总线（bus）;设备（devices）;驱动（drivers）

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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/mutex.h>
 24 #include <linux/pinctrl/devinfo.h>
 25 #include <linux/pm.h>
 26 #include <linux/atomic.h>
 27 #include <linux/ratelimit.h>
 28 #include <linux/uidgid.h>
 29 #include <linux/gfp.h>
 30 #include <asm/device.h>
 31
 32 struct device;
 33 struct device_private;
 34 struct device_driver;
 35 struct driver_private;
 36 struct module;
 37 struct class;
 38 struct subsys_private;
 39 struct bus_type;
 40 struct device_node;
 41 struct fwnode_handle;
 42 struct iommu_ops;
 43 struct iommu_group;
 44
 45 struct bus_attribute {
 46         struct attribute        attr;
 47         ssize_t (*show)(struct bus_type *bus, char *buf);
 48         ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
 49 };
 50
 51 #define BUS_ATTR(_name, _mode, _show, _store)   \
 52         struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
 53 #define BUS_ATTR_RW(_name) \
 54         struct bus_attribute bus_attr_##_name = __ATTR_RW(_name)
 55 #define BUS_ATTR_RO(_name) \
 56         struct bus_attribute bus_attr_##_name = __ATTR_RO(_name)
 57
 58 extern int __must_check bus_create_file(struct bus_type *,
 59                                         struct bus_attribute *);
 60 extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
 61
 62 /**
 63  * struct bus_type - The bus type of the device
 64  *
 65  * @name:       The name of the bus.
 66  * @dev_name:   Used for subsystems to enumerate devices like ("foo%u", dev->id).
 67  * @dev_root:   Default device to use as the parent.
 68  * @dev_attrs:  Default attributes of the devices on the bus.
 69  * @bus_groups: Default attributes of the bus.
 70  * @dev_groups: Default attributes of the devices on the bus.
 71  * @drv_groups: Default attributes of the device drivers on the bus.
 72  * @match:      Called, perhaps multiple times, whenever a new device or driver
 73  *              is added for this bus. It should return a nonzero value if the
 74  *              given device can be handled by the given driver.
 75  * @uevent:     Called when a device is added, removed, or a few other things
 76  *              that generate uevents to add the environment variables.
 77  * @probe:      Called when a new device or driver add to this bus, and callback
 78  *              the specific driver's probe to initial the matched device.
 79  * @remove:     Called when a device removed from this bus.
 80  * @shutdown:   Called at shut-down time to quiesce the device.
 81  *
 82  * @online:     Called to put the device back online (after offlining it).
 83  * @offline:    Called to put the device offline for hot-removal. May fail.
 84  *
 85  * @suspend:    Called when a device on this bus wants to go to sleep mode.
 86  * @resume:     Called to bring a device on this bus out of sleep mode.
 87  * @pm:         Power management operations of this bus, callback the specific
 88  *              device driver's pm-ops.
 89  * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
 90  *              driver implementations to a bus and allow the driver to do
 91  *              bus-specific setup
 92  * @p:          The private data of the driver core, only the driver core can
 93  *              touch this.
 94  * @lock_key:   Lock class key for use by the lock validator
 95  *
 96  * A bus is a channel between the processor and one or more devices. For the
 97  * purposes of the device model, all devices are connected via a bus, even if
 98  * it is an internal, virtual, "platform" bus. Buses can plug into each other.
 99  * A USB controller is usually a PCI device, for example. The device model
100  * represents the actual connections between buses and the devices they control.
101  * A bus is represented by the bus_type structure. It contains the name, the
102  * default attributes, the bus' methods, PM operations, and the driver core's
103  * private data.
104  */
105 struct bus_type {
         const char              *name;
         const char              *dev_name;
         struct device           *dev_root;
         struct device_attribute *dev_attrs;     /* use dev_groups instead */
         const struct attribute_group **bus_groups;
         const struct attribute_group **dev_groups;
         const struct attribute_group **drv_groups;

