// SPDX-License-Identifier: GPL-2.0
/*
 * The driver-specific portions of the 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.
 * Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 * Copyright (c) 2012-2019 Linux Foundation
 *
 * See Documentation/driver-api/driver-model/ for more information.
 */

#ifndef _DEVICE_DRIVER_H_
#define _DEVICE_DRIVER_H_

#include <linux/kobject.h>
#include <linux/klist.h>
#include <linux/pm.h>
#include <linux/device/bus.h>
#include <linux/module.h>

/**
 * enum probe_type - device driver probe type to try
 *      Device drivers may opt in for special handling of their
 *      respective probe routines. This tells the core what to
 *      expect and prefer.
 *
 * @PROBE_DEFAULT_STRATEGY: Used by drivers that work equally well
 *      whether probed synchronously or asynchronously.
 * @PROBE_PREFER_ASYNCHRONOUS: Drivers for "slow" devices which
 *      probing order is not essential for booting the system may
 *      opt into executing their probes asynchronously.
 * @PROBE_FORCE_SYNCHRONOUS: Use this to annotate drivers that need
 *      their probe routines to run synchronously with driver and
 *      device registration (with the exception of -EPROBE_DEFER
 *      handling - re-probing always ends up being done asynchronously).
 *
 * Note that the end goal is to switch the kernel to use asynchronous
 * probing by default, so annotating drivers with
 * %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
 * to speed up boot process while we are validating the rest of the
 * drivers.
 */
enum probe_type {
        PROBE_DEFAULT_STRATEGY,
        PROBE_PREFER_ASYNCHRONOUS,
        PROBE_FORCE_SYNCHRONOUS,
};

/**
 * struct device_driver - The basic device driver structure
 * @name:       Name of the device driver.
 * @bus:        The bus which the device of this driver belongs to.
 * @owner:      The module owner.
 * @mod_name:   Used for built-in modules.
 * @suppress_bind_attrs: Disables bind/unbind via sysfs.
 * @probe_type: Type of the probe (synchronous or asynchronous) to use.
 * @of_match_table: The open firmware table.
 * @acpi_match_table: The ACPI match table.
 * @probe:      Called to query the existence of a specific device,
 *              whether this driver can work with it, and bind the driver
 *              to a specific device.
 * @sync_state: Called to sync device state to software state after all the
 *              state tracking consumers linked to this device (present at
 *              the time of late_initcall) have successfully bound to a
 *              driver. If the device has no consumers, this function will
 *              be called at late_initcall_sync level. If the device has
 *              consumers that are never bound to a driver, this function
 *              will never get called until they do.
 * @remove:     Called when the device is removed from the system to
 *              unbind a device from this driver.
 * @shutdown:   Called at shut-down time to quiesce the device.
 * @suspend:    Called to put the device to sleep mode. Usually to a
 *              low power state.
 * @resume:     Called to bring a device from sleep mode.
 * @groups:     Default attributes that get created by the driver core
 *              automatically.
 * @dev_groups: Additional attributes attached to device instance once
 *              it is bound to the driver.
 * @pm:         Power management operations of the device which matched
 *              this driver.
 * @coredump:   Called when sysfs entry is written to. The device driver
 *              is expected to call the dev_coredump API resulting in a
 *              uevent.
 * @p:          Driver core's private data, no one other than the driver
 *              core can touch this.
 *
 * The device driver-model tracks all of the drivers known to the system.
 * The main reason for this tracking is to enable the driver core to match
 * up drivers with new devices. Once drivers are known objects within the
 * system, however, a number of other things become possible. Device drivers
 * can export information and configuration variables that are independent
 * of any specific device.
 */
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 */
        enum probe_type probe_type;

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

        int (*probe) (struct device *dev);
        void (*sync_state)(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 attribute_group **dev_groups;

        const struct dev_pm_ops *pm;
        void (*coredump) (struct device *dev);

        struct driver_private *p;
};


extern int __must_check driver_register(struct device_driver *drv);
extern void driver_unregister(struct device_driver *drv);

extern struct device_driver *driver_find(const char *name,
                                         struct bus_type *bus);
extern int driver_probe_done(void);
extern void wait_for_device_probe(void);

/* sysfs interface for exporting driver attributes */

struct driver_attribute {
        struct attribute attr;
        ssize_t (*show)(struct device_driver *driver, char *buf);
        ssize_t (*store)(struct device_driver *driver, const char *buf,
                         size_t count);
};

