linux/include/linux/device.h
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * device.h - generic, centralized driver model
   4 *
   5 * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
   6 * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
   7 * Copyright (c) 2008-2009 Novell Inc.
   8 *
   9 * See Documentation/driver-api/driver-model/ for more information.
  10 */
  11
  12#ifndef _DEVICE_H_
  13#define _DEVICE_H_
  14
  15#include <linux/dev_printk.h>
  16#include <linux/energy_model.h>
  17#include <linux/ioport.h>
  18#include <linux/kobject.h>
  19#include <linux/klist.h>
  20#include <linux/list.h>
  21#include <linux/lockdep.h>
  22#include <linux/compiler.h>
  23#include <linux/types.h>
  24#include <linux/mutex.h>
  25#include <linux/pm.h>
  26#include <linux/atomic.h>
  27#include <linux/uidgid.h>
  28#include <linux/gfp.h>
  29#include <linux/overflow.h>
  30#include <linux/device/bus.h>
  31#include <linux/device/class.h>
  32#include <linux/device/driver.h>
  33#include <asm/device.h>
  34
  35struct device;
  36struct device_private;
  37struct device_driver;
  38struct driver_private;
  39struct module;
  40struct class;
  41struct subsys_private;
  42struct device_node;
  43struct fwnode_handle;
  44struct iommu_ops;
  45struct iommu_group;
  46struct dev_pin_info;
  47struct dev_iommu;
  48
  49/**
  50 * struct subsys_interface - interfaces to device functions
  51 * @name:       name of the device function
  52 * @subsys:     subsytem of the devices to attach to
  53 * @node:       the list of functions registered at the subsystem
  54 * @add_dev:    device hookup to device function handler
  55 * @remove_dev: device hookup to device function handler
  56 *
  57 * Simple interfaces attached to a subsystem. Multiple interfaces can
  58 * attach to a subsystem and its devices. Unlike drivers, they do not
  59 * exclusively claim or control devices. Interfaces usually represent
  60 * a specific functionality of a subsystem/class of devices.
  61 */
  62struct subsys_interface {
  63        const char *name;
  64        struct bus_type *subsys;
  65        struct list_head node;
  66        int (*add_dev)(struct device *dev, struct subsys_interface *sif);
  67        void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
  68};
  69
  70int subsys_interface_register(struct subsys_interface *sif);
  71void subsys_interface_unregister(struct subsys_interface *sif);
  72
  73int subsys_system_register(struct bus_type *subsys,
  74                           const struct attribute_group **groups);
  75int subsys_virtual_register(struct bus_type *subsys,
  76                            const struct attribute_group **groups);
  77
  78/*
  79 * The type of device, "struct device" is embedded in. A class
  80 * or bus can contain devices of different types
  81 * like "partitions" and "disks", "mouse" and "event".
  82 * This identifies the device type and carries type-specific
  83 * information, equivalent to the kobj_type of a kobject.
  84 * If "name" is specified, the uevent will contain it in
  85 * the DEVTYPE variable.
