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
22 /**
23 * enum probe_type - device driver probe type to try
24 * Device drivers may opt in for special handling of their
25 * respective probe routines. This tells the core what to
26 * expect and prefer.
27 *
28 * @PROBE_DEFAULT_STRATEGY: Used by drivers that work equally well
29 * whether probed synchronously or asynchronously.
30 * @PROBE_PREFER_ASYNCHRONOUS: Drivers for "slow" devices which
31 * probing order is not essential for booting the system may
32 * opt into executing their probes asynchronously.
33 * @PROBE_FORCE_SYNCHRONOUS: Use this to annotate drivers that need
34 * their probe routines to run synchronously with driver and
35 * device registration (with the exception of -EPROBE_DEFER
36 * handling - re-probing always ends up being done asynchronously).
37 *
38 * Note that the end goal is to switch the kernel to use asynchronous
39 * probing by default, so annotating drivers with
40 * %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
41 * to speed up boot process while we are validating the rest of the
42 * drivers.
43 */
44 enum probe_type {
45 PROBE_DEFAULT_STRATEGY,
46 PROBE_PREFER_ASYNCHRONOUS,
47 PROBE_FORCE_SYNCHRONOUS,
48 };
49
50 /**
51 * struct device_driver - The basic device driver structure
52 * @name: Name of the device driver.
53 * @bus: The bus which the device of this driver belongs to.
54 * @owner: The module owner.
55 * @mod_name: Used for built-in modules.
56 * @suppress_bind_attrs: Disables bind/unbind via sysfs.
57 * @probe_type: Type of the probe (synchronous or asynchronous) to use.
58 * @of_match_table: The open firmware table.
59 * @acpi_match_table: The ACPI match table.
60 * @probe: Called to query the existence of a specific device,
61 * whether this driver can work with it, and bind the driver
62 * to a specific device.
63 * @sync_state: Called to sync device state to software state after all the
64 * state tracking consumers linked to this device (present at
65 * the time of late_initcall) have successfully bound to a
66 * driver. If the device has no consumers, this function will
67 * be called at late_initcall_sync level. If the device has
68 * consumers that are never bound to a driver, this function
69 * will never get called until they do.
70 * @remove: Called when the device is removed from the system to
71 * unbind a device from this driver.
72 * @shutdown: Called at shut-down time to quiesce the device.
73 * @suspend: Called to put the device to sleep mode. Usually to a
74 * low power state.
75 * @resume: Called to bring a device from sleep mode.
76 * @groups: Default attributes that get created by the driver core
77 * automatically.
78 * @dev_groups: Additional attributes attached to device instance once the
79 * it is bound to the driver.
80 * @pm: Power management operations of the device which matched
81 * this driver.
82 * @coredump: Called when sysfs entry is written to. The device driver
83 * is expected to call the dev_coredump API resulting in a
84 * uevent.
85 * @p: Driver core's private data, no one other than the driver
86 * core can touch this.
87 *
88 * The device driver-model tracks all of the drivers known to the system.
89 * The main reason for this tracking is to enable the driver core to match
90 * up drivers with new devices. Once drivers are known objects within the
91 * system, however, a number of other things become possible. Device drivers
92 * can export information and configuration variables that are independent
93 * of any specific device.
94 */
95 struct device_driver {
96 const char *name;
97 struct bus_type *bus;
98
99 struct module *owner;
100 const char *mod_name; /* used for built-in modules */
101
102 bool suppress_bind_attrs; /* disables bind/unbind via sysfs */
103 enum probe_type probe_type;
104
105 const struct of_device_id *of_match_table;
106 const struct acpi_device_id *acpi_match_table;
107
108 int (*probe) (struct device *dev);
109 void (*sync_state)(struct device *dev);
110 int (*remove) (struct device *dev);
111 void (*shutdown) (struct device *dev);
112 int (*suspend) (struct device *dev, pm_message_t state);
113 int (*resume) (struct device *dev);
114 const struct attribute_group **groups;
115 const struct attribute_group **dev_groups;
116
117 const struct dev_pm_ops *pm;
118 void (*coredump) (struct device *dev);
119
120 struct driver_private *p;
121
122 ANDROID_KABI_RESERVE(1);
123 ANDROID_KABI_RESERVE(2);
124 ANDROID_KABI_RESERVE(3);
125 ANDROID_KABI_RESERVE(4);
126 };
127
128
129 extern int __must_check driver_register(struct device_driver *drv);
130 extern void driver_unregister(struct device_driver *drv);
131
132 extern struct device_driver *driver_find(const char *name,
133 struct bus_type *bus);
134 extern int driver_probe_done(void);
135 extern void wait_for_device_probe(void);
136
137 /* sysfs interface for exporting driver attributes */
138
139 struct driver_attribute {
140 struct attribute attr;
141 ssize_t (*show)(struct device_driver *driver, char *buf);
142 ssize_t (*store)(struct device_driver *driver, const char *buf,
143 size_t count);
144 };
145
146 #define DRIVER_ATTR_RW(_name) \
147 struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
148 #define DRIVER_ATTR_RO(_name) \
149 struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
150 #define DRIVER_ATTR_WO(_name) \
151 struct driver_attribute driver_attr_##_name = __ATTR_WO(_name)
152
153 extern int __must_check driver_create_file(struct device_driver *driver,
154 const struct driver_attribute *attr);
155 extern void driver_remove_file(struct device_driver *driver,
156 const struct driver_attribute *attr);
157
158 extern int __must_check driver_for_each_device(struct device_driver *drv,
159 struct device *start,
160 void *data,
161 int (*fn)(struct device *dev,
162 void *));
163 struct device *driver_find_device(struct device_driver *drv,
164 struct device *start, const void *data,
165 int (*match)(struct device *dev, const void *data));
166
167 /**
168 * driver_find_device_by_name - device iterator for locating a particular device
169 * of a specific name.
