LXR linux/include/linux/device.h

   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/module.h>
  24#include <linux/pm.h>
  25#include <linux/semaphore.h>
  26#include <asm/atomic.h>
  27#include <asm/device.h>
  28
  29struct device;
  30struct device_private;
  31struct device_driver;
  32struct driver_private;
  33struct class;
  34struct class_private;
  35struct bus_type;
  36struct bus_type_private;
  37
  38struct bus_attribute {
  39        struct attribute        attr;
  40        ssize_t (*show)(struct bus_type *bus, char *buf);
  41        ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
  42};
  43
  44#define BUS_ATTR(_name, _mode, _show, _store)   \
  45struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
  46
  47extern int __must_check bus_create_file(struct bus_type *,
  48                                        struct bus_attribute *);
  49extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
  50
  51struct bus_type {
  52        const char              *name;
  53        struct bus_attribute    *bus_attrs;
  54        struct device_attribute *dev_attrs;
  55        struct driver_attribute *drv_attrs;
  56
  57        int (*match)(struct device *dev, struct device_driver *drv);
  58        int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
  59        int (*probe)(struct device *dev);
  60        int (*remove)(struct device *dev);
  61        void (*shutdown)(struct device *dev);
  62
  63        int (*suspend)(struct device *dev, pm_message_t state);
  64        int (*resume)(struct device *dev);
  65
  66        const struct dev_pm_ops *pm;
  67
  68        struct bus_type_private *p;
  69};
  70
  71extern int __must_check bus_register(struct bus_type *bus);
  72extern void bus_unregister(struct bus_type *bus);
  73
  74extern int __must_check bus_rescan_devices(struct bus_type *bus);
  75
  76/* iterator helpers for buses */
  77
  78int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
  79                     int (*fn)(struct device *dev, void *data));
  80struct device *bus_find_device(struct bus_type *bus, struct device *start,
  81                               void *data,
  82                               int (*match)(struct device *dev, void *data));
  83struct device *bus_find_device_by_name(struct bus_type *bus,
  84                                       struct device *start,
  85                                       const char *name);
  86
  87int __must_check bus_for_each_drv(struct bus_type *bus,
  88                                  struct device_driver *start, void *data,
  89                                  int (*fn)(struct device_driver *, void *));
  90
  91void bus_sort_breadthfirst(struct bus_type *bus,
  92                           int (*compare)(const struct device *a,
  93                                          const struct device *b));
  94/*
  95 * Bus notifiers: Get notified of addition/removal of devices
  96 * and binding/unbinding of drivers to devices.
  97 * In the long run, it should be a replacement for the platform
  98 * notify hooks.
  99 */
 100struct notifier_block;
 101
 102extern int bus_register_notifier(struct bus_type *bus,
 103                                 struct notifier_block *nb);
 104extern int bus_unregister_notifier(struct bus_type *bus,
 105                                   struct notifier_block *nb);
 106
 107/* All 4 notifers below get called with the target struct device *
 108 * as an argument. Note that those functions are likely to be called
 109 * with the device lock held in the core, so be careful.