  86 */
  87struct device_type {
  88        const char *name;
  89        const struct attribute_group **groups;
  90        int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
  91        char *(*devnode)(struct device *dev, umode_t *mode,
  92                         kuid_t *uid, kgid_t *gid);
  93        void (*release)(struct device *dev);
  94
  95        const struct dev_pm_ops *pm;
  96};
  97
  98/* interface for exporting device attributes */
  99struct device_attribute {
 100        struct attribute        attr;
 101        ssize_t (*show)(struct device *dev, struct device_attribute *attr,
 102                        char *buf);
 103        ssize_t (*store)(struct device *dev, struct device_attribute *attr,
 104                         const char *buf, size_t count);
 105};
 106
 107struct dev_ext_attribute {
 108        struct device_attribute attr;
 109        void *var;
 110};
 111
 112ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
 113                          char *buf);
 114ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
 115                           const char *buf, size_t count);
 116ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
 117                        char *buf);
 118ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
 119                         const char *buf, size_t count);
 120ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
 121                        char *buf);
 122ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
 123                         const char *buf, size_t count);
 124
 125#define DEVICE_ATTR(_name, _mode, _show, _store) \
 126        struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
 127#define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
 128        struct device_attribute dev_attr_##_name = \
 129                __ATTR_PREALLOC(_name, _mode, _show, _store)
 130#define DEVICE_ATTR_RW(_name) \
 131        struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
 132#define DEVICE_ATTR_ADMIN_RW(_name) \
 133        struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600)
 134#define DEVICE_ATTR_RO(_name) \
 135        struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
 136#define DEVICE_ATTR_ADMIN_RO(_name) \
 137        struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
 138#define DEVICE_ATTR_WO(_name) \
 139        struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
 140#define DEVICE_ULONG_ATTR(_name, _mode, _var) \
 141        struct dev_ext_attribute dev_attr_##_name = \
 142                { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
 143#define DEVICE_INT_ATTR(_name, _mode, _var) \
 144        struct dev_ext_attribute dev_attr_##_name = \
 145                { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
 146#define DEVICE_BOOL_ATTR(_name, _mode, _var) \
 147        struct dev_ext_attribute dev_attr_##_name = \
 148                { __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
 149#define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
 150        struct device_attribute dev_attr_##_name =              \
 151                __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
 152
 153int device_create_file(struct device *device,
 154                       const struct device_attribute *entry);
 155void device_remove_file(struct device *dev,
 156                        const struct device_attribute *attr);
 157bool device_remove_file_self(struct device *dev,
 158                             const struct device_attribute *attr);
 159int __must_check device_create_bin_file(struct device *dev,
 160                                        const struct bin_attribute *attr);
 161void device_remove_bin_file(struct device *dev,
 162                            const struct bin_attribute *attr);
 163
 164/* device resource management */
 165typedef void (*dr_release_t)(struct device *dev, void *res);
 166typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
 167
 168#ifdef CONFIG_DEBUG_DEVRES
 169void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
 170                          int nid, const char *name) __malloc;
 171#define devres_alloc(release, size, gfp) \
 172        __devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
 173#define devres_alloc_node(release, size, gfp, nid) \
 174        __devres_alloc_node(release, size, gfp, nid, #release)
 175#else
 176void *devres_alloc_node(dr_release_t release, size_t size,
 177                        gfp_t gfp, int nid) __malloc;
 178static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
 179{
 180        return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
 181}
 182#endif
 183
 184void devres_for_each_res(struct device *dev, dr_release_t release,
 185                         dr_match_t match, void *match_data,
 186                         void (*fn)(struct device *, void *, void *),
 187                         void *data);
 188void devres_free(void *res);
 189void devres_add(struct device *dev, void *res);
 190void *devres_find(struct device *dev, dr_release_t release,
 191                  dr_match_t match, void *match_data);
 192void *devres_get(struct device *dev, void *new_res,
 193                 dr_match_t match, void *match_data);
 194void *devres_remove(struct device *dev, dr_release_t release,
 195                    dr_match_t match, void *match_data);
 196int devres_destroy(struct device *dev, dr_release_t release,
 197                   dr_match_t match, void *match_data);
 198int devres_release(struct device *dev, dr_release_t release,
 199                   dr_match_t match, void *match_data);
 200
 201/* devres group */
 202void * __must_check devres_open_group(struct device *dev, void *id, gfp_t gfp);
 203void devres_close_group(struct device *dev, void *id);
 204void devres_remove_group(struct device *dev, void *id);
 205int devres_release_group(struct device *dev, void *id);
 206
 207/* managed devm_k.alloc/kfree for device drivers */
