1 /*
2  * device.h - generic, centralized driver model
3  *
4  * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
5  * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
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 *driver_find(const char *name,
242 					 struct bus_type *bus);
243 extern int driver_probe_done(void);
244 extern void wait_for_device_probe(void);
245 
246 
247 /* sysfs interface for exporting driver attributes */
248 
249 struct driver_attribute {
250 	struct attribute attr;
251 	ssize_t (*show)(struct device_driver *driver, char *buf);
252 	ssize_t (*store)(struct device_driver *driver, const char *buf,
253 			 size_t count);
254 };
255 
256 #define DRIVER_ATTR(_name, _mode, _show, _store)	\
257 struct driver_attribute driver_attr_##_name =		\
258 	__ATTR(_name, _mode, _show, _store)
259 
260 extern int __must_check driver_create_file(struct device_driver *driver,
261 					const struct driver_attribute *attr);
262 extern void driver_remove_file(struct device_driver *driver,
263 			       const struct driver_attribute *attr);
264 
265 extern int __must_check driver_for_each_device(struct device_driver *drv,
266 					       struct device *start,
267 					       void *data,
268 					       int (*fn)(struct device *dev,
269 							 void *));
270 struct device *driver_find_device(struct device_driver *drv,
271 				  struct device *start, void *data,
272 				  int (*match)(struct device *dev, void *data));
273 
274 /**
275  * struct subsys_interface - interfaces to device functions
276  * @name:       name of the device function
277  * @subsys:     subsytem of the devices to attach to
278  * @node:       the list of functions registered at the subsystem
279  * @add_dev:    device hookup to device function handler
280  * @remove_dev: device hookup to device function handler
281  *
282  * Simple interfaces attached to a subsystem. Multiple interfaces can
283  * attach to a subsystem and its devices. Unlike drivers, they do not
284  * exclusively claim or control devices. Interfaces usually represent
285  * a specific functionality of a subsystem/class of devices.
286  */
287 struct subsys_interface {
288 	const char *name;
289 	struct bus_type *subsys;
290 	struct list_head node;
291 	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
292 	int (*remove_dev)(struct device *dev, struct subsys_interface *sif);
293 };
294 
295 int subsys_interface_register(struct subsys_interface *sif);
296 void subsys_interface_unregister(struct subsys_interface *sif);
297 
298 int subsys_system_register(struct bus_type *subsys,
299 			   const struct attribute_group **groups);
300 
301 /**
302  * struct class - device classes
303  * @name:	Name of the class.
304  * @owner:	The module owner.
305  * @class_attrs: Default attributes of this class.
306  * @dev_attrs:	Default attributes of the devices belong to the class.
307  * @dev_bin_attrs: Default binary attributes of the devices belong to the class.
308  * @dev_kobj:	The kobject that represents this class and links it into the hierarchy.
309  * @dev_uevent:	Called when a device is added, removed from this class, or a
310  *		few other things that generate uevents to add the environment
311  *		variables.
312  * @devnode:	Callback to provide the devtmpfs.
313  * @class_release: Called to release this class.
314  * @dev_release: Called to release the device.
315  * @suspend:	Used to put the device to sleep mode, usually to a low power
316  *		state.
317  * @resume:	Used to bring the device from the sleep mode.
318  * @ns_type:	Callbacks so sysfs can detemine namespaces.
319  * @namespace:	Namespace of the device belongs to this class.
320  * @pm:		The default device power management operations of this class.
321  * @p:		The private data of the driver core, no one other than the
322  *		driver core can touch this.
323  *
324  * A class is a higher-level view of a device that abstracts out low-level
325  * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
326  * at the class level, they are all simply disks. Classes allow user space
327  * to work with devices based on what they do, rather than how they are
328  * connected or how they work.
