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 <linux/ratelimit.h> 27 #include <asm/device.h> 28 29 struct device; 30 struct device_private; 31 struct device_driver; 32 struct driver_private; 33 struct module; 34 struct class; 35 struct subsys_private; 36 struct bus_type; 37 struct device_node; 38 struct iommu_ops; 39 40 struct bus_attribute { 41 struct attribute attr; 42 ssize_t (*show)(struct bus_type *bus, char *buf); 43 ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count); 44 }; 45 46 #define BUS_ATTR(_name, _mode, _show, _store) \ 47 struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store) 48 49 extern int __must_check bus_create_file(struct bus_type *, 50 struct bus_attribute *); 51 extern void bus_remove_file(struct bus_type *, struct bus_attribute *); 52 53 /** 54 * struct bus_type - The bus type of the device 55 * 56 * @name: The name of the bus. 57 * @dev_name: Used for subsystems to enumerate devices like ("foo%u", dev->id). 58 * @dev_root: Default device to use as the parent. 59 * @bus_attrs: Default attributes of the bus. 60 * @dev_attrs: Default attributes of the devices on the bus. 61 * @drv_attrs: Default attributes of the device drivers on the bus. 62 * @match: Called, perhaps multiple times, whenever a new device or driver 63 * is added for this bus. It should return a nonzero value if the 64 * given device can be handled by the given driver. 65 * @uevent: Called when a device is added, removed, or a few other things 66 * that generate uevents to add the environment variables. 67 * @probe: Called when a new device or driver add to this bus, and callback 68 * the specific driver's probe to initial the matched device. 69 * @remove: Called when a device removed from this bus. 70 * @shutdown: Called at shut-down time to quiesce the device. 71 * @suspend: Called when a device on this bus wants to go to sleep mode. 72 * @resume: Called to bring a device on this bus out of sleep mode. 73 * @pm: Power management operations of this bus, callback the specific 74 * device driver's pm-ops. 75 * @iommu_ops: IOMMU specific operations for this bus, used to attach IOMMU 76 * driver implementations to a bus and allow the driver to do 77 * bus-specific setup 78 * @p: The private data of the driver core, only the driver core can 79 * touch this. 80 * 81 * A bus is a channel between the processor and one or more devices. For the 82 * purposes of the device model, all devices are connected via a bus, even if 83 * it is an internal, virtual, "platform" bus. Buses can plug into each other. 84 * A USB controller is usually a PCI device, for example. The device model 85 * represents the actual connections between buses and the devices they control. 86 * A bus is represented by the bus_type structure. It contains the name, the 87 * default attributes, the bus' methods, PM operations, and the driver core's 88 * private data. 89 */ 90 struct bus_type { 91 const char *name; 92 const char *dev_name; 93 struct device *dev_root; 94 struct bus_attribute *bus_attrs; 95 struct device_attribute *dev_attrs; 96 struct driver_attribute *drv_attrs; 97 98 int (*match)(struct device *dev, struct device_driver *drv); 99 int (*uevent)(struct device *dev, struct kobj_uevent_env *env); 100 int (*probe)(struct device *dev); 101 int (*remove)(struct device *dev); 102 void (*shutdown)(struct device *dev); 103 104 int (*suspend)(struct device *dev, pm_message_t state); 105 int (*resume)(struct device *dev); 106 107 const struct dev_pm_ops *pm; 108 109 struct iommu_ops *iommu_ops; 110 111 struct subsys_private *p; 112 }; 113 114 /* This is a #define to keep the compiler from merging different 115 * instances of the __key variable */ 116 #define bus_register(subsys) \ 117 ({ \ 118 static struct lock_class_key __key; \ 119 __bus_register(subsys, &__key); \ 120 }) 121 extern int __must_check __bus_register(struct bus_type *bus, 122 struct lock_class_key *key); 123 extern void bus_unregister(struct bus_type *bus); 124 125 extern int __must_check bus_rescan_devices(struct bus_type *bus); 126 127 /* iterator helpers for buses */ 128 struct subsys_dev_iter { 129 struct klist_iter ki; 130 const struct device_type *type; 131 }; 132 void subsys_dev_iter_init(struct subsys_dev_iter *iter, 133 struct bus_type *subsys, 134 struct device *start, 135 const struct device_type *type); 136 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter); 137 void subsys_dev_iter_exit(struct subsys_dev_iter *iter); 138 139 