2 * device.h - generic, centralized driver model
6 * Copyright (c) 2008-2009 Novell Inc.
8 * This file is released under the GPLv2
10 * See Documentation/driver-model/ for more information.
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/pinctrl/devinfo.h>
26 #include <linux/atomic.h>
27 #include <linux/ratelimit.h>
28 #include <linux/uidgid.h>
29 #include <linux/gfp.h>
30 #include <asm/device.h>
33 struct device_private;
35 struct driver_private;
38 struct subsys_private;
45 struct bus_attribute {
46 struct attribute attr;
47 ssize_t (*show)(struct bus_type *bus, char *buf);
48 ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
51 #define BUS_ATTR(_name, _mode, _show, _store) \
52 struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
53 #define BUS_ATTR_RW(_name) \
54 struct bus_attribute bus_attr_##_name = __ATTR_RW(_name)
55 #define BUS_ATTR_RO(_name) \
56 struct bus_attribute bus_attr_##_name = __ATTR_RO(_name)
58 extern int __must_check bus_create_file(struct bus_type *,
59 struct bus_attribute *);
60 extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
63 * struct bus_type - The bus type of the device
65 * @name: The name of the bus.
66 * @dev_name: Used for subsystems to enumerate devices like ("foo%u", dev->id).
67 * @dev_root: Default device to use as the parent.
68 * @dev_attrs: Default attributes of the devices on the bus.
69 * @bus_groups: Default attributes of the bus.
70 * @dev_groups: Default attributes of the devices on the bus.
71 * @drv_groups: Default attributes of the device drivers on the bus.
72 * @match: Called, perhaps multiple times, whenever a new device or driver
73 * is added for this bus. It should return a nonzero value if the
74 * given device can be handled by the given driver.
75 * @uevent: Called when a device is added, removed, or a few other things
76 * that generate uevents to add the environment variables.
77 * @probe: Called when a new device or driver add to this bus, and callback
78 * the specific driver's probe to initial the matched device.
79 * @remove: Called when a device removed from this bus.
80 * @shutdown: Called at shut-down time to quiesce the device.
82 * @online: Called to put the device back online (after offlining it).
83 * @offline: Called to put the device offline for hot-removal. May fail.
85 * @suspend: Called when a device on this bus wants to go to sleep mode.
86 * @resume: Called to bring a device on this bus out of sleep mode.
87 * @pm: Power management operations of this bus, callback the specific
88 * device driver's pm-ops.
89 * @iommu_ops: IOMMU specific operations for this bus, used to attach IOMMU
90 * driver implementations to a bus and allow the driver to do
92 * @p: The private data of the driver core, only the driver core can
94 * @lock_key: Lock class key for use by the lock validator
96 * A bus is a channel between the processor and one or more devices. For the
97 * purposes of the device model, all devices are connected via a bus, even if
98 * it is an internal, virtual, "platform" bus. Buses can plug into each other.
99 * A USB controller is usually a PCI device, for example. The device model
100 * represents the actual connections between buses and the devices they control.
101 * A bus is represented by the bus_type structure. It contains the name, the
102 * default attributes, the bus' methods, PM operations, and the driver core's
107 const char *dev_name;
108 struct device *dev_root;
109 struct device_attribute *dev_attrs; /* use dev_groups instead */
110 const struct attribute_group **bus_groups;
111 const struct attribute_group **dev_groups;
112 const struct attribute_group **drv_groups;
114 int (*match)(struct device *dev, struct device_driver *drv);
115 int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
116 int (*probe)(struct device *dev);
117 int (*remove)(struct device *dev);
118 void (*shutdown)(struct device *dev);
120 int (*online)(struct device *dev);
121 int (*offline)(struct device *dev);
123 int (*suspend)(struct device *dev, pm_message_t state);
124 int (*resume)(struct device *dev);
126 const struct dev_pm_ops *pm;
128 const struct iommu_ops *iommu_ops;
130 struct subsys_private *p;
131 struct lock_class_key lock_key;
134 extern int __must_check bus_register(struct bus_type *bus);
136 extern void bus_unregister(struct bus_type *bus);
138 extern int __must_check bus_rescan_devices(struct bus_type *bus);
140 /* iterator helpers for buses */
141 struct subsys_dev_iter {
142 struct klist_iter ki;
143 const struct device_type *type;
145 void subsys_dev_iter_init(struct subsys_dev_iter *iter,
146 struct bus_type *subsys,
147 struct device *start,
148 const struct device_type *type);
149 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
150 void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
152 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
153 int (*fn)(struct device *dev, void *data));
154 struct device *bus_find_device(struct bus_type *bus, struct device *start,
156 int (*match)(struct device *dev, void *data));
157 struct device *bus_find_device_by_name(struct bus_type *bus,
158 struct device *start,
160 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
161 struct device *hint);
162 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
163 void *data, int (*fn)(struct device_driver *, void *));
164 void bus_sort_breadthfirst(struct bus_type *bus,
165 int (*compare)(const struct device *a,
166 const struct device *b));
168 * Bus notifiers: Get notified of addition/removal of devices
169 * and binding/unbinding of drivers to devices.