329  */
330 struct class {
331 	const char		*name;
332 	struct module		*owner;
333 
334 	struct class_attribute		*class_attrs;
335 	struct device_attribute		*dev_attrs;
336 	struct bin_attribute		*dev_bin_attrs;
337 	struct kobject			*dev_kobj;
338 
339 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
340 	char *(*devnode)(struct device *dev, umode_t *mode);
341 
342 	void (*class_release)(struct class *class);
343 	void (*dev_release)(struct device *dev);
344 
345 	int (*suspend)(struct device *dev, pm_message_t state);
346 	int (*resume)(struct device *dev);
347 
348 	const struct kobj_ns_type_operations *ns_type;
349 	const void *(*namespace)(struct device *dev);
350 
351 	const struct dev_pm_ops *pm;
352 
353 	struct subsys_private *p;
354 };
355 
356 struct class_dev_iter {
357 	struct klist_iter		ki;
358 	const struct device_type	*type;
359 };
360 
361 extern struct kobject *sysfs_dev_block_kobj;
362 extern struct kobject *sysfs_dev_char_kobj;
363 extern int __must_check __class_register(struct class *class,
364 					 struct lock_class_key *key);
365 extern void class_unregister(struct class *class);
366 
367 /* This is a #define to keep the compiler from merging different
368  * instances of the __key variable */
369 #define class_register(class)			\
370 ({						\
371 	static struct lock_class_key __key;	\
372 	__class_register(class, &__key);	\
373 })
374 
375 struct class_compat;
376 struct class_compat *class_compat_register(const char *name);
377 void class_compat_unregister(struct class_compat *cls);
378 int class_compat_create_link(struct class_compat *cls, struct device *dev,
379 			     struct device *device_link);
380 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
381 			      struct device *device_link);
382 
383 extern void class_dev_iter_init(struct class_dev_iter *iter,
384 				struct class *class,
385 				struct device *start,
386 				const struct device_type *type);
387 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
388 extern void class_dev_iter_exit(struct class_dev_iter *iter);
389 
390 extern int class_for_each_device(struct class *class, struct device *start,
391 				 void *data,
392 				 int (*fn)(struct device *dev, void *data));
393 extern struct device *class_find_device(struct class *class,
394 					struct device *start, void *data,
395 					int (*match)(struct device *, void *));
396 
397 struct class_attribute {
398 	struct attribute attr;
399 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
400 			char *buf);
401 	ssize_t (*store)(struct class *class, struct class_attribute *attr,
402 			const char *buf, size_t count);
403 	const void *(*namespace)(struct class *class,
404 				 const struct class_attribute *attr);
405 };
406 
407 #define CLASS_ATTR(_name, _mode, _show, _store)			\
408 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
409 
410 extern int __must_check class_create_file(struct class *class,
411 					  const struct class_attribute *attr);
412 extern void class_remove_file(struct class *class,
413 			      const struct class_attribute *attr);
414 
415 /* Simple class attribute that is just a static string */
416 
417 struct class_attribute_string {
418 	struct class_attribute attr;
419 	char *str;
420 };
421 
422 /* Currently read-only only */
423 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
424 	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
425 #define CLASS_ATTR_STRING(_name, _mode, _str) \
426 	struct class_attribute_string class_attr_##_name = \
427 		_CLASS_ATTR_STRING(_name, _mode, _str)
428 
429 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
430                         char *buf);
431 
432 struct class_interface {
433 	struct list_head	node;
434 	struct class		*class;
435 
436 	int (*add_dev)		(struct device *, struct class_interface *);
437 	void (*remove_dev)	(struct device *, struct class_interface *);
438 };
439 
440 extern int __must_check class_interface_register(struct class_interface *);
441 extern void class_interface_unregister(struct class_interface *);
442 
443 extern struct class * __must_check __class_create(struct module *owner,
444 						  const char *name,
445 						  struct lock_class_key *key);
446 extern void class_destroy(struct class *cls);
447 
448 /* This is a #define to keep the compiler from merging different
449  * instances of the __key variable */
450 #define class_create(owner, name)		\
451 ({						\
452 	static struct lock_class_key __key;	\
453 	__class_create(owner, name, &__key);	\
454 })
455 
456 /*
457  * The type of device, "struct device" is embedded in. A class
458  * or bus can contain devices of different types
459  * like "partitions" and "disks", "mouse" and "event".
460  * This identifies the device type and carries type-specific
461  * information, equivalent to the kobj_type of a kobject.
462  * If "name" is specified, the uevent will contain it in
463  * the DEVTYPE variable.