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data, 140 int (*fn)(struct device *dev, void *data)); 141 struct device *bus_find_device(struct bus_type *bus, struct device *start, 142 void *data, 143 int (*match)(struct device *dev, void *data)); 144 struct device *bus_find_device_by_name(struct bus_type *bus, 145 struct device *start, 146 const char *name); 147 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id, 148 struct device *hint); 149 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start, 150 void *data, int (*fn)(struct device_driver *, void *)); 151 void bus_sort_breadthfirst(struct bus_type *bus, 152 int (*compare)(const struct device *a, 153 const struct device *b)); 154 /* 155 * Bus notifiers: Get notified of addition/removal of devices 156 * and binding/unbinding of drivers to devices. 157 * In the long run, it should be a replacement for the platform 158 * notify hooks. 159 */ 160 struct notifier_block; 161 162 extern int bus_register_notifier(struct bus_type *bus, 163 struct notifier_block *nb); 164 extern int bus_unregister_notifier(struct bus_type *bus, 165 struct notifier_block *nb); 166 167 /* All 4 notifers below get called with the target struct device * 168 * as an argument. Note that those functions are likely to be called 169 * with the device lock held in the core, so be careful. 170 */ 171 #define BUS_NOTIFY_ADD_DEVICE 0x00000001 /* device added */ 172 #define BUS_NOTIFY_DEL_DEVICE 0x00000002 /* device removed */ 173 #define BUS_NOTIFY_BIND_DRIVER 0x00000003 /* driver about to be 174 bound */ 175 #define BUS_NOTIFY_BOUND_DRIVER 0x00000004 /* driver bound to device */ 176 #define BUS_NOTIFY_UNBIND_DRIVER 0x00000005 /* driver about to be 177 unbound */ 178 #define BUS_NOTIFY_UNBOUND_DRIVER 0x00000006 /* driver is unbound 179 from the device */ 180 181 extern struct kset *bus_get_kset(struct bus_type *bus); 182 extern struct klist *bus_get_device_klist(struct bus_type *bus); 183 184 /** 185 * struct device_driver - The basic device driver structure 186 * @name: Name of the device driver. 187 * @bus: The bus which the device of this driver belongs to. 188 * @owner: The module owner. 189 * @mod_name: Used for built-in modules. 190 * @suppress_bind_attrs: Disables bind/unbind via sysfs. 191 * @of_match_table: The open firmware table. 192 * @probe: Called to query the existence of a specific device, 193 * whether this driver can work with it, and bind the driver 194 * to a specific device. 195 * @remove: Called when the device is removed from the system to 196 * unbind a device from this driver. 197 * @shutdown: Called at shut-down time to quiesce the device. 198 * @suspend: Called to put the device to sleep mode. Usually to a 199 * low power state. 200 * @resume: Called to bring a device from sleep mode. 201 * @groups: Default attributes that get created by the driver core 202 * automatically. 203 * @pm: Power management operations of the device which matched 204 * this driver. 205 * @p: Driver core's private data, no one other than the driver 206 * core can touch this. 207 * 208 * The device driver-model tracks all of the drivers known to the system. 209 * The main reason for this tracking is to enable the driver core to match 210 * up drivers with new devices. Once drivers are known objects within the 211 * system, however, a number of other things become possible. Device drivers 212 * can export information and configuration variables that are independent 213 * of any specific device. 214 */ 215 struct device_driver { 216 const char *name; 217 struct bus_type *bus; 218 219 struct module *owner; 220 const char *mod_name; /* used for built-in modules */ 221 222 bool suppress_bind_attrs; /* disables bind/unbind via sysfs */ 223 224 const struct of_device_id *of_match_table; 225 226 int (*probe) (struct device *dev); 227 int (*remove) (struct device *dev); 228 void (*shutdown) (struct device *dev); 229 int (*suspend) (struct device *dev, pm_message_t state); 230 int (*resume) (struct device *dev); 231 const struct attribute_group **groups; 232 233 const struct dev_pm_ops *pm; 234 235 struct driver_private *p; 236 }; 237 238 239 extern int __must_check driver_register(struct device_driver *drv); 240 extern void driver_unregister(struct device_driver *drv); 241 242 extern struct device_driver *driver_find(const char *name, 243 struct bus_type *bus); 244 extern int driver_probe_done(void); 245 extern void wait_for_device_probe(void); 246 247 248 /* sysfs