170 * @drv: the driver we're iterating
171 * @name: name of the device to match
172 */
driver_find_device_by_name(struct device_driver * drv,const char * name)173 static inline struct device *driver_find_device_by_name(struct device_driver *drv,
174 const char *name)
175 {
176 return driver_find_device(drv, NULL, name, device_match_name);
177 }
178
179 /**
180 * driver_find_device_by_of_node- device iterator for locating a particular device
181 * by of_node pointer.
182 * @drv: the driver we're iterating
183 * @np: of_node pointer to match.
184 */
185 static inline struct device *
driver_find_device_by_of_node(struct device_driver * drv,const struct device_node * np)186 driver_find_device_by_of_node(struct device_driver *drv,
187 const struct device_node *np)
188 {
189 return driver_find_device(drv, NULL, np, device_match_of_node);
190 }
191
192 /**
193 * driver_find_device_by_fwnode- device iterator for locating a particular device
194 * by fwnode pointer.
195 * @drv: the driver we're iterating
196 * @fwnode: fwnode pointer to match.
197 */
198 static inline struct device *
driver_find_device_by_fwnode(struct device_driver * drv,const struct fwnode_handle * fwnode)199 driver_find_device_by_fwnode(struct device_driver *drv,
200 const struct fwnode_handle *fwnode)
201 {
202 return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
203 }
204
205 /**
206 * driver_find_device_by_devt- device iterator for locating a particular device
207 * by devt.
208 * @drv: the driver we're iterating
209 * @devt: devt pointer to match.
210 */
driver_find_device_by_devt(struct device_driver * drv,dev_t devt)211 static inline struct device *driver_find_device_by_devt(struct device_driver *drv,
212 dev_t devt)
213 {
214 return driver_find_device(drv, NULL, &devt, device_match_devt);
215 }
216
driver_find_next_device(struct device_driver * drv,struct device * start)217 static inline struct device *driver_find_next_device(struct device_driver *drv,
218 struct device *start)
219 {
220 return driver_find_device(drv, start, NULL, device_match_any);
221 }
222
223 #ifdef CONFIG_ACPI
224 /**
225 * driver_find_device_by_acpi_dev : device iterator for locating a particular
226 * device matching the ACPI_COMPANION device.
227 * @drv: the driver we're iterating
228 * @adev: ACPI_COMPANION device to match.
229 */
230 static inline struct device *
driver_find_device_by_acpi_dev(struct device_driver * drv,const struct acpi_device * adev)231 driver_find_device_by_acpi_dev(struct device_driver *drv,
232 const struct acpi_device *adev)
233 {
234 return driver_find_device(drv, NULL, adev, device_match_acpi_dev);
235 }
236 #else
237 static inline struct device *
driver_find_device_by_acpi_dev(struct device_driver * drv,const void * adev)238 driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
239 {
240 return NULL;
241 }
242 #endif
243
244 extern int driver_deferred_probe_timeout;
245 void driver_deferred_probe_add(struct device *dev);
246 int driver_deferred_probe_check_state(struct device *dev);
247 void driver_init(void);
248
249 /**
250 * module_driver() - Helper macro for drivers that don't do anything
251 * special in module init/exit. This eliminates a lot of boilerplate.
252 * Each module may only use this macro once, and calling it replaces
253 * module_init() and module_exit().
254 *
255 * @__driver: driver name
256 * @__register: register function for this driver type
257 * @__unregister: unregister function for this driver type
258 * @...: Additional arguments to be passed to __register and __unregister.
259 *
260 * Use this macro to construct bus specific macros for registering
261 * drivers, and do not use it on its own.
262 */
263 #define module_driver(__driver, __register, __unregister, ...) \
264 static int __init __driver##_init(void) \
265 { \
266 return __register(&(__driver) , ##__VA_ARGS__); \
267 } \
268 module_init(__driver##_init); \
269 static void __exit __driver##_exit(void) \
270 { \
271 __unregister(&(__driver) , ##__VA_ARGS__); \
272 } \
273 module_exit(__driver##_exit);
274
275 /**
276 * builtin_driver() - Helper macro for drivers that don't do anything
277 * special in init and have no exit. This eliminates some boilerplate.
278 * Each driver may only use this macro once, and calling it replaces
279 * device_initcall (or in some cases, the legacy __initcall). This is
280 * meant to be a direct parallel of module_driver() above but without
281 * the __exit stuff that is not used for builtin cases.
282 *
283 * @__driver: driver name
284 * @__register: register function for this driver type
285 * @...: Additional arguments to be passed to __register
286 *
287 * Use this macro to construct bus specific macros for registering
288 * drivers, and do not use it on its own.
289 */
290 #define builtin_driver(__driver, __register, ...) \
291 static int __init __driver##_init(void) \
292 { \
293 return __register(&(__driver) , ##__VA_ARGS__); \
294 } \
295 device_initcall(__driver##_init);
296
297 #endif /* _DEVICE_DRIVER_H_ */
298