 208void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
 209void *devm_krealloc(struct device *dev, void *ptr, size_t size,
 210                    gfp_t gfp) __must_check;
 211__printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
 212                                     const char *fmt, va_list ap) __malloc;
 213__printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
 214                                    const char *fmt, ...) __malloc;
 215static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
 216{
 217        return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
 218}
 219static inline void *devm_kmalloc_array(struct device *dev,
 220                                       size_t n, size_t size, gfp_t flags)
 221{
 222        size_t bytes;
 223
 224        if (unlikely(check_mul_overflow(n, size, &bytes)))
 225                return NULL;
 226
 227        return devm_kmalloc(dev, bytes, flags);
 228}
 229static inline void *devm_kcalloc(struct device *dev,
 230                                 size_t n, size_t size, gfp_t flags)
 231{
 232        return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
 233}
 234void devm_kfree(struct device *dev, const void *p);
 235char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
 236const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp);
 237void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp);
 238
 239unsigned long devm_get_free_pages(struct device *dev,
 240                                  gfp_t gfp_mask, unsigned int order);
 241void devm_free_pages(struct device *dev, unsigned long addr);
 242
 243void __iomem *devm_ioremap_resource(struct device *dev,
 244                                    const struct resource *res);
 245void __iomem *devm_ioremap_resource_wc(struct device *dev,
 246                                       const struct resource *res);
 247
 248void __iomem *devm_of_iomap(struct device *dev,
 249                            struct device_node *node, int index,
 250                            resource_size_t *size);
 251
 252/* allows to add/remove a custom action to devres stack */
 253int devm_add_action(struct device *dev, void (*action)(void *), void *data);
 254void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
 255void devm_release_action(struct device *dev, void (*action)(void *), void *data);
 256
 257static inline int devm_add_action_or_reset(struct device *dev,
 258                                           void (*action)(void *), void *data)
 259{
 260        int ret;
 261
 262        ret = devm_add_action(dev, action, data);
 263        if (ret)
 264                action(data);
 265
 266        return ret;
 267}
 268
 269/**
 270 * devm_alloc_percpu - Resource-managed alloc_percpu
 271 * @dev: Device to allocate per-cpu memory for
 272 * @type: Type to allocate per-cpu memory for
 273 *
 274 * Managed alloc_percpu. Per-cpu memory allocated with this function is
 275 * automatically freed on driver detach.
 276 *
 277 * RETURNS:
 278 * Pointer to allocated memory on success, NULL on failure.
 279 */
 280#define devm_alloc_percpu(dev, type)      \
 281        ((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
 282                                                      __alignof__(type)))
 283
 284void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
 285                                   size_t align);
 286void devm_free_percpu(struct device *dev, void __percpu *pdata);
 287
 288struct device_dma_parameters {
 289        /*
 290         * a low level driver may set these to teach IOMMU code about
 291         * sg limitations.
 292         */
 293        unsigned int max_segment_size;
 294        unsigned long segment_boundary_mask;
 295};
 296
 297/**
 298 * enum device_link_state - Device link states.
 299 * @DL_STATE_NONE: The presence of the drivers is not being tracked.
 300 * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
 301 * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
 302 * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
 303 * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
 304 * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
 305 */
 306enum device_link_state {
 307        DL_STATE_NONE = -1,
 308        DL_STATE_DORMANT = 0,
 309        DL_STATE_AVAILABLE,
 310        DL_STATE_CONSUMER_PROBE,
 311        DL_STATE_ACTIVE,
 312        DL_STATE_SUPPLIER_UNBIND,
 313};
 314
 315/*
 316 * Device link flags.
 317 *
 318 * STATELESS: The core will not remove this link automatically.
 319 * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
 320 * PM_RUNTIME: If set, the runtime PM framework will use this link.
 321 * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
 322 * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
 323 * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
 324 * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
 325 * SYNC_STATE_ONLY: Link only affects sync_state() behavior.
 326 */
 327#define DL_FLAG_STATELESS               BIT(0)
 328#define DL_FLAG_AUTOREMOVE_CONSUMER     BIT(1)
 329#define DL_FLAG_PM_RUNTIME              BIT(2)
 330#define DL_FLAG_RPM_ACTIVE              BIT(3)
 331#define DL_FLAG_AUTOREMOVE_SUPPLIER     BIT(4)
 332#define DL_FLAG_AUTOPROBE_CONSUMER      BIT(5)
 333#define DL_FLAG_MANAGED                 BIT(6)
 334#define DL_FLAG_SYNC_STATE_ONLY         BIT(7)
 335
 336/**
 337 * enum dl_dev_state - Device driver presence tracking information.
 338 * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
 339 * @DL_DEV_PROBING: A driver is probing.
 340 * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
 341 * @DL_DEV_UNBINDING: The driver is unbinding from the device.
 342 */
 343enum dl_dev_state {
 344        DL_DEV_NO_DRIVER = 0,
 345        DL_DEV_PROBING,
 346        DL_DEV_DRIVER_BOUND,
 347        DL_DEV_UNBINDING,
 348};
 349
 350/**
 351 * struct dev_links_info - Device data related to device links.
 352 * @suppliers: List of links to supplier devices.
