1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * device.h - generic, centralized 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 * 9 * See Documentation/driver-api/driver-model/ for more information. 10 */ 11 12 #ifndef _DEVICE_H_ 13 #define _DEVICE_H_ 14 15 #include <linux/dev_printk.h> 16 #include <linux/energy_model.h> 17 #include <linux/ioport.h> 18 #include <linux/kobject.h> 19 #include <linux/klist.h> 20 #include <linux/list.h> 21 #include <linux/lockdep.h> 22 #include <linux/compiler.h> 23 #include <linux/types.h> 24 #include <linux/mutex.h> 25 #include <linux/pm.h> 26 #include <linux/atomic.h> 27 #include <linux/uidgid.h> 28 #include <linux/gfp.h> 29 #include <linux/overflow.h> 30 #include <linux/device/bus.h> 31 #include <linux/device/class.h> 32 #include <linux/device/driver.h> 33 #include <asm/device.h> 34 35 struct device; 36 struct device_private; 37 struct device_driver; 38 struct driver_private; 39 struct module; 40 struct class; 41 struct subsys_private; 42 struct device_node; 43 struct fwnode_handle; 44 struct iommu_ops; 45 struct iommu_group; 46 struct dev_pin_info; 47 struct dev_iommu; 48 struct msi_device_data; 49 50 /** 51 * struct subsys_interface - interfaces to device functions 52 * @name: name of the device function 53 * @subsys: subsystem of the devices to attach to 54 * @node: the list of functions registered at the subsystem 55 * @add_dev: device hookup to device function handler 56 * @remove_dev: device hookup to device function handler 57 * 58 * Simple interfaces attached to a subsystem. Multiple interfaces can 59 * attach to a subsystem and its devices. Unlike drivers, they do not 60 * exclusively claim or control devices. Interfaces usually represent 61 * a specific functionality of a subsystem/class of devices. 62 */ 63 struct subsys_interface { 64 const char *name; 65 struct bus_type *subsys; 66 struct list_head node; 67 int (*add_dev)(struct device *dev, struct subsys_interface *sif); 68 void (*remove_dev)(struct device *dev, struct subsys_interface *sif); 69 }; 70 71 int subsys_interface_register(struct subsys_interface *sif); 72 void subsys_interface_unregister(struct subsys_interface *sif); 73 74 int subsys_system_register(struct bus_type *subsys, 75 const struct attribute_group **groups); 76 int subsys_virtual_register(struct bus_type *subsys, 77 const struct attribute_group **groups); 78 79 /* 80 * The type of device, "struct device" is embedded in. A class 81 * or bus can contain devices of different types 82 * like "partitions" and "disks", "mouse" and "event". 83 * This identifies the device type and carries type-specific 84 * information, equivalent to the kobj_type of a kobject. 85 * If "name" is specified, the uevent will contain it in 86 * the DEVTYPE variable. 87 */ 88 struct device_type { 89 const char *name; 90 const struct attribute_group **groups; 91 int (*uevent)(const struct device *dev, struct kobj_uevent_env *env); 92 char *(*devnode)(const struct device *dev, umode_t *mode, 93 kuid_t *uid, kgid_t *gid); 94 void (*release)(struct device *dev); 95 96 const struct dev_pm_ops *pm; 97 }; 98 99 /* interface for exporting device attributes */ 100 struct device_attribute { 101 struct attribute attr; 102 ssize_t (*show)(struct device *dev, struct device_attribute *attr, 103 char *buf); 104 ssize_t (*store)(struct device *dev, struct device_attribute *attr, 105 const char *buf, size_t count); 106 }; 107 108 struct dev_ext_attribute { 109 struct device_attribute attr; 110 void *var; 111 }; 112 113 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr, 114 char *buf); 115 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr, 116 const char *buf, size_t count); 117 ssize_t device_show_int(struct device *dev, struct device_attribute *attr, 118 char *buf); 119 ssize_t device_store_int(struct device *dev, struct device_attribute *attr, 120 const char *buf, size_t count); 121 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr, 122 char *buf); 123 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr, 124 const char *buf, size_t count); 125 126 #define DEVICE_ATTR(_name, _mode, _show, _store) \ 127 struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store) 128 #define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \ 129 struct device_attribute dev_attr_##_name = \ 130 __ATTR_PREALLOC(_name, _mode, _show, _store) 131 #define DEVICE_ATTR_RW(_name) \ 132 struct device_attribute dev_attr_##_name = __ATTR_RW(_name) 133 #define DEVICE_ATTR_ADMIN_RW(_name) \ 134 struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600) 135 #define DEVICE_ATTR_RO(_name) \ 136 struct device_attribute dev_attr_##_name = __ATTR_RO(_name) 137 #define DEVICE_ATTR_ADMIN_RO(_name) \ 138 struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400) 139 #define DEVICE_ATTR_WO(_name) \ 140 struct device_attribute dev_attr_##_name = __ATTR_WO(_name) 141 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \ 142 struct dev_ext_attribute dev_attr_##_name = \ 143 { __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) } 144 #define DEVICE_INT_ATTR(_name, _mode, _var) \ 145 struct dev_ext_attribute dev_attr_##_name = \ 146 { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) } 147 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \ 148 struct dev_ext_attribute dev_attr_##_name = \ 149 { __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) } 150 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \ 151 struct device_attribute dev_attr_##_name = \ 152 __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) 153 154 int device_create_file(struct device *device, 155 const struct device_attribute *entry); 156 void device_remove_file(struct device *dev, 157 const struct device_attribute *attr); 158 bool device_remove_file_self(struct device *dev, 159 const struct device_attribute *attr); 160 int __must_check device_create_bin_file(struct device *dev, 161 const struct bin_attribute *attr); 162 void device_remove_bin_file(struct device *dev, 163 const struct bin_attribute *attr); 164 165 /* device resource management */ 166 typedef void (*dr_release_t)(struct device *dev, void *res); 167 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data); 168 169 void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, 170 int nid, const char *name) __malloc; 171 #define devres_alloc(release, size, gfp) \ 172 __devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release) 173 #define devres_alloc_node(release, size, gfp, nid) \ 174 __devres_alloc_node(release, size, gfp, nid, #release) 175 176 void devres_for_each_res(struct device *dev, dr_release_t release, 177 dr_match_t match, void *match_data, 178 void (*fn)(struct device *, void *, void *), 179 void *data); 180 void devres_free(void *res); 181 void devres_add(struct device *dev, void *res); 182 void *devres_find(struct device *dev, dr_release_t release, 183 dr_match_t match, void *match_data); 184 void *devres_get(struct device *dev, void *new_res, 185 dr_match_t match, void *match_data); 186 void *devres_remove(struct device *dev, dr_release_t release, 187 dr_match_t match, void *match_data); 188 int devres_destroy(struct device *dev, dr_release_t release, 189 dr_match_t match, void *match_data); 190 int devres_release(struct device *dev, dr_release_t release, 191 dr_match_t match, void *match_data); 192 193 /* devres group */ 194 void * __must_check devres_open_group(struct device *dev, void *id, gfp_t gfp); 195 void devres_close_group(struct device *dev, void *id); 196 void devres_remove_group(struct device *dev, void *id); 197 int devres_release_group(struct device *dev, void *id); 198 199 /* managed devm_k.alloc/kfree for device drivers */ 200 void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __alloc_size(2); 201 void *devm_krealloc(struct device *dev, void *ptr, size_t size, 202 gfp_t gfp) __must_check __realloc_size(3); 203 __printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp, 204 const char *fmt, va_list ap) __malloc; 205 __printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp, 206 const char *fmt, ...) __malloc; 207 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp) 208 { 209 return devm_kmalloc(dev, size, gfp | __GFP_ZERO); 210 } 211 static inline void *devm_kmalloc_array(struct device *dev, 212 size_t n, size_t size, gfp_t flags) 213 { 214 size_t bytes; 215 216 if (unlikely(check_mul_overflow(n, size, &bytes))) 217 return NULL; 218 219 return devm_kmalloc(dev, bytes, flags); 220 } 221 static inline void *devm_kcalloc(struct device *dev, 222 size_t n, size_t size, gfp_t flags) 223 { 224 return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO); 225 } 226 void devm_kfree(struct device *dev, const void *p); 227 char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc; 228 const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp); 229 void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp) 230 __realloc_size(3); 231 232 unsigned long devm_get_free_pages(struct device *dev, 233 gfp_t gfp_mask, unsigned int order); 234 void devm_free_pages(struct device *dev, unsigned long addr); 235 236 void __iomem *devm_ioremap_resource(struct device *dev, 237 const struct resource *res); 238 void __iomem *devm_ioremap_resource_wc(struct device *dev, 239 const struct resource *res); 240 241 void __iomem *devm_of_iomap(struct device *dev, 242 struct device_node *node, int index, 243 resource_size_t *size); 244 245 /* allows to add/remove a custom action to devres stack */ 246 void devm_remove_action(struct device *dev, void (*action)(void *), void *data); 247 void devm_release_action(struct device *dev, void (*action)(void *), void *data); 248 249 int __devm_add_action(struct device *dev, void (*action)(void *), void *data, const char *name); 250 #define devm_add_action(release, action, data) \ 251 __devm_add_action(release, action, data, #action) 252 253 static inline int __devm_add_action_or_reset(struct device *dev, void (*action)(void *), 254 void *data, const char *name) 255 { 256 int ret; 257 258 ret = __devm_add_action(dev, action, data, name); 259 if (ret) 260 action(data); 261 262 return ret; 263 } 264 #define devm_add_action_or_reset(release, action, data) \ 265 __devm_add_action_or_reset(release, action, data, #action) 266 267 /** 268 * devm_alloc_percpu - Resource-managed alloc_percpu 269 * @dev: Device to allocate per-cpu memory for 270 * @type: Type to allocate per-cpu memory for 271 * 272 * Managed alloc_percpu. Per-cpu memory allocated with this function is 273 * automatically freed on driver detach. 