170 * In the long run, it should be a replacement for the platform
173 struct notifier_block;
175 extern int bus_register_notifier(struct bus_type *bus,
176 struct notifier_block *nb);
177 extern int bus_unregister_notifier(struct bus_type *bus,
178 struct notifier_block *nb);
180 /* All 4 notifers below get called with the target struct device *
181 * as an argument. Note that those functions are likely to be called
182 * with the device lock held in the core, so be careful.
184 #define BUS_NOTIFY_ADD_DEVICE 0x00000001 /* device added */
185 #define BUS_NOTIFY_DEL_DEVICE 0x00000002 /* device to be removed */
186 #define BUS_NOTIFY_REMOVED_DEVICE 0x00000003 /* device removed */
187 #define BUS_NOTIFY_BIND_DRIVER 0x00000004 /* driver about to be
189 #define BUS_NOTIFY_BOUND_DRIVER 0x00000005 /* driver bound to device */
190 #define BUS_NOTIFY_UNBIND_DRIVER 0x00000006 /* driver about to be
192 #define BUS_NOTIFY_UNBOUND_DRIVER 0x00000007 /* driver is unbound
195 extern struct kset *bus_get_kset(struct bus_type *bus);
196 extern struct klist *bus_get_device_klist(struct bus_type *bus);
199 * struct device_driver - The basic device driver structure
200 * @name: Name of the device driver.
201 * @bus: The bus which the device of this driver belongs to.
202 * @owner: The module owner.
203 * @mod_name: Used for built-in modules.
204 * @suppress_bind_attrs: Disables bind/unbind via sysfs.
205 * @of_match_table: The open firmware table.
206 * @acpi_match_table: The ACPI match table.
207 * @probe: Called to query the existence of a specific device,
208 * whether this driver can work with it, and bind the driver
209 * to a specific device.
210 * @remove: Called when the device is removed from the system to
211 * unbind a device from this driver.
212 * @shutdown: Called at shut-down time to quiesce the device.
213 * @suspend: Called to put the device to sleep mode. Usually to a
215 * @resume: Called to bring a device from sleep mode.
216 * @groups: Default attributes that get created by the driver core
218 * @pm: Power management operations of the device which matched
220 * @p: Driver core's private data, no one other than the driver
221 * core can touch this.
223 * The device driver-model tracks all of the drivers known to the system.
224 * The main reason for this tracking is to enable the driver core to match
225 * up drivers with new devices. Once drivers are known objects within the
226 * system, however, a number of other things become possible. Device drivers
227 * can export information and configuration variables that are independent
228 * of any specific device.
230 struct device_driver {
232 struct bus_type *bus;
234 struct module *owner;
235 const char *mod_name; /* used for built-in modules */
237 bool suppress_bind_attrs; /* disables bind/unbind via sysfs */
239 const struct of_device_id *of_match_table;
240 const struct acpi_device_id *acpi_match_table;
242 int (*probe) (struct device *dev);
243 int (*remove) (struct device *dev);
244 void (*shutdown) (struct device *dev);
245 int (*suspend) (struct device *dev, pm_message_t state);
246 int (*resume) (struct device *dev);
247 const struct attribute_group **groups;
249 const struct dev_pm_ops *pm;
251 struct driver_private *p;
255 extern int __must_check driver_register(struct device_driver *drv);
256 extern void driver_unregister(struct device_driver *drv);
258 extern struct device_driver *driver_find(const char *name,
259 struct bus_type *bus);
260 extern int driver_probe_done(void);
261 extern void wait_for_device_probe(void);
264 /* sysfs interface for exporting driver attributes */
266 struct driver_attribute {
267 struct attribute attr;
268 ssize_t (*show)(struct device_driver *driver, char *buf);
269 ssize_t (*store)(struct device_driver *driver, const char *buf,
273 #define DRIVER_ATTR(_name, _mode, _show, _store) \
274 struct driver_attribute driver_attr_##_name = __ATTR(_name, _mode, _show, _store)
275 #define DRIVER_ATTR_RW(_name) \
276 struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
277 #define DRIVER_ATTR_RO(_name) \
278 struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
279 #define DRIVER_ATTR_WO(_name) \
280 struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
282 extern int __must_check driver_create_file(struct device_driver *driver,
283 const struct driver_attribute *attr);
284 extern void driver_remove_file(struct device_driver *driver,
285 const struct driver_attribute *attr);
287 extern int __must_check driver_for_each_device(struct device_driver *drv,
288 struct device *start,
290 int (*fn)(struct device *dev,
292 struct device *driver_find_device(struct device_driver *drv,
293 struct device *start, void *data,
294 int (*match)(struct device *dev, void *data));
297 * struct subsys_interface - interfaces to device functions
298 * @name: name of the device function
299 * @subsys: subsytem of the devices to attach to
300 * @node: the list of functions registered at the subsystem
301 * @add_dev: device hookup to device function handler
302 * @remove_dev: device hookup to device function handler
304 * Simple interfaces attached to a subsystem. Multiple interfaces can
305 * attach to a subsystem and its devices. Unlike drivers, they do not
306 * exclusively claim or control devices. Interfaces usually represent
307 * a specific functionality of a subsystem/class of devices.
