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
23 /**
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
27 * expect and prefer.
28 *
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).
38 *
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
43 * drivers.
44 */
45 enum probe_type {
46 PROBE_DEFAULT_STRATEGY,
47 PROBE_PREFER_ASYNCHRONOUS,
48 PROBE_FORCE_SYNCHRONOUS,
49 };
50
51 /**
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
75 * low power state.
76 * @resume: Called to bring a device from sleep mode.
77 * @groups: Default attributes that get created by the driver core
78 * automatically.
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
82 * this driver.
83 * @coredump: Called when sysfs entry is written to. The device driver
84 * is expected to call the dev_coredump API resulting in a
85 * uevent.
86 * @p: Driver core's private data, no one other than the driver
87 * core can touch this.
88 *
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.
95 */
96 struct device_driver {
97 const char *name;
98 struct bus_type *bus;
99
100 struct module *owner;
101 const char *mod_name; /* used for built-in modules */
102
103 bool suppress_bind_attrs; /* disables bind/unbind via sysfs */
104 enum probe_type probe_type;
105
106 const struct of_device_id *of_match_table;
107 const struct acpi_device_id *acpi_match_table;
108
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;
117
118 const struct dev_pm_ops *pm;
119 void (*coredump) (struct device *dev);
120
121 struct driver_private *p;
122
123 ANDROID_KABI_RESERVE(1);
124 ANDROID_KABI_RESERVE(2);
125 ANDROID_KABI_RESERVE(3);
126 ANDROID_KABI_RESERVE(4);
127 };
128
129
130 extern int __must_check driver_register(struct device_driver *drv);
131 extern void driver_unregister(struct device_driver *drv);
132
133 extern struct device_driver *driver_find(const char *name,
134 struct bus_type *bus);
135 extern int driver_probe_done(void);
136 extern void wait_for_device_probe(void);
137 extern void flush_deferred_probe_now(void);
138 void __init wait_for_init_devices_probe(void);
139
140 /* sysfs interface for exporting driver attributes */
141
142 struct driver_attribute {
143 struct attribute attr;
144 ssize_t (*show)(struct device_driver *driver, char *buf);
145 ssize_t (*store)(struct device_driver *driver, const char *buf,
146 size_t count);
147 };
148
149 #define DRIVER_ATTR_RW(_name) \
150 struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
151 #define DRIVER_ATTR_RO(_name) \
152 struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
153 #define DRIVER_ATTR_WO(_name) \
154 struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
155
156 extern int __must_check driver_create_file(struct device_driver *driver,
157 const struct driver_attribute *attr);
158 extern void driver_remove_file(struct device_driver *driver,
159 const struct driver_attribute *attr);
160
161 int driver_set_override(struct device *dev, const char **override,
162 const char *s, size_t len);
163 extern int __must_check driver_for_each_device(struct device_driver *drv,
164 struct device *start,
165 void *data,
166 int (*fn)(struct device *dev,
167 void *));
168 struct device *driver_find_device(struct device_driver *drv,
169 struct device *start, const void *data,
170 int (*match)(struct device *dev, const void *data));
171
172 /**
173 * driver_find_device_by_name - device iterator for locating a particular device
174 * of a specific name.
175 * @drv: the driver we're iterating
176 * @name: name of the device to match
177 */
driver_find_device_by_name(struct device_driver * drv,const char * name)178 static inline struct device *driver_find_device_by_name(struct device_driver *drv,
179 const char *name)
180 {
181 return driver_find_device(drv, NULL, name, device_match_name);
182 }
183
184 /**
185 * driver_find_device_by_of_node- device iterator for locating a particular device
186 * by of_node pointer.
187 * @drv: the driver we're iterating
188 * @np: of_node pointer to match.
189 */
190 static inline struct device *
driver_find_device_by_of_node(struct device_driver * drv,const struct device_node * np)191 driver_find_device_by_of_node(struct device_driver *drv,
192 const struct device_node *np)
193 {
194 return driver_find_device(drv, NULL, np, device_match_of_node);
195 }
196
197 /**
198 * driver_find_device_by_fwnode- device iterator for locating a particular device
199 * by fwnode pointer.
