xref: /linux-6.15/include/linux/device.h (revision a5c43003)
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/module.h>
24 #include <linux/pm.h>
25 #include <asm/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 class;
33 struct class_private;
34 struct bus_type;
35 struct bus_type_private;
36 
37 struct bus_attribute {
38 	struct attribute	attr;
39 	ssize_t (*show)(struct bus_type *bus, char *buf);
40 	ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
41 };
42 
43 #define BUS_ATTR(_name, _mode, _show, _store)	\
44 struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
45 
46 extern int __must_check bus_create_file(struct bus_type *,
47 					struct bus_attribute *);
48 extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
49 
50 struct bus_type {
51 	const char		*name;
52 	struct bus_attribute	*bus_attrs;
53 	struct device_attribute	*dev_attrs;
54 	struct driver_attribute	*drv_attrs;
55 
56 	int (*match)(struct device *dev, struct device_driver *drv);
57 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
58 	int (*probe)(struct device *dev);
59 	int (*remove)(struct device *dev);
60 	void (*shutdown)(struct device *dev);
61 
62 	int (*suspend)(struct device *dev, pm_message_t state);
63 	int (*resume)(struct device *dev);
64 
65 	const struct dev_pm_ops *pm;
66 
67 	struct bus_type_private *p;
68 };
69 
70 extern int __must_check bus_register(struct bus_type *bus);
71 extern void bus_unregister(struct bus_type *bus);
72 
73 extern int __must_check bus_rescan_devices(struct bus_type *bus);
74 
75 /* iterator helpers for buses */
76 
77 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
78 		     int (*fn)(struct device *dev, void *data));
79 struct device *bus_find_device(struct bus_type *bus, struct device *start,
80 			       void *data,
81 			       int (*match)(struct device *dev, void *data));
82 struct device *bus_find_device_by_name(struct bus_type *bus,
83 				       struct device *start,
84 				       const char *name);
85 
86 int __must_check bus_for_each_drv(struct bus_type *bus,
87 				  struct device_driver *start, void *data,
88 				  int (*fn)(struct device_driver *, void *));
89 
90 void bus_sort_breadthfirst(struct bus_type *bus,
91 			   int (*compare)(const struct device *a,
92 					  const struct device *b));
93 /*
94  * Bus notifiers: Get notified of addition/removal of devices
95  * and binding/unbinding of drivers to devices.
96  * In the long run, it should be a replacement for the platform
97  * notify hooks.
98  */
99 struct notifier_block;
100 
101 extern int bus_register_notifier(struct bus_type *bus,
102 				 struct notifier_block *nb);
103 extern int bus_unregister_notifier(struct bus_type *bus,
104 				   struct notifier_block *nb);
105 
106 /* All 4 notifers below get called with the target struct device *
107  * as an argument. Note that those functions are likely to be called
108  * with the device lock held in the core, so be careful.
109  */
110 #define BUS_NOTIFY_ADD_DEVICE		0x00000001 /* device added */
111 #define BUS_NOTIFY_DEL_DEVICE		0x00000002 /* device removed */
112 #define BUS_NOTIFY_BOUND_DRIVER		0x00000003 /* driver bound to device */
113 #define BUS_NOTIFY_UNBIND_DRIVER	0x00000004 /* driver about to be
114 						      unbound */
115 #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000005 /* driver is unbound
116 						      from the device */
117 
118 extern struct kset *bus_get_kset(struct bus_type *bus);
119 extern struct klist *bus_get_device_klist(struct bus_type *bus);
120 
121 struct device_driver {
122 	const char		*name;
123 	struct bus_type		*bus;
124 
125 	struct module		*owner;
126 	const char		*mod_name;	/* used for built-in modules */
127 
128 	bool suppress_bind_attrs;	/* disables bind/unbind via sysfs */
129 
130 	int (*probe) (struct device *dev);
131 	int (*remove) (struct device *dev);
132 	void (*shutdown) (struct device *dev);
133 	int (*suspend) (struct device *dev, pm_message_t state);
134 	int (*resume) (struct device *dev);
135 	const struct attribute_group **groups;
136 
137 	const struct dev_pm_ops *pm;
138 
139 	struct driver_private *p;
140 };
141 
142 
143 extern int __must_check driver_register(struct device_driver *drv);
144 extern void driver_unregister(struct device_driver *drv);
145 
146 extern struct device_driver *get_driver(struct device_driver *drv);
147 extern void put_driver(struct device_driver *drv);
148 extern struct device_driver *driver_find(const char *name,
149 					 struct bus_type *bus);
150 extern int driver_probe_done(void);
151 extern void wait_for_device_probe(void);
152 
153 
154 /* sysfs interface for exporting driver attributes */
155 
156 struct driver_attribute {
157 	struct attribute attr;
158 	ssize_t (*show)(struct device_driver *driver, char *buf);
159 	ssize_t (*store)(struct device_driver *driver, const char *buf,
160 			 size_t count);
161 };
162 
163 #define DRIVER_ATTR(_name, _mode, _show, _store)	\
164 struct driver_attribute driver_attr_##_name =		\
165 	__ATTR(_name, _mode, _show, _store)
166 
167 extern int __must_check driver_create_file(struct device_driver *driver,
168 					const struct driver_attribute *attr);
169 extern void driver_remove_file(struct device_driver *driver,