309 struct subsys_interface {
311 struct bus_type *subsys;
312 struct list_head node;
313 int (*add_dev)(struct device *dev, struct subsys_interface *sif);
314 int (*remove_dev)(struct device *dev, struct subsys_interface *sif);
317 int subsys_interface_register(struct subsys_interface *sif);
318 void subsys_interface_unregister(struct subsys_interface *sif);
320 int subsys_system_register(struct bus_type *subsys,
321 const struct attribute_group **groups);
322 int subsys_virtual_register(struct bus_type *subsys,
323 const struct attribute_group **groups);
326 * struct class - device classes
327 * @name: Name of the class.
328 * @owner: The module owner.
329 * @class_attrs: Default attributes of this class.
330 * @dev_groups: Default attributes of the devices that belong to the class.
331 * @dev_kobj: The kobject that represents this class and links it into the hierarchy.
332 * @dev_uevent: Called when a device is added, removed from this class, or a
333 * few other things that generate uevents to add the environment
335 * @devnode: Callback to provide the devtmpfs.
336 * @class_release: Called to release this class.
337 * @dev_release: Called to release the device.
338 * @suspend: Used to put the device to sleep mode, usually to a low power
340 * @resume: Used to bring the device from the sleep mode.
341 * @ns_type: Callbacks so sysfs can detemine namespaces.
342 * @namespace: Namespace of the device belongs to this class.
343 * @pm: The default device power management operations of this class.
344 * @p: The private data of the driver core, no one other than the
345 * driver core can touch this.
347 * A class is a higher-level view of a device that abstracts out low-level
348 * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
349 * at the class level, they are all simply disks. Classes allow user space
350 * to work with devices based on what they do, rather than how they are
351 * connected or how they work.
355 struct module *owner;
357 struct class_attribute *class_attrs;
358 const struct attribute_group **dev_groups;
359 struct kobject *dev_kobj;
361 int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
362 char *(*devnode)(struct device *dev, umode_t *mode);
364 void (*class_release)(struct class *class);
365 void (*dev_release)(struct device *dev);
367 int (*suspend)(struct device *dev, pm_message_t state);
368 int (*resume)(struct device *dev);
370 const struct kobj_ns_type_operations *ns_type;
371 const void *(*namespace)(struct device *dev);
373 const struct dev_pm_ops *pm;
375 struct subsys_private *p;
378 struct class_dev_iter {
379 struct klist_iter ki;
380 const struct device_type *type;
383 extern struct kobject *sysfs_dev_block_kobj;
384 extern struct kobject *sysfs_dev_char_kobj;
385 extern int __must_check __class_register(struct class *class,
386 struct lock_class_key *key);
387 extern void class_unregister(struct class *class);
389 /* This is a #define to keep the compiler from merging different
390 * instances of the __key variable */
391 #define class_register(class) \
393 static struct lock_class_key __key; \
394 __class_register(class, &__key); \
398 struct class_compat *class_compat_register(const char *name);
399 void class_compat_unregister(struct class_compat *cls);
400 int class_compat_create_link(struct class_compat *cls, struct device *dev,
401 struct device *device_link);
402 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
403 struct device *device_link);
405 extern void class_dev_iter_init(struct class_dev_iter *iter,
407 struct device *start,
408 const struct device_type *type);
409 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
410 extern void class_dev_iter_exit(struct class_dev_iter *iter);
412 extern int class_for_each_device(struct class *class, struct device *start,
414 int (*fn)(struct device *dev, void *data));
415 extern struct device *class_find_device(struct class *class,
416 struct device *start, const void *data,
417 int (*match)(struct device *, const void *));
419 struct class_attribute {
420 struct attribute attr;
421 ssize_t (*show)(struct class *class, struct class_attribute *attr,
423 ssize_t (*store)(struct class *class, struct class_attribute *attr,
424 const char *buf, size_t count);
427 #define CLASS_ATTR(_name, _mode, _show, _store) \
428 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
429 #define CLASS_ATTR_RW(_name) \
430 struct class_attribute class_attr_##_name = __ATTR_RW(_name)
431 #define CLASS_ATTR_RO(_name) \
432 struct class_attribute class_attr_##_name = __ATTR_RO(_name)
434 extern int __must_check class_create_file_ns(struct class *class,
435 const struct class_attribute *attr,
437 extern void class_remove_file_ns(struct class *class,
438 const struct class_attribute *attr,
441 static inline int __must_check class_create_file(struct class *class,
442 const struct class_attribute *attr)
444 return class_create_file_ns(class, attr, NULL);
447 static inline void class_remove_file(struct class *class,
448 const struct class_attribute *attr)
450 return class_remove_file_ns(class, attr, NULL);
453 /* Simple class attribute that is just a static string */
454 struct class_attribute_string {
455 struct class_attribute attr;
459 /* Currently read-only only */
460 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
461 { __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
462 #define CLASS_ATTR_STRING(_name, _mode, _str) \
463 struct class_attribute_string class_attr_##_name = \
464 _CLASS_ATTR_STRING(_name, _mode, _str)
466 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
469 struct class_interface {
470 struct list_head node;
473 int (*add_dev) (struct device *, struct class_interface *);
474 void (*remove_dev) (struct device *, struct class_interface *);
477 extern int __must_check class_interface_register(struct class_interface *);
478 extern void class_interface_unregister(struct class_interface *);
480 extern struct class * __must_check __class_create(struct module *owner,
482 struct lock_class_key *key);
483 extern void class_destroy(struct class *cls);
485 /* This is a #define to keep the compiler from merging different
486 * instances of the __key variable */
487 #define class_create(owner, name) \
489 static struct lock_class_key __key; \
490 __class_create(owner, name, &__key); \
494 * The type of device, "struct device" is embedded in. A class
495 * or bus can contain devices of different types
496 * like "partitions" and "disks", "mouse" and "event".
