1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * The driver-specific portions of the 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 * Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 * Copyright (c) 2012-2019 Linux Foundation
10 *
11 * See Documentation/driver-api/driver-model/ for more information.
12 */
13
14 #ifndef _DEVICE_DRIVER_H_
15 #define _DEVICE_DRIVER_H_
16
17 #include <linux/kobject.h>
18 #include <linux/klist.h>
19 #include <linux/pm.h>
20 #include <linux/device/bus.h>
21 #include <linux/module.h>
22 #include <linux/device-id/acpi.h>
23 #include <linux/device-id/of.h>
24
25 /**
26 * enum probe_type - device driver probe type to try
27 * Device drivers may opt in for special handling of their
28 * respective probe routines. This tells the core what to
29 * expect and prefer.
30 *
31 * @PROBE_DEFAULT_STRATEGY: Used by drivers that work equally well
32 * whether probed synchronously or asynchronously.
33 * @PROBE_PREFER_ASYNCHRONOUS: Drivers for "slow" devices which
34 * probing order is not essential for booting the system may
35 * opt into executing their probes asynchronously.
36 * @PROBE_FORCE_SYNCHRONOUS: Use this to annotate drivers that need
37 * their probe routines to run synchronously with driver and
38 * device registration (with the exception of -EPROBE_DEFER
39 * handling - re-probing always ends up being done asynchronously).
40 *
41 * Note that the end goal is to switch the kernel to use asynchronous
42 * probing by default, so annotating drivers with
43 * %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
44 * to speed up boot process while we are validating the rest of the
45 * drivers.
46 */
47 enum probe_type {
48 PROBE_DEFAULT_STRATEGY,
49 PROBE_PREFER_ASYNCHRONOUS,
50 PROBE_FORCE_SYNCHRONOUS,
51 };
52
53 /**
54 * struct device_driver - The basic device driver structure
55 * @name: Name of the device driver.
56 * @bus: The bus which the device of this driver belongs to.
57 * @owner: The module owner.
58 * @mod_name: Used for built-in modules.
59 * @suppress_bind_attrs: Disables bind/unbind via sysfs.
60 * @probe_type: Type of the probe (synchronous or asynchronous) to use.
61 * @of_match_table: The open firmware table.
62 * @acpi_match_table: The ACPI match table.
63 * @probe: Called to query the existence of a specific device,
64 * whether this driver can work with it, and bind the driver
65 * to a specific device.
66 * @sync_state: Called to sync device state to software state after all the
67 * state tracking consumers linked to this device (present at
68 * the time of late_initcall) have successfully bound to a
69 * driver. If the device has no consumers, this function will
70 * be called at late_initcall_sync level. If the device has
71 * consumers that are never bound to a driver, this function
72 * will never get called until they do.
73 * @remove: Called when the device is removed from the system to
74 * unbind a device from this driver.
75 * @shutdown: Called at shut-down time to quiesce the device.
76 * @suspend: Called to put the device to sleep mode. Usually to a
77 * low power state.
78 * @resume: Called to bring a device from sleep mode.
79 * @groups: Default attributes that get created by the driver core
80 * automatically.
81 * @dev_groups: Additional attributes attached to device instance once
82 * it is bound to the driver.
83 * @pm: Power management operations of the device which matched
84 * this driver.
85 * @coredump: Called when sysfs entry is written to. The device driver
86 * is expected to call the dev_coredump API resulting in a
87 * uevent.
88 * @p: Driver core's private data, no one other than the driver
89 * core can touch this.
90 * @p_cb: Callbacks private to the driver core; no one other than the
91 * driver core is allowed to touch this.
92 *
93 * The device driver-model tracks all of the drivers known to the system.
94 * The main reason for this tracking is to enable the driver core to match
95 * up drivers with new devices. Once drivers are known objects within the
96 * system, however, a number of other things become possible. Device drivers
97 * can export information and configuration variables that are independent
98 * of any specific device.
99 */
100 struct device_driver {
101 const char *name;
102 const struct bus_type *bus;
103
104 struct module *owner;
105 const char *mod_name; /* used for built-in modules */
106
107 bool suppress_bind_attrs; /* disables bind/unbind via sysfs */
108 enum probe_type probe_type;
109
110 const struct of_device_id *of_match_table;
111 const struct acpi_device_id *acpi_match_table;
112
113 int (*probe) (struct device *dev);
114 void (*sync_state)(struct device *dev);
115 int (*remove) (struct device *dev);
116 void (*shutdown) (struct device *dev);
117 int (*suspend) (struct device *dev, pm_message_t state);
118 int (*resume) (struct device *dev);
119 const struct attribute_group *const *groups;
120 const struct attribute_group *const *dev_groups;
121
122 const struct dev_pm_ops *pm;
123 void (*coredump) (struct device *dev);
124
125 struct driver_private *p;
126 struct {
127 /*
128 * Called after remove() but before devres entries are released.
129 * This is a Rust only callback.
130 */
131 void (*post_unbind_rust)(struct device *dev);
132 } p_cb;
133 };
134
135
136 int __must_check driver_register(struct device_driver *drv);
137 void driver_unregister(struct device_driver *drv);
138
139 struct device_driver *driver_find(const char *name, const struct bus_type *bus);
140 bool __init driver_probe_done(void);
141 void wait_for_device_probe(void);
142 void __init wait_for_init_devices_probe(void);
143
144 /* sysfs interface for exporting driver attributes */
145
146 struct driver_attribute {
147 struct attribute attr;
148 ssize_t (*show)(struct device_driver *driver, char *buf);
149 ssize_t (*store)(struct device_driver *driver, const char *buf,
150 size_t count);
151 };
152
153 #define DRIVER_ATTR_RW(_name) \
154 struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
155 #define DRIVER_ATTR_RO(_name) \
156 struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
157 #define DRIVER_ATTR_WO(_name) \
158 struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
159
160 int __must_check driver_create_file(const struct device_driver *driver,
161 const struct driver_attribute *attr);
162 void driver_remove_file(const struct device_driver *driver,
163 const struct driver_attribute *attr);
164
165 int __must_check driver_for_each_device(struct device_driver *drv, struct device *start,
166 void *data, device_iter_t fn);
167 struct device *driver_find_device(const struct device_driver *drv,
168 struct device *start, const void *data,
169 device_match_t match);
170
171 /**
172 * driver_find_device_by_name - device iterator for locating a particular device
173 * of a specific name.