interface for exporting driver attributes */ 249 250 struct driver_attribute { 251 struct attribute attr; 252 ssize_t (*show)(struct device_driver *driver, char *buf); 253 ssize_t (*store)(struct device_driver *driver, const char *buf, 254 size_t count); 255 }; 256 257 #define DRIVER_ATTR(_name, _mode, _show, _store) \ 258 struct driver_attribute driver_attr_##_name = \ 259 __ATTR(_name, _mode, _show, _store) 260 261 extern int __must_check driver_create_file(struct device_driver *driver, 262 const struct driver_attribute *attr); 263 extern void driver_remove_file(struct device_driver *driver, 264 const struct driver_attribute *attr); 265 266 extern int __must_check driver_for_each_device(struct device_driver *drv, 267 struct device *start, 268 void *data, 269 int (*fn)(struct device *dev, 270 void *)); 271 struct device *driver_find_device(struct device_driver *drv, 272 struct device *start, void *data, 273 int (*match)(struct device *dev, void *data)); 274 275 /** 276 * struct subsys_interface - interfaces to device functions 277 * @name: name of the device function 278 * @subsys: subsytem of the devices to attach to 279 * @node: the list of functions registered at the subsystem 280 * @add_dev: device hookup to device function handler 281 * @remove_dev: device hookup to device function handler 282 * 283 * Simple interfaces attached to a subsystem. Multiple interfaces can 284 * attach to a subsystem and its devices. Unlike drivers, they do not 285 * exclusively claim or control devices. Interfaces usually represent 286 * a specific functionality of a subsystem/class of devices. 287 */ 288 struct subsys_interface { 289 const char *name; 290 struct bus_type *subsys; 291 struct list_head node; 292 int (*add_dev)(struct device *dev, struct subsys_interface *sif); 293 int (*remove_dev)(struct device *dev, struct subsys_interface *sif); 294 }; 295 296 int subsys_interface_register(struct subsys_interface *sif); 297 void subsys_interface_unregister(struct subsys_interface *sif); 298 299 int subsys_system_register(struct bus_type *subsys, 300 const struct attribute_group **groups); 301 302 /** 303 * struct class - device classes 304 * @name: Name of the class. 305 * @owner: The module owner. 306 * @class_attrs: Default attributes of this class. 307 * @dev_attrs: Default attributes of the devices belong to the class. 308 * @dev_bin_attrs: Default binary attributes of the devices belong to the class. 309 * @dev_kobj: The kobject that represents this class and links it into the hierarchy. 310 * @dev_uevent: Called when a device is added, removed from this class, or a 311 * few other things that generate uevents to add the environment 312 * variables. 313 * @devnode: Callback to provide the devtmpfs. 314 * @class_release: Called to release this class. 315 * @dev_release: Called to release the device. 316 * @suspend: Used to put the device to sleep mode, usually to a low power 317 * state. 318 * @resume: Used to bring the device from the sleep mode. 319 * @ns_type: Callbacks so sysfs can detemine namespaces. 320 * @namespace: Namespace of the device belongs to this class. 321 * @pm: The default device power management operations of this class. 322 * @p: The private data of the driver core, no one other than the 323 * driver core can touch this. 324 * 325 * A class is a higher-level view of a device that abstracts out low-level 326 * implementation details. Drivers may see a SCSI disk or an ATA disk, but, 327 * at the class level, they are all simply disks. Classes allow user space 328 * to work with devices based on what they do, rather than how they are 329 * connected or how they work. 330 */ 331 struct class { 332 const char *name; 333 struct module *owner; 334 335 struct class_attribute *class_attrs; 336 struct device_attribute *dev_attrs; 337 struct bin_attribute *dev_bin_attrs; 338 struct kobject *dev_kobj; 339 340 int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env); 341 char *(*devnode)(struct device *dev, umode_t *mode); 342 343 void (*class_release)(struct class *class); 344 void (*dev_release)(struct device *dev); 345 346 int (*suspend)(struct device *dev, pm_message_t state); 347 int (*resume)(struct device *dev); 348 349 const struct kobj_ns_type_operations *ns_type; 350 const void *(*namespace)(struct device *dev); 351 352 const struct dev_pm_ops *pm; 353 354 struct subsys_private *p; 355 }; 356 357 struct class_dev_iter { 358 struct klist_iter ki; 359 const struct device_type *type; 