         int (*match)(struct device *dev, struct device_driver *drv);
         int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
         int (*probe)(struct device *dev);
         int (*remove)(struct device *dev);
         void (*shutdown)(struct device *dev);

         int (*online)(struct device *dev);
         int (*offline)(struct device *dev);

         int (*suspend)(struct device *dev, pm_message_t state);
         int (*resume)(struct device *dev);

         const struct dev_pm_ops *pm;

         const struct iommu_ops *iommu_ops;

         struct subsys_private *p;
         struct lock_class_key lock_key;
 };
133
134 extern int __must_check bus_register(struct bus_type *bus);
135
136 extern void bus_unregister(struct bus_type *bus);
137
138 extern int __must_check bus_rescan_devices(struct bus_type *bus);
139
140 /* iterator helpers for buses */
141 struct subsys_dev_iter {
142         struct klist_iter               ki;
143         const struct device_type        *type;
144 };
145 void subsys_dev_iter_init(struct subsys_dev_iter *iter,
146                          struct bus_type *subsys,
147                          struct device *start,
148                          const struct device_type *type);
149 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
150 void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
151
152 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
153                      int (*fn)(struct device *dev, void *data));
154 struct device *bus_find_device(struct bus_type *bus, struct device *start,
155                                void *data,
156                                int (*match)(struct device *dev, void *data));
157 struct device *bus_find_device_by_name(struct bus_type *bus,
158                                        struct device *start,
159                                        const char *name);
160 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
161                                         struct device *hint);
162 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
163                      void *data, int (*fn)(struct device_driver *, void *));
164 void bus_sort_breadthfirst(struct bus_type *bus,
165                            int (*compare)(const struct device *a,
166                                           const struct device *b));
167 /*
168  * Bus notifiers: Get notified of addition/removal of devices
169  * and binding/unbinding of drivers to devices.
170  * In the long run, it should be a replacement for the platform
171  * notify hooks.
172  */
173 struct notifier_block;
174
175 extern int bus_register_notifier(struct bus_type *bus,
176                                  struct notifier_block *nb);
177 extern int bus_unregister_notifier(struct bus_type *bus,
178                                    struct notifier_block *nb);
179
180 /* All 4 notifers below get called with the target struct device *
181  * as an argument. Note that those functions are likely to be called
182  * with the device lock held in the core, so be careful.
183  */
184 #define BUS_NOTIFY_ADD_DEVICE           0x00000001 /* device added */
185 #define BUS_NOTIFY_DEL_DEVICE           0x00000002 /* device to be removed */
186 #define BUS_NOTIFY_REMOVED_DEVICE       0x00000003 /* device removed */
187 #define BUS_NOTIFY_BIND_DRIVER          0x00000004 /* driver about to be
188                                                       bound */
189 #define BUS_NOTIFY_BOUND_DRIVER         0x00000005 /* driver bound to device */
190 #define BUS_NOTIFY_UNBIND_DRIVER        0x00000006 /* driver about to be
191                                                       unbound */
192 #define BUS_NOTIFY_UNBOUND_DRIVER       0x00000007 /* driver is unbound
193                                                       from the device */
194
195 extern struct kset *bus_get_kset(struct bus_type *bus);
196 extern struct klist *bus_get_device_klist(struct bus_type *bus);
197
198 /**
199  * struct device_driver - The basic device driver structure
200  * @name:       Name of the device driver.
201  * @bus:        The bus which the device of this driver belongs to.
202  * @owner:      The module owner.
203  * @mod_name:   Used for built-in modules.
204  * @suppress_bind_attrs: Disables bind/unbind via sysfs.
205  * @of_match_table: The open firmware table.
206  * @acpi_match_table: The ACPI match table.
207  * @probe:      Called to query the existence of a specific device,
208  *              whether this driver can work with it, and bind the driver
209  *              to a specific device.
210  * @remove:     Called when the device is removed from the system to
211  *              unbind a device from this driver.
212  * @shutdown:   Called at shut-down time to quiesce the device.
213  * @suspend:    Called to put the device to sleep mode. Usually to a
214  *              low power state.
215  * @resume:     Called to bring a device from sleep mode.
216  * @groups:     Default attributes that get created by the driver core
217  *              automatically.
218  * @pm:         Power management operations of the device which matched
219  *              this driver.
220  * @p:          Driver core's private data, no one other than the driver
221  *              core can touch this.
222  *
223  * The device driver-model tracks all of the drivers known to the system.
224  * The main reason for this tracking is to enable the driver core to match
225  * up drivers with new devices. Once drivers are known objects within the
226  * system, however, a number of other things become possible. Device drivers
227  * can export information and configuration variables that are independent
228  * of any specific device.
229  */
230 struct device_driver {
         const char              *name;
         struct bus_type         *bus;

