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_add_kobj(struct device_driver *drv, 268 struct kobject *kobj, 269 const char *fmt, ...); 270 271 extern int __must_check driver_for_each_device(struct device_driver *drv, 272 struct device *start, 273 void *data, 274 int (*fn)(struct device *dev, 275 void *)); 276 struct device *driver_find_device(struct device_driver *drv, 277 struct device *start, void *data, 278 int (*match)(struct device *dev, void *data)); 279 280 /** 281 * struct subsys_interface - interfaces to device functions 282 * @name name of the device function 283 * @subsystem subsytem of the devices to attach to 284 * @node the list of functions registered at the subsystem 285 * @add device hookup to device function handler 286 * @remove device hookup to device function handler 287 * 288 * Simple interfaces attached to a subsystem. Multiple interfaces can 289 * attach to a subsystem and its devices. Unlike drivers, they do not 290 * exclusively claim or control devices. Interfaces usually represent 291 * a specific functionality of a subsystem/class of devices. 292 */ 293 struct subsys_interface { 294 const char *name; 295 struct bus_type *subsys; 296 struct list_head node; 297 int (*add_dev)(struct device *dev, struct subsys_interface *sif); 298 int (*remove_dev)(struct device *dev, struct subsys_interface *sif); 299 }; 300 301 int subsys_interface_register(struct subsys_interface *sif); 302 void subsys_interface_unregister(struct subsys_interface *sif); 303 304 int subsys_system_register(struct bus_type *subsys, 305 const struct attribute_group **groups); 306 307 /** 308 * struct class - device classes 309 * @name: Name of the class. 310 * @owner: The module owner. 311 * @class_attrs: Default attributes of this class. 312 * @dev_attrs: Default attributes of the devices belong to the class. 313 * @dev_bin_attrs: Default binary attributes of the devices belong to the class. 314 * @dev_kobj: The kobject that represents this class and links it into the hierarchy. 315 * @dev_uevent: Called when a device is added, removed from this class, or a 316 * few other things that generate uevents to add the environment 317 * variables. 318 * @devnode: Callback to provide the devtmpfs. 319 * @class_release: Called to release this class. 320 * @dev_release: Called to release the device. 321 * @suspend: Used to put the device to sleep mode, usually to a low power 322 * state. 323 * @resume: Used to bring the device from the sleep mode. 324 * @ns_type: Callbacks so sysfs can detemine namespaces. 325 * @namespace: Namespace of the device belongs to this class. 326 * @pm: The default device power management operations of this class. 327 * @p: The private data of the driver core, no one other than the 328 * driver core can touch this. 329 * 330 * A class is a higher-level view of a device that abstracts out low-level 331 * implementation details. Drivers may see a SCSI disk or an ATA disk, but, 332 * at the class level, they are all simply disks. Classes allow user space 333 * to work with devices based on what they do, rather than how they are 334 * connected or how they work. 335 */ 336 struct class { 337 const char *name; 338 struct module *owner; 339 340 struct class_attribute *class_attrs; 341 struct device_attribute *dev_attrs; 342 struct bin_attribute *dev_bin_attrs; 343 struct kobject *dev_kobj; 344 345 int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env); 346 char *(*devnode)(struct device *dev, umode_t *mode); 347 348 void (*class_release)(struct class *class); 349 void (*dev_release)(struct device *dev); 350 351 int (*suspend)(struct device *dev, pm_message_t state); 352 int (*resume)(struct device *dev); 353 354 const struct kobj_ns_type_operations *ns_type; 355 const void *(*namespace)(struct device *dev); 356 357 const struct dev_pm_ops *pm; 358 359 struct subsys_private *p; 360 }; 361 362 struct class_dev_iter { 363 struct klist_iter ki; 364 