360 }; 361 362 extern struct kobject *sysfs_dev_block_kobj; 363 extern struct kobject *sysfs_dev_char_kobj; 364 extern int __must_check __class_register(struct class *class, 365 struct lock_class_key *key); 366 extern void class_unregister(struct class *class); 367 368 /* This is a #define to keep the compiler from merging different 369 * instances of the __key variable */ 370 #define class_register(class) \ 371 ({ \ 372 static struct lock_class_key __key; \ 373 __class_register(class, &__key); \ 374 }) 375 376 struct class_compat; 377 struct class_compat *class_compat_register(const char *name); 378 void class_compat_unregister(struct class_compat *cls); 379 int class_compat_create_link(struct class_compat *cls, struct device *dev, 380 struct device *device_link); 381 void class_compat_remove_link(struct class_compat *cls, struct device *dev, 382 struct device *device_link); 383 384 extern void class_dev_iter_init(struct class_dev_iter *iter, 385 struct class *class, 386 struct device *start, 387 const struct device_type *type); 388 extern struct device *class_dev_iter_next(struct class_dev_iter *iter); 389 extern void class_dev_iter_exit(struct class_dev_iter *iter); 390 391 extern int class_for_each_device(struct class *class, struct device *start, 392 void *data, 393 int (*fn)(struct device *dev, void *data)); 394 extern struct device *class_find_device(struct class *class, 395 struct device *start, void *data, 396 int (*match)(struct device *, void *)); 397 398 struct class_attribute { 399 struct attribute attr; 400 ssize_t (*show)(struct class *class, struct class_attribute *attr, 401 char *buf); 402 ssize_t (*store)(struct class *class, struct class_attribute *attr, 403 const char *buf, size_t count); 404 const void *(*namespace)(struct class *class, 405 const struct class_attribute *attr); 406 }; 407 408 #define CLASS_ATTR(_name, _mode, _show, _store) \ 409 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store) 410 411 extern int __must_check class_create_file(struct class *class, 412 const struct class_attribute *attr); 413 extern void class_remove_file(struct class *class, 414 const struct class_attribute *attr); 415 416 /* Simple class attribute that is just a static string */ 417 418 struct class_attribute_string { 419 struct class_attribute attr; 420 char *str; 421 }; 422 423 /* Currently read-only only */ 424 #define _CLASS_ATTR_STRING(_name, _mode, _str) \ 425 { __ATTR(_name, _mode, show_class_attr_string, NULL), _str } 426 #define CLASS_ATTR_STRING(_name, _mode, _str) \ 427 struct class_attribute_string class_attr_##_name = \ 428 _CLASS_ATTR_STRING(_name, _mode, _str) 429 430 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr, 431 char *buf); 432 433 struct class_interface { 434 struct list_head node; 435 struct class *class; 436 437 int (*add_dev) (struct device *, struct class_interface *); 438 void (*remove_dev) (struct device *, struct class_interface *); 439 }; 440 441 extern int __must_check class_interface_register(struct class_interface *); 442 extern void class_interface_unregister(struct class_interface *); 443 444 extern struct class * __must_check __class_create(struct module *owner, 445 const char *name, 446 struct lock_class_key *key); 447 extern void class_destroy(struct class *cls); 448 449 /* This is a #define to keep the compiler from merging different 450 * instances of the __key variable */ 451 #define class_create(owner, name) \ 452 ({ \ 453 static struct lock_class_key __key; \ 454 __class_create(owner, name, &__key); \ 455 }) 456 457 /* 458 * The type of device, "struct device" is embedded in. A class 459 * or bus can contain devices of different types 460 * like "partitions" and "disks", "mouse" and "event". 461 * This identifies the device type and carries type-specific 462 * information, equivalent to the kobj_type of a kobject. 463 * If "name" is specified, the uevent will contain it in 464 * the DEVTYPE variable. 