274 * 275 * RETURNS: 276 * Pointer to allocated memory on success, NULL on failure. 277 */ 278 #define devm_alloc_percpu(dev, type) \ 279 ((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \ 280 __alignof__(type))) 281 282 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size, 283 size_t align); 284 void devm_free_percpu(struct device *dev, void __percpu *pdata); 285 286 struct device_dma_parameters { 287 /* 288 * a low level driver may set these to teach IOMMU code about 289 * sg limitations. 290 */ 291 unsigned int max_segment_size; 292 unsigned int min_align_mask; 293 unsigned long segment_boundary_mask; 294 }; 295 296 /** 297 * enum device_link_state - Device link states. 298 * @DL_STATE_NONE: The presence of the drivers is not being tracked. 299 * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present. 300 * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not. 301 * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present). 302 * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present. 303 * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding. 304 */ 305 enum device_link_state { 306 DL_STATE_NONE = -1, 307 DL_STATE_DORMANT = 0, 308 DL_STATE_AVAILABLE, 309 DL_STATE_CONSUMER_PROBE, 310 DL_STATE_ACTIVE, 311 DL_STATE_SUPPLIER_UNBIND, 312 }; 313 314 /* 315 * Device link flags. 316 * 317 * STATELESS: The core will not remove this link automatically. 318 * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind. 319 * PM_RUNTIME: If set, the runtime PM framework will use this link. 320 * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation. 321 * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind. 322 * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds. 323 * MANAGED: The core tracks presence of supplier/consumer drivers (internal). 324 * SYNC_STATE_ONLY: Link only affects sync_state() behavior. 325 * INFERRED: Inferred from data (eg: firmware) and not from driver actions. 326 */ 327 #define DL_FLAG_STATELESS BIT(0) 328 #define DL_FLAG_AUTOREMOVE_CONSUMER BIT(1) 329 #define DL_FLAG_PM_RUNTIME BIT(2) 330 #define DL_FLAG_RPM_ACTIVE BIT(3) 331 #define DL_FLAG_AUTOREMOVE_SUPPLIER BIT(4) 332 #define DL_FLAG_AUTOPROBE_CONSUMER BIT(5) 333 #define DL_FLAG_MANAGED BIT(6) 334 #define DL_FLAG_SYNC_STATE_ONLY BIT(7) 335 #define DL_FLAG_INFERRED BIT(8) 336 #define DL_FLAG_CYCLE BIT(9) 337 338 /** 339 * enum dl_dev_state - Device driver presence tracking information. 340 * @DL_DEV_NO_DRIVER: There is no driver attached to the device. 341 * @DL_DEV_PROBING: A driver is probing. 342 * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device. 343 * @DL_DEV_UNBINDING: The driver is unbinding from the device. 344 */ 345 enum dl_dev_state { 346 DL_DEV_NO_DRIVER = 0, 347 DL_DEV_PROBING, 348 DL_DEV_DRIVER_BOUND, 349 DL_DEV_UNBINDING, 350 }; 351 352 /** 353 * enum device_removable - Whether the device is removable. The criteria for a 354 * device to be classified as removable is determined by its subsystem or bus. 355 * @DEVICE_REMOVABLE_NOT_SUPPORTED: This attribute is not supported for this 356 * device (default). 357 * @DEVICE_REMOVABLE_UNKNOWN: Device location is Unknown. 358 * @DEVICE_FIXED: Device is not removable by the user. 359 * @DEVICE_REMOVABLE: Device is removable by the user. 360 */ 361 enum device_removable { 362 DEVICE_REMOVABLE_NOT_SUPPORTED = 0, /* must be 0 */ 363 DEVICE_REMOVABLE_UNKNOWN, 364 DEVICE_FIXED, 365 DEVICE_REMOVABLE, 366 }; 367 368 /** 369 * struct dev_links_info - Device data related to device links. 370 * @suppliers: List of links to supplier devices. 371 * @consumers: List of links to consumer devices. 372 * @defer_sync: Hook to global list of devices that have deferred sync_state. 373 * @status: Driver status information. 374 */ 375 struct dev_links_info { 376 struct list_head suppliers; 377 struct list_head consumers; 378 struct list_head defer_sync; 379 enum dl_dev_state status; 380 }; 381 382 /** 383 * struct dev_msi_info - Device data related to MSI 384 * @domain: The MSI interrupt domain associated to the device 385 * @data: Pointer to MSI device data 386 */ 387 struct dev_msi_info { 388 #ifdef CONFIG_GENERIC_MSI_IRQ 389 struct irq_domain *domain; 390 struct msi_device_data *data; 391 #endif 392 }; 393 394 /** 395 * enum device_physical_location_panel - Describes which panel surface of the 396 * system's housing the device connection point resides on. 397 * @DEVICE_PANEL_TOP: Device connection point is on the top panel. 