1 // SPDX-License-Identifier: GPL-2.0
3 * The driver-specific portions of the driver model
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 * Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 * Copyright (c) 2012-2019 Linux Foundation
11 * See Documentation/driver-api/driver-model/ for more information.
14 #ifndef _DEVICE_DRIVER_H_
15 #define _DEVICE_DRIVER_H_
17 #include <linux/kobject.h>
18 #include <linux/klist.h>
20 #include <linux/device/bus.h>
21 #include <linux/module.h>
24 * enum probe_type - device driver probe type to try
25 * Device drivers may opt in for special handling of their
26 * respective probe routines. This tells the core what to
29 * @PROBE_DEFAULT_STRATEGY: Used by drivers that work equally well
30 * whether probed synchronously or asynchronously.
31 * @PROBE_PREFER_ASYNCHRONOUS: Drivers for "slow" devices which
32 * probing order is not essential for booting the system may
33 * opt into executing their probes asynchronously.
34 * @PROBE_FORCE_SYNCHRONOUS: Use this to annotate drivers that need
35 * their probe routines to run synchronously with driver and
36 * device registration (with the exception of -EPROBE_DEFER
37 * handling - re-probing always ends up being done asynchronously).
39 * Note that the end goal is to switch the kernel to use asynchronous
40 * probing by default, so annotating drivers with
41 * %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
42 * to speed up boot process while we are validating the rest of the
46 PROBE_DEFAULT_STRATEGY,
47 PROBE_PREFER_ASYNCHRONOUS,
48 PROBE_FORCE_SYNCHRONOUS,
52 * struct device_driver - The basic device driver structure
53 * @name: Name of the device driver.
54 * @bus: The bus which the device of this driver belongs to.
55 * @owner: The module owner.
56 * @mod_name: Used for built-in modules.
57 * @suppress_bind_attrs: Disables bind/unbind via sysfs.
58 * @probe_type: Type of the probe (synchronous or asynchronous) to use.
59 * @of_match_table: The open firmware table.
60 * @acpi_match_table: The ACPI match table.
61 * @probe: Called to query the existence of a specific device,
62 * whether this driver can work with it, and bind the driver
63 * to a specific device.
64 * @sync_state: Called to sync device state to software state after all the
65 * state tracking consumers linked to this device (present at
66 * the time of late_initcall) have successfully bound to a
67 * driver. If the device has no consumers, this function will
68 * be called at late_initcall_sync level. If the device has
69 * consumers that are never bound to a driver, this function
70 * will never get called until they do.
71 * @remove: Called when the device is removed from the system to
72 * unbind a device from this driver.
73 * @shutdown: Called at shut-down time to quiesce the device.
74 * @suspend: Called to put the device to sleep mode. Usually to a
76 * @resume: Called to bring a device from sleep mode.
77 * @groups: Default attributes that get created by the driver core
79 * @dev_groups: Additional attributes attached to device instance once
80 * it is bound to the driver.
81 * @pm: Power management operations of the device which matched
83 * @coredump: Called when sysfs entry is written to. The device driver
84 * is expected to call the dev_coredump API resulting in a
86 * @p: Driver core's private data, no one other than the driver
87 * core can touch this.
89 * The device driver-model tracks all of the drivers known to the system.
90 * The main reason for this tracking is to enable the driver core to match
91 * up drivers with new devices. Once drivers are known objects within the
92 * system, however, a number of other things become possible. Device drivers
93 * can export information and configuration variables that are independent
94 * of any specific device.
96 struct device_driver {
100 struct module *owner;
101 const char *mod_name; /* used for built-in modules */
103 bool suppress_bind_attrs; /* disables bind/unbind via sysfs */
104 enum probe_type probe_type;
106 const struct of_device_id *of_match_table;
107 const struct acpi_device_id *acpi_match_table;
109 int (*probe) (struct device *dev);
110 void (*sync_state)(struct device *dev);
111 int (*remove) (struct device *dev);
112 void (*shutdown) (struct device *dev);
113 int (*suspend) (struct device *dev, pm_message_t state);
114 int (*resume) (struct device *dev);
115 const struct attribute_group **groups;
116 const struct attribute_group **dev_groups;
118 const struct dev_pm_ops *pm;
119 void (*coredump) (struct device *dev);
121 struct driver_private *p;
125 extern int __must_check driver_register(struct device_driver *drv);
126 extern void driver_unregister(struct device_driver *drv);
128 extern struct device_driver *driver_find(const char *name,
129 struct bus_type *bus);
130 extern int driver_probe_done(void);
131 extern void wait_for_device_probe(void);
132 void __init wait_for_init_devices_probe(void);
134 /* sysfs interface for exporting driver attributes */
136 struct driver_attribute {
137 struct attribute attr;
138 ssize_t (*show)(struct device_driver *driver, char *buf);
139 ssize_t (*store)(struct device_driver *driver, const char *buf,
143 #define DRIVER_ATTR_RW(_name) \
144 struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
145 #define DRIVER_ATTR_RO(_name) \
146 struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
147 #define DRIVER_ATTR_WO(_name) \
148 struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
150 extern int __must_check driver_create_file(struct device_driver *driver,
151 const struct driver_attribute *attr);
152 extern void driver_remove_file(struct device_driver *driver,
153 const struct driver_attribute *attr);
155 int driver_set_override(struct device *dev, const char **override,
156 const char *s, size_t len);
157 extern int __must_check driver_for_each_device(struct device_driver *drv,
158 struct device *start,
160 int (*fn)(struct device *dev,
162 struct device *driver_find_device(struct device_driver *drv,
163 struct device *start, const void *data,
164 int (*match)(struct device *dev, const void *data));
167 * driver_find_device_by_name - device iterator for locating a particular device
168 * of a specific name.
