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 const 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 int __must_check driver_register(struct device_driver *drv); 126 void driver_unregister(struct device_driver *drv); 127 128 struct device_driver *driver_find(const char *name, const struct bus_type *bus); 129 bool __init driver_probe_done(void); 130 void wait_for_device_probe(void); 131 void __init wait_for_init_devices_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 int __must_check driver_create_file(const struct device_driver *driver, 150 const struct driver_attribute *attr); 151 void driver_remove_file(const struct device_driver *driver, 152 const struct driver_attribute *attr); 153 154 int driver_set_override(struct device *dev, const char **override, 155 const char *s, size_t len); 156 int __must_check driver_for_each_device(struct device_driver *drv, struct device *start, 157 void *data, device_iter_t fn); 158 struct device *driver_find_device(const struct device_driver *drv, 159 struct device *start, const void *data, 160 device_match_t match); 161 162 /** 163 * driver_find_device_by_name - device iterator for locating a particular device 164 * of a specific name. 165 * @drv: the driver we're iterating 166 * @name: name of the device to match 167 */ 168 static inline struct device *driver_find_device_by_name(const struct device_driver *drv, 169 const char *name) 170 { 171 return driver_find_device(drv, NULL, name, device_match_name); 172 } 173 174 /** 175 * driver_find_device_by_of_node- device iterator for locating a particular device 176 * by of_node pointer. 177 * @drv: the driver we're iterating 178 * @np: of_node pointer to match. 179 */ 180 static inline struct device * 181 driver_find_device_by_of_node(const struct device_driver *drv, 182 const struct device_node *np) 183 { 184 return driver_find_device(drv, NULL, np, device_match_of_node); 185 } 186 187 /** 188 * driver_find_device_by_fwnode- device iterator for locating a particular device 189 * by fwnode pointer. 190 * @drv: the driver we're iterating 191 * @fwnode: fwnode pointer to match. 192 */ 193 static inline struct device * 194 driver_find_device_by_fwnode(struct device_driver *drv, 195 const struct fwnode_handle *fwnode) 196 { 197 return driver_find_device(drv, NULL, fwnode, device_match_fwnode); 198 } 199 200 /** 201 * driver_find_device_by_devt- device iterator for locating a particular device 202 * by devt. 203 * @drv: the driver we're iterating 204 * @devt: devt pointer to match. 205 */ 206 static inline struct device *driver_find_device_by_devt(const struct device_driver *drv, 207 dev_t devt) 208 { 209 return driver_find_device(drv, NULL, &devt, device_match_devt); 210 } 211 212 static inline struct device *driver_find_next_device(const struct device_driver *drv, 213 struct device *start) 214 { 215 return driver_find_device(drv, start, NULL, device_match_any); 216 } 217 218 #ifdef CONFIG_ACPI 219 /** 220 * driver_find_device_by_acpi_dev : device iterator for locating a particular 221 * device matching the ACPI_COMPANION device. 222 * @drv: the driver we're iterating 223 * @adev: ACPI_COMPANION device to match. 224 */ 225 static inline struct device * 226 driver_find_device_by_acpi_dev(const struct device_driver *drv, 227 const struct acpi_device *adev) 228 { 229 return driver_find_device(drv, NULL, adev, device_match_acpi_dev); 230 } 231 #else 232 static inline struct device * 233 driver_find_device_by_acpi_dev(const struct device_driver *drv, const void *adev) 234 { 235 return NULL; 236 } 237 #endif 238 239 void driver_deferred_probe_add(struct device *dev); 240 int driver_deferred_probe_check_state(struct device *dev); 241 void driver_init(void); 242 243 /** 244 * module_driver() - Helper macro for drivers that don't do anything 245 * special in module init/exit. This eliminates a lot of boilerplate. 246 * Each module may only use this macro once, and calling it replaces 247 * module_init() and module_exit(). 248 * 249 * @__driver: driver name 250 * @__register: register function for this driver type 251 * @__unregister: unregister function for this driver type 252 * @...: Additional arguments to be passed to __register and __unregister. 253 * 254 * Use this macro to construct bus specific macros for registering 255 * drivers, and do not use it on its own. 256 */ 257 #define module_driver(__driver, __register, __unregister, ...) \ 258 static int __init __driver##_init(void) \ 259 { \ 260 return __register(&(__driver) , ##__VA_ARGS__); \ 261 } \ 262 module_init(__driver##_init); \ 263 static void __exit __driver##_exit(void) \ 264 { \ 265 __unregister(&(__driver) , ##__VA_ARGS__); \ 266 } \ 267 module_exit(__driver##_exit); 268 269 /** 270 * builtin_driver() - Helper macro for drivers that don't do anything 271 * special in init and have no exit. This eliminates some boilerplate. 272 * Each driver may only use this macro once, and calling it replaces 273 * device_initcall (or in some cases, the legacy __initcall). This is 274 * meant to be a direct parallel of module_driver() above but without 275 * the __exit stuff that is not used for builtin cases. 276 * 277 * @__driver: driver name 278 * @__register: register function for this driver type 279 * @...: Additional arguments to be passed to __register 280 * 281 * Use this macro to construct bus specific macros for registering 282 * drivers, and do not use it on its own. 283 */ 284 #define builtin_driver(__driver, __register, ...) \ 285 static int __init __driver##_init(void) \ 286 { \ 287 return __register(&(__driver) , ##__VA_ARGS__); \ 288 } \ 289 device_initcall(__driver##_init); 290 291 #endif /* _DEVICE_DRIVER_H_ */ 292