const struct device_type *type; 365 }; 366 367 extern struct kobject *sysfs_dev_block_kobj; 368 extern struct kobject *sysfs_dev_char_kobj; 369 extern int __must_check __class_register(struct class *class, 370 struct lock_class_key *key); 371 extern void class_unregister(struct class *class); 372 373 /* This is a #define to keep the compiler from merging different 374 * instances of the __key variable */ 375 #define class_register(class) \ 376 ({ \ 377 static struct lock_class_key __key; \ 378 __class_register(class, &__key); \ 379 }) 380 381 struct class_compat; 382 struct class_compat *class_compat_register(const char *name); 383 void class_compat_unregister(struct class_compat *cls); 384 int class_compat_create_link(struct class_compat *cls, struct device *dev, 385 struct device *device_link); 386 void class_compat_remove_link(struct class_compat *cls, struct device *dev, 387 struct device *device_link); 388 389 extern void class_dev_iter_init(struct class_dev_iter *iter, 390 struct class *class, 391 struct device *start, 392 const struct device_type *type); 393 extern struct device *class_dev_iter_next(struct class_dev_iter *iter); 394 extern void class_dev_iter_exit(struct class_dev_iter *iter); 395 396 extern int class_for_each_device(struct class *class, struct device *start, 397 void *data, 398 int (*fn)(struct device *dev, void *data)); 399 extern struct device *class_find_device(struct class *class, 400 struct device *start, void *data, 401 int (*match)(struct device *, void *)); 402 403 struct class_attribute { 404 struct attribute attr; 405 ssize_t (*show)(struct class *class, struct class_attribute *attr, 406 char *buf); 407 ssize_t (*store)(struct class *class, struct class_attribute *attr, 408 const char *buf, size_t count); 409 const void *(*namespace)(struct class *class, 410 const struct class_attribute *attr); 411 }; 412 413 #define CLASS_ATTR(_name, _mode, _show, _store) \ 414 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store) 415 416 extern int __must_check class_create_file(struct class *class, 417 const struct class_attribute *attr); 418 extern void class_remove_file(struct class *class, 419 const struct class_attribute *attr); 420 421 /* Simple class attribute that is just a static string */ 422 423 struct class_attribute_string { 424 struct class_attribute attr; 425 char *str; 426 }; 427 428 /* Currently read-only only */ 429 #define _CLASS_ATTR_STRING(_name, _mode, _str) \ 430 { __ATTR(_name, _mode, show_class_attr_string, NULL), _str } 431 #define CLASS_ATTR_STRING(_name, _mode, _str) \ 432 struct class_attribute_string class_attr_##_name = \ 433 _CLASS_ATTR_STRING(_name, _mode, _str) 434 435 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr, 436 char *buf); 437 438 struct class_interface { 439 struct list_head node; 440 struct class *class; 441 442 int (*add_dev) (struct device *, struct class_interface *); 443 void (*remove_dev) (struct device *, struct class_interface *); 444 }; 445 446 extern int __must_check class_interface_register(struct class_interface *); 447 extern void class_interface_unregister(struct class_interface *); 448 449 extern struct class * __must_check __class_create(struct module *owner, 450 const char *name, 451 struct lock_class_key *key); 452 extern void class_destroy(struct class *cls); 453 454 /* This is a #define to keep the compiler from merging different 455 * instances of the __key variable */ 456 #define class_create(owner, name) \ 457 ({ \ 458 static struct lock_class_key __key; \ 459 __class_create(owner, name, &__key); \ 460 }) 461 462 /* 463 * The type of device, "struct device" is embedded in. A class 464 * or bus can contain devices of different types 465 * like "partitions" and "disks", "mouse" and "event". 466 * This identifies the device type and carries type-specific 467 * information, equivalent to the kobj_type of a kobject. 468 * If "name" is specified, the uevent will contain it in 469 * the DEVTYPE variable. 