#define DRIVER_ATTR_RW(_name) \
        struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
#define DRIVER_ATTR_RO(_name) \
        struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
#define DRIVER_ATTR_WO(_name) \
        struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)

extern int __must_check driver_create_file(struct device_driver *driver,
                                        const struct driver_attribute *attr);
extern void driver_remove_file(struct device_driver *driver,
                               const struct driver_attribute *attr);

extern int __must_check driver_for_each_device(struct device_driver *drv,
                                               struct device *start,
                                               void *data,
                                               int (*fn)(struct device *dev,
                                                         void *));
struct device *driver_find_device(struct device_driver *drv,
                                  struct device *start, const void *data,
                                  int (*match)(struct device *dev, const void *data));

/**
 * driver_find_device_by_name - device iterator for locating a particular device
 * of a specific name.
 * @drv: the driver we're iterating
 * @name: name of the device to match
 */
static inline struct device *driver_find_device_by_name(struct device_driver *drv,
                                                        const char *name)
{
        return driver_find_device(drv, NULL, name, device_match_name);
}

/**
 * driver_find_device_by_of_node- device iterator for locating a particular device
 * by of_node pointer.
 * @drv: the driver we're iterating
 * @np: of_node pointer to match.
 */
static inline struct device *
driver_find_device_by_of_node(struct device_driver *drv,
                              const struct device_node *np)
{
        return driver_find_device(drv, NULL, np, device_match_of_node);
}

/**
 * driver_find_device_by_fwnode- device iterator for locating a particular device
 * by fwnode pointer.
 * @drv: the driver we're iterating
 * @fwnode: fwnode pointer to match.
 */
static inline struct device *
driver_find_device_by_fwnode(struct device_driver *drv,
                             const struct fwnode_handle *fwnode)
{
        return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
}

/**
 * driver_find_device_by_devt- device iterator for locating a particular device
 * by devt.
 * @drv: the driver we're iterating
 * @devt: devt pointer to match.
 */
static inline struct device *driver_find_device_by_devt(struct device_driver *drv,
                                                        dev_t devt)
{
        return driver_find_device(drv, NULL, &devt, device_match_devt);
}

static inline struct device *driver_find_next_device(struct device_driver *drv,
                                                     struct device *start)
{
        return driver_find_device(drv, start, NULL, device_match_any);
}

#ifdef CONFIG_ACPI
/**
 * driver_find_device_by_acpi_dev : device iterator for locating a particular
 * device matching the ACPI_COMPANION device.
 * @drv: the driver we're iterating
 * @adev: ACPI_COMPANION device to match.
 */
static inline struct device *
driver_find_device_by_acpi_dev(struct device_driver *drv,
                               const struct acpi_device *adev)
{
        return driver_find_device(drv, NULL, adev, device_match_acpi_dev);
}
#else
static inline struct device *
driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
{
        return NULL;
}
#endif

extern int driver_deferred_probe_timeout;
void driver_deferred_probe_add(struct device *dev);
int driver_deferred_probe_check_state(struct device *dev);
void driver_init(void);

/**
 * module_driver() - Helper macro for drivers that don't do anything
 * special in module init/exit. This eliminates a lot of boilerplate.
 * Each module may only use this macro once, and calling it replaces
 * module_init() and module_exit().
 *
 * @__driver: driver name
 * @__register: register function for this driver type
 * @__unregister: unregister function for this driver type
 * @...: Additional arguments to be passed to __register and __unregister.
 *
 * Use this macro to construct bus specific macros for registering
 * drivers, and do not use it on its own.
 */
#define module_driver(__driver, __register, __unregister, ...) \
static int __init __driver##_init(void) \
{ \
        return __register(&(__driver) , ##__VA_ARGS__); \
} \
module_init(__driver##_init); \
static void __exit __driver##_exit(void) \
{ \
        __unregister(&(__driver) , ##__VA_ARGS__); \
} \
module_exit(__driver##_exit);

/**
 * builtin_driver() - Helper macro for drivers that don't do anything
 * special in init and have no exit. This eliminates some boilerplate.
 * Each driver may only use this macro once, and calling it replaces
 * device_initcall (or in some cases, the legacy __initcall).  This is
 * meant to be a direct parallel of module_driver() above but without
 * the __exit stuff that is not used for builtin cases.
 *
 * @__driver: driver name
 * @__register: register function for this driver type
 * @...: Additional arguments to be passed to __register
 *
 * Use this macro to construct bus specific macros for registering
 * drivers, and do not use it on its own.
 */
#define builtin_driver(__driver, __register, ...) \
static int __init __driver##_init(void) \
{ \
        return __register(&(__driver) , ##__VA_ARGS__); \
} \
device_initcall(__driver##_init);

#endif  /* _DEVICE_DRIVER_H_ */