497 * This identifies the device type and carries type-specific
498 * information, equivalent to the kobj_type of a kobject.
499 * If "name" is specified, the uevent will contain it in
500 * the DEVTYPE variable.
504 const struct attribute_group **groups;
505 int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
506 char *(*devnode)(struct device *dev, umode_t *mode,
507 kuid_t *uid, kgid_t *gid);
508 void (*release)(struct device *dev);
510 const struct dev_pm_ops *pm;
513 /* interface for exporting device attributes */
514 struct device_attribute {
515 struct attribute attr;
516 ssize_t (*show)(struct device *dev, struct device_attribute *attr,
518 ssize_t (*store)(struct device *dev, struct device_attribute *attr,
519 const char *buf, size_t count);
522 struct dev_ext_attribute {
523 struct device_attribute attr;
527 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
529 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
530 const char *buf, size_t count);
531 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
533 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
534 const char *buf, size_t count);
535 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
537 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
538 const char *buf, size_t count);
540 #define DEVICE_ATTR(_name, _mode, _show, _store) \
541 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
542 #define DEVICE_ATTR_RW(_name) \
543 struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
544 #define DEVICE_ATTR_RO(_name) \
545 struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
546 #define DEVICE_ATTR_WO(_name) \
547 struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
548 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
549 struct dev_ext_attribute dev_attr_##_name = \
550 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
551 #define DEVICE_INT_ATTR(_name, _mode, _var) \
552 struct dev_ext_attribute dev_attr_##_name = \
553 { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
554 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
555 struct dev_ext_attribute dev_attr_##_name = \
556 { __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
557 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
558 struct device_attribute dev_attr_##_name = \
559 __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
561 extern int device_create_file(struct device *device,
562 const struct device_attribute *entry);
563 extern void device_remove_file(struct device *dev,
564 const struct device_attribute *attr);
565 extern bool device_remove_file_self(struct device *dev,
566 const struct device_attribute *attr);
567 extern int __must_check device_create_bin_file(struct device *dev,
568 const struct bin_attribute *attr);
569 extern void device_remove_bin_file(struct device *dev,
570 const struct bin_attribute *attr);
572 /* device resource management */
573 typedef void (*dr_release_t)(struct device *dev, void *res);
574 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
576 #ifdef CONFIG_DEBUG_DEVRES
577 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
579 #define devres_alloc(release, size, gfp) \
580 __devres_alloc(release, size, gfp, #release)
582 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
584 extern void devres_for_each_res(struct device *dev, dr_release_t release,
585 dr_match_t match, void *match_data,
586 void (*fn)(struct device *, void *, void *),
588 extern void devres_free(void *res);
589 extern void devres_add(struct device *dev, void *res);
590 extern void *devres_find(struct device *dev, dr_release_t release,
591 dr_match_t match, void *match_data);
592 extern void *devres_get(struct device *dev, void *new_res,
593 dr_match_t match, void *match_data);
594 extern void *devres_remove(struct device *dev, dr_release_t release,
595 dr_match_t match, void *match_data);
596 extern int devres_destroy(struct device *dev, dr_release_t release,
597 dr_match_t match, void *match_data);
598 extern int devres_release(struct device *dev, dr_release_t release,
599 dr_match_t match, void *match_data);
602 extern void * __must_check devres_open_group(struct device *dev, void *id,
604 extern void devres_close_group(struct device *dev, void *id);
605 extern void devres_remove_group(struct device *dev, void *id);
606 extern int devres_release_group(struct device *dev, void *id);
608 /* managed devm_k.alloc/kfree for device drivers */
609 extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp);
610 extern char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
612 extern __printf(3, 4)
613 char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...);
614 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
616 return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
618 static inline void *devm_kmalloc_array(struct device *dev,
619 size_t n, size_t size, gfp_t flags)
621 if (size != 0 && n > SIZE_MAX / size)
623 return devm_kmalloc(dev, n * size, flags);
625 static inline void *devm_kcalloc(struct device *dev,
626 size_t n, size_t size, gfp_t flags)
628 return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
630 extern void devm_kfree(struct device *dev, void *p);
631 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp);
632 extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
635 extern unsigned long devm_get_free_pages(struct device *dev,
636 gfp_t gfp_mask, unsigned int order);
637 extern void devm_free_pages(struct device *dev, unsigned long addr);
639 void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
641 /* allows to add/remove a custom action to devres stack */
642 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
643 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
645 struct device_dma_parameters {
647 * a low level driver may set these to teach IOMMU code about
650 unsigned int max_segment_size;
651 unsigned long segment_boundary_mask;
655 * struct device - The basic device structure
656 * @parent: The device's "parent" device, the device to which it is attached.