464  */
465 struct device_type {
466 	const char *name;
467 	const struct attribute_group **groups;
468 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
469 	char *(*devnode)(struct device *dev, umode_t *mode);
470 	void (*release)(struct device *dev);
471 
472 	const struct dev_pm_ops *pm;
473 };
474 
475 /* interface for exporting device attributes */
476 struct device_attribute {
477 	struct attribute	attr;
478 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
479 			char *buf);
480 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
481 			 const char *buf, size_t count);
482 };
483 
484 struct dev_ext_attribute {
485 	struct device_attribute attr;
486 	void *var;
487 };
488 
489 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
490 			  char *buf);
491 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
492 			   const char *buf, size_t count);
493 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
494 			char *buf);
495 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
496 			 const char *buf, size_t count);
497 
498 #define DEVICE_ATTR(_name, _mode, _show, _store) \
499 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
500 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
501 	struct dev_ext_attribute dev_attr_##_name = \
502 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
503 #define DEVICE_INT_ATTR(_name, _mode, _var) \
504 	struct dev_ext_attribute dev_attr_##_name = \
505 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
506 
507 extern int device_create_file(struct device *device,
508 			      const struct device_attribute *entry);
509 extern void device_remove_file(struct device *dev,
510 			       const struct device_attribute *attr);
511 extern int __must_check device_create_bin_file(struct device *dev,
512 					const struct bin_attribute *attr);
513 extern void device_remove_bin_file(struct device *dev,
514 				   const struct bin_attribute *attr);
515 extern int device_schedule_callback_owner(struct device *dev,
516 		void (*func)(struct device *dev), struct module *owner);
517 
518 /* This is a macro to avoid include problems with THIS_MODULE */
519 #define device_schedule_callback(dev, func)			\
520 	device_schedule_callback_owner(dev, func, THIS_MODULE)
521 
522 /* device resource management */
523 typedef void (*dr_release_t)(struct device *dev, void *res);
524 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
525 
526 #ifdef CONFIG_DEBUG_DEVRES
527 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
528 			     const char *name);
529 #define devres_alloc(release, size, gfp) \
530 	__devres_alloc(release, size, gfp, #release)
531 #else
532 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
533 #endif
534 extern void devres_free(void *res);
535 extern void devres_add(struct device *dev, void *res);
536 extern void *devres_find(struct device *dev, dr_release_t release,
537 			 dr_match_t match, void *match_data);
538 extern void *devres_get(struct device *dev, void *new_res,
539 			dr_match_t match, void *match_data);
540 extern void *devres_remove(struct device *dev, dr_release_t release,
541 			   dr_match_t match, void *match_data);
542 extern int devres_destroy(struct device *dev, dr_release_t release,
543 			  dr_match_t match, void *match_data);
544 
545 /* devres group */
546 extern void * __must_check devres_open_group(struct device *dev, void *id,
547 					     gfp_t gfp);
548 extern void devres_close_group(struct device *dev, void *id);
549 extern void devres_remove_group(struct device *dev, void *id);
550 extern int devres_release_group(struct device *dev, void *id);
551 
552 /* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
553 extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
554 extern void devm_kfree(struct device *dev, void *p);
555 
556 void __iomem *devm_request_and_ioremap(struct device *dev,
557 			struct resource *res);
558 
559 struct device_dma_parameters {
560 	/*
561 	 * a low level driver may set these to teach IOMMU code about
562 	 * sg limitations.
563 	 */
564 	unsigned int max_segment_size;
565 	unsigned long segment_boundary_mask;
566 };
567 
568 /**
569  * struct device - The basic device structure
570  * @parent:	The device's "parent" device, the device to which it is attached.
571  * 		In most cases, a parent device is some sort of bus or host
572  * 		controller. If parent is NULL, the device, is a top-level device,
573  * 		which is not usually what you want.
574  * @p:		Holds the private data of the driver core portions of the device.
575  * 		See the comment of the struct device_private for detail.
576  * @kobj:	A top-level, abstract class from which other classes are derived.
577  * @init_name:	Initial name of the device.
578  * @type:	The type of device.
579  * 		This identifies the device type and carries type-specific
580  * 		information.
