// SPDX-License-Identifier: GPL-2.0
/*
 * device.h - generic, centralized driver model
 *
 * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
 * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (c) 2008-2009 Novell Inc.
 *
 * See Documentation/driver-api/driver-model/ for more information.
 */

#ifndef _DEVICE_H_
#define _DEVICE_H_

#include <linux/dev_printk.h>
#include <linux/energy_model.h>
#include <linux/ioport.h>
#include <linux/kobject.h>
#include <linux/klist.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/atomic.h>
#include <linux/uidgid.h>
#include <linux/gfp.h>
#include <linux/overflow.h>
#include <linux/device/bus.h>
#include <linux/device/class.h>
#include <linux/device/driver.h>
#include <asm/device.h>

struct device;
struct device_private;
struct device_driver;
struct driver_private;
struct module;
struct class;
struct subsys_private;
struct device_node;
struct fwnode_handle;
struct iommu_ops;
struct iommu_group;
struct dev_pin_info;
struct dev_iommu;

/**
 * struct subsys_interface - interfaces to device functions
 * @name:       name of the device function
 * @subsys:     subsytem of the devices to attach to
 * @node:       the list of functions registered at the subsystem
 * @add_dev:    device hookup to device function handler
 * @remove_dev: device hookup to device function handler
 *
 * Simple interfaces attached to a subsystem. Multiple interfaces can
 * attach to a subsystem and its devices. Unlike drivers, they do not
 * exclusively claim or control devices. Interfaces usually represent
 * a specific functionality of a subsystem/class of devices.
 */
struct subsys_interface {
        const char *name;
        struct bus_type *subsys;
        struct list_head node;
        int (*add_dev)(struct device *dev, struct subsys_interface *sif);
        void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
};

int subsys_interface_register(struct subsys_interface *sif);
void subsys_interface_unregister(struct subsys_interface *sif);

int subsys_system_register(struct bus_type *subsys,
                           const struct attribute_group **groups);
int subsys_virtual_register(struct bus_type *subsys,
                            const struct attribute_group **groups);

/*
 * The type of device, "struct device" is embedded in. A class
 * or bus can contain devices of different types
 * like "partitions" and "disks", "mouse" and "event".
 * This identifies the device type and carries type-specific
 * information, equivalent to the kobj_type of a kobject.
 * If "name" is specified, the uevent will contain it in
 * the DEVTYPE variable.
 */
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;
};

/* interface for exporting device attributes */
struct device_attribute {
        struct attribute        attr;
        ssize_t (*show)(struct device *dev, struct device_attribute *attr,
                        char *buf);
        ssize_t (*store)(struct device *dev, struct device_attribute *attr,
                         const char *buf, size_t count);
};

struct dev_ext_attribute {
        struct device_attribute attr;
        void *var;
};

ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
                          char *buf);
ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
                           const char *buf, size_t count);
ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
                        char *buf);
ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
                         const char *buf, size_t count);
ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
                        char *buf);
ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
                         const char *buf, size_t count);

#define DEVICE_ATTR(_name, _mode, _show, _store) \
        struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
#define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
        struct device_attribute dev_attr_##_name = \
                __ATTR_PREALLOC(_name, _mode, _show, _store)
#define DEVICE_ATTR_RW(_name) \
        struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
#define DEVICE_ATTR_ADMIN_RW(_name) \
        struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600)
#define DEVICE_ATTR_RO(_name) \
        struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
#define DEVICE_ATTR_ADMIN_RO(_name) \
        struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
#define DEVICE_ATTR_WO(_name) \
        struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
#define DEVICE_ULONG_ATTR(_name, _mode, _var) \
        struct dev_ext_attribute dev_attr_##_name = \
                { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
#define DEVICE_INT_ATTR(_name, _mode, _var) \
        struct dev_ext_attribute dev_attr_##_name = \
                { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
#define DEVICE_BOOL_ATTR(_name, _mode, _var) \
        struct dev_ext_attribute dev_attr_##_name = \
                { __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
#define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
        struct device_attribute dev_attr_##_name =              \
                __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)

int device_create_file(struct device *device,
                       const struct device_attribute *entry);
void device_remove_file(struct device *dev,
                        const struct device_attribute *attr);
bool device_remove_file_self(struct device *dev,
                             const struct device_attribute *attr);
int __must_check device_create_bin_file(struct device *dev,
                                        const struct bin_attribute *attr);
void device_remove_bin_file(struct device *dev,
                            const struct bin_attribute *attr);