465 */ 466 struct device_type { 467 const char *name; 468 const struct attribute_group **groups; 469 int (*uevent)(struct device *dev, struct kobj_uevent_env *env); 470 char *(*devnode)(struct device *dev, umode_t *mode); 471 void (*release)(struct device *dev); 472 473 const struct dev_pm_ops *pm; 474 }; 475 476 /* interface for exporting device attributes */ 477 struct device_attribute { 478 struct attribute attr; 479 ssize_t (*show)(struct device *dev, struct device_attribute *attr, 480 char *buf); 481 ssize_t (*store)(struct device *dev, struct device_attribute *attr, 482 const char *buf, size_t count); 483 }; 484 485 struct dev_ext_attribute { 486 struct device_attribute attr; 487 void *var; 488 }; 489 490 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr, 491 char *buf); 492 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr, 493 const char *buf, size_t count); 494 ssize_t device_show_int(struct device *dev, struct device_attribute *attr, 495 char *buf); 496 ssize_t device_store_int(struct device *dev, struct device_attribute *attr, 497 const char *buf, size_t count); 498 499 #define DEVICE_ATTR(_name, _mode, _show, _store) \ 500 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store) 501 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \ 502 struct dev_ext_attribute dev_attr_##_name = \ 503 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) } 504 #define DEVICE_INT_ATTR(_name, _mode, _var) \ 505 struct dev_ext_attribute dev_attr_##_name = \ 506 { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) } 507 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \ 508 struct device_attribute dev_attr_##_name = \ 509 __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) 510 511 extern int device_create_file(struct device *device, 512 const struct device_attribute *entry); 513 extern void device_remove_file(struct device *dev, 514 const struct device_attribute *attr); 515 extern int __must_check device_create_bin_file(struct device *dev, 516 const struct bin_attribute *attr); 517 extern void device_remove_bin_file(struct device *dev, 518 const struct bin_attribute *attr); 519 extern int device_schedule_callback_owner(struct device *dev, 520 void (*func)(struct device *dev), struct module *owner); 521 522 /* This is a macro to avoid include problems with THIS_MODULE */ 523 #define device_schedule_callback(dev, func) \ 524 device_schedule_callback_owner(dev, func, THIS_MODULE) 525 526 /* device resource management */ 527 typedef void (*dr_release_t)(struct device *dev, void *res); 528 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data); 529 530 #ifdef CONFIG_DEBUG_DEVRES 531 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp, 532 const char *name); 533 #define devres_alloc(release, size, gfp) \ 534 __devres_alloc(release, size, gfp, #release) 535 #else 536 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp); 537 #endif 538 extern void devres_free(void *res); 539 extern void devres_add(struct device *dev, void *res); 540 extern void *devres_find(struct device *dev, dr_release_t release, 541 dr_match_t match, void *match_data); 542 extern void *devres_get(struct device *dev, void *new_res, 543 dr_match_t match, void *match_data); 544 extern void *devres_remove(struct device *dev, dr_release_t release, 545 dr_match_t match, void *match_data); 546 extern int devres_destroy(struct device *dev, dr_release_t release, 547 dr_match_t match, void *match_data); 548 extern int devres_release(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 * @id: device instance 616 * @devres_lock: Spinlock to protect the resource of the device. 617 * @devres_head: The resources list of the device. 618 * @knode_class: The node used to add the device to the class list. 619 * @class: The class of the device. 620 * @groups: Optional attribute groups. 621 * @release: Callback to free the device after all references have 622 * gone away. This should be set by the allocator of the 623 * device (i.e. the bus driver that discovered the device). 624 * 625 * At the lowest level, every device in a Linux system is represented by an 626 * instance of struct device. The device structure contains the information 627 * that the device model core needs to model the system. Most subsystems, 628 * however, track additional information about the devices they host. As a 629 * result, it is rare for devices to be represented by bare device structures; 630 * instead, that structure, like kobject structures, is usually embedded within 631 * a higher-level representation of the device. 632 */ 633 struct device { 634 struct device *parent; 635 636 struct device_private *p; 637 638 struct kobject kobj; 639 const char *init_name; /* initial name of the device */ 640 const struct device_type *type; 641 642 struct mutex mutex; /* mutex to synchronize calls to 643 * its driver. 