 110 */
 111#define BUS_NOTIFY_ADD_DEVICE           0x00000001 /* device added */
 112#define BUS_NOTIFY_DEL_DEVICE           0x00000002 /* device removed */
 113#define BUS_NOTIFY_BOUND_DRIVER         0x00000003 /* driver bound to device */
 114#define BUS_NOTIFY_UNBIND_DRIVER        0x00000004 /* driver about to be
 115                                                      unbound */
 116#define BUS_NOTIFY_UNBOUND_DRIVER       0x00000005 /* driver is unbound
 117                                                      from the device */
 118
 119extern struct kset *bus_get_kset(struct bus_type *bus);
 120extern struct klist *bus_get_device_klist(struct bus_type *bus);
 121
 122struct device_driver {
 123        const char              *name;
 124        struct bus_type         *bus;
 125
 126        struct module           *owner;
 127        const char              *mod_name;      /* used for built-in modules */
 128
 129        bool suppress_bind_attrs;       /* disables bind/unbind via sysfs */
 130
 131        int (*probe) (struct device *dev);
 132        int (*remove) (struct device *dev);
 133        void (*shutdown) (struct device *dev);
 134        int (*suspend) (struct device *dev, pm_message_t state);
 135        int (*resume) (struct device *dev);
 136        const struct attribute_group **groups;
 137
 138        const struct dev_pm_ops *pm;
 139
 140        struct driver_private *p;
 141};
 142
 143
 144extern int __must_check driver_register(struct device_driver *drv);
 145extern void driver_unregister(struct device_driver *drv);
 146
 147extern struct device_driver *get_driver(struct device_driver *drv);
 148extern void put_driver(struct device_driver *drv);
 149extern struct device_driver *driver_find(const char *name,
 150                                         struct bus_type *bus);
 151extern int driver_probe_done(void);
 152extern void wait_for_device_probe(void);
 153
 154
 155/* sysfs interface for exporting driver attributes */
 156
 157struct driver_attribute {
 158        struct attribute attr;
 159        ssize_t (*show)(struct device_driver *driver, char *buf);
 160        ssize_t (*store)(struct device_driver *driver, const char *buf,
 161                         size_t count);
 162};
 163
 164#define DRIVER_ATTR(_name, _mode, _show, _store)        \
 165struct driver_attribute driver_attr_##_name =           \
 166        __ATTR(_name, _mode, _show, _store)
 167
 168extern int __must_check driver_create_file(struct device_driver *driver,
 169                                        const struct driver_attribute *attr);
 170extern void driver_remove_file(struct device_driver *driver,
 171                               const struct driver_attribute *attr);
 172
 173extern int __must_check driver_add_kobj(struct device_driver *drv,
 174                                        struct kobject *kobj,
 175                                        const char *fmt, ...);
 176
 177extern int __must_check driver_for_each_device(struct device_driver *drv,
 178                                               struct device *start,
 179                                               void *data,
 180                                               int (*fn)(struct device *dev,
 181                                                         void *));
 182struct device *driver_find_device(struct device_driver *drv,
 183                                  struct device *start, void *data,
 184                                  int (*match)(struct device *dev, void *data));
 185
 186/*
 187 * device classes
 188 */
 189struct class {
 190        const char              *name;
 191        struct module           *owner;
 192
 193        struct class_attribute          *class_attrs;
 194        struct device_attribute         *dev_attrs;
 195        struct kobject                  *dev_kobj;
 196
 197        int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
 198        char *(*devnode)(struct device *dev, mode_t *mode);
 199
 200        void (*class_release)(struct class *class);
 201        void (*dev_release)(struct device *dev);
 202
 203        int (*suspend)(struct device *dev, pm_message_t state);
 204        int (*resume)(struct device *dev);
 205
 206        const struct dev_pm_ops *pm;
 207
 208        struct class_private *p;
 209};
 210
 211struct class_dev_iter {
 212        struct klist_iter               ki;
 213        const struct device_type        *type;
 214};
 215
 216extern struct kobject *sysfs_dev_block_kobj;
 217extern struct kobject *sysfs_dev_char_kobj;
 218extern int __must_check __class_register(struct class *class,