581  * @mutex:	Mutex to synchronize calls to its driver.
582  * @bus:	Type of bus device is on.
583  * @driver:	Which driver has allocated this
584  * @platform_data: Platform data specific to the device.
585  * 		Example: For devices on custom boards, as typical of embedded
586  * 		and SOC based hardware, Linux often uses platform_data to point
587  * 		to board-specific structures describing devices and how they
588  * 		are wired.  That can include what ports are available, chip
589  * 		variants, which GPIO pins act in what additional roles, and so
590  * 		on.  This shrinks the "Board Support Packages" (BSPs) and
591  * 		minimizes board-specific #ifdefs in drivers.
592  * @power:	For device power management.
593  * 		See Documentation/power/devices.txt for details.
594  * @pm_domain:	Provide callbacks that are executed during system suspend,
595  * 		hibernation, system resume and during runtime PM transitions
596  * 		along with subsystem-level and driver-level callbacks.
597  * @numa_node:	NUMA node this device is close to.
598  * @dma_mask:	Dma mask (if dma'ble device).
599  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
600  * 		hardware supports 64-bit addresses for consistent allocations
601  * 		such descriptors.
602  * @dma_parms:	A low level driver may set these to teach IOMMU code about
603  * 		segment limitations.
604  * @dma_pools:	Dma pools (if dma'ble device).
605  * @dma_mem:	Internal for coherent mem override.
606  * @archdata:	For arch-specific additions.
607  * @of_node:	Associated device tree node.
608  * @devt:	For creating the sysfs "dev".
609  * @id:		device instance
610  * @devres_lock: Spinlock to protect the resource of the device.
611  * @devres_head: The resources list of the device.
612  * @knode_class: The node used to add the device to the class list.
613  * @class:	The class of the device.
614  * @groups:	Optional attribute groups.
615  * @release:	Callback to free the device after all references have
616  * 		gone away. This should be set by the allocator of the
617  * 		device (i.e. the bus driver that discovered the device).
618  *
619  * At the lowest level, every device in a Linux system is represented by an
620  * instance of struct device. The device structure contains the information
621  * that the device model core needs to model the system. Most subsystems,
622  * however, track additional information about the devices they host. As a
623  * result, it is rare for devices to be represented by bare device structures;
624  * instead, that structure, like kobject structures, is usually embedded within
625  * a higher-level representation of the device.
626  */
627 struct device {
628 	struct device		*parent;
629 
630 	struct device_private	*p;
631 
632 	struct kobject kobj;
633 	const char		*init_name; /* initial name of the device */
634 	const struct device_type *type;
635 
636 	struct mutex		mutex;	/* mutex to synchronize calls to
637 					 * its driver.
638 					 */
639 
640 	struct bus_type	*bus;		/* type of bus device is on */
641 	struct device_driver *driver;	/* which driver has allocated this
642 					   device */
643 	void		*platform_data;	/* Platform specific data, device
644 					   core doesn't touch it */
645 	struct dev_pm_info	power;
646 	struct dev_pm_domain	*pm_domain;
647 
648 #ifdef CONFIG_NUMA
649 	int		numa_node;	/* NUMA node this device is close to */
650 #endif
651 	u64		*dma_mask;	/* dma mask (if dma'able device) */
652 	u64		coherent_dma_mask;/* Like dma_mask, but for
653 					     alloc_coherent mappings as
654 					     not all hardware supports
655 					     64 bit addresses for consistent
656 					     allocations such descriptors. */
657 
658 	struct device_dma_parameters *dma_parms;
659 
660 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
661 
662 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
663 					     override */
664 	/* arch specific additions */
665 	struct dev_archdata	archdata;
666 
667 	struct device_node	*of_node; /* associated device tree node */
668 
669 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
670 	u32			id;	/* device instance */
671 
672 	spinlock_t		devres_lock;
673 	struct list_head	devres_head;
674 
675 	struct klist_node	knode_class;
676 	struct class		*class;
677 	const struct attribute_group **groups;	/* optional groups */
678 