470 */ 471 struct device_type { 472 const char *name; 473 const struct attribute_group **groups; 474 int (*uevent)(struct device *dev, struct kobj_uevent_env *env); 475 char *(*devnode)(struct device *dev, umode_t *mode); 476 void (*release)(struct device *dev); 477 478 const struct dev_pm_ops *pm; 479 }; 480 481 /* interface for exporting device attributes */ 482 struct device_attribute { 483 struct attribute attr; 484 ssize_t (*show)(struct device *dev, struct device_attribute *attr, 485 char *buf); 486 ssize_t (*store)(struct device *dev, struct device_attribute *attr, 487 const char *buf, size_t count); 488 }; 489 490 struct dev_ext_attribute { 491 struct device_attribute attr; 492 void *var; 493 }; 494 495 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr, 496 char *buf); 497 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr, 498 const char *buf, size_t count); 499 ssize_t device_show_int(struct device *dev, struct device_attribute *attr, 500 char *buf); 501 ssize_t device_store_int(struct device *dev, struct device_attribute *attr, 502 const char *buf, size_t count); 503 504 #define DEVICE_ATTR(_name, _mode, _show, _store) \ 505 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store) 506 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \ 507 struct dev_ext_attribute dev_attr_##_name = \ 508 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) } 509 #define DEVICE_INT_ATTR(_name, _mode, _var) \ 510 struct dev_ext_attribute dev_attr_##_name = \ 511 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) } 512 513 extern int device_create_file(struct device *device, 514 const struct device_attribute *entry); 515 extern void device_remove_file(struct device *dev, 516 const struct device_attribute *attr); 517 extern int __must_check device_create_bin_file(struct device *dev, 518 const struct bin_attribute *attr); 519 extern void device_remove_bin_file(struct device *dev, 520 const struct bin_attribute *attr); 521 extern int device_schedule_callback_owner(struct device *dev, 522 void (*func)(struct device *dev), struct module *owner); 523 524 /* This is a macro to avoid include problems with THIS_MODULE */ 525 #define device_schedule_callback(dev, func) \ 526 device_schedule_callback_owner(dev, func, THIS_MODULE) 527 528 /* device resource management */ 529 typedef void (*dr_release_t)(struct device *dev, void *res); 530 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data); 531 532 #ifdef CONFIG_DEBUG_DEVRES 533 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp, 534 const char *name); 535 #define devres_alloc(release, size, gfp) \ 536 __devres_alloc(release, size, gfp, #release) 537 #else 538 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp); 539 #endif 540 extern void devres_free(void *res); 541 extern void devres_add(struct device *dev, void *res); 542 extern void *devres_find(struct device *dev, dr_release_t release, 543 dr_match_t match, void *match_data); 544 extern void *devres_get(struct device *dev, void *new_res, 545 dr_match_t match, void *match_data); 546 extern void *devres_remove(struct device *dev, dr_release_t release, 547 dr_match_t match, void *match_data); 548 extern int devres_destroy(struct device *dev, dr_release_t release, 549 dr_match_t match, void *match_data); 550 551 /* devres group */ 552 extern void * __must_check devres_open_group(struct device *dev, void *id, 553 gfp_t gfp); 554 extern void devres_close_group(struct device *dev, void *id); 555 extern void devres_remove_group(struct device *dev, void *id); 556 extern int devres_release_group(struct device *dev, void *id); 557 558 /* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */ 559 extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp); 560 extern void devm_kfree(struct device *dev, void *p); 561 562 void __iomem *devm_request_and_ioremap(struct device *dev, 563 struct resource *res); 564 565 struct device_dma_parameters { 566 /* 567 * a low level driver may set these to teach IOMMU code about 568 * sg limitations. 