1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * dock.c - ACPI dock station driver 4 * 5 * Copyright (C) 2006, 2014, Intel Corp. 6 * Author: Kristen Carlson Accardi <kristen.c.accardi@intel.com> 7 * Rafael J. Wysocki <rafael.j.wysocki@intel.com> 8 */ 9 10#include <linux/kernel.h> 11#include <linux/moduleparam.h> 12#include <linux/slab.h> 13#include <linux/init.h> 14#include <linux/types.h> 15#include <linux/notifier.h> 16#include <linux/platform_device.h> 17#include <linux/jiffies.h> 18#include <linux/stddef.h> 19#include <linux/acpi.h> 20 21#include "internal.h" 22 23static bool immediate_undock = 1; 24module_param(immediate_undock, bool, 0644); 25MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to " 26 "undock immediately when the undock button is pressed, 0 will cause" 27 " the driver to wait for userspace to write the undock sysfs file " 28 " before undocking"); 29 30struct dock_station { 31 acpi_handle handle; 32 unsigned long last_dock_time; 33 u32 flags; 34 struct list_head dependent_devices; 35 36 struct list_head sibling; 37 struct platform_device *dock_device; 38}; 39static LIST_HEAD(dock_stations); 40static int dock_station_count; 41 42struct dock_dependent_device { 43 struct list_head list; 44 struct acpi_device *adev; 45}; 46 47#define DOCK_DOCKING 0x00000001 48#define DOCK_UNDOCKING 0x00000002 49#define DOCK_IS_DOCK 0x00000010 50#define DOCK_IS_ATA 0x00000020 51#define DOCK_IS_BAT 0x00000040 52#define DOCK_EVENT 3 53#define UNDOCK_EVENT 2 54 55enum dock_callback_type { 56 DOCK_CALL_HANDLER, 57 DOCK_CALL_FIXUP, 58 DOCK_CALL_UEVENT, 59}; 60 61/***************************************************************************** 62 * Dock Dependent device functions * 63 *****************************************************************************/ 64/** 65 * add_dock_dependent_device - associate a device with the dock station 66 * @ds: Dock station. 67 * @adev: Dependent ACPI device object. 68 * 69 * Add the dependent device to the dock's dependent device list. 70 */ 71static int add_dock_dependent_device(struct dock_station *ds, 72 struct acpi_device *adev) 73{ 74 struct dock_dependent_device *dd; 75 76 dd = kzalloc(sizeof(*dd), GFP_KERNEL); 77 if (!dd) 78 return -ENOMEM; 79 80 dd->adev = adev; 81 INIT_LIST_HEAD(&dd->list); 82 list_add_tail(&dd->list, &ds->dependent_devices); 83 84 return 0; 85} 86 87static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event, 88 enum dock_callback_type cb_type) 89{ 90 struct acpi_device *adev = dd->adev; 91 92 acpi_lock_hp_context(); 93 94 if (!adev->hp) 95 goto out; 96 97 if (cb_type == DOCK_CALL_FIXUP) { 98 void (*fixup)(struct acpi_device *); 99 100 fixup = adev->hp->fixup; 101 if (fixup) { 102 acpi_unlock_hp_context(); 103 fixup(adev); 104 return; 105 } 106 } else if (cb_type == DOCK_CALL_UEVENT) { 107 void (*uevent)(struct acpi_device *, u32); 108 109 uevent = adev->hp->uevent; 110 if (uevent) { 111 acpi_unlock_hp_context(); 112 uevent(adev, event); 113 return; 114 } 115 } else { 116 int (*notify)(struct acpi_device *, u32); 117 118 notify = adev->hp->notify; 119 if (notify) { 120 acpi_unlock_hp_context(); 121 notify(adev, event); 122 return; 123 } 124 } 125 126 out: 127 acpi_unlock_hp_context(); 128} 129 130static struct dock_station *find_dock_station(acpi_handle handle) 131{ 132 struct dock_station *ds; 133 134 list_for_each_entry(ds, &dock_stations, sibling) 135 if (ds->handle == handle) 136 return ds; 137 138 return NULL; 139} 140 141/** 142 * find_dock_dependent_device - get a device dependent on this dock 143 * @ds: the dock station 144 * @adev: ACPI device object to find. 145 * 146 * iterate over the dependent device list for this dock. If the 147 * dependent device matches the handle, return. 