679 	void	(*release)(struct device *dev);
680 };
681 
682 /* Get the wakeup routines, which depend on struct device */
683 #include <linux/pm_wakeup.h>
684 
dev_name(const struct device * dev)685 static inline const char *dev_name(const struct device *dev)
686 {
687 	/* Use the init name until the kobject becomes available */
688 	if (dev->init_name)
689 		return dev->init_name;
690 
691 	return kobject_name(&dev->kobj);
692 }
693 
694 extern __printf(2, 3)
695 int dev_set_name(struct device *dev, const char *name, ...);
696 
697 #ifdef CONFIG_NUMA
dev_to_node(struct device * dev)698 static inline int dev_to_node(struct device *dev)
699 {
700 	return dev->numa_node;
701 }
set_dev_node(struct device * dev,int node)702 static inline void set_dev_node(struct device *dev, int node)
703 {
704 	dev->numa_node = node;
705 }
706 #else
dev_to_node(struct device * dev)707 static inline int dev_to_node(struct device *dev)
708 {
709 	return -1;
710 }
set_dev_node(struct device * dev,int node)711 static inline void set_dev_node(struct device *dev, int node)
712 {
713 }
714 #endif
715 
dev_to_psd(struct device * dev)716 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
717 {
718 	return dev ? dev->power.subsys_data : NULL;
719 }
720 
dev_get_uevent_suppress(const struct device * dev)721 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
722 {
723 	return dev->kobj.uevent_suppress;
724 }
725 
dev_set_uevent_suppress(struct device * dev,int val)726 static inline void dev_set_uevent_suppress(struct device *dev, int val)
727 {
728 	dev->kobj.uevent_suppress = val;
729 }
730 
device_is_registered(struct device * dev)731 static inline int device_is_registered(struct device *dev)
732 {
733 	return dev->kobj.state_in_sysfs;
734 }
735 
device_enable_async_suspend(struct device * dev)736 static inline void device_enable_async_suspend(struct device *dev)
737 {
738 	if (!dev->power.is_prepared)
739 		dev->power.async_suspend = true;
740 }
741 
device_disable_async_suspend(struct device * dev)742 static inline void device_disable_async_suspend(struct device *dev)
743 {
744 	if (!dev->power.is_prepared)
745 		dev->power.async_suspend = false;
746 }
747 
device_async_suspend_enabled(struct device * dev)748 static inline bool device_async_suspend_enabled(struct device *dev)
749 {
750 	return !!dev->power.async_suspend;
751 }
752 
pm_suspend_ignore_children(struct device * dev,bool enable)753 static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
754 {
755 	dev->power.ignore_children = enable;
756 }
757 
device_lock(struct device * dev)758 static inline void device_lock(struct device *dev)
759 {
760 	mutex_lock(&dev->mutex);
761 }
762 
device_trylock(struct device * dev)763 static inline int device_trylock(struct device *dev)
764 {
765 	return mutex_trylock(&dev->mutex);
766 }
767 
device_unlock(struct device * dev)768 static inline void device_unlock(struct device *dev)
769 {
770 	mutex_unlock(&dev->mutex);
771 }
772 
773 void driver_init(void);
774 
775 /*
776  * High level routines for use by the bus drivers
777  */
778 extern int __must_check device_register(struct device *dev);
779 extern void device_unregister(struct device *dev);
780 extern void device_initialize(struct device *dev);
781 extern int __must_check device_add(struct device *dev);
782 extern void device_del(struct device *dev);
783 extern int device_for_each_child(struct device *dev, void *data,
784 		     int (*fn)(struct device *dev, void *data));
785 extern struct device *device_find_child(struct device *dev, void *data,
786 				int (*match)(struct device *dev, void *data));
787 extern int device_rename(struct device *dev, const char *new_name);
788 extern int device_move(struct device *dev, struct device *new_parent,
789 		       enum dpm_order dpm_order);
790 extern const char *device_get_devnode(struct device *dev,
791 				      umode_t *mode, const char **tmp);
792 extern void *dev_get_drvdata(const struct device *dev);
793 extern int dev_set_drvdata(struct device *dev, void *data);
794 
795 /*
796  * Root device objects for grouping under /sys/devices
797  */
798 extern struct device *__root_device_register(const char *name,
799 					     struct module *owner);
800 
801 /*
802  * This is a macro to avoid include problems with THIS_MODULE,
803  * just as per what is done for device_schedule_callback() above.