657 * In most cases, a parent device is some sort of bus or host
658 * controller. If parent is NULL, the device, is a top-level device,
659 * which is not usually what you want.
660 * @p: Holds the private data of the driver core portions of the device.
661 * See the comment of the struct device_private for detail.
662 * @kobj: A top-level, abstract class from which other classes are derived.
663 * @init_name: Initial name of the device.
664 * @type: The type of device.
665 * This identifies the device type and carries type-specific
667 * @mutex: Mutex to synchronize calls to its driver.
668 * @bus: Type of bus device is on.
669 * @driver: Which driver has allocated this
670 * @platform_data: Platform data specific to the device.
671 * Example: For devices on custom boards, as typical of embedded
672 * and SOC based hardware, Linux often uses platform_data to point
673 * to board-specific structures describing devices and how they
674 * are wired. That can include what ports are available, chip
675 * variants, which GPIO pins act in what additional roles, and so
676 * on. This shrinks the "Board Support Packages" (BSPs) and
677 * minimizes board-specific #ifdefs in drivers.
678 * @driver_data: Private pointer for driver specific info.
679 * @power: For device power management.
680 * See Documentation/power/devices.txt for details.
681 * @pm_domain: Provide callbacks that are executed during system suspend,
682 * hibernation, system resume and during runtime PM transitions
683 * along with subsystem-level and driver-level callbacks.
684 * @pins: For device pin management.
685 * See Documentation/pinctrl.txt for details.
686 * @numa_node: NUMA node this device is close to.
687 * @dma_mask: Dma mask (if dma'ble device).
688 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
689 * hardware supports 64-bit addresses for consistent allocations
691 * @dma_pfn_offset: offset of DMA memory range relatively of RAM
692 * @dma_parms: A low level driver may set these to teach IOMMU code about
693 * segment limitations.
694 * @dma_pools: Dma pools (if dma'ble device).
695 * @dma_mem: Internal for coherent mem override.
696 * @cma_area: Contiguous memory area for dma allocations
697 * @archdata: For arch-specific additions.
698 * @of_node: Associated device tree node.
699 * @fwnode: Associated device node supplied by platform firmware.
700 * @devt: For creating the sysfs "dev".
701 * @id: device instance
702 * @devres_lock: Spinlock to protect the resource of the device.
703 * @devres_head: The resources list of the device.
704 * @knode_class: The node used to add the device to the class list.
705 * @class: The class of the device.
706 * @groups: Optional attribute groups.
707 * @release: Callback to free the device after all references have
708 * gone away. This should be set by the allocator of the
709 * device (i.e. the bus driver that discovered the device).
710 * @iommu_group: IOMMU group the device belongs to.
712 * @offline_disabled: If set, the device is permanently online.
713 * @offline: Set after successful invocation of bus type's .offline().
715 * At the lowest level, every device in a Linux system is represented by an
716 * instance of struct device. The device structure contains the information
717 * that the device model core needs to model the system. Most subsystems,
718 * however, track additional information about the devices they host. As a
719 * result, it is rare for devices to be represented by bare device structures;
720 * instead, that structure, like kobject structures, is usually embedded within
721 * a higher-level representation of the device.
724 struct device *parent;
726 struct device_private *p;
729 const char *init_name; /* initial name of the device */
730 const struct device_type *type;
732 struct mutex mutex; /* mutex to synchronize calls to
736 struct bus_type *bus; /* type of bus device is on */
737 struct device_driver *driver; /* which driver has allocated this
739 void *platform_data; /* Platform specific data, device
740 core doesn't touch it */
741 void *driver_data; /* Driver data, set and get with
742 dev_set/get_drvdata */
743 struct dev_pm_info power;
744 struct dev_pm_domain *pm_domain;
746 #ifdef CONFIG_PINCTRL
747 struct dev_pin_info *pins;
751 int numa_node; /* NUMA node this device is close to */
753 u64 *dma_mask; /* dma mask (if dma'able device) */
754 u64 coherent_dma_mask;/* Like dma_mask, but for
755 alloc_coherent mappings as
756 not all hardware supports
757 64 bit addresses for consistent
758 allocations such descriptors. */
759 unsigned long dma_pfn_offset;
761 struct device_dma_parameters *dma_parms;
763 struct list_head dma_pools; /* dma pools (if dma'ble) */
765 struct dma_coherent_mem *dma_mem; /* internal for coherent mem
767 #ifdef CONFIG_DMA_CMA
768 struct cma *cma_area; /* contiguous memory area for dma
771 /* arch specific additions */
772 struct dev_archdata archdata;
774 struct device_node *of_node; /* associated device tree node */
775 struct fwnode_handle *fwnode; /* firmware device node */
777 dev_t devt; /* dev_t, creates the sysfs "dev" */
778 u32 id; /* device instance */
780 spinlock_t devres_lock;
781 struct list_head devres_head;
783 struct klist_node knode_class;
785 const struct attribute_group **groups; /* optional groups */
787 void (*release)(struct device *dev);
788 struct iommu_group *iommu_group;
790 bool offline_disabled:1;
794 static inline struct device *kobj_to_dev(struct kobject *kobj)
796 return container_of(kobj, struct device, kobj);
799 /* Get the wakeup routines, which depend on struct device */