170 			       const struct driver_attribute *attr);
171 
172 extern int __must_check driver_add_kobj(struct device_driver *drv,
173 					struct kobject *kobj,
174 					const char *fmt, ...);
175 
176 extern int __must_check driver_for_each_device(struct device_driver *drv,
177 					       struct device *start,
178 					       void *data,
179 					       int (*fn)(struct device *dev,
180 							 void *));
181 struct device *driver_find_device(struct device_driver *drv,
182 				  struct device *start, void *data,
183 				  int (*match)(struct device *dev, void *data));
184 
185 /*
186  * device classes
187  */
188 struct class {
189 	const char		*name;
190 	struct module		*owner;
191 
192 	struct class_attribute		*class_attrs;
193 	struct device_attribute		*dev_attrs;
194 	struct kobject			*dev_kobj;
195 
196 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
197 	char *(*devnode)(struct device *dev, mode_t *mode);
198 
199 	void (*class_release)(struct class *class);
200 	void (*dev_release)(struct device *dev);
201 
202 	int (*suspend)(struct device *dev, pm_message_t state);
203 	int (*resume)(struct device *dev);
204 
205 	const struct kobj_ns_type_operations *ns_type;
206 	const void *(*namespace)(struct device *dev);
207 
208 	const struct dev_pm_ops *pm;
209 
210 	struct class_private *p;
211 };
212 
213 struct class_dev_iter {
214 	struct klist_iter		ki;
215 	const struct device_type	*type;
216 };
217 
218 extern struct kobject *sysfs_dev_block_kobj;
219 extern struct kobject *sysfs_dev_char_kobj;
220 extern int __must_check __class_register(struct class *class,
221 					 struct lock_class_key *key);
222 extern void class_unregister(struct class *class);
223 
224 /* This is a #define to keep the compiler from merging different
225  * instances of the __key variable */
226 #define class_register(class)			\
227 ({						\
228 	static struct lock_class_key __key;	\
229 	__class_register(class, &__key);	\
230 })
231 
232 struct class_compat;
233 struct class_compat *class_compat_register(const char *name);
234 void class_compat_unregister(struct class_compat *cls);
235 int class_compat_create_link(struct class_compat *cls, struct device *dev,
236 			     struct device *device_link);
237 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
238 			      struct device *device_link);
239 
240 extern void class_dev_iter_init(struct class_dev_iter *iter,
241 				struct class *class,
242 				struct device *start,
243 				const struct device_type *type);
244 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
245 extern void class_dev_iter_exit(struct class_dev_iter *iter);
246 
247 extern int class_for_each_device(struct class *class, struct device *start,
248 				 void *data,
249 				 int (*fn)(struct device *dev, void *data));
250 extern struct device *class_find_device(struct class *class,
251 					struct device *start, void *data,
252 					int (*match)(struct device *, void *));
253 
254 struct class_attribute {
255 	struct attribute attr;
256 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
257 			char *buf);
258 	ssize_t (*store)(struct class *class, struct class_attribute *attr,
259 			const char *buf, size_t count);
260 };
261 
262 #define CLASS_ATTR(_name, _mode, _show, _store)			\
263 struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
264 
265 extern int __must_check class_create_file(struct class *class,
266 					  const struct class_attribute *attr);
267 extern void class_remove_file(struct class *class,
268 			      const struct class_attribute *attr);
269 
270 /* Simple class attribute that is just a static string */
271 
272 struct class_attribute_string {
273 	struct class_attribute attr;
274 	char *str;
275 };
276 
277 /* Currently read-only only */
278 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
279 	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
280 #define CLASS_ATTR_STRING(_name, _mode, _str) \
281 	struct class_attribute_string class_attr_##_name = \
282 		_CLASS_ATTR_STRING(_name, _mode, _str)
283 
284 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
285                         char *buf);
286 
287 struct class_interface {
288 	struct list_head	node;
289 	struct class		*class;
290 
291 	int (*add_dev)		(struct device *, struct class_interface *);
292 	void (*remove_dev)	(struct device *, struct class_interface *);
293 };
294 
295 extern int __must_check class_interface_register(struct class_interface *);
296 extern void class_interface_unregister(struct class_interface *);
297 
298 extern struct class * __must_check __class_create(struct module *owner,
299 						  const char *name,
300 						  struct lock_class_key *key);
301 extern void class_destroy(struct class *cls);
302 
303 /* This is a #define to keep the compiler from merging different
304  * instances of the __key variable */
305 #define class_create(owner, name)		\
306 ({						\
307 	static struct lock_class_key __key;	\
308 	__class_create(owner, name, &__key);	\
309 })
310 
311 /*
312  * The type of device, "struct device" is embedded in. A class
313  * or bus can contain devices of different types
314  * like "partitions" and "disks", "mouse" and "event".