         struct module           *owner;
         const char              *mod_name;      /* used for built-in modules */

         bool suppress_bind_attrs;       /* disables bind/unbind via sysfs */

         const struct of_device_id       *of_match_table;
         const struct acpi_device_id     *acpi_match_table;

         int (*probe) (struct device *dev);
         int (*remove) (struct device *dev);
         void (*shutdown) (struct device *dev);
         int (*suspend) (struct device *dev, pm_message_t state);
         int (*resume) (struct device *dev);
         const struct attribute_group **groups;

         const struct dev_pm_ops *pm;

         struct driver_private *p;
 };
253
254
255 extern int __must_check driver_register(struct device_driver *drv);
256 extern void driver_unregister(struct device_driver *drv);
257
258 extern struct device_driver *driver_find(const char *name,
259                                          struct bus_type *bus);
260 extern int driver_probe_done(void);
261 extern void wait_for_device_probe(void);
262
263
264 /* sysfs interface for exporting driver attributes */
265
266 struct driver_attribute {
267         struct attribute attr;
268         ssize_t (*show)(struct device_driver *driver, char *buf);
269         ssize_t (*store)(struct device_driver *driver, const char *buf,
270                          size_t count);
271 };
272
273 #define DRIVER_ATTR(_name, _mode, _show, _store) \
274         struct driver_attribute driver_attr_##_name = __ATTR(_name, _mode, _show, _store)
275 #define DRIVER_ATTR_RW(_name) \
276         struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
277 #define DRIVER_ATTR_RO(_name) \
278         struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
279 #define DRIVER_ATTR_WO(_name) \
280         struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
281
282 extern int __must_check driver_create_file(struct device_driver *driver,
283                                         const struct driver_attribute *attr);
284 extern void driver_remove_file(struct device_driver *driver,
285                                const struct driver_attribute *attr);
286
287 extern int __must_check driver_for_each_device(struct device_driver *drv,
288                                                struct device *start,
289                                                void *data,
290                                                int (*fn)(struct device *dev,
291                                                          void *));
292 struct device *driver_find_device(struct device_driver *drv,
293                                   struct device *start, void *data,
294                                   int (*match)(struct device *dev, void *data));
295
296 /**
297  * struct subsys_interface - interfaces to device functions
298  * @name:       name of the device function
299  * @subsys:     subsytem of the devices to attach to
300  * @node:       the list of functions registered at the subsystem
301  * @add_dev:    device hookup to device function handler
302  * @remove_dev: device hookup to device function handler
303  *
304  * Simple interfaces attached to a subsystem. Multiple interfaces can
305  * attach to a subsystem and its devices. Unlike drivers, they do not
306  * exclusively claim or control devices. Interfaces usually represent
307  * a specific functionality of a subsystem/class of devices.
308  */
309 struct subsys_interface {
310         const char *name;
311         struct bus_type *subsys;
312         struct list_head node;
313         int (*add_dev)(struct device *dev, struct subsys_interface *sif);
314         int (*remove_dev)(struct device *dev, struct subsys_interface *sif);
315 };
316
317 int subsys_interface_register(struct subsys_interface *sif);
318 void subsys_interface_unregister(struct subsys_interface *sif);
319
320 int subsys_system_register(struct bus_type *subsys,
321                            const struct attribute_group **groups);
322 int subsys_virtual_register(struct bus_type *subsys,
323                             const struct attribute_group **groups);
324
325 /**
326  * struct class - device classes