 353 * @consumers: List of links to consumer devices.
 354 * @needs_suppliers: Hook to global list of devices waiting for suppliers.
 355 * @defer_hook: Hook to global list of devices that have deferred sync_state or
 356 *              deferred fw_devlink.
 357 * @need_for_probe: If needs_suppliers is on a list, this indicates if the
 358 *                  suppliers are needed for probe or not.
 359 * @status: Driver status information.
 360 */
 361struct dev_links_info {
 362        struct list_head suppliers;
 363        struct list_head consumers;
 364        struct list_head needs_suppliers;
 365        struct list_head defer_hook;
 366        bool need_for_probe;
 367        enum dl_dev_state status;
 368};
 369
 370/**
 371 * struct device - The basic device structure
 372 * @parent:     The device's "parent" device, the device to which it is attached.
 373 *              In most cases, a parent device is some sort of bus or host
 374 *              controller. If parent is NULL, the device, is a top-level device,
 375 *              which is not usually what you want.
 376 * @p:          Holds the private data of the driver core portions of the device.
 377 *              See the comment of the struct device_private for detail.
 378 * @kobj:       A top-level, abstract class from which other classes are derived.
 379 * @init_name:  Initial name of the device.
 380 * @type:       The type of device.
 381 *              This identifies the device type and carries type-specific
 382 *              information.
 383 * @mutex:      Mutex to synchronize calls to its driver.
 384 * @lockdep_mutex: An optional debug lock that a subsystem can use as a
 385 *              peer lock to gain localized lockdep coverage of the device_lock.
 386 * @bus:        Type of bus device is on.
 387 * @driver:     Which driver has allocated this
 388 * @platform_data: Platform data specific to the device.
 389 *              Example: For devices on custom boards, as typical of embedded
 390 *              and SOC based hardware, Linux often uses platform_data to point
 391 *              to board-specific structures describing devices and how they
 392 *              are wired.  That can include what ports are available, chip
 393 *              variants, which GPIO pins act in what additional roles, and so
 394 *              on.  This shrinks the "Board Support Packages" (BSPs) and
 395 *              minimizes board-specific #ifdefs in drivers.
 396 * @driver_data: Private pointer for driver specific info.
 397 * @links:      Links to suppliers and consumers of this device.
 398 * @power:      For device power management.
 399 *              See Documentation/driver-api/pm/devices.rst for details.
 400 * @pm_domain:  Provide callbacks that are executed during system suspend,
 401 *              hibernation, system resume and during runtime PM transitions
 402 *              along with subsystem-level and driver-level callbacks.
 403 * @em_pd:      device's energy model performance domain
 404 * @pins:       For device pin management.
 405 *              See Documentation/driver-api/pinctl.rst for details.
 406 * @msi_list:   Hosts MSI descriptors
 407 * @msi_domain: The generic MSI domain this device is using.
 408 * @numa_node:  NUMA node this device is close to.
 409 * @dma_ops:    DMA mapping operations for this device.
 410 * @dma_mask:   Dma mask (if dma'ble device).
 411 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
 412 *              hardware supports 64-bit addresses for consistent allocations
 413 *              such descriptors.
 414 * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
 415 *              DMA limit than the device itself supports.
 416 * @dma_range_map: map for DMA memory ranges relative to that of RAM
 417 * @dma_parms:  A low level driver may set these to teach IOMMU code about
 418 *              segment limitations.
 419 * @dma_pools:  Dma pools (if dma'ble device).
 420 * @dma_mem:    Internal for coherent mem override.
 421 * @cma_area:   Contiguous memory area for dma allocations
 422 * @archdata:   For arch-specific additions.
 423 * @of_node:    Associated device tree node.
 424 * @fwnode:     Associated device node supplied by platform firmware.
 425 * @devt:       For creating the sysfs "dev".
 426 * @id:         device instance
 427 * @devres_lock: Spinlock to protect the resource of the device.
 428 * @devres_head: The resources list of the device.
 429 * @knode_class: The node used to add the device to the class list.
 430 * @class:      The class of the device.
 431 * @groups:     Optional attribute groups.
 432 * @release:    Callback to free the device after all references have
 433 *              gone away. This should be set by the allocator of the
 434 *              device (i.e. the bus driver that discovered the device).
 435 * @iommu_group: IOMMU group the device belongs to.