200 * @drv: the driver we're iterating
201 * @fwnode: fwnode pointer to match.
202 */
203 static inline struct device *
driver_find_device_by_fwnode(struct device_driver * drv,const struct fwnode_handle * fwnode)204 driver_find_device_by_fwnode(struct device_driver *drv,
205 const struct fwnode_handle *fwnode)
206 {
207 return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
208 }
209
210 /**
211 * driver_find_device_by_devt- device iterator for locating a particular device
212 * by devt.
213 * @drv: the driver we're iterating
214 * @devt: devt pointer to match.
215 */
driver_find_device_by_devt(struct device_driver * drv,dev_t devt)216 static inline struct device *driver_find_device_by_devt(struct device_driver *drv,
217 dev_t devt)
218 {
219 return driver_find_device(drv, NULL, &devt, device_match_devt);
220 }
221
driver_find_next_device(struct device_driver * drv,struct device * start)222 static inline struct device *driver_find_next_device(struct device_driver *drv,
223 struct device *start)
224 {
225 return driver_find_device(drv, start, NULL, device_match_any);
226 }
227
228 #ifdef CONFIG_ACPI
229 /**
230 * driver_find_device_by_acpi_dev : device iterator for locating a particular
231 * device matching the ACPI_COMPANION device.
232 * @drv: the driver we're iterating
233 * @adev: ACPI_COMPANION device to match.
234 */
235 static inline struct device *
driver_find_device_by_acpi_dev(struct device_driver * drv,const struct acpi_device * adev)236 driver_find_device_by_acpi_dev(struct device_driver *drv,
237 const struct acpi_device *adev)
238 {
239 return driver_find_device(drv, NULL, adev, device_match_acpi_dev);
240 }
241 #else
242 static inline struct device *
driver_find_device_by_acpi_dev(struct device_driver * drv,const void * adev)243 driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
244 {
245 return NULL;
246 }
247 #endif
248
249 extern int driver_deferred_probe_timeout;
250 void driver_deferred_probe_add(struct device *dev);
251 int driver_deferred_probe_check_state(struct device *dev);
252 void driver_init(void);
253
254 /**
255 * module_driver() - Helper macro for drivers that don't do anything
256 * special in module init/exit. This eliminates a lot of boilerplate.
257 * Each module may only use this macro once, and calling it replaces
258 * module_init() and module_exit().
259 *
260 * @__driver: driver name
261 * @__register: register function for this driver type
262 * @__unregister: unregister function for this driver type
263 * @...: Additional arguments to be passed to __register and __unregister.
264 *
265 * Use this macro to construct bus specific macros for registering
266 * drivers, and do not use it on its own.
267 */
268 #define module_driver(__driver, __register, __unregister, ...) \
269 static int __init __driver##_init(void) \
270 { \
271 return __register(&(__driver) , ##__VA_ARGS__); \
272 } \
273 module_init(__driver##_init); \
274 static void __exit __driver##_exit(void) \
275 { \
276 __unregister(&(__driver) , ##__VA_ARGS__); \
277 } \
278 module_exit(__driver##_exit);
279
280 /**
281 * builtin_driver() - Helper macro for drivers that don't do anything
282 * special in init and have no exit. This eliminates some boilerplate.
283 * Each driver may only use this macro once, and calling it replaces
284 * device_initcall (or in some cases, the legacy __initcall). This is
285 * meant to be a direct parallel of module_driver() above but without
286 * the __exit stuff that is not used for builtin cases.
287 *
288 * @__driver: driver name
289 * @__register: register function for this driver type
290 * @...: Additional arguments to be passed to __register
291 *
292 * Use this macro to construct bus specific macros for registering
293 * drivers, and do not use it on its own.
294 */
295 #define builtin_driver(__driver, __register, ...) \
296 static int __init __driver##_init(void) \
297 { \
298 return __register(&(__driver) , ##__VA_ARGS__); \
299 } \
300 device_initcall(__driver##_init);
301
302 #endif /* _DEVICE_DRIVER_H_ */
303