327  * @name:       Name of the class.
328  * @owner:      The module owner.
329  * @class_attrs: Default attributes of this class.
330  * @dev_groups: Default attributes of the devices that belong to the class.
331  * @dev_kobj:   The kobject that represents this class and links it into the hierarchy.
332  * @dev_uevent: Called when a device is added, removed from this class, or a
333  *              few other things that generate uevents to add the environment
334  *              variables.
335  * @devnode:    Callback to provide the devtmpfs.
336  * @class_release: Called to release this class.
337  * @dev_release: Called to release the device.
338  * @suspend:    Used to put the device to sleep mode, usually to a low power
339  *              state.
340  * @resume:     Used to bring the device from the sleep mode.
341  * @ns_type:    Callbacks so sysfs can detemine namespaces.
342  * @namespace:  Namespace of the device belongs to this class.
343  * @pm:         The default device power management operations of this class.
344  * @p:          The private data of the driver core, no one other than the
345  *              driver core can touch this.
346  *
347  * A class is a higher-level view of a device that abstracts out low-level
348  * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
349  * at the class level, they are all simply disks. Classes allow user space
350  * to work with devices based on what they do, rather than how they are
351  * connected or how they work.
352  */
353 struct class {
354         const char              *name;
355         struct module           *owner;
356
357         struct class_attribute          *class_attrs;
358         const struct attribute_group    **dev_groups;
359         struct kobject                  *dev_kobj;
360
361         int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
362         char *(*devnode)(struct device *dev, umode_t *mode);
363
364         void (*class_release)(struct class *class);
365         void (*dev_release)(struct device *dev);
366
367         int (*suspend)(struct device *dev, pm_message_t state);
368         int (*resume)(struct device *dev);
369
370         const struct kobj_ns_type_operations *ns_type;
371         const void *(*namespace)(struct device *dev);
372
373         const struct dev_pm_ops *pm;
374
375         struct subsys_private *p;
376 };
377
378 struct class_dev_iter {
379         struct klist_iter               ki;
380         const struct device_type        *type;
381 };
382
383 extern struct kobject *sysfs_dev_block_kobj;
384 extern struct kobject *sysfs_dev_char_kobj;
385 extern int __must_check __class_register(struct class *class,
386                                          struct lock_class_key *key);
387 extern void class_unregister(struct class *class);
388
389 /* This is a #define to keep the compiler from merging different
390  * instances of the __key variable */
391 #define class_register(class)                   \
392 ({                                              \
393         static struct lock_class_key __key;     \
394         __class_register(class, &__key);        \
395 })
396
397 struct class_compat;
398 struct class_compat *class_compat_register(const char *name);
399 void class_compat_unregister(struct class_compat *cls);
400 int class_compat_create_link(struct class_compat *cls, struct device *dev,
401                              struct device *device_link);
402 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
403                               struct device *device_link);
404
405 extern void class_dev_iter_init(struct class_dev_iter *iter,
406                                 struct class *class,
407                                 struct device *start,
408                                 const struct device_type *type);
409 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
410 extern void class_dev_iter_exit(struct class_dev_iter *iter);
411
412 extern int class_for_each_device(struct class *class, struct device *start,
413                                  void *data,
414                                  int (*fn)(struct device *dev, void *data));