 436 * @iommu:      Per device generic IOMMU runtime data
 437 *
 438 * @offline_disabled: If set, the device is permanently online.
 439 * @offline:    Set after successful invocation of bus type's .offline().
 440 * @of_node_reused: Set if the device-tree node is shared with an ancestor
 441 *              device.
 442 * @state_synced: The hardware state of this device has been synced to match
 443 *                the software state of this device by calling the driver/bus
 444 *                sync_state() callback.
 445 * @dma_coherent: this particular device is dma coherent, even if the
 446 *              architecture supports non-coherent devices.
 447 * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
 448 *              streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
 449 *              and optionall (if the coherent mask is large enough) also
 450 *              for dma allocations.  This flag is managed by the dma ops
 451 *              instance from ->dma_supported.
 452 *
 453 * At the lowest level, every device in a Linux system is represented by an
 454 * instance of struct device. The device structure contains the information
 455 * that the device model core needs to model the system. Most subsystems,
 456 * however, track additional information about the devices they host. As a
 457 * result, it is rare for devices to be represented by bare device structures;
 458 * instead, that structure, like kobject structures, is usually embedded within
 459 * a higher-level representation of the device.
 460 */
 461struct device {
 462        struct kobject kobj;
 463        struct device           *parent;
 464
 465        struct device_private   *p;
 466
 467        const char              *init_name; /* initial name of the device */
 468        const struct device_type *type;
 469
 470        struct bus_type *bus;           /* type of bus device is on */
 471        struct device_driver *driver;   /* which driver has allocated this
 472                                           device */
 473        void            *platform_data; /* Platform specific data, device
 474                                           core doesn't touch it */
 475        void            *driver_data;   /* Driver data, set and get with
 476                                           dev_set_drvdata/dev_get_drvdata */
 477#ifdef CONFIG_PROVE_LOCKING
 478        struct mutex            lockdep_mutex;
 479#endif
 480        struct mutex            mutex;  /* mutex to synchronize calls to
 481                                         * its driver.
 482                                         */
 483
 484        struct dev_links_info   links;
 485        struct dev_pm_info      power;
 486        struct dev_pm_domain    *pm_domain;
 487
 488#ifdef CONFIG_ENERGY_MODEL
 489        struct em_perf_domain   *em_pd;
 490#endif
 491
 492#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
 493        struct irq_domain       *msi_domain;
 494#endif
 495#ifdef CONFIG_PINCTRL
 496        struct dev_pin_info     *pins;
 497#endif
 498#ifdef CONFIG_GENERIC_MSI_IRQ
 499        struct list_head        msi_list;
 500#endif
 501#ifdef CONFIG_DMA_OPS
 502        const struct dma_map_ops *dma_ops;
 503#endif
 504        u64             *dma_mask;      /* dma mask (if dma'able device) */
 505        u64             coherent_dma_mask;/* Like dma_mask, but for
 506                                             alloc_coherent mappings as
 507                                             not all hardware supports
 508                                             64 bit addresses for consistent
 509                                             allocations such descriptors. */
 510        u64             bus_dma_limit;  /* upstream dma constraint */
 511        const struct bus_dma_region *dma_range_map;
 512
 513        struct device_dma_parameters *dma_parms;
 514
 515        struct list_head        dma_pools;      /* dma pools (if dma'ble) */
 516
 517#ifdef CONFIG_DMA_DECLARE_COHERENT
 518        struct dma_coherent_mem *dma_mem; /* internal for coherent mem
 519                                             override */
 520#endif
 521#ifdef CONFIG_DMA_CMA
 522        struct cma *cma_area;           /* contiguous memory area for dma
 523                                           allocations */
 524#endif
 525        /* arch specific additions */
 526        struct dev_archdata     archdata;
 527
 528        struct device_node      *of_node; /* associated device tree node */
 529        struct fwnode_handle    *fwnode; /* firmware device node */
 530
 531#ifdef CONFIG_NUMA
 532        int             numa_node;      /* NUMA node this device is close to */
 533#endif
 534        dev_t                   devt;   /* dev_t, creates the sysfs "dev" */
 535        u32                     id;     /* device instance */
 536
 537        spinlock_t              devres_lock;
 538        struct list_head        devres_head;
 539
 540        struct class            *class;
 541        const struct attribute_group **groups;  /* optional groups */
 542
 543        void    (*release)(struct device *dev);
 544        struct iommu_group      *iommu_group;
 545        struct dev_iommu        *iommu;
 546
 547        bool                    offline_disabled:1;
 548        bool                    offline:1;
 549        bool                    of_node_reused:1;
 550        bool                    state_synced:1;
 551#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
 552    defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
 553    defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
 554        bool                    dma_coherent:1;
 555#endif
 556#ifdef CONFIG_DMA_OPS_BYPASS
 557        bool                    dma_ops_bypass : 1;
 558#endif
 559};
 560
 561/**
 562 * struct device_link - Device link representation.