/* device resource management */
typedef void (*dr_release_t)(struct device *dev, void *res);
typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);

#ifdef CONFIG_DEBUG_DEVRES
void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
                          int nid, const char *name) __malloc;
#define devres_alloc(release, size, gfp) \
        __devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
#define devres_alloc_node(release, size, gfp, nid) \
        __devres_alloc_node(release, size, gfp, nid, #release)
#else
void *devres_alloc_node(dr_release_t release, size_t size,
                        gfp_t gfp, int nid) __malloc;
static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
{
        return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
}
#endif

void devres_for_each_res(struct device *dev, dr_release_t release,
                         dr_match_t match, void *match_data,
                         void (*fn)(struct device *, void *, void *),
                         void *data);
void devres_free(void *res);
void devres_add(struct device *dev, void *res);
void *devres_find(struct device *dev, dr_release_t release,
                  dr_match_t match, void *match_data);
void *devres_get(struct device *dev, void *new_res,
                 dr_match_t match, void *match_data);
void *devres_remove(struct device *dev, dr_release_t release,
                    dr_match_t match, void *match_data);
int devres_destroy(struct device *dev, dr_release_t release,
                   dr_match_t match, void *match_data);
int devres_release(struct device *dev, dr_release_t release,
                   dr_match_t match, void *match_data);

/* devres group */
void * __must_check devres_open_group(struct device *dev, void *id, gfp_t gfp);
void devres_close_group(struct device *dev, void *id);
void devres_remove_group(struct device *dev, void *id);
int devres_release_group(struct device *dev, void *id);

/* managed devm_k.alloc/kfree for device drivers */
void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
__printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
                                     const char *fmt, va_list ap) __malloc;
__printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
                                    const char *fmt, ...) __malloc;
static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
{
        return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
}
static inline void *devm_kmalloc_array(struct device *dev,
                                       size_t n, size_t size, gfp_t flags)
{
        size_t bytes;

        if (unlikely(check_mul_overflow(n, size, &bytes)))
                return NULL;

        return devm_kmalloc(dev, bytes, flags);
}
static inline void *devm_kcalloc(struct device *dev,
                                 size_t n, size_t size, gfp_t flags)
{
        return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
}
void devm_kfree(struct device *dev, const void *p);
char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp);
void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp);

unsigned long devm_get_free_pages(struct device *dev,
                                  gfp_t gfp_mask, unsigned int order);
void devm_free_pages(struct device *dev, unsigned long addr);

void __iomem *devm_ioremap_resource(struct device *dev,
                                    const struct resource *res);
void __iomem *devm_ioremap_resource_wc(struct device *dev,
                                       const struct resource *res);

void __iomem *devm_of_iomap(struct device *dev,
                            struct device_node *node, int index,
                            resource_size_t *size);

/* allows to add/remove a custom action to devres stack */
int devm_add_action(struct device *dev, void (*action)(void *), void *data);
void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
void devm_release_action(struct device *dev, void (*action)(void *), void *data);

static inline int devm_add_action_or_reset(struct device *dev,
                                           void (*action)(void *), void *data)
{
        int ret;

        ret = devm_add_action(dev, action, data);
        if (ret)
                action(data);

        return ret;
}

/**
 * devm_alloc_percpu - Resource-managed alloc_percpu
 * @dev: Device to allocate per-cpu memory for
 * @type: Type to allocate per-cpu memory for
 *
 * Managed alloc_percpu. Per-cpu memory allocated with this function is
 * automatically freed on driver detach.
 *
 * RETURNS:
 * Pointer to allocated memory on success, NULL on failure.
 */
#define devm_alloc_percpu(dev, type)      \
        ((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
                                                      __alignof__(type)))

void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
                                   size_t align);
void devm_free_percpu(struct device *dev, void __percpu *pdata);

struct device_dma_parameters {
        /*
         * a low level driver may set these to teach IOMMU code about
         * sg limitations.
         */
        unsigned int max_segment_size;
        unsigned long segment_boundary_mask;
};