398 * @DEVICE_PANEL_BOTTOM: Device connection point is on the bottom panel. 399 * @DEVICE_PANEL_LEFT: Device connection point is on the left panel. 400 * @DEVICE_PANEL_RIGHT: Device connection point is on the right panel. 401 * @DEVICE_PANEL_FRONT: Device connection point is on the front panel. 402 * @DEVICE_PANEL_BACK: Device connection point is on the back panel. 403 * @DEVICE_PANEL_UNKNOWN: The panel with device connection point is unknown. 404 */ 405 enum device_physical_location_panel { 406 DEVICE_PANEL_TOP, 407 DEVICE_PANEL_BOTTOM, 408 DEVICE_PANEL_LEFT, 409 DEVICE_PANEL_RIGHT, 410 DEVICE_PANEL_FRONT, 411 DEVICE_PANEL_BACK, 412 DEVICE_PANEL_UNKNOWN, 413 }; 414 415 /** 416 * enum device_physical_location_vertical_position - Describes vertical 417 * position of the device connection point on the panel surface. 418 * @DEVICE_VERT_POS_UPPER: Device connection point is at upper part of panel. 419 * @DEVICE_VERT_POS_CENTER: Device connection point is at center part of panel. 420 * @DEVICE_VERT_POS_LOWER: Device connection point is at lower part of panel. 421 */ 422 enum device_physical_location_vertical_position { 423 DEVICE_VERT_POS_UPPER, 424 DEVICE_VERT_POS_CENTER, 425 DEVICE_VERT_POS_LOWER, 426 }; 427 428 /** 429 * enum device_physical_location_horizontal_position - Describes horizontal 430 * position of the device connection point on the panel surface. 431 * @DEVICE_HORI_POS_LEFT: Device connection point is at left part of panel. 432 * @DEVICE_HORI_POS_CENTER: Device connection point is at center part of panel. 433 * @DEVICE_HORI_POS_RIGHT: Device connection point is at right part of panel. 434 */ 435 enum device_physical_location_horizontal_position { 436 DEVICE_HORI_POS_LEFT, 437 DEVICE_HORI_POS_CENTER, 438 DEVICE_HORI_POS_RIGHT, 439 }; 440 441 /** 442 * struct device_physical_location - Device data related to physical location 443 * of the device connection point. 444 * @panel: Panel surface of the system's housing that the device connection 445 * point resides on. 446 * @vertical_position: Vertical position of the device connection point within 447 * the panel. 448 * @horizontal_position: Horizontal position of the device connection point 449 * within the panel. 450 * @dock: Set if the device connection point resides in a docking station or 451 * port replicator. 452 * @lid: Set if this device connection point resides on the lid of laptop 453 * system. 454 */ 455 struct device_physical_location { 456 enum device_physical_location_panel panel; 457 enum device_physical_location_vertical_position vertical_position; 458 enum device_physical_location_horizontal_position horizontal_position; 459 bool dock; 460 bool lid; 461 }; 462 463 /** 464 * struct device - The basic device structure 465 * @parent: The device's "parent" device, the device to which it is attached. 466 * In most cases, a parent device is some sort of bus or host 467 * controller. If parent is NULL, the device, is a top-level device, 468 * which is not usually what you want. 469 * @p: Holds the private data of the driver core portions of the device. 470 * See the comment of the struct device_private for detail. 471 * @kobj: A top-level, abstract class from which other classes are derived. 472 * @init_name: Initial name of the device. 473 * @type: The type of device. 474 * This identifies the device type and carries type-specific 475 * information. 476 * @mutex: Mutex to synchronize calls to its driver. 477 * @bus: Type of bus device is on. 478 * @driver: Which driver has allocated this 479 * @platform_data: Platform data specific to the device. 480 * Example: For devices on custom boards, as typical of embedded 481 * and SOC based hardware, Linux often uses platform_data to point 482 * to board-specific structures describing devices and how they 483 * are wired. That can include what ports are available, chip 484 * variants, which GPIO pins act in what additional roles, and so 485 * on. This shrinks the "Board Support Packages" (BSPs) and 486 * minimizes board-specific #ifdefs in drivers. 487 * @driver_data: Private pointer for driver specific info. 488 * @links: Links to suppliers and consumers of this device. 489 * @power: For device power management. 490 * See Documentation/driver-api/pm/devices.rst for details. 491 * @pm_domain: Provide callbacks that are executed during system suspend, 492 * hibernation, system resume and during runtime PM transitions 493 * along with subsystem-level and driver-level callbacks. 494 * @em_pd: device's energy model performance domain 495 * @pins: For device pin management. 496 * See Documentation/driver-api/pin-control.rst for details. 497 * @msi: MSI related data 498 * @numa_node: NUMA node this device is close to. 499 * @dma_ops: DMA mapping operations for this device. 500 * @dma_mask: Dma mask (if dma'ble device). 501 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all 502 * hardware supports 64-bit addresses for consistent allocations 503 * such descriptors. 