315  * This identifies the device type and carries type-specific
316  * information, equivalent to the kobj_type of a kobject.
317  * If "name" is specified, the uevent will contain it in
318  * the DEVTYPE variable.
319  */
320 struct device_type {
321 	const char *name;
322 	const struct attribute_group **groups;
323 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
324 	char *(*devnode)(struct device *dev, mode_t *mode);
325 	void (*release)(struct device *dev);
326 
327 	const struct dev_pm_ops *pm;
328 };
329 
330 /* interface for exporting device attributes */
331 struct device_attribute {
332 	struct attribute	attr;
333 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
334 			char *buf);
335 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
336 			 const char *buf, size_t count);
337 };
338 
339 #define DEVICE_ATTR(_name, _mode, _show, _store) \
340 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
341 
342 extern int __must_check device_create_file(struct device *device,
343 					const struct device_attribute *entry);
344 extern void device_remove_file(struct device *dev,
345 			       const struct device_attribute *attr);
346 extern int __must_check device_create_bin_file(struct device *dev,
347 					const struct bin_attribute *attr);
348 extern void device_remove_bin_file(struct device *dev,
349 				   const struct bin_attribute *attr);
350 extern int device_schedule_callback_owner(struct device *dev,
351 		void (*func)(struct device *dev), struct module *owner);
352 
353 /* This is a macro to avoid include problems with THIS_MODULE */
354 #define device_schedule_callback(dev, func)			\
355 	device_schedule_callback_owner(dev, func, THIS_MODULE)
356 
357 /* device resource management */
358 typedef void (*dr_release_t)(struct device *dev, void *res);
359 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
360 
361 #ifdef CONFIG_DEBUG_DEVRES
362 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
363 			     const char *name);
364 #define devres_alloc(release, size, gfp) \
365 	__devres_alloc(release, size, gfp, #release)
366 #else
367 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
368 #endif
369 extern void devres_free(void *res);
370 extern void devres_add(struct device *dev, void *res);
371 extern void *devres_find(struct device *dev, dr_release_t release,
372 			 dr_match_t match, void *match_data);
373 extern void *devres_get(struct device *dev, void *new_res,
374 			dr_match_t match, void *match_data);
375 extern void *devres_remove(struct device *dev, dr_release_t release,
376 			   dr_match_t match, void *match_data);
377 extern int devres_destroy(struct device *dev, dr_release_t release,
378 			  dr_match_t match, void *match_data);
379 
380 /* devres group */
381 extern void * __must_check devres_open_group(struct device *dev, void *id,
382 					     gfp_t gfp);
383 extern void devres_close_group(struct device *dev, void *id);
384 extern void devres_remove_group(struct device *dev, void *id);
385 extern int devres_release_group(struct device *dev, void *id);
386 
387 /* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
388 extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
389 extern void devm_kfree(struct device *dev, void *p);
390 
391 struct device_dma_parameters {
392 	/*
393 	 * a low level driver may set these to teach IOMMU code about
394 	 * sg limitations.
395 	 */
396 	unsigned int max_segment_size;
397 	unsigned long segment_boundary_mask;
398 };
399 
400 struct device {
401 	struct device		*parent;
402 
403 	struct device_private	*p;
404 
405 	struct kobject kobj;
406 	const char		*init_name; /* initial name of the device */
407 	struct device_type	*type;
408 
409 	struct mutex		mutex;	/* mutex to synchronize calls to
410 					 * its driver.