/**
 * struct device_connection - Device Connection Descriptor
 * @fwnode: The device node of the connected device
 * @endpoint: The names of the two devices connected together
 * @id: Unique identifier for the connection
 * @list: List head, private, for internal use only
 *
 * NOTE: @fwnode is not used together with @endpoint. @fwnode is used when
 * platform firmware defines the connection. When the connection is registered
 * with device_connection_add() @endpoint is used instead.
 */
struct device_connection {
        struct fwnode_handle    *fwnode;
        const char              *endpoint[2];
        const char              *id;
        struct list_head        list;
};

typedef void *(*devcon_match_fn_t)(struct device_connection *con, int ep,
                                   void *data);

void *fwnode_connection_find_match(struct fwnode_handle *fwnode,
                                   const char *con_id, void *data,
                                   devcon_match_fn_t match);
void *device_connection_find_match(struct device *dev, const char *con_id,
                                   void *data, devcon_match_fn_t match);

struct device *device_connection_find(struct device *dev, const char *con_id);

void device_connection_add(struct device_connection *con);
void device_connection_remove(struct device_connection *con);

/**
 * device_connections_add - Add multiple device connections at once
 * @cons: Zero terminated array of device connection descriptors
 */
static inline void device_connections_add(struct device_connection *cons)
{
        struct device_connection *c;

        for (c = cons; c->endpoint[0]; c++)
                device_connection_add(c);
}

/**
 * device_connections_remove - Remove multiple device connections at once
 * @cons: Zero terminated array of device connection descriptors
 */
static inline void device_connections_remove(struct device_connection *cons)
{
        struct device_connection *c;

        for (c = cons; c->endpoint[0]; c++)
                device_connection_remove(c);
}

/**
 * enum device_link_state - Device link states.
 * @DL_STATE_NONE: The presence of the drivers is not being tracked.
 * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
 * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
 * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
 * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
 * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
 */
enum device_link_state {
        DL_STATE_NONE = -1,
        DL_STATE_DORMANT = 0,
        DL_STATE_AVAILABLE,
        DL_STATE_CONSUMER_PROBE,
        DL_STATE_ACTIVE,
        DL_STATE_SUPPLIER_UNBIND,
};

/*
 * Device link flags.
 *
 * STATELESS: The core will not remove this link automatically.
 * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
 * PM_RUNTIME: If set, the runtime PM framework will use this link.
 * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
 * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
 * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
 * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
 * SYNC_STATE_ONLY: Link only affects sync_state() behavior.
 */
#define DL_FLAG_STATELESS               BIT(0)
#define DL_FLAG_AUTOREMOVE_CONSUMER     BIT(1)
#define DL_FLAG_PM_RUNTIME              BIT(2)
#define DL_FLAG_RPM_ACTIVE              BIT(3)
#define DL_FLAG_AUTOREMOVE_SUPPLIER     BIT(4)
#define DL_FLAG_AUTOPROBE_CONSUMER      BIT(5)
#define DL_FLAG_MANAGED                 BIT(6)
#define DL_FLAG_SYNC_STATE_ONLY         BIT(7)

/**
 * enum dl_dev_state - Device driver presence tracking information.
 * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
 * @DL_DEV_PROBING: A driver is probing.
 * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
 * @DL_DEV_UNBINDING: The driver is unbinding from the device.
 */
enum dl_dev_state {
        DL_DEV_NO_DRIVER = 0,
        DL_DEV_PROBING,
        DL_DEV_DRIVER_BOUND,
        DL_DEV_UNBINDING,
};

/**
 * struct dev_links_info - Device data related to device links.
 * @suppliers: List of links to supplier devices.
 * @consumers: List of links to consumer devices.
 * @needs_suppliers: Hook to global list of devices waiting for suppliers.
 * @defer_hook: Hook to global list of devices that have deferred sync_state or
 *              deferred fw_devlink.
 * @need_for_probe: If needs_suppliers is on a list, this indicates if the
 *                  suppliers are needed for probe or not.
 * @status: Driver status information.
 */
struct dev_links_info {
        struct list_head suppliers;
        struct list_head consumers;
        struct list_head needs_suppliers;
        struct list_head defer_hook;
        bool need_for_probe;
        enum dl_dev_state status;
};