169 * @drv: the driver we're iterating
170 * @name: name of the device to match
172 static inline struct device *driver_find_device_by_name(struct device_driver *drv,
175 return driver_find_device(drv, NULL, name, device_match_name);
179 * driver_find_device_by_of_node- device iterator for locating a particular device
180 * by of_node pointer.
181 * @drv: the driver we're iterating
182 * @np: of_node pointer to match.
184 static inline struct device *
185 driver_find_device_by_of_node(struct device_driver *drv,
186 const struct device_node *np)
188 return driver_find_device(drv, NULL, np, device_match_of_node);
192 * driver_find_device_by_fwnode- device iterator for locating a particular device
194 * @drv: the driver we're iterating
195 * @fwnode: fwnode pointer to match.
197 static inline struct device *
198 driver_find_device_by_fwnode(struct device_driver *drv,
199 const struct fwnode_handle *fwnode)
201 return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
205 * driver_find_device_by_devt- device iterator for locating a particular device
207 * @drv: the driver we're iterating
208 * @devt: devt pointer to match.
210 static inline struct device *driver_find_device_by_devt(struct device_driver *drv,
213 return driver_find_device(drv, NULL, &devt, device_match_devt);
216 static inline struct device *driver_find_next_device(struct device_driver *drv,
217 struct device *start)
219 return driver_find_device(drv, start, NULL, device_match_any);
224 * driver_find_device_by_acpi_dev : device iterator for locating a particular
225 * device matching the ACPI_COMPANION device.
226 * @drv: the driver we're iterating
227 * @adev: ACPI_COMPANION device to match.
229 static inline struct device *
230 driver_find_device_by_acpi_dev(struct device_driver *drv,
231 const struct acpi_device *adev)
233 return driver_find_device(drv, NULL, adev, device_match_acpi_dev);
236 static inline struct device *
237 driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
243 extern int driver_deferred_probe_timeout;
244 void driver_deferred_probe_add(struct device *dev);
245 int driver_deferred_probe_check_state(struct device *dev);
246 void driver_init(void);
249 * module_driver() - Helper macro for drivers that don't do anything
250 * special in module init/exit. This eliminates a lot of boilerplate.
251 * Each module may only use this macro once, and calling it replaces
252 * module_init() and module_exit().
254 * @__driver: driver name
255 * @__register: register function for this driver type
256 * @__unregister: unregister function for this driver type
257 * @...: Additional arguments to be passed to __register and __unregister.
259 * Use this macro to construct bus specific macros for registering
260 * drivers, and do not use it on its own.
262 #define module_driver(__driver, __register, __unregister, ...) \
263 static int __init __driver##_init(void) \
265 return __register(&(__driver) , ##__VA_ARGS__); \
267 module_init(__driver##_init); \
268 static void __exit __driver##_exit(void) \
270 __unregister(&(__driver) , ##__VA_ARGS__); \
272 module_exit(__driver##_exit);
275 * builtin_driver() - Helper macro for drivers that don't do anything
276 * special in init and have no exit. This eliminates some boilerplate.
277 * Each driver may only use this macro once, and calling it replaces
278 * device_initcall (or in some cases, the legacy __initcall). This is
279 * meant to be a direct parallel of module_driver() above but without
280 * the __exit stuff that is not used for builtin cases.
282 * @__driver: driver name
283 * @__register: register function for this driver type
284 * @...: Additional arguments to be passed to __register
286 * Use this macro to construct bus specific macros for registering
287 * drivers, and do not use it on its own.
289 #define builtin_driver(__driver, __register, ...) \
290 static int __init __driver##_init(void) \
292 return __register(&(__driver) , ##__VA_ARGS__); \
294 device_initcall(__driver##_init);
296 #endif /* _DEVICE_DRIVER_H_ */