411 					 */
412 
413 	struct bus_type	*bus;		/* type of bus device is on */
414 	struct device_driver *driver;	/* which driver has allocated this
415 					   device */
416 	void		*platform_data;	/* Platform specific data, device
417 					   core doesn't touch it */
418 	struct dev_pm_info	power;
419 
420 #ifdef CONFIG_NUMA
421 	int		numa_node;	/* NUMA node this device is close to */
422 #endif
423 	u64		*dma_mask;	/* dma mask (if dma'able device) */
424 	u64		coherent_dma_mask;/* Like dma_mask, but for
425 					     alloc_coherent mappings as
426 					     not all hardware supports
427 					     64 bit addresses for consistent
428 					     allocations such descriptors. */
429 
430 	struct device_dma_parameters *dma_parms;
431 
432 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
433 
434 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
435 					     override */
436 	/* arch specific additions */
437 	struct dev_archdata	archdata;
438 
439 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
440 
441 	spinlock_t		devres_lock;
442 	struct list_head	devres_head;
443 
444 	struct klist_node	knode_class;
445 	struct class		*class;
446 	const struct attribute_group **groups;	/* optional groups */
447 
448 	void	(*release)(struct device *dev);
449 };
450 
451 /* Get the wakeup routines, which depend on struct device */
452 #include <linux/pm_wakeup.h>
453 
454 static inline const char *dev_name(const struct device *dev)
455 {
456 	/* Use the init name until the kobject becomes available */
457 	if (dev->init_name)
458 		return dev->init_name;
459 
460 	return kobject_name(&dev->kobj);
461 }
462 
463 extern int dev_set_name(struct device *dev, const char *name, ...)
464 			__attribute__((format(printf, 2, 3)));
465 
466 #ifdef CONFIG_NUMA
467 static inline int dev_to_node(struct device *dev)
468 {
469 	return dev->numa_node;
470 }
471 static inline void set_dev_node(struct device *dev, int node)
472 {
473 	dev->numa_node = node;
474 }
475 #else
476 static inline int dev_to_node(struct device *dev)
477 {
478 	return -1;
479 }
480 static inline void set_dev_node(struct device *dev, int node)
481 {
482 }
483 #endif
484 
485 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
486 {
487 	return dev->kobj.uevent_suppress;
488 }
489 
490 static inline void dev_set_uevent_suppress(struct device *dev, int val)
491 {
492 	dev->kobj.uevent_suppress = val;
493 }
494 
495 static inline int device_is_registered(struct device *dev)
496 {
497 	return dev->kobj.state_in_sysfs;
498 }
499 
500 static inline void device_enable_async_suspend(struct device *dev)
501 {
502 	if (dev->power.status == DPM_ON)
503 		dev->power.async_suspend = true;
504 }
505 
506 static inline void device_disable_async_suspend(struct device *dev)
507 {
508 	if (dev->power.status == DPM_ON)
509 		dev->power.async_suspend = false;
510 }
511 
512 static inline bool device_async_suspend_enabled(struct device *dev)
513 {
514 	return !!dev->power.async_suspend;
515 }
516 
517 static inline void device_lock(struct device *dev)
518 {
519 	mutex_lock(&dev->mutex);
520 }
521 
522 static inline int device_trylock(struct device *dev)
523 {
524 	return mutex_trylock(&dev->mutex);
525 }
526 
527 static inline void device_unlock(struct device *dev)
528 {
529 	mutex_unlock(&dev->mutex);
530 }
531 
532 void driver_init(void);
533 
534 /*
535  * High level routines for use by the bus drivers
536  */
537 extern int __must_check device_register(struct device *dev);
538 extern void device_unregister(struct device *dev);
539 extern void device_initialize(struct device *dev);
540 extern int __must_check device_add(struct device *dev);
541 extern void device_del(struct device *dev);
542 extern int device_for_each_child(struct device *dev, void *data,
543 		     int (*fn)(struct device *dev, void *data));
544 extern struct device *device_find_child(struct device *dev, void *data,
545 				int (*match)(struct device *dev, void *data));
546 extern int device_rename(struct device *dev, char *new_name);
547 extern int device_move(struct device *dev, struct device *new_parent,
548 		       enum dpm_order dpm_order);
549 extern const char *device_get_devnode(struct device *dev,
550 				      mode_t *mode, const char **tmp);
551 extern void *dev_get_drvdata(const struct device *dev);
552 extern void dev_set_drvdata(struct device *dev, void *data);
553 
554 /*
555  * Root device objects for grouping under /sys/devices
556  */
557 extern struct device *__root_device_register(const char *name,
558 					     struct module *owner);
559 static inline struct device *root_device_register(const char *name)
560 {
561 	return __root_device_register(name, THIS_MODULE);
562 }
563 extern void root_device_unregister(struct device *root);
564 
565 static inline void *dev_get_platdata(const struct device *dev)
566 {
567 	return dev->platform_data;
568 }
569 
570 /*
571  * Manual binding of a device to driver. See drivers/base/bus.c
572  * for information on use.