 563 * @supplier: The device on the supplier end of the link.
 564 * @s_node: Hook to the supplier device's list of links to consumers.
 565 * @consumer: The device on the consumer end of the link.
 566 * @c_node: Hook to the consumer device's list of links to suppliers.
 567 * @link_dev: device used to expose link details in sysfs
 568 * @status: The state of the link (with respect to the presence of drivers).
 569 * @flags: Link flags.
 570 * @rpm_active: Whether or not the consumer device is runtime-PM-active.
 571 * @kref: Count repeated addition of the same link.
 572 * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
 573 * @supplier_preactivated: Supplier has been made active before consumer probe.
 574 */
 575struct device_link {
 576        struct device *supplier;
 577        struct list_head s_node;
 578        struct device *consumer;
 579        struct list_head c_node;
 580        struct device link_dev;
 581        enum device_link_state status;
 582        u32 flags;
 583        refcount_t rpm_active;
 584        struct kref kref;
 585#ifdef CONFIG_SRCU
 586        struct rcu_head rcu_head;
 587#endif
 588        bool supplier_preactivated; /* Owned by consumer probe. */
 589};
 590
 591static inline struct device *kobj_to_dev(struct kobject *kobj)
 592{
 593        return container_of(kobj, struct device, kobj);
 594}
 595
 596/**
 597 * device_iommu_mapped - Returns true when the device DMA is translated
 598 *                       by an IOMMU
 599 * @dev: Device to perform the check on
 600 */
 601static inline bool device_iommu_mapped(struct device *dev)
 602{
 603        return (dev->iommu_group != NULL);
 604}
 605
 606/* Get the wakeup routines, which depend on struct device */
 607#include <linux/pm_wakeup.h>
 608
 609static inline const char *dev_name(const struct device *dev)
 610{
 611        /* Use the init name until the kobject becomes available */
 612        if (dev->init_name)
 613                return dev->init_name;
 614
 615        return kobject_name(&dev->kobj);
 616}
 617
 618__printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);
 619
 620#ifdef CONFIG_NUMA
 621static inline int dev_to_node(struct device *dev)
 622{
 623        return dev->numa_node;
 624}
 625static inline void set_dev_node(struct device *dev, int node)
 626{
 627        dev->numa_node = node;
 628}
 629#else
 630static inline int dev_to_node(struct device *dev)
 631{
 632        return NUMA_NO_NODE;
 633}
 634static inline void set_dev_node(struct device *dev, int node)
 635{
 636}
 637#endif
 638
 639static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
 640{
 641#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
 642        return dev->msi_domain;
 643#else
 644        return NULL;
 645#endif
 646}
 647
 648static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
 649{
 650#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
 651        dev->msi_domain = d;
 652#endif
 653}
 654
 655static inline void *dev_get_drvdata(const struct device *dev)
 656{
 657        return dev->driver_data;
 658}
 659
 660static inline void dev_set_drvdata(struct device *dev, void *data)
 661{
 662        dev->driver_data = data;
 663}
 664
 665static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
 666{
 667        return dev ? dev->power.subsys_data : NULL;
 668}
 669
 670static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
 671{
 672        return dev->kobj.uevent_suppress;
 673}
 674
 675static inline void dev_set_uevent_suppress(struct device *dev, int val)
 676{
 677        dev->kobj.uevent_suppress = val;
 678}
 679
 680static inline int device_is_registered(struct device *dev)
 681{
 682        return dev->kobj.state_in_sysfs;
 683}
 684
 685static inline void device_enable_async_suspend(struct device *dev)
 686{
 687        if (!dev->power.is_prepared)
 688                dev->power.async_suspend = true;
 689}
 690
 691static inline void device_disable_async_suspend(struct device *dev)
 692{
 693        if (!dev->power.is_prepared)
 694                dev->power.async_suspend = false;
 695}
 696
 697static inline bool device_async_suspend_enabled(struct device *dev)
 698{
 699        return !!dev->power.async_suspend;
 700}
 701
 702static inline bool device_pm_not_required(struct device *dev)
 703{
 704        return dev->power.no_pm;
 705}
 706