644 */ 645 646 struct bus_type *bus; /* type of bus device is on */ 647 struct device_driver *driver; /* which driver has allocated this 648 device */ 649 void *platform_data; /* Platform specific data, device 650 core doesn't touch it */ 651 struct dev_pm_info power; 652 struct dev_pm_domain *pm_domain; 653 654 #ifdef CONFIG_NUMA 655 int numa_node; /* NUMA node this device is close to */ 656 #endif 657 u64 *dma_mask; /* dma mask (if dma'able device) */ 658 u64 coherent_dma_mask;/* Like dma_mask, but for 659 alloc_coherent mappings as 660 not all hardware supports 661 64 bit addresses for consistent 662 allocations such descriptors. */ 663 664 struct device_dma_parameters *dma_parms; 665 666 struct list_head dma_pools; /* dma pools (if dma'ble) */ 667 668 struct dma_coherent_mem *dma_mem; /* internal for coherent mem 669 override */ 670 #ifdef CONFIG_CMA 671 struct cma *cma_area; /* contiguous memory area for dma 672 allocations */ 673 #endif 674 /* arch specific additions */ 675 struct dev_archdata archdata; 676 677 struct device_node *of_node; /* associated device tree node */ 678 679 dev_t devt; /* dev_t, creates the sysfs "dev" */ 680 u32 id; /* device instance */ 681 682 spinlock_t devres_lock; 683 struct list_head devres_head; 684 685 struct klist_node knode_class; 686 struct class *class; 687 const struct attribute_group **groups; /* optional groups */ 688 689 void (*release)(struct device *dev); 690 }; 691 692 /* Get the wakeup routines, which depend on struct device */ 693 #include <linux/pm_wakeup.h> 694 695 static inline const char *dev_name(const struct device *dev) 696 { 697 /* Use the init name until the kobject becomes available */ 698 if (dev->init_name) 699 return dev->init_name; 700 701 return kobject_name(&dev->kobj); 702 } 703 704 extern __printf(2, 3) 705 int dev_set_name(struct device *dev, const char *name, ...); 706 707 #ifdef CONFIG_NUMA 708 static inline int dev_to_node(struct device *dev) 709 { 710 return dev->numa_node; 711 } 712 static inline void set_dev_node(struct device *dev, int node) 713 { 714 dev->numa_node = node; 715 } 716 #else 717 static inline int dev_to_node(struct device *dev) 718 { 719 return -1; 720 } 721 static inline void set_dev_node(struct device *dev, int node) 722 { 723 } 724 #endif 725 726 static inline struct pm_subsys_data *dev_to_psd(struct device *dev) 727 { 728 return dev ? dev->power.subsys_data : NULL; 729 } 730 731 static inline unsigned int dev_get_uevent_suppress(const struct device *dev) 732 { 733 return dev->kobj.uevent_suppress; 734 } 735 736 static inline void dev_set_uevent_suppress(struct device *dev, int val) 737 { 738 dev->kobj.uevent_suppress = val; 739 } 740 741 static inline int device_is_registered(struct device *dev) 742 { 743 return dev->kobj.state_in_sysfs; 744 } 745 746 static inline void device_enable_async_suspend(struct device *dev) 747 { 748 if (!dev->power.is_prepared) 749 dev->power.async_suspend = true; 750 } 751 752 static inline void device_disable_async_suspend(struct device *dev) 753 { 754 if (!dev->power.is_prepared) 755 dev->power.async_suspend = false; 756 } 757 758 static inline bool device_async_suspend_enabled(struct device *dev) 759 { 760 return !!dev->power.async_suspend; 761 } 762 763 static inline void pm_suspend_ignore_children(struct device *dev, bool enable) 764 { 765 dev->power.ignore_children = enable; 766 } 767 768 static inline void device_lock(struct device *dev) 769 { 770 mutex_lock(&dev->mutex); 771 } 772 773 static inline int device_trylock(struct device *dev) 774 { 775 return mutex_trylock(&dev->mutex); 776 } 777 778 static inline void device_unlock(struct device *dev) 779 { 780 mutex_unlock(&dev->mutex); 781 } 782 783 void driver_init(void); 784 785 /* 786 * High level routines for use by the bus drivers 787 */ 788 extern int __must_check device_register(struct device *dev); 789 extern void device_unregister(struct device *dev); 790 extern void device_initialize(struct device *dev); 791 extern int __must_check device_add(struct device *dev); 792 extern void device_del(struct device *dev); 793 extern int device_for_each_child(struct device *dev, void *data, 794 int (*fn)(struct device *dev, void *data)); 795 extern struct device *device_find_child(struct device *dev, void *data, 796 int (*match)(struct device *dev, void *data)); 797 extern int device_rename(struct device *dev, const char *new_name); 798 extern int device_move(struct device *dev, struct device *new_parent, 799 enum dpm_order dpm_order); 800 extern const char *device_get_devnode(struct device *dev, 801 umode_t *mode, const char **tmp); 802 extern void *dev_get_drvdata(const struct device *dev); 803 extern int dev_set_drvdata(struct device *dev, void *data); 804 805 /* 806 * Root device objects for grouping under /sys/devices 807 */ 808 extern struct device *__root_device_register(const char *name, 809 struct module *owner); 810 811 /* 812 * This is a macro to avoid include problems with THIS_MODULE, 813 * just as per what is done for device_schedule_callback() above. 