/**
 * struct device - The basic device structure
 * @parent:     The device's "parent" device, the device to which it is attached.
 *              In most cases, a parent device is some sort of bus or host
 *              controller. If parent is NULL, the device, is a top-level device,
 *              which is not usually what you want.
 * @p:          Holds the private data of the driver core portions of the device.
 *              See the comment of the struct device_private for detail.
 * @kobj:       A top-level, abstract class from which other classes are derived.
 * @init_name:  Initial name of the device.
 * @type:       The type of device.
 *              This identifies the device type and carries type-specific
 *              information.
 * @mutex:      Mutex to synchronize calls to its driver.
 * @lockdep_mutex: An optional debug lock that a subsystem can use as a
 *              peer lock to gain localized lockdep coverage of the device_lock.
 * @bus:        Type of bus device is on.
 * @driver:     Which driver has allocated this
 * @platform_data: Platform data specific to the device.
 *              Example: For devices on custom boards, as typical of embedded
 *              and SOC based hardware, Linux often uses platform_data to point
 *              to board-specific structures describing devices and how they
 *              are wired.  That can include what ports are available, chip
 *              variants, which GPIO pins act in what additional roles, and so
 *              on.  This shrinks the "Board Support Packages" (BSPs) and
 *              minimizes board-specific #ifdefs in drivers.
 * @driver_data: Private pointer for driver specific info.
 * @links:      Links to suppliers and consumers of this device.
 * @power:      For device power management.
 *              See Documentation/driver-api/pm/devices.rst for details.
 * @pm_domain:  Provide callbacks that are executed during system suspend,
 *              hibernation, system resume and during runtime PM transitions
 *              along with subsystem-level and driver-level callbacks.
 * @em_pd:      device's energy model performance domain
 * @pins:       For device pin management.
 *              See Documentation/driver-api/pinctl.rst for details.
 * @msi_list:   Hosts MSI descriptors
 * @msi_domain: The generic MSI domain this device is using.
 * @numa_node:  NUMA node this device is close to.
 * @dma_ops:    DMA mapping operations for this device.
 * @dma_mask:   Dma mask (if dma'ble device).
 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
 *              hardware supports 64-bit addresses for consistent allocations
 *              such descriptors.
 * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
 *              DMA limit than the device itself supports.
 * @dma_pfn_offset: offset of DMA memory range relatively of RAM
 * @dma_parms:  A low level driver may set these to teach IOMMU code about
 *              segment limitations.
 * @dma_pools:  Dma pools (if dma'ble device).
 * @dma_mem:    Internal for coherent mem override.
 * @cma_area:   Contiguous memory area for dma allocations
 * @archdata:   For arch-specific additions.
 * @of_node:    Associated device tree node.
 * @fwnode:     Associated device node supplied by platform firmware.
 * @devt:       For creating the sysfs "dev".
 * @id:         device instance
 * @devres_lock: Spinlock to protect the resource of the device.
 * @devres_head: The resources list of the device.
 * @knode_class: The node used to add the device to the class list.
 * @class:      The class of the device.
 * @groups:     Optional attribute groups.
 * @release:    Callback to free the device after all references have
 *              gone away. This should be set by the allocator of the
 *              device (i.e. the bus driver that discovered the device).
 * @iommu_group: IOMMU group the device belongs to.
 * @iommu:      Per device generic IOMMU runtime data
 *
 * @offline_disabled: If set, the device is permanently online.
 * @offline:    Set after successful invocation of bus type's .offline().
 * @of_node_reused: Set if the device-tree node is shared with an ancestor
 *              device.
 * @state_synced: The hardware state of this device has been synced to match
 *                the software state of this device by calling the driver/bus
 *                sync_state() callback.
 * @dma_coherent: this particular device is dma coherent, even if the
 *              architecture supports non-coherent devices.
 * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
 *              streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
 *              and optionall (if the coherent mask is large enough) also
 *              for dma allocations.  This flag is managed by the dma ops
 *              instance from ->dma_supported.
 *
 * At the lowest level, every device in a Linux system is represented by an
 * instance of struct device. The device structure contains the information
 * that the device model core needs to model the system. Most subsystems,
 * however, track additional information about the devices they host. As a
 * result, it is rare for devices to be represented by bare device structures;
 * instead, that structure, like kobject structures, is usually embedded within
 * a higher-level representation of the device.
 */
struct device {
        struct kobject kobj;
        struct device           *parent;

        struct device_private   *p;