800 #include <linux/pm_wakeup.h>
802 static inline const char *dev_name(const struct device *dev)
804 /* Use the init name until the kobject becomes available */
806 return dev->init_name;
808 return kobject_name(&dev->kobj);
811 extern __printf(2, 3)
812 int dev_set_name(struct device *dev, const char *name, ...);
815 static inline int dev_to_node(struct device *dev)
817 return dev->numa_node;
819 static inline void set_dev_node(struct device *dev, int node)
821 dev->numa_node = node;
824 static inline int dev_to_node(struct device *dev)
828 static inline void set_dev_node(struct device *dev, int node)
833 static inline void *dev_get_drvdata(const struct device *dev)
835 return dev->driver_data;
838 static inline void dev_set_drvdata(struct device *dev, void *data)
840 dev->driver_data = data;
843 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
845 return dev ? dev->power.subsys_data : NULL;
848 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
850 return dev->kobj.uevent_suppress;
853 static inline void dev_set_uevent_suppress(struct device *dev, int val)
855 dev->kobj.uevent_suppress = val;
858 static inline int device_is_registered(struct device *dev)
860 return dev->kobj.state_in_sysfs;
863 static inline void device_enable_async_suspend(struct device *dev)
865 if (!dev->power.is_prepared)
866 dev->power.async_suspend = true;
869 static inline void device_disable_async_suspend(struct device *dev)
871 if (!dev->power.is_prepared)
872 dev->power.async_suspend = false;
875 static inline bool device_async_suspend_enabled(struct device *dev)
877 return !!dev->power.async_suspend;
880 static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
882 dev->power.ignore_children = enable;
885 static inline void dev_pm_syscore_device(struct device *dev, bool val)
887 #ifdef CONFIG_PM_SLEEP
888 dev->power.syscore = val;
892 static inline void device_lock(struct device *dev)
894 mutex_lock(&dev->mutex);
897 static inline int device_trylock(struct device *dev)
899 return mutex_trylock(&dev->mutex);
902 static inline void device_unlock(struct device *dev)
904 mutex_unlock(&dev->mutex);
907 static inline void device_lock_assert(struct device *dev)
909 lockdep_assert_held(&dev->mutex);
912 static inline struct device_node *dev_of_node(struct device *dev)
914 if (!IS_ENABLED(CONFIG_OF))
919 void driver_init(void);
922 * High level routines for use by the bus drivers
924 extern int __must_check device_register(struct device *dev);
925 extern void device_unregister(struct device *dev);
926 extern void device_initialize(struct device *dev);
927 extern int __must_check device_add(struct device *dev);
928 extern void device_del(struct device *dev);
929 extern int device_for_each_child(struct device *dev, void *data,
930 int (*fn)(struct device *dev, void *data));
931 extern struct device *device_find_child(struct device *dev, void *data,
932 int (*match)(struct device *dev, void *data));
933 extern int device_rename(struct device *dev, const char *new_name);
934 extern int device_move(struct device *dev, struct device *new_parent,
935 enum dpm_order dpm_order);
936 extern const char *device_get_devnode(struct device *dev,
937 umode_t *mode, kuid_t *uid, kgid_t *gid,
940 static inline bool device_supports_offline(struct device *dev)
942 return dev->bus && dev->bus->offline && dev->bus->online;
945 extern void lock_device_hotplug(void);
946 extern void unlock_device_hotplug(void);
947 extern int lock_device_hotplug_sysfs(void);
948 extern int device_offline(struct device *dev);
949 extern int device_online(struct device *dev);
950 extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
951 extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
954 * Root device objects for grouping under /sys/devices
956 extern struct device *__root_device_register(const char *name,
957 struct module *owner);
959 /* This is a macro to avoid include problems with THIS_MODULE */
960 #define root_device_register(name) \
961 __root_device_register(name, THIS_MODULE)
963 extern void root_device_unregister(struct device *root);
965 static inline void *dev_get_platdata(const struct device *dev)
967 return dev->platform_data;
971 * Manual binding of a device to driver. See drivers/base/bus.c
972 * for information on use.
974 extern int __must_check device_bind_driver(struct device *dev);
975 extern void device_release_driver(struct device *dev);
976 extern int __must_check device_attach(struct device *dev);
977 extern int __must_check driver_attach(struct device_driver *drv);
978 extern int __must_check device_reprobe(struct device *dev);
981 * Easy functions for dynamically creating devices on the fly
983 extern struct device *device_create_vargs(struct class *cls,
984 struct device *parent,
989 extern __printf(5, 6)
990 struct device *device_create(struct class *cls, struct device *parent,
991 dev_t devt, void *drvdata,
992 const char *fmt, ...);
993 extern __printf(6, 7)
994 struct device *device_create_with_groups(struct class *cls,
995 struct device *parent, dev_t devt, void *drvdata,
996 const struct attribute_group **groups,
997 const char *fmt, ...);
998 extern void device_destroy(struct class *cls, dev_t devt);
1001 * Platform "fixup" functions - allow the platform to have their say
1002 * about devices and actions that the general device layer doesn't
1005 /* Notify platform of device discovery */
1006 extern int (*platform_notify)(struct device *dev);
1008 extern int (*platform_notify_remove)(struct device *dev);
1012 * get_device - atomically increment the reference count for the device.