 219                                         struct lock_class_key *key);
 220extern void class_unregister(struct class *class);
 221
 222/* This is a #define to keep the compiler from merging different
 223 * instances of the __key variable */
 224#define class_register(class)                   \
 225({                                              \
 226        static struct lock_class_key __key;     \
 227        __class_register(class, &__key);        \
 228})
 229
 230struct class_compat;
 231struct class_compat *class_compat_register(const char *name);
 232void class_compat_unregister(struct class_compat *cls);
 233int class_compat_create_link(struct class_compat *cls, struct device *dev,
 234                             struct device *device_link);
 235void class_compat_remove_link(struct class_compat *cls, struct device *dev,
 236                              struct device *device_link);
 237
 238extern void class_dev_iter_init(struct class_dev_iter *iter,
 239                                struct class *class,
 240                                struct device *start,
 241                                const struct device_type *type);
 242extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
 243extern void class_dev_iter_exit(struct class_dev_iter *iter);
 244
 245extern int class_for_each_device(struct class *class, struct device *start,
 246                                 void *data,
 247                                 int (*fn)(struct device *dev, void *data));
 248extern struct device *class_find_device(struct class *class,
 249                                        struct device *start, void *data,
 250                                        int (*match)(struct device *, void *));
 251
 252struct class_attribute {
 253        struct attribute attr;
 254        ssize_t (*show)(struct class *class, struct class_attribute *attr,
 255                        char *buf);
 256        ssize_t (*store)(struct class *class, struct class_attribute *attr,
 257                        const char *buf, size_t count);
 258};
 259
 260#define CLASS_ATTR(_name, _mode, _show, _store)                 \
 261struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
 262
 263extern int __must_check class_create_file(struct class *class,
 264                                          const struct class_attribute *attr);
 265extern void class_remove_file(struct class *class,
 266                              const struct class_attribute *attr);
 267
 268/* Simple class attribute that is just a static string */
 269
 270struct class_attribute_string {
 271        struct class_attribute attr;
 272        char *str;
 273};
 274
 275/* Currently read-only only */
 276#define _CLASS_ATTR_STRING(_name, _mode, _str) \
 277        { __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
 278#define CLASS_ATTR_STRING(_name, _mode, _str) \
 279        struct class_attribute_string class_attr_##_name = \
 280                _CLASS_ATTR_STRING(_name, _mode, _str)
 281
 282extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
 283                        char *buf);
 284
 285struct class_interface {
 286        struct list_head        node;
 287        struct class            *class;
 288
 289        int (*add_dev)          (struct device *, struct class_interface *);
 290        void (*remove_dev)      (struct device *, struct class_interface *);
 291};
 292
 293extern int __must_check class_interface_register(struct class_interface *);
 294extern void class_interface_unregister(struct class_interface *);
 295
 296extern struct class * __must_check __class_create(struct module *owner,
 297                                                  const char *name,
 298                                                  struct lock_class_key *key);
 299extern void class_destroy(struct class *cls);
 300
 301/* This is a #define to keep the compiler from merging different
 302 * instances of the __key variable */
 303#define class_create(owner, name)               \
 304({                                              \
 305        static struct lock_class_key __key;     \
 306        __class_create(owner, name, &__key);    \
 307})
 308
 309/*
 310 * The type of device, "struct device" is embedded in. A class
 311 * or bus can contain devices of different types
 312 * like "partitions" and "disks", "mouse" and "event".
 313 * This identifies the device type and carries type-specific
 314 * information, equivalent to the kobj_type of a kobject.
 315 * If "name" is specified, the uevent will contain it in
 316 * the DEVTYPE variable.
