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 */ 44enum 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 */ 95struct 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}; 122 123 124extern int __must_check driver_register(struct device_driver *drv); 125extern void driver_unregister(struct device_driver *drv); 126 127extern struct device_driver *driver_find(const char *name, 128 struct bus_type *bus); 129extern int driver_probe_done(void); 130extern void wait_for_device_probe(void); 131 132/* sysfs interface for exporting driver attributes */ 133 134struct driver_attribute { 135 struct attribute attr; 136 ssize_t (*show)(struct device_driver *driver, char *buf); 137 ssize_t (*store)(struct device_driver *driver, const char *buf, 138 size_t count); 139}; 140 141#define DRIVER_ATTR_RW(_name) \ 142 struct driver_attribute driver_attr_##_name = __ATTR_RW(_name) 143#define DRIVER_ATTR_RO(_name) \ 144 struct driver_attribute driver_attr_##_name = __ATTR_RO(_name) 145#define DRIVER_ATTR_WO(_name) \ 146 struct driver_attribute driver_attr_##_name = __ATTR_WO(_name) 147 148extern int __must_check driver_create_file(struct device_driver *driver, 149 const struct driver_attribute *attr); 150extern void driver_remove_file(struct device_driver *driver, 151 const struct driver_attribute *attr); 152 153extern int __must_check driver_for_each_device(struct device_driver *drv, 154 struct device *start, 155 void *data, 156 int (*fn)(struct device *dev, 157 void *)); 158struct device *driver_find_device(struct device_driver *drv, 159 struct device *start, const void *data, 160 int (*match)(struct device *dev, const void *data)); 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 */ 168static inline struct device *driver_find_device_by_name(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 */ 180static inline struct device * 181driver_find_device_by_of_node(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 */ 193static inline struct device * 194driver_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 */ 206static inline struct device *driver_find_device_by_devt(struct device_driver *drv, 207 dev_t devt) 208{ 209 return driver_find_device(drv, NULL, &devt, device_match_devt); 210} 211 212static inline struct device *driver_find_next_device(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 */ 225static inline struct device * 226driver_find_device_by_acpi_dev(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 232static inline struct device * 233driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev) 234{ 235 return NULL; 236} 237#endif 238 239extern int driver_deferred_probe_timeout; 240void driver_deferred_probe_add(struct device *dev); 241int driver_deferred_probe_check_state(struct device *dev); 242void driver_init(void); 243 244/** 245 * module_driver() - Helper macro for drivers that don't do anything 246 * special in module init/exit. This eliminates a lot of boilerplate. 247 * Each module may only use this macro once, and calling it replaces 248 * module_init() and module_exit(). 249 * 250 * @__driver: driver name 251 * @__register: register function for this driver type 252 * @__unregister: unregister function for this driver type 253 * @...: Additional arguments to be passed to __register and __unregister. 254 * 255 * Use this macro to construct bus specific macros for registering 256 * drivers, and do not use it on its own. 257 */ 258#define module_driver(__driver, __register, __unregister, ...) \ 259static int __init __driver##_init(void) \ 260{ \ 261 return __register(&(__driver) , ##__VA_ARGS__); \ 262} \ 263module_init(__driver##_init); \ 264static void __exit __driver##_exit(void) \ 265{ \ 266 __unregister(&(__driver) , ##__VA_ARGS__); \ 267} \ 268module_exit(__driver##_exit); 269 270/** 271 * builtin_driver() - Helper macro for drivers that don't do anything 272 * special in init and have no exit. This eliminates some boilerplate. 273 * Each driver may only use this macro once, and calling it replaces 274 * device_initcall (or in some cases, the legacy __initcall). This is 275 * meant to be a direct parallel of module_driver() above but without 276 * the __exit stuff that is not used for builtin cases. 277 * 278 * @__driver: driver name 279 * @__register: register function for this driver type 280 * @...: Additional arguments to be passed to __register 281 * 282 * Use this macro to construct bus specific macros for registering 283 * drivers, and do not use it on its own. 284 */ 285#define builtin_driver(__driver, __register, ...) \ 286static int __init __driver##_init(void) \ 287{ \ 288 return __register(&(__driver) , ##__VA_ARGS__); \ 289} \ 290device_initcall(__driver##_init); 291 292#endif /* _DEVICE_DRIVER_H_ */ 293