504 * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller 505 * DMA limit than the device itself supports. 506 * @dma_range_map: map for DMA memory ranges relative to that of RAM 507 * @dma_parms: A low level driver may set these to teach IOMMU code about 508 * segment limitations. 509 * @dma_pools: Dma pools (if dma'ble device). 510 * @dma_mem: Internal for coherent mem override. 511 * @cma_area: Contiguous memory area for dma allocations 512 * @dma_io_tlb_mem: Pointer to the swiotlb pool used. Not for driver use. 513 * @archdata: For arch-specific additions. 514 * @of_node: Associated device tree node. 515 * @fwnode: Associated device node supplied by platform firmware. 516 * @devt: For creating the sysfs "dev". 517 * @id: device instance 518 * @devres_lock: Spinlock to protect the resource of the device. 519 * @devres_head: The resources list of the device. 520 * @knode_class: The node used to add the device to the class list. 521 * @class: The class of the device. 522 * @groups: Optional attribute groups. 523 * @release: Callback to free the device after all references have 524 * gone away. This should be set by the allocator of the 525 * device (i.e. the bus driver that discovered the device). 526 * @iommu_group: IOMMU group the device belongs to. 527 * @iommu: Per device generic IOMMU runtime data 528 * @physical_location: Describes physical location of the device connection 529 * point in the system housing. 530 * @removable: Whether the device can be removed from the system. This 531 * should be set by the subsystem / bus driver that discovered 532 * the device. 533 * 534 * @offline_disabled: If set, the device is permanently online. 535 * @offline: Set after successful invocation of bus type's .offline(). 536 * @of_node_reused: Set if the device-tree node is shared with an ancestor 537 * device. 538 * @state_synced: The hardware state of this device has been synced to match 539 * the software state of this device by calling the driver/bus 540 * sync_state() callback. 541 * @can_match: The device has matched with a driver at least once or it is in 542 * a bus (like AMBA) which can't check for matching drivers until 543 * other devices probe successfully. 544 * @dma_coherent: this particular device is dma coherent, even if the 545 * architecture supports non-coherent devices. 546 * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the 547 * streaming DMA operations (->map_* / ->unmap_* / ->sync_*), 548 * and optionall (if the coherent mask is large enough) also 549 * for dma allocations. This flag is managed by the dma ops 550 * instance from ->dma_supported. 551 * 552 * At the lowest level, every device in a Linux system is represented by an 553 * instance of struct device. The device structure contains the information 554 * that the device model core needs to model the system. Most subsystems, 555 * however, track additional information about the devices they host. As a 556 * result, it is rare for devices to be represented by bare device structures; 557 * instead, that structure, like kobject structures, is usually embedded within 558 * a higher-level representation of the device. 559 */ 560 struct device { 561 struct kobject kobj; 562 struct device *parent; 563 564 struct device_private *p; 565 566 const char *init_name; /* initial name of the device */ 567 const struct device_type *type; 568 569 const struct bus_type *bus; /* type of bus device is on */ 570 struct device_driver *driver; /* which driver has allocated this 571 device */ 572 void *platform_data; /* Platform specific data, device 573 core doesn't touch it */ 574 void *driver_data; /* Driver data, set and get with 575 dev_set_drvdata/dev_get_drvdata */ 576 struct mutex mutex; /* mutex to synchronize calls to 577 * its driver. 578 */ 579 580 struct dev_links_info links; 581 struct dev_pm_info power; 582 struct dev_pm_domain *pm_domain; 583 584 #ifdef CONFIG_ENERGY_MODEL 585 struct em_perf_domain *em_pd; 586 #endif 587 588 #ifdef CONFIG_PINCTRL 589 struct dev_pin_info *pins; 590 #endif 591 struct dev_msi_info msi; 592 #ifdef CONFIG_DMA_OPS 593 const struct dma_map_ops *dma_ops; 594 #endif 595 u64 *dma_mask; /* dma mask (if dma'able device) */ 596 u64 coherent_dma_mask;/* Like dma_mask, but for 597 alloc_coherent mappings as 598 not all hardware supports 599 64 bit addresses for consistent 600 allocations such descriptors. */ 601 u64 bus_dma_limit; /* upstream dma constraint */ 602 const struct bus_dma_region *dma_range_map; 603 604 struct device_dma_parameters *dma_parms; 605 606 struct list_head dma_pools; /* dma pools (if dma'ble) */ 607 608 #ifdef CONFIG_DMA_DECLARE_COHERENT 609 struct dma_coherent_mem *dma_mem; /* internal for coherent mem 610 override */ 611 #endif 612 #ifdef CONFIG_DMA_CMA 613 struct cma *cma_area; /* contiguous memory area for dma 614 allocations */ 615 #endif 616 #ifdef CONFIG_SWIOTLB 617 struct io_tlb_mem *dma_io_tlb_mem; 618 #endif 619 /* arch specific additions */ 620 struct dev_archdata archdata; 621 622 struct device_node *of_node; /* associated device tree