 317 */
 318struct device_type {
 319        const char *name;
 320        const struct attribute_group **groups;
 321        int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
 322        char *(*devnode)(struct device *dev, mode_t *mode);
 323        void (*release)(struct device *dev);
 324
 325        const struct dev_pm_ops *pm;
 326};
 327
 328/* interface for exporting device attributes */
 329struct device_attribute {
 330        struct attribute        attr;
 331        ssize_t (*show)(struct device *dev, struct device_attribute *attr,
 332                        char *buf);
 333        ssize_t (*store)(struct device *dev, struct device_attribute *attr,
 334                         const char *buf, size_t count);
 335};
 336
 337#define DEVICE_ATTR(_name, _mode, _show, _store) \
 338struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
 339
 340extern int __must_check device_create_file(struct device *device,
 341                                        const struct device_attribute *entry);
 342extern void device_remove_file(struct device *dev,
 343                               const struct device_attribute *attr);
 344extern int __must_check device_create_bin_file(struct device *dev,
 345                                        const struct bin_attribute *attr);
 346extern void device_remove_bin_file(struct device *dev,
 347                                   const struct bin_attribute *attr);
 348extern int device_schedule_callback_owner(struct device *dev,
 349                void (*func)(struct device *dev), struct module *owner);
 350
 351/* This is a macro to avoid include problems with THIS_MODULE */
 352#define device_schedule_callback(dev, func)                     \
 353        device_schedule_callback_owner(dev, func, THIS_MODULE)
 354
 355/* device resource management */
 356typedef void (*dr_release_t)(struct device *dev, void *res);
 357typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
 358
 359#ifdef CONFIG_DEBUG_DEVRES
 360extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
 361                             const char *name);
 362#define devres_alloc(release, size, gfp) \
 363        __devres_alloc(release, size, gfp, #release)
 364#else
 365extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
 366#endif
 367extern void devres_free(void *res);
 368extern void devres_add(struct device *dev, void *res);
 369extern void *devres_find(struct device *dev, dr_release_t release,
 370                         dr_match_t match, void *match_data);
 371extern void *devres_get(struct device *dev, void *new_res,
 372                        dr_match_t match, void *match_data);
 373extern void *devres_remove(struct device *dev, dr_release_t release,
 374                           dr_match_t match, void *match_data);
 375extern int devres_destroy(struct device *dev, dr_release_t release,
 376                          dr_match_t match, void *match_data);
 377
 378/* devres group */
 379extern void * __must_check devres_open_group(struct device *dev, void *id,
 380                                             gfp_t gfp);
 381extern void devres_close_group(struct device *dev, void *id);
 382extern void devres_remove_group(struct device *dev, void *id);
 383extern int devres_release_group(struct device *dev, void *id);
 384
 385/* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
 386extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
 387extern void devm_kfree(struct device *dev, void *p);
 388
 389struct device_dma_parameters {
 390        /*
 391         * a low level driver may set these to teach IOMMU code about
 392         * sg limitations.
 393         */
 394        unsigned int max_segment_size;
 395        unsigned long segment_boundary_mask;
 396};
 397
 398struct device {
 399        struct device           *parent;
 400
 401        struct device_private   *p;
 402
 403        struct kobject kobj;
 404        const char              *init_name; /* initial name of the device */
 405        struct device_type      *type;
 406
 407        struct semaphore        sem;    /* semaphore to synchronize calls to
 408                                         * its driver.
 409                                         */
 410
 411        struct bus_type *bus;           /* type of bus device is on */
 412        struct device_driver *driver;   /* which driver has allocated this
 413                                           device */
 414        void            *platform_data; /* Platform specific data, device
 415                                           core doesn't touch it */
 416        struct dev_pm_info      power;
 417
 418#ifdef CONFIG_NUMA
 419        int             numa_node;      /* NUMA node this device is close to */
 420#endif
 421        u64             *dma_mask;      /* dma mask (if dma'able device) */
 422        u64             coherent_dma_mask;/* Like dma_mask, but for
 423                                             alloc_coherent mappings as
 424                                             not all hardware supports
 425                                             64 bit addresses for consistent
 426                                             allocations such descriptors. */
 427
 428        struct device_dma_parameters *dma_parms;
 429
 430        struct list_head        dma_pools;      /* dma pools (if dma'ble) */
 431
 432        struct dma_coherent_mem *dma_mem; /* internal for coherent mem
 433                                             override */
 434        /* arch specific additions */
 435        struct dev_archdata     archdata;
 436
 437        dev_t                   devt;   /* dev_t, creates the sysfs "dev" */
 438
 439        spinlock_t              devres_lock;
 440        struct list_head        devres_head;
 441
 442        struct klist_node       knode_class;
 443        struct class            *class;
 444        const struct attribute_group **groups;  /* optional groups */
 445
 446        void    (*release)(struct device *dev);
 447};
 448
 449/* Get the wakeup routines, which depend on struct device */
 450#include <linux/pm_wakeup.h>
 451
 452static inline const char *dev_name(const struct device *dev)
 453{
 454        return kobject_name(&dev->kobj);
 455}
 456
 457extern int dev_set_name(struct device *dev, const char *name, ...)