569 */ 570 unsigned int max_segment_size; 571 unsigned long segment_boundary_mask; 572 }; 573 574 /** 575 * struct device - The basic device structure 576 * @parent: The device's "parent" device, the device to which it is attached. 577 * In most cases, a parent device is some sort of bus or host 578 * controller. If parent is NULL, the device, is a top-level device, 579 * which is not usually what you want. 580 * @p: Holds the private data of the driver core portions of the device. 581 * See the comment of the struct device_private for detail. 582 * @kobj: A top-level, abstract class from which other classes are derived. 583 * @init_name: Initial name of the device. 584 * @type: The type of device. 585 * This identifies the device type and carries type-specific 586 * information. 587 * @mutex: Mutex to synchronize calls to its driver. 588 * @bus: Type of bus device is on. 589 * @driver: Which driver has allocated this 590 * @platform_data: Platform data specific to the device. 591 * Example: For devices on custom boards, as typical of embedded 592 * and SOC based hardware, Linux often uses platform_data to point 593 * to board-specific structures describing devices and how they 594 * are wired. That can include what ports are available, chip 595 * variants, which GPIO pins act in what additional roles, and so 596 * on. This shrinks the "Board Support Packages" (BSPs) and 597 * minimizes board-specific #ifdefs in drivers. 598 * @power: For device power management. 599 * See Documentation/power/devices.txt for details. 600 * @pm_domain: Provide callbacks that are executed during system suspend, 601 * hibernation, system resume and during runtime PM transitions 602 * along with subsystem-level and driver-level callbacks. 603 * @numa_node: NUMA node this device is close to. 604 * @dma_mask: Dma mask (if dma'ble device). 605 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all 606 * hardware supports 64-bit addresses for consistent allocations 607 * such descriptors. 608 * @dma_parms: A low level driver may set these to teach IOMMU code about 609 * segment limitations. 610 * @dma_pools: Dma pools (if dma'ble device). 611 * @dma_mem: Internal for coherent mem override. 612 * @archdata: For arch-specific additions. 613 * @of_node: Associated device tree node. 614 * @devt: For creating the sysfs "dev". 615 * @devres_lock: Spinlock to protect the resource of the device. 616 * @devres_head: The resources list of the device. 617 * @knode_class: The node used to add the device to the class list. 618 * @class: The class of the device. 619 * @groups: Optional attribute groups. 620 * @release: Callback to free the device after all references have 621 * gone away. This should be set by the allocator of the 622 * device (i.e. the bus driver that discovered the device). 623 * 624 * At the lowest level, every device in a Linux system is represented by an 625 * instance of struct device. The device structure contains the information 626 * that the device model core needs to model the system. Most subsystems, 627 * however, track additional information about the devices they host. As a 628 * result, it is rare for devices to be represented by bare device structures; 629 * instead, that structure, like kobject structures, is usually embedded within 630 * a higher-level representation of the device. 631 */ 632 struct device { 633 struct device *parent; 634 635 struct device_private *p; 636 637 struct kobject kobj; 638 const char *init_name; /* initial name of the device */ 639 const struct device_type *type; 640 641 struct mutex mutex; /* mutex to synchronize calls to 642 * its driver. 