1015 extern struct device *get_device(struct device *dev);
1016 extern void put_device(struct device *dev);
1018 #ifdef CONFIG_DEVTMPFS
1019 extern int devtmpfs_create_node(struct device *dev);
1020 extern int devtmpfs_delete_node(struct device *dev);
1021 extern int devtmpfs_mount(const char *mntdir);
1023 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
1024 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
1025 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
1028 /* drivers/base/power/shutdown.c */
1029 extern void device_shutdown(void);
1031 /* debugging and troubleshooting/diagnostic helpers. */
1032 extern const char *dev_driver_string(const struct device *dev);
1035 #ifdef CONFIG_PRINTK
1037 extern __printf(3, 0)
1038 int dev_vprintk_emit(int level, const struct device *dev,
1039 const char *fmt, va_list args);
1040 extern __printf(3, 4)
1041 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...);
1043 extern __printf(3, 4)
1044 void dev_printk(const char *level, const struct device *dev,
1045 const char *fmt, ...);
1046 extern __printf(2, 3)
1047 void dev_emerg(const struct device *dev, const char *fmt, ...);
1048 extern __printf(2, 3)
1049 void dev_alert(const struct device *dev, const char *fmt, ...);
1050 extern __printf(2, 3)
1051 void dev_crit(const struct device *dev, const char *fmt, ...);
1052 extern __printf(2, 3)
1053 void dev_err(const struct device *dev, const char *fmt, ...);
1054 extern __printf(2, 3)
1055 void dev_warn(const struct device *dev, const char *fmt, ...);
1056 extern __printf(2, 3)
1057 void dev_notice(const struct device *dev, const char *fmt, ...);
1058 extern __printf(2, 3)
1059 void _dev_info(const struct device *dev, const char *fmt, ...);
1063 static inline __printf(3, 0)
1064 int dev_vprintk_emit(int level, const struct device *dev,
1065 const char *fmt, va_list args)
1067 static inline __printf(3, 4)
1068 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
1071 static inline void __dev_printk(const char *level, const struct device *dev,
1072 struct va_format *vaf)
1074 static inline __printf(3, 4)
1075 void dev_printk(const char *level, const struct device *dev,
1076 const char *fmt, ...)
1079 static inline __printf(2, 3)
1080 void dev_emerg(const struct device *dev, const char *fmt, ...)
1082 static inline __printf(2, 3)
1083 void dev_crit(const struct device *dev, const char *fmt, ...)
1085 static inline __printf(2, 3)
1086 void dev_alert(const struct device *dev, const char *fmt, ...)
1088 static inline __printf(2, 3)
1089 void dev_err(const struct device *dev, const char *fmt, ...)
1091 static inline __printf(2, 3)
1092 void dev_warn(const struct device *dev, const char *fmt, ...)
1094 static inline __printf(2, 3)
1095 void dev_notice(const struct device *dev, const char *fmt, ...)
1097 static inline __printf(2, 3)
1098 void _dev_info(const struct device *dev, const char *fmt, ...)
1104 * Stupid hackaround for existing uses of non-printk uses dev_info
1106 * Note that the definition of dev_info below is actually _dev_info
1107 * and a macro is used to avoid redefining dev_info
1110 #define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg)
1112 #if defined(CONFIG_DYNAMIC_DEBUG)
1113 #define dev_dbg(dev, format, ...) \
1115 dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
1117 #elif defined(DEBUG)
1118 #define dev_dbg(dev, format, arg...) \
1119 dev_printk(KERN_DEBUG, dev, format, ##arg)
1121 #define dev_dbg(dev, format, arg...) \
1124 dev_printk(KERN_DEBUG, dev, format, ##arg); \
1128 #ifdef CONFIG_PRINTK
1129 #define dev_level_once(dev_level, dev, fmt, ...) \
1131 static bool __print_once __read_mostly; \
1133 if (!__print_once) { \
1134 __print_once = true; \
1135 dev_level(dev, fmt, ##__VA_ARGS__); \
1139 #define dev_level_once(dev_level, dev, fmt, ...) \
1142 dev_level(dev, fmt, ##__VA_ARGS__); \
1146 #define dev_emerg_once(dev, fmt, ...) \
1147 dev_level_once(dev_emerg, dev, fmt, ##__VA_ARGS__)
1148 #define dev_alert_once(dev, fmt, ...) \
1149 dev_level_once(dev_alert, dev, fmt, ##__VA_ARGS__)
1150 #define dev_crit_once(dev, fmt, ...) \
1151 dev_level_once(dev_crit, dev, fmt, ##__VA_ARGS__)
1152 #define dev_err_once(dev, fmt, ...) \
1153 dev_level_once(dev_err, dev, fmt, ##__VA_ARGS__)