 458                        __attribute__((format(printf, 2, 3)));
 459
 460#ifdef CONFIG_NUMA
 461static inline int dev_to_node(struct device *dev)
 462{
 463        return dev->numa_node;
 464}
 465static inline void set_dev_node(struct device *dev, int node)
 466{
 467        dev->numa_node = node;
 468}
 469#else
 470static inline int dev_to_node(struct device *dev)
 471{
 472        return -1;
 473}
 474static inline void set_dev_node(struct device *dev, int node)
 475{
 476}
 477#endif
 478
 479static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
 480{
 481        return dev->kobj.uevent_suppress;
 482}
 483
 484static inline void dev_set_uevent_suppress(struct device *dev, int val)
 485{
 486        dev->kobj.uevent_suppress = val;
 487}
 488
 489static inline int device_is_registered(struct device *dev)
 490{
 491        return dev->kobj.state_in_sysfs;
 492}
 493
 494static inline void device_enable_async_suspend(struct device *dev)
 495{
 496        if (dev->power.status == DPM_ON)
 497                dev->power.async_suspend = true;
 498}
 499
 500static inline void device_disable_async_suspend(struct device *dev)
 501{
 502        if (dev->power.status == DPM_ON)
 503                dev->power.async_suspend = false;
 504}
 505
 506static inline bool device_async_suspend_enabled(struct device *dev)
 507{
 508        return !!dev->power.async_suspend;
 509}
 510
 511static inline void device_lock(struct device *dev)
 512{
 513        down(&dev->sem);
 514}
 515
 516static inline int device_trylock(struct device *dev)
 517{
 518        return down_trylock(&dev->sem);
 519}
 520
 521static inline void device_unlock(struct device *dev)
 522{
 523        up(&dev->sem);
 524}
 525
 526void driver_init(void);
 527
 528/*
 529 * High level routines for use by the bus drivers
 530 */
 531extern int __must_check device_register(struct device *dev);
 532extern void device_unregister(struct device *dev);
 533extern void device_initialize(struct device *dev);
 534extern int __must_check device_add(struct device *dev);
 535extern void device_del(struct device *dev);
 536extern int device_for_each_child(struct device *dev, void *data,
 537                     int (*fn)(struct device *dev, void *data));
 538extern struct device *device_find_child(struct device *dev, void *data,
 539                                int (*match)(struct device *dev, void *data));
 540extern int device_rename(struct device *dev, char *new_name);
 541extern int device_move(struct device *dev, struct device *new_parent,
 542                       enum dpm_order dpm_order);
 543extern const char *device_get_devnode(struct device *dev,
 544                                      mode_t *mode, const char **tmp);
 545extern void *dev_get_drvdata(const struct device *dev);
 546extern void dev_set_drvdata(struct device *dev, void *data);
 547
 548/*
 549 * Root device objects for grouping under /sys/devices
 550 */
 551extern struct device *__root_device_register(const char *name,
 552                                             struct module *owner);
 553static inline struct device *root_device_register(const char *name)
 554{
 555        return __root_device_register(name, THIS_MODULE);
 556}
 557extern void root_device_unregister(struct device *root);
 558
 559static inline void *dev_get_platdata(const struct device *dev)
 560{
 561        return dev->platform_data;
 562}
 563
 564/*
 565 * Manual binding of a device to driver. See drivers/base/bus.c
 566 * for information on use.
 567 */
 568extern int __must_check device_bind_driver(struct device *dev);
 569extern void device_release_driver(struct device *dev);
 570extern int  __must_check device_attach(struct device *dev);
 571extern int __must_check driver_attach(struct device_driver *drv);
 572extern int __must_check device_reprobe(struct device *dev);
 573
 574/*
 575 * Easy functions for dynamically creating devices on the fly
 576 */
 577extern struct device *device_create_vargs(struct class *cls,
 578                                          struct device *parent,
 579                                          dev_t devt,
 580                                          void *drvdata,
 581                                          const char *fmt,
 582                                          va_list vargs);
 583extern struct device *device_create(struct class *cls, struct device *parent,
 584                                    dev_t devt, void *drvdata,
 585                                    const char *fmt, ...)