814 */ 815 #define root_device_register(name) \ 816 __root_device_register(name, THIS_MODULE) 817 818 extern void root_device_unregister(struct device *root); 819 820 static inline void *dev_get_platdata(const struct device *dev) 821 { 822 return dev->platform_data; 823 } 824 825 /* 826 * Manual binding of a device to driver. See drivers/base/bus.c 827 * for information on use. 828 */ 829 extern int __must_check device_bind_driver(struct device *dev); 830 extern void device_release_driver(struct device *dev); 831 extern int __must_check device_attach(struct device *dev); 832 extern int __must_check driver_attach(struct device_driver *drv); 833 extern int __must_check device_reprobe(struct device *dev); 834 835 /* 836 * Easy functions for dynamically creating devices on the fly 837 */ 838 extern struct device *device_create_vargs(struct class *cls, 839 struct device *parent, 840 dev_t devt, 841 void *drvdata, 842 const char *fmt, 843 va_list vargs); 844 extern __printf(5, 6) 845 struct device *device_create(struct class *cls, struct device *parent, 846 dev_t devt, void *drvdata, 847 const char *fmt, ...); 848 extern void device_destroy(struct class *cls, dev_t devt); 849 850 /* 851 * Platform "fixup" functions - allow the platform to have their say 852 * about devices and actions that the general device layer doesn't 853 * know about. 854 */ 855 /* Notify platform of device discovery */ 856 extern int (*platform_notify)(struct device *dev); 857 858 extern int (*platform_notify_remove)(struct device *dev); 859 860 861 /* 862 * get_device - atomically increment the reference count for the device. 863 * 864 */ 865 extern struct device *get_device(struct device *dev); 866 extern void put_device(struct device *dev); 867 868 extern void wait_for_device_probe(void); 869 870 #ifdef CONFIG_DEVTMPFS 871 extern int devtmpfs_create_node(struct device *dev); 872 extern int devtmpfs_delete_node(struct device *dev); 873 extern int devtmpfs_mount(const char *mntdir); 874 #else 875 static inline int devtmpfs_create_node(struct device *dev) { return 0; } 876 static inline int devtmpfs_delete_node(struct device *dev) { return 0; } 877 static inline int devtmpfs_mount(const char *mountpoint) { return 0; } 878 #endif 879 880 /* drivers/base/power/shutdown.c */ 881 extern void device_shutdown(void); 882 883 /* debugging and troubleshooting/diagnostic helpers. */ 884 extern const char *dev_driver_string(const struct device *dev); 885 886 887 #ifdef CONFIG_PRINTK 888 889 extern int __dev_printk(const char *level, const struct device *dev, 890 struct va_format *vaf); 891 extern __printf(3, 4) 892 int dev_printk(const char *level, const struct device *dev, 893 const char *fmt, ...) 894 ; 895 extern __printf(2, 3) 896 int dev_emerg(const struct device *dev, const char *fmt, ...); 897 extern __printf(2, 3) 898 int dev_alert(const struct device *dev, const char *fmt, ...); 899 extern __printf(2, 3) 900 int dev_crit(const struct device *dev, const char *fmt, ...); 901 extern __printf(2, 3) 902 int dev_err(const struct device *dev, const char *fmt, ...); 903 extern __printf(2, 3) 904 int dev_warn(const struct device *dev, const char *fmt, ...); 905 extern __printf(2, 3) 906 int dev_notice(const struct device *dev, const char *fmt, ...); 907 extern __printf(2, 3) 908 int _dev_info(const struct device *dev, const char *fmt, ...); 909 910 #else 911 912 static inline int __dev_printk(const char *level, const struct device *dev, 913 struct va_format *vaf) 914 { return 0; } 915 static inline __printf(3, 4) 916 int dev_printk(const char *level, const struct device *dev, 917 const char *fmt, ...) 918 { return 0; } 919 920 static inline __printf(2, 3) 921 int dev_emerg(const struct device *dev, const char *fmt, ...) 922 { return 0; } 923 static inline __printf(2, 3) 924 int dev_crit(const struct device *dev, const char *fmt, ...) 925 { return 0; } 926 static inline __printf(2, 3) 927 int dev_alert(const struct device *dev, const char *fmt, ...) 928 { return 0; } 929 static inline __printf(2, 3) 930 int dev_err(const struct device *dev, const char *fmt, ...) 