long sysfs_deprecated; 993 #else 994 #define sysfs_deprecated 0 995 #endif 996 997 /** 998 * module_driver() - Helper macro for drivers that don't do anything 999 * special in module init/exit. This eliminates a lot of boilerplate. 1000 * Each module may only use this macro once, and calling it replaces 1001 * module_init() and module_exit(). 1002 * 1003 * @__driver: driver name 1004 * @__register: register function for this driver type 1005 * @__unregister: unregister function for this driver type 1006 * 1007 * Use this macro to construct bus specific macros for registering 1008 * drivers, and do not use it on its own. 1009 */ 1010 #define module_driver(__driver, __register, __unregister) \ 1011 static int __init __driver##_init(void) \ 1012 { \ 1013 return __register(&(__driver)); \ 1014 } \ 1015 module_init(__driver##_init); \ 1016 static void __exit __driver##_exit(void) \ 1017 { \ 1018 __unregister(&(__driver)); \ 1019 } \ 1020 module_exit(__driver##_exit); 1021 1022 #endif /* _DEVICE_H_ */ 1023