804  */
805 #define root_device_register(name) \
806 	__root_device_register(name, THIS_MODULE)
807 
808 extern void root_device_unregister(struct device *root);
809 
dev_get_platdata(const struct device * dev)810 static inline void *dev_get_platdata(const struct device *dev)
811 {
812 	return dev->platform_data;
813 }
814 
815 /*
816  * Manual binding of a device to driver. See drivers/base/bus.c
817  * for information on use.
818  */
819 extern int __must_check device_bind_driver(struct device *dev);
820 extern void device_release_driver(struct device *dev);
821 extern int  __must_check device_attach(struct device *dev);
822 extern int __must_check driver_attach(struct device_driver *drv);
823 extern int __must_check device_reprobe(struct device *dev);
824 
825 /*
826  * Easy functions for dynamically creating devices on the fly
827  */
828 extern struct device *device_create_vargs(struct class *cls,
829 					  struct device *parent,
830 					  dev_t devt,
831 					  void *drvdata,
832 					  const char *fmt,
833 					  va_list vargs);
834 extern __printf(5, 6)
835 struct device *device_create(struct class *cls, struct device *parent,
836 			     dev_t devt, void *drvdata,
837 			     const char *fmt, ...);
838 extern void device_destroy(struct class *cls, dev_t devt);
839 
840 /*
841  * Platform "fixup" functions - allow the platform to have their say
842  * about devices and actions that the general device layer doesn't
843  * know about.
844  */
845 /* Notify platform of device discovery */
846 extern int (*platform_notify)(struct device *dev);
847 
848 extern int (*platform_notify_remove)(struct device *dev);
849 
850 
851 /*
852  * get_device - atomically increment the reference count for the device.
853  *
854  */
855 extern struct device *get_device(struct device *dev);
856 extern void put_device(struct device *dev);
857 
858 extern void wait_for_device_probe(void);
859 
860 #ifdef CONFIG_DEVTMPFS
861 extern int devtmpfs_create_node(struct device *dev);
862 extern int devtmpfs_delete_node(struct device *dev);
863 extern int devtmpfs_mount(const char *mntdir);
864 #else
devtmpfs_create_node(struct device * dev)865 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
devtmpfs_delete_node(struct device * dev)866 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
devtmpfs_mount(const char * mountpoint)867 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
868 #endif
869 
870 /* drivers/base/power/shutdown.c */
871 extern void device_shutdown(void);
872 
873 /* debugging and troubleshooting/diagnostic helpers. */
874 extern const char *dev_driver_string(const struct device *dev);
875 
876 
877 #ifdef CONFIG_PRINTK
878 
879 extern int __dev_printk(const char *level, const struct device *dev,
880 			struct va_format *vaf);
881 extern __printf(3, 4)
882 int dev_printk(const char *level, const struct device *dev,
883 	       const char *fmt, ...)
884 	;
885 extern __printf(2, 3)
886 int dev_emerg(const struct device *dev, const char *fmt, ...);
887 extern __printf(2, 3)
888 int dev_alert(const struct device *dev, const char *fmt, ...);
889 extern __printf(2, 3)
890 int dev_crit(const struct device *dev, const char *fmt, ...);
891 extern __printf(2, 3)
892 int dev_err(const struct device *dev, const char *fmt, ...);
893 extern __printf(2, 3)
894 int dev_warn(const struct device *dev, const char *fmt, ...);
895 extern __printf(2, 3)
896 int dev_notice(const struct device *dev, const char *fmt, ...);
897 extern __printf(2, 3)
898 int _dev_info(const struct device *dev, const char *fmt, ...);
899 
900 #else
901 
__dev_printk(const char * level,const struct device * dev,struct va_format * vaf)902 static inline int __dev_printk(const char *level, const struct device *dev,
903 			       struct va_format *vaf)
904 { return 0; }
905 static inline __printf(3, 4)
dev_printk(const char * level,const struct device * dev,const char * fmt,...)906 int dev_printk(const char *level, const struct device *dev,
907 	       const char *fmt, ...)