node */ 623 struct fwnode_handle *fwnode; /* firmware device node */ 624 625 #ifdef CONFIG_NUMA 626 int numa_node; /* NUMA node this device is close to */ 627 #endif 628 dev_t devt; /* dev_t, creates the sysfs "dev" */ 629 u32 id; /* device instance */ 630 631 spinlock_t devres_lock; 632 struct list_head devres_head; 633 634 const struct class *class; 635 const struct attribute_group **groups; /* optional groups */ 636 637 void (*release)(struct device *dev); 638 struct iommu_group *iommu_group; 639 struct dev_iommu *iommu; 640 641 struct device_physical_location *physical_location; 642 643 enum device_removable removable; 644 645 bool offline_disabled:1; 646 bool offline:1; 647 bool of_node_reused:1; 648 bool state_synced:1; 649 bool can_match:1; 650 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ 651 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ 652 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) 653 bool dma_coherent:1; 654 #endif 655 #ifdef CONFIG_DMA_OPS_BYPASS 656 bool dma_ops_bypass : 1; 657 #endif 658 }; 659 660 /** 661 * struct device_link - Device link representation. 662 * @supplier: The device on the supplier end of the link. 663 * @s_node: Hook to the supplier device's list of links to consumers. 664 * @consumer: The device on the consumer end of the link. 665 * @c_node: Hook to the consumer device's list of links to suppliers. 666 * @link_dev: device used to expose link details in sysfs 667 * @status: The state of the link (with respect to the presence of drivers). 668 * @flags: Link flags. 669 * @rpm_active: Whether or not the consumer device is runtime-PM-active. 670 * @kref: Count repeated addition of the same link. 671 * @rm_work: Work structure used for removing the link. 672 * @supplier_preactivated: Supplier has been made active before consumer probe. 673 */ 674 struct device_link { 675 struct device *supplier; 676 struct list_head s_node; 677 struct device *consumer; 678 struct list_head c_node; 679 struct device link_dev; 680 enum device_link_state status; 681 u32 flags; 682 refcount_t rpm_active; 683 struct kref kref; 684 struct work_struct rm_work; 685 bool supplier_preactivated; /* Owned by consumer probe. */ 686 }; 687 688 #define kobj_to_dev(__kobj) container_of_const(__kobj, struct device, kobj) 689 690 /** 691 * device_iommu_mapped - Returns true when the device DMA is translated 692 * by an IOMMU 693 * @dev: Device to perform the check on 694 */ 695 static inline bool device_iommu_mapped(struct device *dev) 696 { 697 return (dev->iommu_group != NULL); 698 } 699 700 /* Get the wakeup routines, which depend on struct device */ 701 #include <linux/pm_wakeup.h> 702 703 static inline const char *dev_name(const struct device *dev) 704 { 705 /* Use the init name until the kobject becomes available */ 706 if (dev->init_name) 707 return dev->init_name; 708 709 return kobject_name(&dev->kobj); 710 } 711 712 /** 713 * dev_bus_name - Return a device's bus/class name, if at all possible 714 * @dev: struct device to get the bus/class name of 715 * 716 * Will return the name of the bus/class the device is attached to. If it is 717 * not attached to a bus/class, an empty string will be returned. 718 */ 719 static inline const char *dev_bus_name(const struct device *dev) 720 { 721 return dev->bus ? dev->bus->name : (dev->class ? dev->class->name : ""); 722 } 723 724 __printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...); 725 726 #ifdef CONFIG_NUMA 727 static inline int dev_to_node(struct device *dev) 728 { 729 return dev->numa_node; 730 } 731 static inline void set_dev_node(struct device *dev, int node) 732 { 733 dev->numa_node = node; 734 } 735 #else 736 static inline int dev_to_node(struct device *dev) 737 { 738 return NUMA_NO_NODE; 739 } 740 static inline void set_dev_node(struct device *dev, int node) 741 { 742 } 743 #endif 744 745 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev) 746 { 747 #ifdef CONFIG_GENERIC_MSI_IRQ 748 return dev->msi.domain; 749 #else 750 return NULL; 751 #endif 752 } 753 754 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d) 755 { 756 #ifdef CONFIG_GENERIC_MSI_IRQ 757 dev->msi.domain = d; 758 #endif 759 } 760 761 static inline void *dev_get_drvdata(const struct device *dev) 762 { 763 return dev->driver_data; 764 } 765 766 static inline void dev_set_drvdata(struct device *dev, void *data) 767 { 768 dev->driver_data = data; 769 } 770 771 static inline struct pm_subsys_data *dev_to_psd(struct device *dev) 772 { 773 return dev ? dev->power.subsys_data : NULL; 774 } 775 776 static inline unsigned int dev_get_uevent_suppress(const struct device *dev) 777 { 778 return dev->kobj.uevent_suppress; 779 } 780 781 static inline void dev_set_uevent_suppress(struct device *dev, int val) 782 { 783 dev->kobj.uevent_suppress = val; 784 } 785 786 static inline int device_is_registered(struct device *dev) 787 { 788 return dev->kobj.state_in_sysfs; 789 } 790 791 static inline void device_enable_async_suspend(struct device *dev) 792 { 793 if (!dev->power.is_prepared) 794 dev->power.async_suspend = true; 795 } 796 797 static inline void device_disable_async_suspend(struct device *dev) 798 { 799 if (!dev->power.is_prepared) 800 dev->power.async_suspend = false; 801 } 802 803 static inline bool device_async_suspend_enabled(struct device *dev) 804 { 805 return !!dev->power.async_suspend; 806 } 807 808 static inline bool device_pm_not_required(struct device *dev) 809 { 810 return dev->power.no_pm; 811 } 812 813 static inline void device_set_pm_not_required(struct device *dev) 814 { 815 dev->power.no_pm = true; 816 } 817 818 static inline void dev_pm_syscore_device(struct device *dev, bool val) 819 { 820 #ifdef CONFIG_PM_SLEEP 821 dev->power.syscore = val; 822 #endif 823 } 824 825 static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags) 826 { 827 dev->power.driver_flags = flags; 828 } 829 830 static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags) 831 { 832 return !!(dev->power.driver_flags & flags); 833 } 834 835 static inline void device_lock(struct device *dev) 836 { 837 mutex_lock(&dev->mutex); 838 } 839 840 static inline int device_lock_interruptible(struct device *dev) 841 { 842 return mutex_lock_interruptible(&dev->mutex); 843 } 844 845 static inline int device_trylock(struct device *dev) 846 { 847 return mutex_trylock(&dev->mutex); 848 } 849 850 static inline void device_unlock(struct device *dev) 851 { 852 mutex_unlock(&dev->mutex); 853 } 854 855 static inline void device_lock_assert(struct device *dev) 856 { 857 lockdep_assert_held(&dev->mutex); 858 } 859 860 static inline struct device_node *dev_of_node(struct device *dev) 861 { 862 if (!IS_ENABLED(CONFIG_OF) || !dev) 863 return NULL; 864 return dev->of_node; 865 } 866 867 static inline bool dev_has_sync_state(struct device *dev) 868 { 869 if (!dev) 870 return false; 871 if (dev->driver && dev->driver->sync_state) 872 return true; 873 if (dev->bus && dev->bus->sync_state) 874 return true; 875 return false; 876 } 877 878 static inline void dev_set_removable(struct device *dev, 879 enum device_removable removable) 880 { 881 dev->removable = removable; 882 } 883 884 static inline bool dev_is_removable(struct device *dev) 885 { 886 return dev->removable == DEVICE_REMOVABLE; 887 } 888 889 static inline bool dev_removable_is_valid(struct device *dev) 890 { 891 return dev->removable != DEVICE_REMOVABLE_NOT_SUPPORTED; 892 } 893 894 /* 895 * High level routines for use by the bus drivers 896 */ 897 int __must_check device_register(struct device *dev); 898 void device_unregister(struct device *dev); 899 void device_initialize(struct device *dev); 900 int __must_check device_add(struct device *dev); 901 void device_del(struct device *dev); 902 int device_for_each_child(struct device *dev, void *data, 903 int (*fn)(struct device *dev, void *data)); 904 int device_for_each_child_reverse(struct device *dev, void *data, 905 int (*fn)(struct device *dev, void *data)); 906 struct device *device_find_child(struct device *dev, void *data, 907 int (*match)(struct device *dev, void *data)); 908 struct device *device_find_child_by_name(struct device *parent, 909 const char *name); 910 struct device *device_find_any_child(struct device *parent); 911 912 int device_rename(struct device *dev, const char *new_name); 913 int device_move(struct device *dev, struct device *new_parent, 914 enum dpm_order dpm_order); 915 int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid); 916 int device_is_dependent(struct device *dev, void *target); 917 918 static inline bool device_supports_offline(struct device *dev) 919 { 920 return dev->bus && dev->bus->offline && dev->bus->online; 921 } 922 923 #define __device_lock_set_class(dev, name, key) \ 924 do { \ 925 struct device *__d2 __maybe_unused = dev; \ 926 lock_set_class(&__d2->mutex.dep_map, name, key, 0, _THIS_IP_); \ 927 } while (0) 928 929 /** 930 * device_lock_set_class - Specify a temporary lock class while a device 931 * is attached to a driver 932 * @dev: device to modify 933 * @key: lock class key data 934 * 935 * This must be called with the device_lock() already held, for example 936 * from driver ->probe(). Take care to only override the default 937 * lockdep_no_validate class. 938 */ 939 #ifdef CONFIG_LOCKDEP 940 #define device_lock_set_class(dev, key) \ 941 do { \ 942 struct device *__d = dev; \ 943 dev_WARN_ONCE(__d, !lockdep_match_class(&__d->mutex, \ 944 &__lockdep_no_validate__), \ 945 "overriding existing custom lock class\n"); \ 946 __device_lock_set_class(__d, #key, key); \ 947 } while (0) 948 #else 949 #define device_lock_set_class(dev, key) __device_lock_set_class(dev, #key, key) 950 #endif 951 952 /** 953 * device_lock_reset_class - Return a device to the default lockdep novalidate state 954 * @dev: device to modify 955 * 956 * This must be called with the device_lock() already held, for example 957 * from driver ->remove(). 