174 * @drv: the driver we're iterating
175 * @name: name of the device to match
176 */
driver_find_device_by_name(const struct device_driver * drv,const char * name)177 static inline struct device *driver_find_device_by_name(const struct device_driver *drv,
178 const char *name)
179 {
180 return driver_find_device(drv, NULL, name, device_match_name);
181 }
182
183 /**
184 * driver_find_device_by_of_node- device iterator for locating a particular device
185 * by of_node pointer.
186 * @drv: the driver we're iterating
187 * @np: of_node pointer to match.
188 */
189 static inline struct device *
driver_find_device_by_of_node(const struct device_driver * drv,const struct device_node * np)190 driver_find_device_by_of_node(const struct device_driver *drv,
191 const struct device_node *np)
192 {
193 return driver_find_device(drv, NULL, np, device_match_of_node);
194 }
195
196 /**
197 * driver_find_device_by_fwnode- device iterator for locating a particular device
198 * by fwnode pointer.
199 * @drv: the driver we're iterating
200 * @fwnode: fwnode pointer to match.
201 */
202 static inline struct device *
driver_find_device_by_fwnode(struct device_driver * drv,const struct fwnode_handle * fwnode)203 driver_find_device_by_fwnode(struct device_driver *drv,
204 const struct fwnode_handle *fwnode)
205 {
206 return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
207 }
208
209 /**
210 * driver_find_device_by_devt- device iterator for locating a particular device
211 * by devt.
212 * @drv: the driver we're iterating
213 * @devt: devt pointer to match.
214 */
driver_find_device_by_devt(const struct device_driver * drv,dev_t devt)215 static inline struct device *driver_find_device_by_devt(const struct device_driver *drv,
216 dev_t devt)
217 {
218 return driver_find_device(drv, NULL, &devt, device_match_devt);
219 }
220
driver_find_next_device(const struct device_driver * drv,struct device * start)221 static inline struct device *driver_find_next_device(const struct device_driver *drv,
222 struct device *start)
223 {
224 return driver_find_device(drv, start, NULL, device_match_any);
225 }
226
227 #ifdef CONFIG_ACPI
228 /**
229 * driver_find_device_by_acpi_dev : device iterator for locating a particular
230 * device matching the ACPI_COMPANION device.
231 * @drv: the driver we're iterating
232 * @adev: ACPI_COMPANION device to match.
233 */
234 static inline struct device *
driver_find_device_by_acpi_dev(const struct device_driver * drv,const struct acpi_device * adev)235 driver_find_device_by_acpi_dev(const struct device_driver *drv,
236 const struct acpi_device *adev)
237 {
238 return driver_find_device(drv, NULL, adev, device_match_acpi_dev);
239 }
240 #else
241 static inline struct device *
driver_find_device_by_acpi_dev(const struct device_driver * drv,const void * adev)242 driver_find_device_by_acpi_dev(const struct device_driver *drv, const void *adev)
243 {
244 return NULL;
245 }
246 #endif
247
248 void driver_deferred_probe_add(struct device *dev);
249 int driver_deferred_probe_check_state(struct device *dev);
250 void driver_init(void);
251
252 /**
253 * module_driver() - Helper macro for drivers that don't do anything
254 * special in module init/exit. This eliminates a lot of boilerplate.
255 * Each module may only use this macro once, and calling it replaces
256 * module_init() and module_exit().
257 *
258 * @__driver: driver name
259 * @__register: register function for this driver type
260 * @__unregister: unregister function for this driver type
261 * @...: Additional arguments to be passed to __register and __unregister.
262 *
263 * Use this macro to construct bus specific macros for registering
264 * drivers, and do not use it on its own.
265 */
266 #define module_driver(__driver, __register, __unregister, ...) \
267 static int __init __driver##_init(void) \
268 { \
269 return __register(&(__driver) , ##__VA_ARGS__); \
270 } \
271 module_init(__driver##_init); \
272 static void __exit __driver##_exit(void) \
273 { \
274 __unregister(&(__driver) , ##__VA_ARGS__); \
275 } \
276 module_exit(__driver##_exit);
277
278 /**
279 * builtin_driver() - Helper macro for drivers that don't do anything
280 * special in init and have no exit. This eliminates some boilerplate.
281 * Each driver may only use this macro once, and calling it replaces
282 * device_initcall (or in some cases, the legacy __initcall). This is
283 * meant to be a direct parallel of module_driver() above but without
284 * the __exit stuff that is not used for builtin cases.
285 *
286 * @__driver: driver name
287 * @__register: register function for this driver type
288 * @...: Additional arguments to be passed to __register
289 *
290 * Use this macro to construct bus specific macros for registering
291 * drivers, and do not use it on its own.
292 */
293 #define builtin_driver(__driver, __register, ...) \
294 static int __init __driver##_init(void) \
295 { \
296 return __register(&(__driver) , ##__VA_ARGS__); \
297 } \
298 device_initcall(__driver##_init);
299
300 #endif /* _DEVICE_DRIVER_H_ */
301