 586                                    __attribute__((format(printf, 5, 6)));
 587extern void device_destroy(struct class *cls, dev_t devt);
 588
 589/*
 590 * Platform "fixup" functions - allow the platform to have their say
 591 * about devices and actions that the general device layer doesn't
 592 * know about.
 593 */
 594/* Notify platform of device discovery */
 595extern int (*platform_notify)(struct device *dev);
 596
 597extern int (*platform_notify_remove)(struct device *dev);
 598
 599
 600/**
 601 * get_device - atomically increment the reference count for the device.
 602 *
 603 */
 604extern struct device *get_device(struct device *dev);
 605extern void put_device(struct device *dev);
 606
 607extern void wait_for_device_probe(void);
 608
 609#ifdef CONFIG_DEVTMPFS
 610extern int devtmpfs_create_node(struct device *dev);
 611extern int devtmpfs_delete_node(struct device *dev);
 612extern int devtmpfs_mount(const char *mntdir);
 613#else
 614static inline int devtmpfs_create_node(struct device *dev) { return 0; }
 615static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
 616static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
 617#endif
 618
 619/* drivers/base/power/shutdown.c */
 620extern void device_shutdown(void);
 621
 622/* drivers/base/sys.c */
 623extern void sysdev_shutdown(void);
 624
 625/* debugging and troubleshooting/diagnostic helpers. */
 626extern const char *dev_driver_string(const struct device *dev);
 627#define dev_printk(level, dev, format, arg...)  \
 628        printk(level "%s %s: " format , dev_driver_string(dev) , \
 629               dev_name(dev) , ## arg)
 630
 631#define dev_emerg(dev, format, arg...)          \
 632        dev_printk(KERN_EMERG , dev , format , ## arg)
 633#define dev_alert(dev, format, arg...)          \
 634        dev_printk(KERN_ALERT , dev , format , ## arg)
 635#define dev_crit(dev, format, arg...)           \
 636        dev_printk(KERN_CRIT , dev , format , ## arg)
 637#define dev_err(dev, format, arg...)            \
 638        dev_printk(KERN_ERR , dev , format , ## arg)
 639#define dev_warn(dev, format, arg...)           \
 640        dev_printk(KERN_WARNING , dev , format , ## arg)
 641#define dev_notice(dev, format, arg...)         \
 642        dev_printk(KERN_NOTICE , dev , format , ## arg)
 643#define dev_info(dev, format, arg...)           \
 644        dev_printk(KERN_INFO , dev , format , ## arg)
 645
 646#if defined(DEBUG)
 647#define dev_dbg(dev, format, arg...)            \
 648        dev_printk(KERN_DEBUG , dev , format , ## arg)
 649#elif defined(CONFIG_DYNAMIC_DEBUG)
 650#define dev_dbg(dev, format, ...) do { \
 651        dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
 652        } while (0)
 653#else
 654#define dev_dbg(dev, format, arg...)            \
 655        ({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
 656#endif
 657
 658#ifdef VERBOSE_DEBUG
 659#define dev_vdbg        dev_dbg
 660#else
 661
 662#define dev_vdbg(dev, format, arg...)           \
 663        ({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
 664#endif
 665
 666/*
 667 * dev_WARN() acts like dev_printk(), but with the key difference
 668 * of using a WARN/WARN_ON to get the message out, including the
 669 * file/line information and a backtrace.
 670 */
 671#define dev_WARN(dev, format, arg...) \
 672        WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg);
 673
 674/* Create alias, so I can be autoloaded. */
 675#define MODULE_ALIAS_CHARDEV(major,minor) \
 676        MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
 677#define MODULE_ALIAS_CHARDEV_MAJOR(major) \
 678        MODULE_ALIAS("char-major-" __stringify(major) "-*")
 679#endif /* _DEVICE_H_ */
 680