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

        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_drvdata/dev_get_drvdata */
#ifdef CONFIG_PROVE_LOCKING
        struct mutex            lockdep_mutex;
#endif
        struct mutex            mutex;  /* mutex to synchronize calls to
                                         * its driver.
                                         */

        struct dev_links_info   links;
        struct dev_pm_info      power;
        struct dev_pm_domain    *pm_domain;

#ifdef CONFIG_ENERGY_MODEL
        struct em_perf_domain   *em_pd;
#endif

#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
        struct irq_domain       *msi_domain;
#endif
#ifdef CONFIG_PINCTRL
        struct dev_pin_info     *pins;
#endif
#ifdef CONFIG_GENERIC_MSI_IRQ
        struct list_head        msi_list;
#endif
#ifdef CONFIG_DMA_OPS
        const struct dma_map_ops *dma_ops;
#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. */
        u64             bus_dma_limit;  /* upstream dma constraint */
        unsigned long   dma_pfn_offset;

        struct device_dma_parameters *dma_parms;

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

#ifdef CONFIG_DMA_DECLARE_COHERENT
        struct dma_coherent_mem *dma_mem; /* internal for coherent mem
                                             override */
#endif
#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 */

#ifdef CONFIG_NUMA
        int             numa_node;      /* NUMA node this device is close to */
#endif
        dev_t                   devt;   /* dev_t, creates the sysfs "dev" */
        u32                     id;     /* device instance */

        spinlock_t              devres_lock;
        struct list_head        devres_head;

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

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

        bool                    offline_disabled:1;
        bool                    offline:1;
        bool                    of_node_reused:1;
        bool                    state_synced:1;
#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
    defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
    defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
        bool                    dma_coherent:1;
#endif
#ifdef CONFIG_DMA_OPS_BYPASS
        bool                    dma_ops_bypass : 1;
#endif
};

/**
 * struct device_link - Device link representation.
 * @supplier: The device on the supplier end of the link.
 * @s_node: Hook to the supplier device's list of links to consumers.
 * @consumer: The device on the consumer end of the link.
 * @c_node: Hook to the consumer device's list of links to suppliers.
 * @link_dev: device used to expose link details in sysfs
 * @status: The state of the link (with respect to the presence of drivers).
 * @flags: Link flags.
 * @rpm_active: Whether or not the consumer device is runtime-PM-active.
 * @kref: Count repeated addition of the same link.
 * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
 * @supplier_preactivated: Supplier has been made active before consumer probe.
 */
struct device_link {
        struct device *supplier;
        struct list_head s_node;
        struct device *consumer;
        struct list_head c_node;
        struct device link_dev;
        enum device_link_state status;
        u32 flags;
        refcount_t rpm_active;
        struct kref kref;
#ifdef CONFIG_SRCU
        struct rcu_head rcu_head;
#endif
        bool supplier_preactivated; /* Owned by consumer probe. */
};

static inline struct device *kobj_to_dev(struct kobject *kobj)
{
        return container_of(kobj, struct device, kobj);
}

/**
 * device_iommu_mapped - Returns true when the device DMA is translated
 *                       by an IOMMU
 * @dev: Device to perform the check on
 */
static inline bool device_iommu_mapped(struct device *dev)
{
        return (dev->iommu_group != NULL);
}

