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 <[email protected]> 6 * Copyright (c) 2004-2009 Greg Kroah-Hartman <[email protected]> 7 * Copyright (c) 2008-2009 Novell Inc. 8 * Copyright (c) 2012-2019 Greg Kroah-Hartman <[email protected]> 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 * @async_shutdown_enable: Enables devices to be shutdown asynchronously. 60 * @of_match_table: The open firmware table. 61 * @acpi_match_table: The ACPI match table. 62 * @probe: Called to query the existence of a specific device, 63 * whether this driver can work with it, and bind the driver 64 * to a specific device. 65 * @sync_state: Called to sync device state to software state after all the 66 * state tracking consumers linked to this device (present at 67 * the time of late_initcall) have successfully bound to a 68 * driver. If the device has no consumers, this function will 69 * be called at late_initcall_sync level. If the device has 70 * consumers that are never bound to a driver, this function 71 * will never get called until they do. 72 * @remove: Called when the device is removed from the system to 73 * unbind a device from this driver. 74 * @shutdown: Called at shut-down time to quiesce the device. 75 * @suspend: Called to put the device to sleep mode. Usually to a 76 * low power state. 77 * @resume: Called to bring a device from sleep mode. 78 * @groups: Default attributes that get created by the driver core 79 * automatically. 80 * @dev_groups: Additional attributes attached to device instance once 81 * it is bound to the driver. 82 * @pm: Power management operations of the device which matched 83 * this driver. 84 * @coredump: Called when sysfs entry is written to. The device driver 85 * is expected to call the dev_coredump API resulting in a 86 * uevent. 87 * @p: Driver core's private data, no one other than the driver 88 * core can touch this. 89 * 90 * The device driver-model tracks all of the drivers known to the system. 91 * The main reason for this tracking is to enable the driver core to match 92 * up drivers with new devices. Once drivers are known objects within the 93 * system, however, a number of other things become possible. Device drivers 94 * can export information and configuration variables that are independent 95 * of any specific device. 96 */ 97 struct device_driver { 98 const char *name; 99 const struct bus_type *bus; 100 101 struct module *owner; 102 const char *mod_name; /* used for built-in modules */ 103 104 bool suppress_bind_attrs; /* disables bind/unbind via sysfs */ 105 enum probe_type probe_type; 106 bool async_shutdown_enable; 107 108 const struct of_device_id *of_match_table; 109 const struct acpi_device_id *acpi_match_table; 110 111 int (*probe) (struct device *dev); 112 void (*sync_state)(struct device *dev); 113 int (*remove) (struct device *dev); 114 void (*shutdown) (struct device *dev); 115 int (*suspend) (struct device *dev, pm_message_t state); 116 int (*resume) (struct device *dev); 117 const struct attribute_group **groups; 118 const struct attribute_group **dev_groups; 119 120 const struct dev_pm_ops *pm; 121 void (*coredump) (struct device *dev); 122 123 struct driver_private *p; 124 }; 125 126 127 int __must_check driver_register(struct device_driver *drv); 128 void driver_unregister(struct device_driver *drv); 129 130 struct device_driver *driver_find(const char *name, const struct bus_type *bus); 131 bool __init driver_probe_done(void); 132 void wait_for_device_probe(void); 133 void __init wait_for_init_devices_probe(void); 134 135 /* sysfs interface for exporting driver attributes */ 136 137 struct driver_attribute { 138 struct attribute attr; 139 ssize_t (*show)(struct device_driver *driver, char *buf); 140 ssize_t (*store)(struct device_driver *driver, const char *buf, 141 size_t count); 142 }; 143 144 #define DRIVER_ATTR_RW(_name) \ 145 struct driver_attribute driver_attr_##_name = __ATTR_RW(_name) 146 #define DRIVER_ATTR_RO(_name) \ 147 struct driver_attribute driver_attr_##_name = __ATTR_RO(_name) 148 #define DRIVER_ATTR_WO(_name) \ 149 struct driver_attribute driver_attr_##_name = __ATTR_WO(_name) 150 151 int __must_check driver_create_file(const struct device_driver *driver, 152 const struct driver_attribute *attr); 153 void driver_remove_file(const struct device_driver *driver, 154 const struct driver_attribute *attr); 155 156 int driver_set_override(struct device *dev, const char **override, 157 const char *s, size_t len); 158 int __must_check driver_for_each_device(struct device_driver *drv, struct device *start, 159 void *data, int (*fn)(struct device *dev, void *)); 160 struct device *driver_find_device(const struct device_driver *drv, 161 struct device *start, const void *data, 162 device_match_t match); 163 164 /** 165 * driver_find_device_by_name - device iterator for locating a particular device 166 * of a specific name. 167 * @drv: the driver we're iterating 168 * @name: name of the device to match 169 */ 170 static inline struct device *driver_find_device_by_name(const struct device_driver *drv, 171 const char *name) 172 { 173 return driver_find_device(drv, NULL, name, device_match_name); 174 } 175 176 /** 177 * driver_find_device_by_of_node- device iterator for locating a particular device 178 * by of_node pointer. 179 * @drv: the driver we're iterating 180 * @np: of_node pointer to match. 181 */ 182 static inline struct device * 183 driver_find_device_by_of_node(const struct device_driver *drv, 184 const struct device_node *np) 185 { 186 return driver_find_device(drv, NULL, np, device_match_of_node); 187 } 188 189 /** 190 * driver_find_device_by_fwnode- device iterator for locating a particular device 191 * by fwnode pointer. 192 * @drv: the driver we're iterating 193 * @fwnode: fwnode pointer to match. 194 */ 195 static inline struct device * 196 driver_find_device_by_fwnode(struct device_driver *drv, 197 const struct fwnode_handle *fwnode) 198 { 199 return driver_find_device(drv, NULL, fwnode, device_match_fwnode); 200 } 201 202 /** 203 * driver_find_device_by_devt- device iterator for locating a particular device 204 * by devt. 205 * @drv: the driver we're iterating 206 * @devt: devt pointer to match. 207 */ 208 static inline struct device *driver_find_device_by_devt(const struct device_driver *drv, 209 dev_t devt) 210 { 211 return driver_find_device(drv, NULL, &devt, device_match_devt); 212 } 213 214 static inline struct device *driver_find_next_device(const struct device_driver *drv, 215 struct device *start) 216 { 217 return driver_find_device(drv, start, NULL, device_match_any); 218 } 219 220 #ifdef CONFIG_ACPI 221 /** 222 * driver_find_device_by_acpi_dev : device iterator for locating a particular 223 * device matching the ACPI_COMPANION device. 224 * @drv: the driver we're iterating 225 * @adev: ACPI_COMPANION device to match. 226 */ 227 static inline struct device * 228 driver_find_device_by_acpi_dev(const struct device_driver *drv, 229 const struct acpi_device *adev) 230 { 231 return driver_find_device(drv, NULL, adev, device_match_acpi_dev); 232 } 233 #else 234 static inline struct device * 235 driver_find_device_by_acpi_dev(const struct device_driver *drv, const void *adev) 236 { 237 return NULL; 238 } 239 #endif 240 241 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