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 }; 123 124 125 extern int __must_check driver_register(struct device_driver *drv); 126 extern void driver_unregister(struct device_driver *drv); 127 128 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); 132 133 /* sysfs interface for exporting driver attributes */ 134 135 struct driver_attribute { 136 struct attribute attr; 137 ssize_t (*show)(struct device_driver *driver, char *buf); 138 ssize_t (*store)(struct device_driver *driver, const char *buf, 139 size_t count); 140 }; 141 142 #define DRIVER_ATTR_RW(_name) \ 143 struct driver_attribute driver_attr_##_name = __ATTR_RW(_name) 144 #define DRIVER_ATTR_RO(_name) \ 145 struct driver_attribute driver_attr_##_name = __ATTR_RO(_name) 146 #define DRIVER_ATTR_WO(_name) \ 147 struct driver_attribute driver_attr_##_name = __ATTR_WO(_name) 148 149 extern int __must_check driver_create_file(struct device_driver *driver, 150 const struct driver_attribute *attr); 151 extern void driver_remove_file(struct device_driver *driver, 152 const struct driver_attribute *attr); 153 154 extern int __must_check driver_for_each_device(struct device_driver *drv, 155 struct device *start, 156 void *data, 157 int (*fn)(struct device *dev, 158 void *)); 159 struct device *driver_find_device(struct device_driver *drv, 160 struct device *start, const void *data, 161 int (*match)(struct device *dev, const void *data)); 162 163 /** 164 * driver_find_device_by_name - device iterator for locating a particular device 165 * of a specific name. 166 * @drv: the driver we're iterating 167 * @name: name of the device to match 168 */ 169 static inline struct device *driver_find_device_by_name(struct device_driver *drv, 170 const char *name) 171 { 172 return driver_find_device(drv, NULL, name, device_match_name); 173 } 174 175 /** 176 * driver_find_device_by_of_node- device iterator for locating a particular device 177 * by of_node pointer. 178 * @drv: the driver we're iterating 179 * @np: of_node pointer to match. 180 */ 181 static inline struct device * 182 driver_find_device_by_of_node(struct device_driver *drv, 183 const struct device_node *np) 184 { 185 return driver_find_device(drv, NULL, np, device_match_of_node); 186 } 187 188 /** 189 * driver_find_device_by_fwnode- device iterator for locating a particular device 190 * by fwnode pointer. 191 * @drv: the driver we're iterating 192 * @fwnode: fwnode pointer to match. 193 */ 194 static inline struct device * 195 driver_find_device_by_fwnode(struct device_driver *drv, 196 const struct fwnode_handle *fwnode) 197 { 198 return driver_find_device(drv, NULL, fwnode, device_match_fwnode); 199 } 200 201 /** 202 * driver_find_device_by_devt- device iterator for locating a particular device 203 * by devt. 204 * @drv: the driver we're iterating 205 * @devt: devt pointer to match. 206 */ 207 static inline struct device *driver_find_device_by_devt(struct device_driver *drv, 208 dev_t devt) 209 { 210 return driver_find_device(drv, NULL, &devt, device_match_devt); 211 } 212 213 static inline struct device *driver_find_next_device(struct device_driver *drv, 214 struct device *start) 215 { 216 return driver_find_device(drv, start, NULL, device_match_any); 217 } 218 219 #ifdef CONFIG_ACPI 220 /** 221 * driver_find_device_by_acpi_dev : device iterator for locating a particular 222 * device matching the ACPI_COMPANION device. 223 * @drv: the driver we're iterating 224 * @adev: ACPI_COMPANION device to match. 225 */ 226 static inline struct device * 227 driver_find_device_by_acpi_dev(struct device_driver *drv, 228 const struct acpi_device *adev) 229 { 230 return driver_find_device(drv, NULL, adev, device_match_acpi_dev); 231 } 232 #else 233 static inline struct device * 234 driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev) 235 { 236 return NULL; 237 } 238 #endif 239 240 extern int driver_deferred_probe_timeout; 241 void driver_deferred_probe_add(struct device *dev); 242 int driver_deferred_probe_check_state(struct device *dev); 243 void driver_init(void); 244 245 /** 246 * module_driver() - Helper macro for drivers that don't do anything 247 * special in module init/exit. This eliminates a lot of boilerplate. 248 * Each module may only use this macro once, and calling it replaces 249 * module_init() and module_exit(). 250 * 251 * @__driver: driver name 252 * @__register: register function for this driver type 253 * @__unregister: unregister function for this driver type 254 * @...: Additional arguments to be passed to __register and __unregister. 255 * 256 * Use this macro to construct bus specific macros for registering 257 * drivers, and do not use it on its own. 258 */ 259 #define module_driver(__driver, __register, __unregister, ...) \ 260 static int __init __driver##_init(void) \ 261 { \ 262 return __register(&(__driver) , ##__VA_ARGS__); \ 263 } \ 264 module_init(__driver##_init); \ 265 static void __exit __driver##_exit(void) \ 266 { \ 267 __unregister(&(__driver) , ##__VA_ARGS__); \ 268 } \ 269 module_exit(__driver##_exit); 270 271 /** 272 * builtin_driver() - Helper macro for drivers that don't do anything 273 * special in init and have no exit. This eliminates some boilerplate. 274 * Each driver may only use this macro once, and calling it replaces 275 * device_initcall (or in some cases, the legacy __initcall). This is 276 * meant to be a direct parallel of module_driver() above but without 277 * the __exit stuff that is not used for builtin cases. 278 * 279 * @__driver: driver name 280 * @__register: register function for this driver type 281 * @...: Additional arguments to be passed to __register 282 * 283 * Use this macro to construct bus specific macros for registering 284 * drivers, and do not use it on its own. 285 */ 286 #define builtin_driver(__driver, __register, ...) \ 287 static int __init __driver##_init(void) \ 288 { \ 289 return __register(&(__driver) , ##__VA_ARGS__); \ 290 } \ 291 device_initcall(__driver##_init); 292 293 #endif /* _DEVICE_DRIVER_H_ */ 294