415 extern struct device *class_find_device(struct class *class,
416                                         struct device *start, const void *data,
417                                         int (*match)(struct device *, const void *));
418
419 struct class_attribute {
420         struct attribute attr;
421         ssize_t (*show)(struct class *class, struct class_attribute *attr,
422                         char *buf);
423         ssize_t (*store)(struct class *class, struct class_attribute *attr,
424                         const char *buf, size_t count);
425 };
426
427 #define CLASS_ATTR(_name, _mode, _show, _store) \
428         struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
429 #define CLASS_ATTR_RW(_name) \
430         struct class_attribute class_attr_##_name = __ATTR_RW(_name)
431 #define CLASS_ATTR_RO(_name) \
432         struct class_attribute class_attr_##_name = __ATTR_RO(_name)
433
434 extern int __must_check class_create_file_ns(struct class *class,
435                                              const struct class_attribute *attr,
436                                              const void *ns);
437 extern void class_remove_file_ns(struct class *class,
438                                  const struct class_attribute *attr,
439                                  const void *ns);
440
441 static inline int __must_check class_create_file(struct class *class,
442                                         const struct class_attribute *attr)
443 {
444         return class_create_file_ns(class, attr, NULL);
445 }
446
447 static inline void class_remove_file(struct class *class,
448                                      const struct class_attribute *attr)
449 {
450         return class_remove_file_ns(class, attr, NULL);
451 }
452
453 /* Simple class attribute that is just a static string */
454 struct class_attribute_string {
455         struct class_attribute attr;
456         char *str;
457 };
458
459 /* Currently read-only only */
460 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
461         { __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
462 #define CLASS_ATTR_STRING(_name, _mode, _str) \
463         struct class_attribute_string class_attr_##_name = \
464                 _CLASS_ATTR_STRING(_name, _mode, _str)
465
466 extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
467                         char *buf);
468
469 struct class_interface {
470         struct list_head        node;
471         struct class            *class;
472
473         int (*add_dev)          (struct device *, struct class_interface *);
474         void (*remove_dev)      (struct device *, struct class_interface *);
475 };
476
477 extern int __must_check class_interface_register(struct class_interface *);
478 extern void class_interface_unregister(struct class_interface *);
479
480 extern struct class * __must_check __class_create(struct module *owner,
481                                                   const char *name,
482                                                   struct lock_class_key *key);
483 extern void class_destroy(struct class *cls);
484
485 /* This is a #define to keep the compiler from merging different
486  * instances of the __key variable */
487 #define class_create(owner, name)               \
488 ({                                              \
489         static struct lock_class_key __key;     \
490         __class_create(owner, name, &__key);    \
491 })
492
493 /*
494  * The type of device, "struct device" is embedded in. A class
495  * or bus can contain devices of different types
496  * like "partitions" and "disks", "mouse" and "event".
497  * This identifies the device type and carries type-specific
498  * information, equivalent to the kobj_type of a kobject.
499  * If "name" is specified, the uevent will contain it in
500  * the DEVTYPE variable.
501  */
502 struct device_type {
         const char *name;
         const struct attribute_group **groups;
         int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
         char *(*devnode)(struct device *dev, umode_t *mode,
                          kuid_t *uid, kgid_t *gid);
         void (*release)(struct device *dev);