/* Get the wakeup routines, which depend on struct device */
#include <linux/pm_wakeup.h>

static inline const char *dev_name(const struct device *dev)
{
        /* Use the init name until the kobject becomes available */
        if (dev->init_name)
                return dev->init_name;

        return kobject_name(&dev->kobj);
}

__printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);

#ifdef CONFIG_NUMA
static inline int dev_to_node(struct device *dev)
{
        return dev->numa_node;
}
static inline void set_dev_node(struct device *dev, int node)
{
        dev->numa_node = node;
}
#else
static inline int dev_to_node(struct device *dev)
{
        return NUMA_NO_NODE;
}
static inline void set_dev_node(struct device *dev, int node)
{
}
#endif

static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
{
#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
        return dev->msi_domain;
#else
        return NULL;
#endif
}

static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
{
#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
        dev->msi_domain = d;
#endif
}

static inline void *dev_get_drvdata(const struct device *dev)
{
        return dev->driver_data;
}

static inline void dev_set_drvdata(struct device *dev, void *data)
{
        dev->driver_data = data;
}

static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
{
        return dev ? dev->power.subsys_data : NULL;
}

static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
{
        return dev->kobj.uevent_suppress;
}

static inline void dev_set_uevent_suppress(struct device *dev, int val)
{
        dev->kobj.uevent_suppress = val;
}

static inline int device_is_registered(struct device *dev)
{
        return dev->kobj.state_in_sysfs;
}

static inline void device_enable_async_suspend(struct device *dev)
{
        if (!dev->power.is_prepared)
                dev->power.async_suspend = true;
}

static inline void device_disable_async_suspend(struct device *dev)
{
        if (!dev->power.is_prepared)
                dev->power.async_suspend = false;
}

static inline bool device_async_suspend_enabled(struct device *dev)
{
        return !!dev->power.async_suspend;
}

static inline bool device_pm_not_required(struct device *dev)
{
        return dev->power.no_pm;
}

static inline void device_set_pm_not_required(struct device *dev)
{
        dev->power.no_pm = true;
}

static inline void dev_pm_syscore_device(struct device *dev, bool val)
{
#ifdef CONFIG_PM_SLEEP
        dev->power.syscore = val;
#endif
}

static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
{
        dev->power.driver_flags = flags;
}

static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
{
        return !!(dev->power.driver_flags & flags);
}

static inline void device_lock(struct device *dev)
{
        mutex_lock(&dev->mutex);
}

static inline int device_lock_interruptible(struct device *dev)
{
        return mutex_lock_interruptible(&dev->mutex);
}

static inline int device_trylock(struct device *dev)
{
        return mutex_trylock(&dev->mutex);
}

static inline void device_unlock(struct device *dev)
{
        mutex_unlock(&dev->mutex);
}

static inline void device_lock_assert(struct device *dev)
{
        lockdep_assert_held(&dev->mutex);
}

static inline struct device_node *dev_of_node(struct device *dev)
{
        if (!IS_ENABLED(CONFIG_OF) || !dev)
                return NULL;
        return dev->of_node;
}

static inline bool dev_has_sync_state(struct device *dev)
{
        if (!dev)
                return false;
        if (dev->driver && dev->driver->sync_state)
                return true;
        if (dev->bus && dev->bus->sync_state)
                return true;
        return false;
}

/*
 * High level routines for use by the bus drivers
 */
int __must_check device_register(struct device *dev);
void device_unregister(struct device *dev);
void device_initialize(struct device *dev);
int __must_check device_add(struct device *dev);
void device_del(struct device *dev);
int device_for_each_child(struct device *dev, void *data,
                          int (*fn)(struct device *dev, void *data));
int device_for_each_child_reverse(struct device *dev, void *data,
                                  int (*fn)(struct device *dev, void *data));
struct device *device_find_child(struct device *dev, void *data,
                                 int (*match)(struct device *dev, void *data));
struct device *device_find_child_by_name(struct device *parent,
                                         const char *name);
int device_rename(struct device *dev, const char *new_name);
int device_move(struct device *dev, struct device *new_parent,
                enum dpm_order dpm_order);
int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
const char *device_get_devnode(struct device *dev, umode_t *mode, kuid_t *uid,
                               kgid_t *gid, const char **tmp);
int device_is_dependent(struct device *dev, void *target);

static inline bool device_supports_offline(struct device *dev)
{
        return dev->bus && dev->bus->offline && dev->bus->online;
}

void lock_device_hotplug(void);
void unlock_device_hotplug(void);
int lock_device_hotplug_sysfs(void);
int device_offline(struct device *dev);
int device_online(struct device *dev);
void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);

static inline int dev_num_vf(struct device *dev)
{
        if (dev->bus && dev->bus->num_vf)
                return dev->bus->num_vf(dev);
        return 0;
}

