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// SPDX-License-Identifier: GPL-2.0
/*
* The driver-specific portions of the driver model
*
* Copyright (c) 2001-2003 Patrick Mochel <[email protected]>
* Copyright (c) 2004-2009 Greg Kroah-Hartman <[email protected]>
* Copyright (c) 2008-2009 Novell Inc.
* Copyright (c) 2012-2019 Greg Kroah-Hartman <[email protected]>
* 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>
/**
* 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_ */
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