         const struct dev_pm_ops *pm;
 };
 
513 /* interface for exporting device attributes */
514 struct device_attribute {
515         struct attribute        attr;
516         ssize_t (*show)(struct device *dev, struct device_attribute *attr,
517                         char *buf);
518         ssize_t (*store)(struct device *dev, struct device_attribute *attr,
519                          const char *buf, size_t count);
520 };
521
522 struct dev_ext_attribute {
523         struct device_attribute attr;
524         void *var;
525 };
526
527 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
528                           char *buf);
529 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
530                            const char *buf, size_t count);
531 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
532                         char *buf);
533 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
534                          const char *buf, size_t count);
535 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
536                         char *buf);
537 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
538                          const char *buf, size_t count);
539
540 #define DEVICE_ATTR(_name, _mode, _show, _store) \
541         struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
542 #define DEVICE_ATTR_RW(_name) \
543         struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
544 #define DEVICE_ATTR_RO(_name) \
545         struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
546 #define DEVICE_ATTR_WO(_name) \
547         struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
548 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
549         struct dev_ext_attribute dev_attr_##_name = \
550                 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
551 #define DEVICE_INT_ATTR(_name, _mode, _var) \
552         struct dev_ext_attribute dev_attr_##_name = \
553                 { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
554 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
555         struct dev_ext_attribute dev_attr_##_name = \
556                 { __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
557 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
558         struct device_attribute dev_attr_##_name =              \
559                 __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
560
561 extern int device_create_file(struct device *device,
562                               const struct device_attribute *entry);
563 extern void device_remove_file(struct device *dev,
564                                const struct device_attribute *attr);
565 extern bool device_remove_file_self(struct device *dev,
566                                     const struct device_attribute *attr);
567 extern int __must_check device_create_bin_file(struct device *dev,
568                                         const struct bin_attribute *attr);
569 extern void device_remove_bin_file(struct device *dev,
570                                    const struct bin_attribute *attr);
571
572 /* device resource management */
573 typedef void (*dr_release_t)(struct device *dev, void *res);
574 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
575
576 #ifdef CONFIG_DEBUG_DEVRES
577 extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
578                              const char *name);
579 #define devres_alloc(release, size, gfp) \
580         __devres_alloc(release, size, gfp, #release)
581 #else
582 extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
583 #endif
584 extern void devres_for_each_res(struct device *dev, dr_release_t release,
585                                 dr_match_t match, void *match_data,
586                                 void (*fn)(struct device *, void *, void *),
587                                 void *data);
588 extern void devres_free(void *res);
589 extern void devres_add(struct device *dev, void *res);
590 extern void *devres_find(struct device *dev, dr_release_t release,
591                          dr_match_t match, void *match_data);
592 extern void *devres_get(struct device *dev, void *new_res,
593                         dr_match_t match, void *match_data);
594 extern void *devres_remove(struct device *dev, dr_release_t release,
595                            dr_match_t match, void *match_data);
596 extern int devres_destroy(struct device *dev, dr_release_t release,
597                           dr_match_t match, void *match_data);
598 extern int devres_release(struct device *dev, dr_release_t release,
599                           dr_match_t match, void *match_data);
600
601 /* devres group */
602 extern void * __must_check devres_open_group(struct device *dev, void *id,
603                                              gfp_t gfp);
604 extern void devres_close_group(struct device *dev, void *id);
605 extern void devres_remove_group(struct device *dev, void *id);
606 extern int devres_release_group(struct device *dev, void *id);
607
608 /* managed devm_k.alloc/kfree for device drivers */
609 extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp);
610 extern char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
611                              va_list ap);
612 extern __printf(3, 4)
613 char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...);
614 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
615 {
616         return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
617 }
618 static inline void *devm_kmalloc_array(struct device *dev,
619                                        size_t n, size_t size, gfp_t flags)
620 {