/*
 * Root device objects for grouping under /sys/devices
 */
struct device *__root_device_register(const char *name, struct module *owner);

/* This is a macro to avoid include problems with THIS_MODULE */
#define root_device_register(name) \
        __root_device_register(name, THIS_MODULE)

void root_device_unregister(struct device *root);

static inline void *dev_get_platdata(const struct device *dev)
{
        return dev->platform_data;
}

/*
 * Manual binding of a device to driver. See drivers/base/bus.c
 * for information on use.
 */
int __must_check device_bind_driver(struct device *dev);
void device_release_driver(struct device *dev);
int  __must_check device_attach(struct device *dev);
int __must_check driver_attach(struct device_driver *drv);
void device_initial_probe(struct device *dev);
int __must_check device_reprobe(struct device *dev);

bool device_is_bound(struct device *dev);

/*
 * Easy functions for dynamically creating devices on the fly
 */
__printf(5, 6) struct device *
device_create(struct class *cls, struct device *parent, dev_t devt,
              void *drvdata, const char *fmt, ...);
__printf(6, 7) struct device *
device_create_with_groups(struct class *cls, struct device *parent, dev_t devt,
                          void *drvdata, const struct attribute_group **groups,
                          const char *fmt, ...);
void device_destroy(struct class *cls, dev_t devt);

int __must_check device_add_groups(struct device *dev,
                                   const struct attribute_group **groups);
void device_remove_groups(struct device *dev,
                          const struct attribute_group **groups);

static inline int __must_check device_add_group(struct device *dev,
                                        const struct attribute_group *grp)
{
        const struct attribute_group *groups[] = { grp, NULL };

        return device_add_groups(dev, groups);
}

static inline void device_remove_group(struct device *dev,
                                       const struct attribute_group *grp)
{
        const struct attribute_group *groups[] = { grp, NULL };

        return device_remove_groups(dev, groups);
}

int __must_check devm_device_add_groups(struct device *dev,
                                        const struct attribute_group **groups);
void devm_device_remove_groups(struct device *dev,
                               const struct attribute_group **groups);
int __must_check devm_device_add_group(struct device *dev,
                                       const struct attribute_group *grp);
void devm_device_remove_group(struct device *dev,
                              const struct attribute_group *grp);

/*
 * Platform "fixup" functions - allow the platform to have their say
 * about devices and actions that the general device layer doesn't
 * know about.
 */
/* Notify platform of device discovery */
extern int (*platform_notify)(struct device *dev);

extern int (*platform_notify_remove)(struct device *dev);


/*
 * get_device - atomically increment the reference count for the device.
 *
 */
struct device *get_device(struct device *dev);
void put_device(struct device *dev);
bool kill_device(struct device *dev);

#ifdef CONFIG_DEVTMPFS
int devtmpfs_mount(void);
#else
static inline int devtmpfs_mount(void) { return 0; }
#endif

/* drivers/base/power/shutdown.c */
void device_shutdown(void);

/* debugging and troubleshooting/diagnostic helpers. */
const char *dev_driver_string(const struct device *dev);

/* Device links interface. */
struct device_link *device_link_add(struct device *consumer,
                                    struct device *supplier, u32 flags);
void device_link_del(struct device_link *link);
void device_link_remove(void *consumer, struct device *supplier);
void device_links_supplier_sync_state_pause(void);
void device_links_supplier_sync_state_resume(void);

extern __printf(3, 4)
int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);

/* Create alias, so I can be autoloaded. */
#define MODULE_ALIAS_CHARDEV(major,minor) \
        MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
#define MODULE_ALIAS_CHARDEV_MAJOR(major) \
        MODULE_ALIAS("char-major-" __stringify(major) "-*")

#ifdef CONFIG_SYSFS_DEPRECATED
extern long sysfs_deprecated;
#else
#define sysfs_deprecated 0
#endif

#endif /* _DEVICE_H_ */