643 */ 644 645 struct bus_type *bus; /* type of bus device is on */ 646 struct device_driver *driver; /* which driver has allocated this 647 device */ 648 void *platform_data; /* Platform specific data, device 649 core doesn't touch it */ 650 struct dev_pm_info power; 651 struct dev_pm_domain *pm_domain; 652 653 #ifdef CONFIG_NUMA 654 int numa_node; /* NUMA node this device is close to */ 655 #endif 656 u64 *dma_mask; /* dma mask (if dma'able device) */ 657 u64 coherent_dma_mask;/* Like dma_mask, but for 658 alloc_coherent mappings as 659 not all hardware supports 660 64 bit addresses for consistent 661 allocations such descriptors. */ 662 663 struct device_dma_parameters *dma_parms; 664 665 struct list_head dma_pools; /* dma pools (if dma'ble) */ 666 667 struct dma_coherent_mem *dma_mem; /* internal for coherent mem 668 override */ 669 /* arch specific additions */ 670 struct dev_archdata archdata; 671 672 struct device_node *of_node; /* associated device tree node */ 673 674 dev_t devt; /* dev_t, creates the sysfs "dev" */ 675 u32 id; /* device instance */ 676 677 spinlock_t devres_lock; 678 struct list_head devres_head; 679 680 struct klist_node knode_class; 681 struct class *class; 682 const struct attribute_group **groups; /* optional groups */ 683 684 void (*release)(struct device *dev); 685 }; 686 687 /* Get the wakeup routines, which depend on struct device */ 688 #include <linux/pm_wakeup.h> 689 690 static inline const char *dev_name(const struct device *dev) 691 { 692 /* Use the init name until the kobject becomes available */ 693 if (dev->init_name) 694 return dev->init_name; 695 696 return kobject_name(&dev->kobj); 697 } 698 699 extern __printf(2, 3) 700 int dev_set_name(struct device *dev, const char *name, ...); 701 702 #ifdef CONFIG_NUMA 703 static inline int dev_to_node(struct device *dev) 704 { 705 return dev->numa_node; 706 } 707 static inline void set_dev_node(struct device *dev, int node) 708 { 709 dev->numa_node = node; 710 } 711 #else 712 static inline int dev_to_node(struct device *dev) 713 { 714 return -1; 715 } 716 static inline void set_dev_node(struct device *dev, int node) 717 { 718 } 719 #endif 720 721 static inline struct pm_subsys_data *dev_to_psd(struct device *dev) 722 { 723 return dev ? dev->power.subsys_data : NULL; 724 } 725 726 static inline unsigned int dev_get_uevent_suppress(const struct device *dev) 727 { 728 return dev->kobj.uevent_suppress; 729 } 730 731 static inline void dev_set_uevent_suppress(struct device *dev, int val) 732 { 733 dev->kobj.uevent_suppress = val; 734 } 735 736 static inline int device_is_registered(struct device *dev) 737 { 738 return dev->kobj.state_in_sysfs; 739 } 740 741 static inline void device_enable_async_suspend(struct device *dev) 742 { 743 if (!dev->power.is_prepared) 744 dev->power.async_suspend = true; 745 } 746 747 static inline void device_disable_async_suspend(struct device *dev) 748 { 749 if (!dev->power.is_prepared) 750 dev->power.async_suspend = false; 751 } 752 753 static inline bool device_async_suspend_enabled(struct device *dev) 754 { 755 return !!dev->power.async_suspend; 756 } 757 758 static inline void pm_suspend_ignore_children(struct device *dev, bool enable) 759 { 760 dev->power.ignore_children = enable; 761 } 762 763 static inline void device_lock(struct device *dev) 764 { 765 mutex_lock(&dev->mutex); 766 } 767 768 static inline int device_trylock(struct device *dev) 769 { 770 return mutex_trylock(&dev->mutex); 771 } 772 773 static inline void device_unlock(struct device *dev) 774 { 775 mutex_unlock(&dev->mutex); 776 } 777 778 void driver_init(void); 779 780 /* 781 * High level routines for use by the bus drivers 782 */ 783 extern int __must_check device_register(struct device *dev); 784 extern void device_unregister(struct device *dev); 785 extern void device_initialize(struct device *dev); 786 extern int __must_check device_add(struct device *dev); 787 extern void device_del(struct device *dev); 788 extern int device_for_each_child(struct device *dev, void *data, 789 int (*fn)(struct device *dev, void *data)); 790 extern struct device *device_find_child(struct device *dev, void *data, 791 int (*match)(struct device *dev, void *data)); 792 extern int device_rename(struct device *dev, const char *new_name); 793 extern int device_move(struct device *dev, struct device *new_parent, 794 enum dpm_order dpm_order); 795 extern const char *device_get_devnode(struct device *dev, 796 umode_t *mode, const char **tmp); 797 extern void *dev_get_drvdata(const struct device *dev); 798 extern int dev_set_drvdata(struct device *dev, void *data); 799 800 /* 801 * Root device objects for grouping under /sys/devices 802 */ 803 extern struct device *__root_device_register(const char *name, 804 struct module *owner); 805 806 /* 807 * This is a macro to avoid include problems with THIS_MODULE, 808 * just as per what is done for device_schedule_callback() above. 809 */ 810 #define root_device_register(name) \ 811 __root_device_register(name, THIS_MODULE) 812 813 extern void root_device_unregister(struct device *root); 814 815 static inline void *dev_get_platdata(const struct device *dev) 816 { 817 return dev->platform_data; 818 } 819 820 /* 821 * Manual binding of a device to driver. See drivers/base/bus.c 822 * for information on use. 823 */ 824 extern int __must_check device_bind_driver(struct device *dev); 825 extern void device_release_driver(struct device *dev); 826 extern int __must_check device_attach(struct device *dev); 827 extern int __must_check driver_attach(struct device_driver *drv); 828 extern int __must_check device_reprobe(struct device *dev); 829 830 /* 831 * Easy functions for dynamically creating devices on the fly 832 */ 833 extern struct device *device_create_vargs(struct class *cls, 834 struct device *parent, 835 dev_t devt, 836 void *drvdata, 837 const char *fmt, 838 va_list vargs); 839 extern __printf(5, 6) 840 struct device *device_create(struct class *cls, struct device *parent, 841 dev_t devt, void *drvdata, 842 const char *fmt, ...); 843 extern void device_destroy(struct class *cls, dev_t devt); 844 845 /* 846 * Platform "fixup" functions - allow the platform to have their say 847 * about devices and actions that the general device layer doesn't 848 * know about. 849 */ 850 /* Notify platform of device discovery */ 851 extern int (*platform_notify)(struct device *dev); 852 853 extern int (*platform_notify_remove)(struct device *dev); 854 855 856 /* 857 * get_device - atomically increment the reference count for the device. 858 * 859 */ 860 extern struct device *get_device(struct device *dev); 861 extern void put_device(struct device *dev); 862 863 extern void wait_for_device_probe(void); 864 865 #ifdef CONFIG_DEVTMPFS 866 extern int devtmpfs_create_node(struct device *dev); 867 extern int devtmpfs_delete_node(struct device *dev); 868 extern int devtmpfs_mount(const char *mntdir); 869 #else 870 static inline int devtmpfs_create_node(struct device *dev) { return 0; } 871 static inline int devtmpfs_delete_node(struct device *dev) { return 0; } 872 static inline int devtmpfs_mount(const char *mountpoint) { return 0; } 873 #endif 874 875 /* drivers/base/power/shutdown.c */ 876 extern void device_shutdown(void); 877 878 /* debugging and troubleshooting/diagnostic helpers. */ 879 extern const char *dev_driver_string(const struct device *dev); 880 881 882 #ifdef CONFIG_PRINTK 883 884 extern int __dev_printk(const char *level, const struct device *dev, 885 struct va_format *vaf); 886 extern __printf(3, 4) 887 int dev_printk(const char *level, const struct device *dev, 888 const char *fmt, ...) 