573  */
574 extern int __must_check device_bind_driver(struct device *dev);
575 extern void device_release_driver(struct device *dev);
576 extern int  __must_check device_attach(struct device *dev);
577 extern int __must_check driver_attach(struct device_driver *drv);
578 extern int __must_check device_reprobe(struct device *dev);
579 
580 /*
581  * Easy functions for dynamically creating devices on the fly
582  */
583 extern struct device *device_create_vargs(struct class *cls,
584 					  struct device *parent,
585 					  dev_t devt,
586 					  void *drvdata,
587 					  const char *fmt,
588 					  va_list vargs);
589 extern struct device *device_create(struct class *cls, struct device *parent,
590 				    dev_t devt, void *drvdata,
591 				    const char *fmt, ...)
592 				    __attribute__((format(printf, 5, 6)));
593 extern void device_destroy(struct class *cls, dev_t devt);
594 
595 /*
596  * Platform "fixup" functions - allow the platform to have their say
597  * about devices and actions that the general device layer doesn't
598  * know about.
599  */
600 /* Notify platform of device discovery */
601 extern int (*platform_notify)(struct device *dev);
602 
603 extern int (*platform_notify_remove)(struct device *dev);
604 
605 
606 /**
607  * get_device - atomically increment the reference count for the device.
608  *
609  */
610 extern struct device *get_device(struct device *dev);
611 extern void put_device(struct device *dev);
612 
613 extern void wait_for_device_probe(void);
614 
615 #ifdef CONFIG_DEVTMPFS
616 extern int devtmpfs_create_node(struct device *dev);
617 extern int devtmpfs_delete_node(struct device *dev);
618 extern int devtmpfs_mount(const char *mntdir);
619 #else
620 static inline int devtmpfs_create_node(struct device *dev) { return 0; }
621 static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
622 static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
623 #endif
624 
625 /* drivers/base/power/shutdown.c */
626 extern void device_shutdown(void);
627 
628 /* drivers/base/sys.c */
629 extern void sysdev_shutdown(void);
630 
631 /* debugging and troubleshooting/diagnostic helpers. */
632 extern const char *dev_driver_string(const struct device *dev);
633 #define dev_printk(level, dev, format, arg...)	\
634 	printk(level "%s %s: " format , dev_driver_string(dev) , \
635 	       dev_name(dev) , ## arg)
636 
637 #define dev_emerg(dev, format, arg...)		\
638 	dev_printk(KERN_EMERG , dev , format , ## arg)
639 #define dev_alert(dev, format, arg...)		\
640 	dev_printk(KERN_ALERT , dev , format , ## arg)
641 #define dev_crit(dev, format, arg...)		\
642 	dev_printk(KERN_CRIT , dev , format , ## arg)
643 #define dev_err(dev, format, arg...)		\
644 	dev_printk(KERN_ERR , dev , format , ## arg)
645 #define dev_warn(dev, format, arg...)		\
646 	dev_printk(KERN_WARNING , dev , format , ## arg)
647 #define dev_notice(dev, format, arg...)		\
648 	dev_printk(KERN_NOTICE , dev , format , ## arg)
649 #define dev_info(dev, format, arg...)		\
650 	dev_printk(KERN_INFO , dev , format , ## arg)
651 
652 #if defined(DEBUG)
653 #define dev_dbg(dev, format, arg...)		\
654 	dev_printk(KERN_DEBUG , dev , format , ## arg)
655 #elif defined(CONFIG_DYNAMIC_DEBUG)
656 #define dev_dbg(dev, format, ...) do { \
657 	dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
658 	} while (0)
659 #else
660 #define dev_dbg(dev, format, arg...)		\
661 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
662 #endif
663 
664 #ifdef VERBOSE_DEBUG
665 #define dev_vdbg	dev_dbg
666 #else
667 
668 #define dev_vdbg(dev, format, arg...)		\
669 	({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
670 #endif
671 
672 /*
673  * dev_WARN() acts like dev_printk(), but with the key difference
674  * of using a WARN/WARN_ON to get the message out, including the
675  * file/line information and a backtrace.
676  */
677 #define dev_WARN(dev, format, arg...) \
678 	WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg);
679 
680 /* Create alias, so I can be autoloaded. */
681 #define MODULE_ALIAS_CHARDEV(major,minor) \
682 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
683 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
684 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
685 #endif /* _DEVICE_H_ */
686