931 { return 0; } 932 static inline __printf(2, 3) 933 int dev_warn(const struct device *dev, const char *fmt, ...) 934 { return 0; } 935 static inline __printf(2, 3) 936 int dev_notice(const struct device *dev, const char *fmt, ...) 937 { return 0; } 938 static inline __printf(2, 3) 939 int _dev_info(const struct device *dev, const char *fmt, ...) 940 { return 0; } 941 942 #endif 943 944 #define dev_level_ratelimited(dev_level, dev, fmt, ...) \ 945 do { \ 946 static DEFINE_RATELIMIT_STATE(_rs, \ 947 DEFAULT_RATELIMIT_INTERVAL, \ 948 DEFAULT_RATELIMIT_BURST); \ 949 if (__ratelimit(&_rs)) \ 950 dev_level(dev, fmt, ##__VA_ARGS__); \ 951 } while (0) 952 953 #define dev_emerg_ratelimited(dev, fmt, ...) \ 954 dev_level_ratelimited(dev_emerg, dev, fmt, ##__VA_ARGS__) 955 #define dev_alert_ratelimited(dev, fmt, ...) \ 956 dev_level_ratelimited(dev_alert, dev, fmt, ##__VA_ARGS__) 957 #define dev_crit_ratelimited(dev, fmt, ...) \ 958 dev_level_ratelimited(dev_crit, dev, fmt, ##__VA_ARGS__) 959 #define dev_err_ratelimited(dev, fmt, ...) \ 960 dev_level_ratelimited(dev_err, dev, fmt, ##__VA_ARGS__) 961 #define dev_warn_ratelimited(dev, fmt, ...) \ 962 dev_level_ratelimited(dev_warn, dev, fmt, ##__VA_ARGS__) 963 #define dev_notice_ratelimited(dev, fmt, ...) \ 964 dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__) 965 #define dev_info_ratelimited(dev, fmt, ...) \ 966 dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__) 967 #define dev_dbg_ratelimited(dev, fmt, ...) \ 968 dev_level_ratelimited(dev_dbg, dev, fmt, ##__VA_ARGS__) 969 970 /* 971 * Stupid hackaround for existing uses of non-printk uses dev_info 972 * 973 * Note that the definition of dev_info below is actually _dev_info 974 * and a macro is used to avoid redefining dev_info 975 */ 976 977 #define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg) 978 979 #if defined(CONFIG_DYNAMIC_DEBUG) 980 #define dev_dbg(dev, format, ...) \ 981 do { \ 982 dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \ 983 } while (0) 984 #elif defined(DEBUG) 985 #define dev_dbg(dev, format, arg...) \ 986 dev_printk(KERN_DEBUG, dev, format, ##arg) 987 #else 988 #define dev_dbg(dev, format, arg...) \ 989 ({ \ 990 if (0) \ 991 dev_printk(KERN_DEBUG, dev, format, ##arg); \ 992 0; \ 993 }) 994 #endif 995 996 #ifdef VERBOSE_DEBUG 997 #define dev_vdbg dev_dbg 998 #else 999 #define dev_vdbg(dev, format, arg...) \ 1000 ({ \ 1001 if (0) \ 1002 dev_printk(KERN_DEBUG, dev, format, ##arg); \ 1003 0; \ 1004 }) 1005 #endif 1006 1007 /* 1008 * dev_WARN*() acts like dev_printk(), but with the key difference 1009 * of using a WARN/WARN_ON to get the message out, including the 1010 * file/line information and a backtrace. 1011 */ 1012 #define dev_WARN(dev, format, arg...) \ 1013 WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg); 1014 1015 #define dev_WARN_ONCE(dev, condition, format, arg...) \ 1016 WARN_ONCE(condition, "Device %s\n" format, \ 1017 dev_driver_string(dev), ## arg) 1018 1019 /* Create alias, so I can be autoloaded. */ 1020 #define MODULE_ALIAS_CHARDEV(major,minor) \ 1021 MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor)) 1022 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \ 1023 MODULE_ALIAS("char-major-" __stringify(major) "-*") 1024 1025 #ifdef CONFIG_SYSFS_DEPRECATED 1026 extern long sysfs_deprecated; 1027 #else 1028 #define sysfs_deprecated 0 1029 #endif 1030 1031 /** 1032 * module_driver() - Helper macro for drivers that don't do anything 1033 * special in module init/exit. This eliminates a lot of boilerplate. 1034 * Each module may only use this macro once, and calling it replaces 1035 * module_init() and module_exit(). 1036 * 1037 * @__driver: driver name 1038 * @__register: register function for this driver type 1039 * @__unregister: unregister function for this driver type 1040 * @...: Additional arguments to be passed to __register and __unregister. 1041 * 1042 * Use this macro to construct bus specific macros for registering 1043 * drivers, and do not use it on its own. 1044 */ 1045 #define module_driver(__driver, __register, __unregister, ...) \ 1046 static int __init __driver##_init(void) \ 1047 { \ 1048 return __register(&(__driver) , ##__VA_ARGS__); \ 1049 } \ 1050 module_init(__driver##_init); \ 1051 static void __exit __driver##_exit(void) \ 1052 { \ 1053 __unregister(&(__driver) , ##__VA_ARGS__); \ 1054 } \ 1055 module_exit(__driver##_exit); 1056 1057 #endif /* _DEVICE_H_ */ 1058