621         if (size != 0 && n > SIZE_MAX / size)
622                 return NULL;
623         return devm_kmalloc(dev, n * size, flags);
624 }
625 static inline void *devm_kcalloc(struct device *dev,
626                                  size_t n, size_t size, gfp_t flags)
627 {
628         return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
629 }
630 extern void devm_kfree(struct device *dev, void *p);
631 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp);
632 extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
633                           gfp_t gfp);
634
635 extern unsigned long devm_get_free_pages(struct device *dev,
636                                          gfp_t gfp_mask, unsigned int order);
637 extern void devm_free_pages(struct device *dev, unsigned long addr);
638
639 void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
640
641 /* allows to add/remove a custom action to devres stack */
642 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
643 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
644
645 struct device_dma_parameters {
646         /*
647          * a low level driver may set these to teach IOMMU code about
648          * sg limitations.
649          */
650         unsigned int max_segment_size;
651         unsigned long segment_boundary_mask;
652 };
653
654 /**
655  * struct device - The basic device structure
656  * @parent:     The device's "parent" device, the device to which it is attached.
657  *              In most cases, a parent device is some sort of bus or host
658  *              controller. If parent is NULL, the device, is a top-level device,
659  *              which is not usually what you want.
660  * @p:          Holds the private data of the driver core portions of the device.
661  *              See the comment of the struct device_private for detail.
662  * @kobj:       A top-level, abstract class from which other classes are derived.
663  * @init_name:  Initial name of the device.
664  * @type:       The type of device.
665  *              This identifies the device type and carries type-specific
666  *              information.
667  * @mutex:      Mutex to synchronize calls to its driver.
668  * @bus:        Type of bus device is on.
669  * @driver:     Which driver has allocated this
670  * @platform_data: Platform data specific to the device.
671  *              Example: For devices on custom boards, as typical of embedded
672  *              and SOC based hardware, Linux often uses platform_data to point
673  *              to board-specific structures describing devices and how they
674  *              are wired.  That can include what ports are available, chip
675  *              variants, which GPIO pins act in what additional roles, and so
676  *              on.  This shrinks the "Board Support Packages" (BSPs) and
677  *              minimizes board-specific #ifdefs in drivers.
678  * @driver_data: Private pointer for driver specific info.
679  * @power:      For device power management.
680  *              See Documentation/power/devices.txt for details.
681  * @pm_domain:  Provide callbacks that are executed during system suspend,
682  *              hibernation, system resume and during runtime PM transitions
683  *              along with subsystem-level and driver-level callbacks.
684  * @pins:       For device pin management.
685  *              See Documentation/pinctrl.txt for details.
686  * @numa_node:  NUMA node this device is close to.
687  * @dma_mask:   Dma mask (if dma'ble device).
688  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
689  *              hardware supports 64-bit addresses for consistent allocations
690  *              such descriptors.
691  * @dma_pfn_offset: offset of DMA memory range relatively of RAM
692  * @dma_parms:  A low level driver may set these to teach IOMMU code about
693  *              segment limitations.
694  * @dma_pools:  Dma pools (if dma'ble device).
695  * @dma_mem:    Internal for coherent mem override.
696  * @cma_area:   Contiguous memory area for dma allocations
697  * @archdata:   For arch-specific additions.
698  * @of_node:    Associated device tree node.
699  * @fwnode:     Associated device node supplied by platform firmware.
700  * @devt:       For creating the sysfs "dev".
701  * @id:         device instance
702  * @devres_lock: Spinlock to protect the resource of the device.
703  * @devres_head: The resources list of the device.
704  * @knode_class: The node used to add the device to the class list.
705  * @class:      The class of the device.
706  * @groups:     Optional attribute groups.
707  * @release:    Callback to free the device after all references have
708  *              gone away. This should be set by the allocator of the
709  *              device (i.e. the bus driver that discovered the device).
710  * @iommu_group: IOMMU group the device belongs to.
711  *
712  * @offline_disabled: If set, the device is permanently online.
713  * @offline:    Set after successful invocation of bus type's .offline().
714  *
715  * At the lowest level, every device in a Linux system is represented by an
716  * instance of struct device. The device structure contains the information
717  * that the device model core needs to model the system. Most subsystems,
718  * however, track additional information about the devices they host. As a
719  * result, it is rare for devices to be represented by bare device structures;
720  * instead, that structure, like kobject structures, is usually embedded within
721  * a higher-level representation of the device.
722  */
 struct device {
         struct device           *parent;