 707static inline void device_set_pm_not_required(struct device *dev)
 708{
 709        dev->power.no_pm = true;
 710}
 711
 712static inline void dev_pm_syscore_device(struct device *dev, bool val)
 713{
 714#ifdef CONFIG_PM_SLEEP
 715        dev->power.syscore = val;
 716#endif
 717}
 718
 719static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
 720{
 721        dev->power.driver_flags = flags;
 722}
 723
 724static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
 725{
 726        return !!(dev->power.driver_flags & flags);
 727}
 728
 729static inline void device_lock(struct device *dev)
 730{
 731        mutex_lock(&dev->mutex);
 732}
 733
 734static inline int device_lock_interruptible(struct device *dev)
 735{
 736        return mutex_lock_interruptible(&dev->mutex);
 737}
 738
 739static inline int device_trylock(struct device *dev)
 740{
 741        return mutex_trylock(&dev->mutex);
 742}
 743
 744static inline void device_unlock(struct device *dev)
 745{
 746        mutex_unlock(&dev->mutex);
 747}
 748
 749static inline void device_lock_assert(struct device *dev)
 750{
 751        lockdep_assert_held(&dev->mutex);
 752}
 753
 754static inline struct device_node *dev_of_node(struct device *dev)
 755{
 756        if (!IS_ENABLED(CONFIG_OF) || !dev)
 757                return NULL;
 758        return dev->of_node;
 759}
 760
 761static inline bool dev_has_sync_state(struct device *dev)
 762{
 763        if (!dev)
 764                return false;
 765        if (dev->driver && dev->driver->sync_state)
 766                return true;
 767        if (dev->bus && dev->bus->sync_state)
 768                return true;
 769        return false;
 770}
 771
 772/*
 773 * High level routines for use by the bus drivers
 774 */
 775int __must_check device_register(struct device *dev);
 776void device_unregister(struct device *dev);
 777void device_initialize(struct device *dev);
 778int __must_check device_add(struct device *dev);
 779void device_del(struct device *dev);
 780int device_for_each_child(struct device *dev, void *data,
 781                          int (*fn)(struct device *dev, void *data));
 782int device_for_each_child_reverse(struct device *dev, void *data,
 783                                  int (*fn)(struct device *dev, void *data));
 784struct device *device_find_child(struct device *dev, void *data,
 785                                 int (*match)(struct device *dev, void *data));
 786struct device *device_find_child_by_name(struct device *parent,
 787                                         const char *name);
 788int device_rename(struct device *dev, const char *new_name);
 789int device_move(struct device *dev, struct device *new_parent,
 790                enum dpm_order dpm_order);
 791int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
 792const char *device_get_devnode(struct device *dev, umode_t *mode, kuid_t *uid,
 793                               kgid_t *gid, const char **tmp);
 794int device_is_dependent(struct device *dev, void *target);
 795
 796static inline bool device_supports_offline(struct device *dev)
 797{
 798        return dev->bus && dev->bus->offline && dev->bus->online;
 799}
 800
 801void lock_device_hotplug(void);
 802void unlock_device_hotplug(void);
 803int lock_device_hotplug_sysfs(void);
 804int device_offline(struct device *dev);
 805int device_online(struct device *dev);
 806void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
 807void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
 808void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
 809
 810static inline int dev_num_vf(struct device *dev)
 811{
 812        if (dev->bus && dev->bus->num_vf)
 813                return dev->bus->num_vf(dev);
 814        return 0;
 815}
 816
 817/*
 818 * Root device objects for grouping under /sys/devices
 819 */
 820struct device *__root_device_register(const char *name, struct module *owner);
 821
 822/* This is a macro to avoid include problems with THIS_MODULE */
 823#define root_device_register(name) \
 824        __root_device_register(name, THIS_MODULE)
 825
 826void root_device_unregister(struct device *root);
 827
 828static inline void *dev_get_platdata(const struct device *dev)
 829{
 830        return dev->platform_data;
 831}
 832
 833/*
 834 * Manual binding of a device to driver. See drivers/base/bus.c
 835 * for information on use.