889 ; 890 extern __printf(2, 3) 891 int dev_emerg(const struct device *dev, const char *fmt, ...); 892 extern __printf(2, 3) 893 int dev_alert(const struct device *dev, const char *fmt, ...); 894 extern __printf(2, 3) 895 int dev_crit(const struct device *dev, const char *fmt, ...); 896 extern __printf(2, 3) 897 int dev_err(const struct device *dev, const char *fmt, ...); 898 extern __printf(2, 3) 899 int dev_warn(const struct device *dev, const char *fmt, ...); 900 extern __printf(2, 3) 901 int dev_notice(const struct device *dev, const char *fmt, ...); 902 extern __printf(2, 3) 903 int _dev_info(const struct device *dev, const char *fmt, ...); 904 905 #else 906 907 static inline int __dev_printk(const char *level, const struct device *dev, 908 struct va_format *vaf) 909 { return 0; } 910 static inline __printf(3, 4) 911 int dev_printk(const char *level, const struct device *dev, 912 const char *fmt, ...) 913 { return 0; } 914 915 static inline __printf(2, 3) 916 int dev_emerg(const struct device *dev, const char *fmt, ...) 917 { return 0; } 918 static inline __printf(2, 3) 919 int dev_crit(const struct device *dev, const char *fmt, ...) 920 { return 0; } 921 static inline __printf(2, 3) 922 int dev_alert(const struct device *dev, const char *fmt, ...) 923 { return 0; } 924 static inline __printf(2, 3) 925 int dev_err(const struct device *dev, const char *fmt, ...) 926 { return 0; } 927 static inline __printf(2, 3) 928 int dev_warn(const struct device *dev, const char *fmt, ...) 929 { return 0; } 930 static inline __printf(2, 3) 931 int dev_notice(const struct device *dev, const char *fmt, ...) 932 { return 0; } 933 static inline __printf(2, 3) 934 int _dev_info(const struct device *dev, const char *fmt, ...) 935 { return 0; } 936 937 #endif 938 939 /* 940 * Stupid hackaround for existing uses of non-printk uses dev_info 941 * 942 * Note that the definition of dev_info below is actually _dev_info 943 * and a macro is used to avoid redefining dev_info 944 */ 945 946 #define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg) 947 948 #if defined(DEBUG) 949 #define dev_dbg(dev, format, arg...) \ 950 dev_printk(KERN_DEBUG, dev, format, ##arg) 951 #elif defined(CONFIG_DYNAMIC_DEBUG) 952 #define dev_dbg(dev, format, ...) \ 953 do { \ 954 dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \ 955 } while (0) 956 #else 957 #define dev_dbg(dev, format, arg...) \ 958 ({ \ 959 if (0) \ 960 dev_printk(KERN_DEBUG, dev, format, ##arg); \ 961 0; \ 962 }) 963 #endif 964 965 #ifdef VERBOSE_DEBUG 966 #define dev_vdbg dev_dbg 967 #else 968 #define dev_vdbg(dev, format, arg...) \ 969 ({ \ 970 if (0) \ 971 dev_printk(KERN_DEBUG, dev, format, ##arg); \ 972 0; \ 973 }) 974 #endif 975 976 /* 977 * dev_WARN*() acts like dev_printk(), but with the key difference 978 * of using a WARN/WARN_ON to get the message out, including the 979 * file/line information and a backtrace. 980 */ 981 #define dev_WARN(dev, format, arg...) \ 982 WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg); 983 984 #define dev_WARN_ONCE(dev, condition, format, arg...) \ 985 WARN_ONCE(condition, "Device %s\n" format, \ 986 dev_driver_string(dev), ## arg) 987 988 /* Create alias, so I can be autoloaded. */ 989 #define MODULE_ALIAS_CHARDEV(major,minor) \ 990 MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor)) 991 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \ 992 MODULE_ALIAS("char-major-" __stringify(major) "-*") 993 994 #ifdef CONFIG_SYSFS_DEPRECATED 995 extern long sysfs_deprecated; 996 #else 997 #define sysfs_deprecated 0 998 #endif 999 1000 /** 1001 * module_driver() - Helper macro for drivers that don't do anything 1002 * special in module init/exit. This eliminates a lot of boilerplate. 1003 * Each module may only use this macro once, and calling it replaces 1004 * module_init() and module_exit(). 1005 * 1006 * Use this macro to construct bus specific macros for registering 1007 * drivers, and do not use it on its own. 1008 */ 1009 #define module_driver(__driver, __register, __unregister) \ 1010 static int __init __driver##_init(void) \ 1011 { \ 1012 return __register(&(__driver)); \ 1013 } \ 1014 module_init(__driver##_init); \ 1015 static void __exit __driver##_exit(void) \ 1016 { \ 1017 __unregister(&(__driver)); \ 1018 } \ 1019 module_exit(__driver##_exit); 1020 1021 #endif /* _DEVICE_H_ */ 1022