958 */ 959 #define device_lock_reset_class(dev) \ 960 do { \ 961 struct device *__d __maybe_unused = dev; \ 962 lock_set_novalidate_class(&__d->mutex.dep_map, "&dev->mutex", \ 963 _THIS_IP_); \ 964 } while (0) 965 966 void lock_device_hotplug(void); 967 void unlock_device_hotplug(void); 968 int lock_device_hotplug_sysfs(void); 969 int device_offline(struct device *dev); 970 int device_online(struct device *dev); 971 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode); 972 void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode); 973 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2); 974 void device_set_node(struct device *dev, struct fwnode_handle *fwnode); 975 976 static inline int dev_num_vf(struct device *dev) 977 { 978 if (dev->bus && dev->bus->num_vf) 979 return dev->bus->num_vf(dev); 980 return 0; 981 } 982 983 /* 984 * Root device objects for grouping under /sys/devices 985 */ 986 struct device *__root_device_register(const char *name, struct module *owner); 987 988 /* This is a macro to avoid include problems with THIS_MODULE */ 989 #define root_device_register(name) \ 990 __root_device_register(name, THIS_MODULE) 991 992 void root_device_unregister(struct device *root); 993 994 static inline void *dev_get_platdata(const struct device *dev) 995 { 996 return dev->platform_data; 997 } 998 999 /* 1000 * Manual binding of a device to driver. See drivers/base/bus.c 1001 * for information on use. 1002 */ 1003 int __must_check device_driver_attach(struct device_driver *drv, 1004 struct device *dev); 1005 int __must_check device_bind_driver(struct device *dev); 1006 void device_release_driver(struct device *dev); 1007 int __must_check device_attach(struct device *dev); 1008 int __must_check driver_attach(struct device_driver *drv); 1009 void device_initial_probe(struct device *dev); 1010 int __must_check device_reprobe(struct device *dev); 1011 1012 bool device_is_bound(struct device *dev); 1013 1014 /* 1015 * Easy functions for dynamically creating devices on the fly 1016 */ 1017 __printf(5, 6) struct device * 1018 device_create(const struct class *cls, struct device *parent, dev_t devt, 1019 void *drvdata, const char *fmt, ...); 1020 __printf(6, 7) struct device * 1021 device_create_with_groups(const struct class *cls, struct device *parent, dev_t devt, 1022 void *drvdata, const struct attribute_group **groups, 1023 const char *fmt, ...); 1024 void device_destroy(const struct class *cls, dev_t devt); 1025 1026 int __must_check device_add_groups(struct device *dev, 1027 const struct attribute_group **groups); 1028 void device_remove_groups(struct device *dev, 1029 const struct attribute_group **groups); 1030 1031 static inline int __must_check device_add_group(struct device *dev, 1032 const struct attribute_group *grp) 1033 { 1034 const struct attribute_group *groups[] = { grp, NULL }; 1035 1036 return device_add_groups(dev, groups); 1037 } 1038 1039 static inline void device_remove_group(struct device *dev, 1040 const struct attribute_group *grp) 1041 { 1042 const struct attribute_group *groups[] = { grp, NULL }; 1043 1044 return device_remove_groups(dev, groups); 1045 } 1046 1047 int __must_check devm_device_add_groups(struct device *dev, 1048 const struct attribute_group **groups); 1049 int __must_check devm_device_add_group(struct device *dev, 1050 const struct attribute_group *grp); 1051 1052 /* 1053 * Platform "fixup" functions - allow the platform to have their say 1054 * about devices and actions that the general device layer doesn't 1055 * know about. 1056 */ 1057 /* Notify platform of device discovery */ 1058 extern int (*platform_notify)(struct device *dev); 1059 1060 extern int (*platform_notify_remove)(struct device *dev); 1061 1062 1063 /* 1064 * get_device - atomically increment the reference count for the device. 1065 * 1066 */ 1067 struct device *get_device(struct device *dev); 1068 void put_device(struct device *dev); 1069 bool kill_device(struct device *dev); 1070 1071 #ifdef CONFIG_DEVTMPFS 1072 int devtmpfs_mount(void); 1073 #else 1074 static inline int devtmpfs_mount(void) { return 0; } 1075 #endif 1076 1077 /* drivers/base/power/shutdown.c */ 1078 void device_shutdown(void); 1079 1080 /* debugging and troubleshooting/diagnostic helpers. */ 1081 const char *dev_driver_string(const struct device *dev); 1082 1083 /* Device links interface. */ 1084 struct device_link *device_link_add(struct device *consumer, 1085 struct device *supplier, u32 flags); 1086 void device_link_del(struct device_link *link); 1087 void device_link_remove(void *consumer, struct device *supplier); 1088 void device_links_supplier_sync_state_pause(void); 1089 void device_links_supplier_sync_state_resume(void); 1090 1091 __printf(3, 4) int dev_err_probe(const struct device *dev, int err, const char *fmt, ...); 1092 1093 /* Create alias, so I can be autoloaded. */ 1094 #define MODULE_ALIAS_CHARDEV(major,minor) \ 1095 MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor)) 1096 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \ 1097 MODULE_ALIAS("char-major-" __stringify(major) "-*") 1098 1099 #endif /* _DEVICE_H_ */ 1100