908 { return 0; }
909 
910 static inline __printf(2, 3)
dev_emerg(const struct device * dev,const char * fmt,...)911 int dev_emerg(const struct device *dev, const char *fmt, ...)
912 { return 0; }
913 static inline __printf(2, 3)
dev_crit(const struct device * dev,const char * fmt,...)914 int dev_crit(const struct device *dev, const char *fmt, ...)
915 { return 0; }
916 static inline __printf(2, 3)
dev_alert(const struct device * dev,const char * fmt,...)917 int dev_alert(const struct device *dev, const char *fmt, ...)
918 { return 0; }
919 static inline __printf(2, 3)
dev_err(const struct device * dev,const char * fmt,...)920 int dev_err(const struct device *dev, const char *fmt, ...)
921 { return 0; }
922 static inline __printf(2, 3)
dev_warn(const struct device * dev,const char * fmt,...)923 int dev_warn(const struct device *dev, const char *fmt, ...)
924 { return 0; }
925 static inline __printf(2, 3)
dev_notice(const struct device * dev,const char * fmt,...)926 int dev_notice(const struct device *dev, const char *fmt, ...)
927 { return 0; }
928 static inline __printf(2, 3)
_dev_info(const struct device * dev,const char * fmt,...)929 int _dev_info(const struct device *dev, const char *fmt, ...)
930 { return 0; }
931 
932 #endif
933 
934 /*
935  * Stupid hackaround for existing uses of non-printk uses dev_info
936  *
937  * Note that the definition of dev_info below is actually _dev_info
938  * and a macro is used to avoid redefining dev_info
939  */
940 
941 #define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg)
942 
943 #if defined(CONFIG_DYNAMIC_DEBUG)
944 #define dev_dbg(dev, format, ...)		     \
945 do {						     \
946 	dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
947 } while (0)
948 #elif defined(DEBUG)
949 #define dev_dbg(dev, format, arg...)		\
950 	dev_printk(KERN_DEBUG, dev, format, ##arg)
951 #else
952 #define dev_dbg(dev, format, arg...)				\
953 ({								\
954 	if (0)							\
955 		dev_printk(KERN_DEBUG, dev, format, ##arg);	\
956 	0;							\
957 })
958 #endif
959 
960 #ifdef VERBOSE_DEBUG
961 #define dev_vdbg	dev_dbg
962 #else
963 #define dev_vdbg(dev, format, arg...)				\
964 ({								\
965 	if (0)							\
966 		dev_printk(KERN_DEBUG, dev, format, ##arg);	\
967 	0;							\
968 })
969 #endif
970 
971 /*
972  * dev_WARN*() acts like dev_printk(), but with the key difference
973  * of using a WARN/WARN_ON to get the message out, including the
974  * file/line information and a backtrace.
975  */
976 #define dev_WARN(dev, format, arg...) \
977 	WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg);
978 
979 #define dev_WARN_ONCE(dev, condition, format, arg...) \
980 	WARN_ONCE(condition, "Device %s\n" format, \
981 			dev_driver_string(dev), ## arg)
982 
983 /* Create alias, so I can be autoloaded. */
984 #define MODULE_ALIAS_CHARDEV(major,minor) \
985 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
986 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
987 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
988 
989 #ifdef CONFIG_SYSFS_DEPRECATED
990 extern long sysfs_deprecated;
991 #else
992 #define sysfs_deprecated 0
993 #endif
994 
995 /**
996  * module_driver() - Helper macro for drivers that don't do anything
997  * special in module init/exit. This eliminates a lot of boilerplate.
998  * Each module may only use this macro once, and calling it replaces
999  * module_init() and module_exit().
1000  *
1001  * @__driver: driver name
1002  * @__register: register function for this driver type
1003  * @__unregister: unregister function for this driver type
1004  * @...: Additional arguments to be passed to __register and __unregister.
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) , ##__VA_ARGS__); \
1013 } \
1014 module_init(__driver##_init); \
1015 static void __exit __driver##_exit(void) \
1016 { \
1017 	__unregister(&(__driver) , ##__VA_ARGS__); \
1018 } \
1019 module_exit(__driver##_exit);
1020 
1021 #endif /* _DEVICE_H_ */
1022