1154 #define dev_warn_once(dev, fmt, ...) \
1155 dev_level_once(dev_warn, dev, fmt, ##__VA_ARGS__)
1156 #define dev_notice_once(dev, fmt, ...) \
1157 dev_level_once(dev_notice, dev, fmt, ##__VA_ARGS__)
1158 #define dev_info_once(dev, fmt, ...) \
1159 dev_level_once(dev_info, dev, fmt, ##__VA_ARGS__)
1160 #define dev_dbg_once(dev, fmt, ...) \
1161 dev_level_once(dev_dbg, dev, fmt, ##__VA_ARGS__)
1163 #define dev_level_ratelimited(dev_level, dev, fmt, ...) \
1165 static DEFINE_RATELIMIT_STATE(_rs, \
1166 DEFAULT_RATELIMIT_INTERVAL, \
1167 DEFAULT_RATELIMIT_BURST); \
1168 if (__ratelimit(&_rs)) \
1169 dev_level(dev, fmt, ##__VA_ARGS__); \
1172 #define dev_emerg_ratelimited(dev, fmt, ...) \
1173 dev_level_ratelimited(dev_emerg, dev, fmt, ##__VA_ARGS__)
1174 #define dev_alert_ratelimited(dev, fmt, ...) \
1175 dev_level_ratelimited(dev_alert, dev, fmt, ##__VA_ARGS__)
1176 #define dev_crit_ratelimited(dev, fmt, ...) \
1177 dev_level_ratelimited(dev_crit, dev, fmt, ##__VA_ARGS__)
1178 #define dev_err_ratelimited(dev, fmt, ...) \
1179 dev_level_ratelimited(dev_err, dev, fmt, ##__VA_ARGS__)
1180 #define dev_warn_ratelimited(dev, fmt, ...) \
1181 dev_level_ratelimited(dev_warn, dev, fmt, ##__VA_ARGS__)
1182 #define dev_notice_ratelimited(dev, fmt, ...) \
1183 dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
1184 #define dev_info_ratelimited(dev, fmt, ...) \
1185 dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
1186 #if defined(CONFIG_DYNAMIC_DEBUG)
1187 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
1188 #define dev_dbg_ratelimited(dev, fmt, ...) \
1190 static DEFINE_RATELIMIT_STATE(_rs, \
1191 DEFAULT_RATELIMIT_INTERVAL, \
1192 DEFAULT_RATELIMIT_BURST); \
1193 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
1194 if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) && \
1195 __ratelimit(&_rs)) \
1196 __dynamic_dev_dbg(&descriptor, dev, fmt, \
1199 #elif defined(DEBUG)
1200 #define dev_dbg_ratelimited(dev, fmt, ...) \
1202 static DEFINE_RATELIMIT_STATE(_rs, \
1203 DEFAULT_RATELIMIT_INTERVAL, \
1204 DEFAULT_RATELIMIT_BURST); \
1205 if (__ratelimit(&_rs)) \
1206 dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \
1209 #define dev_dbg_ratelimited(dev, fmt, ...) \
1210 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
1213 #ifdef VERBOSE_DEBUG
1214 #define dev_vdbg dev_dbg
1216 #define dev_vdbg(dev, format, arg...) \
1219 dev_printk(KERN_DEBUG, dev, format, ##arg); \
1224 * dev_WARN*() acts like dev_printk(), but with the key difference of
1225 * using WARN/WARN_ONCE to include file/line information and a backtrace.
1227 #define dev_WARN(dev, format, arg...) \
1228 WARN(1, "%s %s: " format, dev_driver_string(dev), dev_name(dev), ## arg);
1230 #define dev_WARN_ONCE(dev, condition, format, arg...) \
1231 WARN_ONCE(condition, "%s %s: " format, \
1232 dev_driver_string(dev), dev_name(dev), ## arg)
1234 /* Create alias, so I can be autoloaded. */
1235 #define MODULE_ALIAS_CHARDEV(major,minor) \
1236 MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
1237 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
1238 MODULE_ALIAS("char-major-" __stringify(major) "-*")
1240 #ifdef CONFIG_SYSFS_DEPRECATED
1241 extern long sysfs_deprecated;
1243 #define sysfs_deprecated 0
1247 * module_driver() - Helper macro for drivers that don't do anything
1248 * special in module init/exit. This eliminates a lot of boilerplate.
1249 * Each module may only use this macro once, and calling it replaces
1250 * module_init() and module_exit().
1252 * @__driver: driver name
1253 * @__register: register function for this driver type
1254 * @__unregister: unregister function for this driver type
1255 * @...: Additional arguments to be passed to __register and __unregister.
1257 * Use this macro to construct bus specific macros for registering
1258 * drivers, and do not use it on its own.
1260 #define module_driver(__driver, __register, __unregister, ...) \
1261 static int __init __driver##_init(void) \
1263 return __register(&(__driver) , ##__VA_ARGS__); \
1265 module_init(__driver##_init); \
1266 static void __exit __driver##_exit(void) \
1268 __unregister(&(__driver) , ##__VA_ARGS__); \
1270 module_exit(__driver##_exit);
1272 #endif /* _DEVICE_H_ */