         struct device_private   *p;

         struct kobject kobj;
         const char              *init_name; /* initial name of the device */
         const struct device_type *type;

         struct mutex            mutex;  /* mutex to synchronize calls to
                                          * its driver.
                                          */

         struct bus_type *bus;           /* type of bus device is on */
         struct device_driver *driver;   /* which driver has allocated this
                                            device */
         void            *platform_data; /* Platform specific data, device
                                            core doesn't touch it */
         void            *driver_data;   /* Driver data, set and get with
                                            dev_set/get_drvdata */
         struct dev_pm_info      power;
         struct dev_pm_domain    *pm_domain;

 #ifdef CONFIG_PINCTRL
         struct dev_pin_info     *pins;
 #endif

 #ifdef CONFIG_NUMA
         int             numa_node;      /* NUMA node this device is close to */
 #endif
         u64             *dma_mask;      /* dma mask (if dma'able device) */
         u64             coherent_dma_mask;/* Like dma_mask, but for
                                              alloc_coherent mappings as
                                              not all hardware supports
                                              64 bit addresses for consistent
                                              allocations such descriptors. */
         unsigned long   dma_pfn_offset;

         struct device_dma_parameters *dma_parms;

         struct list_head        dma_pools;      /* dma pools (if dma'ble) */

         struct dma_coherent_mem *dma_mem; /* internal for coherent mem
                                              override */
 #ifdef CONFIG_DMA_CMA
         struct cma *cma_area;           /* contiguous memory area for dma
                                            allocations */
 #endif
         /* arch specific additions */
         struct dev_archdata     archdata;

         struct device_node      *of_node; /* associated device tree node */
         struct fwnode_handle    *fwnode; /* firmware device node */

         dev_t                   devt;   /* dev_t, creates the sysfs "dev" */
         u32                     id;     /* device instance */

         spinlock_t              devres_lock;
         struct list_head        devres_head;

         struct klist_node       knode_class;
         struct class            *class;
         const struct attribute_group **groups;  /* optional groups */

         void    (*release)(struct device *dev);
         struct iommu_group      *iommu_group;

         bool                    offline_disabled:1;
         bool                    offline:1;
 };
793
794 static inline struct device *kobj_to_dev(struct kobject *kobj)
795 {
796         return container_of(kobj, struct device, kobj);
797 }
798
799 /* Get the wakeup routines, which depend on struct device */
800 #include <linux/pm_wakeup.h>
801
802 static inline const char *dev_name(const struct device *dev)
803 {
804         /* Use the init name until the kobject becomes available */
805         if (dev->init_name)
806                 return dev->init_name;
807
808         return kobject_name(&dev->kobj);
809 }
810
811 extern __printf(2, 3)
812 int dev_set_name(struct device *dev, const char *name, ...);
813
814 #ifdef CONFIG_NUMA
815 static inline int dev_to_node(struct device *dev)
816 {
817         return dev->numa_node;
818 }
819 static inline void set_dev_node(struct device *dev, int node)
820 {
821         dev->numa_node = node;
822 }
823 #else
824 static inline int dev_to_node(struct device *dev)
825 {
826         return -1;
827 }
828 static inline void set_dev_node(struct device *dev, int node)
829 {
830 }
831 #endif
832
833 static inline void *dev_get_drvdata(const struct device *dev)
834 {
835         return dev->driver_data;
836 }
837
838 static inline void dev_set_drvdata(struct device *dev, void *data)
839 {
840         dev->driver_data = data;
841 }
842
843 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
844 {
845         return dev ? dev->power.subsys_data : NULL;
846 }
847
848 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
849 {
850         return dev->kobj.uevent_suppress;
851 }
852
853 static inline void dev_set_uevent_suppress(struct device *dev, int val)
854 {
855         dev->kobj.uevent_suppress = val;
856 }
857
858 static inline int device_is_registered(struct device *dev)
859 {
860         return dev->kobj.state_in_sysfs;
861 }
862
863 static inline void device_enable_async_suspend(struct device *dev)