 836 */
 837int __must_check device_bind_driver(struct device *dev);
 838void device_release_driver(struct device *dev);
 839int  __must_check device_attach(struct device *dev);
 840int __must_check driver_attach(struct device_driver *drv);
 841void device_initial_probe(struct device *dev);
 842int __must_check device_reprobe(struct device *dev);
 843
 844bool device_is_bound(struct device *dev);
 845
 846/*
 847 * Easy functions for dynamically creating devices on the fly
 848 */
 849__printf(5, 6) struct device *
 850device_create(struct class *cls, struct device *parent, dev_t devt,
 851              void *drvdata, const char *fmt, ...);
 852__printf(6, 7) struct device *
 853device_create_with_groups(struct class *cls, struct device *parent, dev_t devt,
 854                          void *drvdata, const struct attribute_group **groups,
 855                          const char *fmt, ...);
 856void device_destroy(struct class *cls, dev_t devt);
 857
 858int __must_check device_add_groups(struct device *dev,
 859                                   const struct attribute_group **groups);
 860void device_remove_groups(struct device *dev,
 861                          const struct attribute_group **groups);
 862
 863static inline int __must_check device_add_group(struct device *dev,
 864                                        const struct attribute_group *grp)
 865{
 866        const struct attribute_group *groups[] = { grp, NULL };
 867
 868        return device_add_groups(dev, groups);
 869}
 870
 871static inline void device_remove_group(struct device *dev,
 872                                       const struct attribute_group *grp)
 873{
 874        const struct attribute_group *groups[] = { grp, NULL };
 875
 876        return device_remove_groups(dev, groups);
 877}
 878
 879int __must_check devm_device_add_groups(struct device *dev,
 880                                        const struct attribute_group **groups);
 881void devm_device_remove_groups(struct device *dev,
 882                               const struct attribute_group **groups);
 883int __must_check devm_device_add_group(struct device *dev,
 884                                       const struct attribute_group *grp);
 885void devm_device_remove_group(struct device *dev,
 886                              const struct attribute_group *grp);
 887
 888/*
 889 * Platform "fixup" functions - allow the platform to have their say
 890 * about devices and actions that the general device layer doesn't
 891 * know about.
 892 */
 893/* Notify platform of device discovery */
 894extern int (*platform_notify)(struct device *dev);
 895
 896extern int (*platform_notify_remove)(struct device *dev);
 897
 898
 899/*
 900 * get_device - atomically increment the reference count for the device.
 901 *
 902 */
 903struct device *get_device(struct device *dev);
 904void put_device(struct device *dev);
 905bool kill_device(struct device *dev);
 906
 907#ifdef CONFIG_DEVTMPFS
 908int devtmpfs_mount(void);
 909#else
 910static inline int devtmpfs_mount(void) { return 0; }
 911#endif
 912
 913/* drivers/base/power/shutdown.c */
 914void device_shutdown(void);
 915
 916/* debugging and troubleshooting/diagnostic helpers. */
 917const char *dev_driver_string(const struct device *dev);
 918
 919/* Device links interface. */
 920struct device_link *device_link_add(struct device *consumer,
 921                                    struct device *supplier, u32 flags);
 922void device_link_del(struct device_link *link);
 923void device_link_remove(void *consumer, struct device *supplier);
 924void device_links_supplier_sync_state_pause(void);
 925void device_links_supplier_sync_state_resume(void);
 926
 927extern __printf(3, 4)
 928int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
 929
 930/* Create alias, so I can be autoloaded. */
 931#define MODULE_ALIAS_CHARDEV(major,minor) \
 932        MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
 933#define MODULE_ALIAS_CHARDEV_MAJOR(major) \
 934        MODULE_ALIAS("char-major-" __stringify(major) "-*")
 935
 936#ifdef CONFIG_SYSFS_DEPRECATED
 937extern long sysfs_deprecated;
 938#else
 939#define sysfs_deprecated 0
 940#endif
 941
 942#endif /* _DEVICE_H_ */
 943