148 */ 149static struct dock_dependent_device * 150find_dock_dependent_device(struct dock_station *ds, struct acpi_device *adev) 151{ 152 struct dock_dependent_device *dd; 153 154 list_for_each_entry(dd, &ds->dependent_devices, list) 155 if (adev == dd->adev) 156 return dd; 157 158 return NULL; 159} 160 161void register_dock_dependent_device(struct acpi_device *adev, 162 acpi_handle dshandle) 163{ 164 struct dock_station *ds = find_dock_station(dshandle); 165 166 if (ds && !find_dock_dependent_device(ds, adev)) 167 add_dock_dependent_device(ds, adev); 168} 169 170/***************************************************************************** 171 * Dock functions * 172 *****************************************************************************/ 173 174/** 175 * is_dock_device - see if a device is on a dock station 176 * @adev: ACPI device object to check. 177 * 178 * If this device is either the dock station itself, 179 * or is a device dependent on the dock station, then it 180 * is a dock device 181 */ 182int is_dock_device(struct acpi_device *adev) 183{ 184 struct dock_station *dock_station; 185 186 if (!dock_station_count) 187 return 0; 188 189 if (acpi_dock_match(adev->handle)) 190 return 1; 191 192 list_for_each_entry(dock_station, &dock_stations, sibling) 193 if (find_dock_dependent_device(dock_station, adev)) 194 return 1; 195 196 return 0; 197} 198EXPORT_SYMBOL_GPL(is_dock_device); 199 200/** 201 * dock_present - see if the dock station is present. 202 * @ds: the dock station 203 * 204 * execute the _STA method. note that present does not 205 * imply that we are docked. 206 */ 207static int dock_present(struct dock_station *ds) 208{ 209 unsigned long long sta; 210 acpi_status status; 211 212 if (ds) { 213 status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta); 214 if (ACPI_SUCCESS(status) && sta) 215 return 1; 216 } 217 return 0; 218} 219 220/** 221 * hot_remove_dock_devices - Remove dock station devices. 222 * @ds: Dock station. 223 */ 224static void hot_remove_dock_devices(struct dock_station *ds) 225{ 226 struct dock_dependent_device *dd; 227 228 /* 229 * Walk the list in reverse order so that devices that have been added 230 * last are removed first (in case there are some indirect dependencies 231 * between them). 232 */ 233 list_for_each_entry_reverse(dd, &ds->dependent_devices, list) 234 dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST, 235 DOCK_CALL_HANDLER); 236 237 list_for_each_entry_reverse(dd, &ds->dependent_devices, list) 238 acpi_bus_trim(dd->adev); 239} 240 241/** 242 * hotplug_dock_devices - Insert devices on a dock station. 243 * @ds: the dock station 244 * @event: either bus check or device check request 245 * 246 * Some devices on the dock station need to have drivers called 247 * to perform hotplug operations after a dock event has occurred. 248 * Traverse the list of dock devices that have registered a 249 * hotplug handler, and call the handler. 250 */ 251static void hotplug_dock_devices(struct dock_station *ds, u32 event) 252{ 253 struct dock_dependent_device *dd; 254 255 /* Call driver specific post-dock fixups. */ 256 list_for_each_entry(dd, &ds->dependent_devices, list) 257 dock_hotplug_event(dd, event, DOCK_CALL_FIXUP); 258 259 /* Call driver specific hotplug functions. */ 260 list_for_each_entry(dd, &ds->dependent_devices, list) 261 dock_hotplug_event(dd, event, DOCK_CALL_HANDLER); 262 263 /* 264 * Check if all devices have been enumerated already. If not, run 265 * acpi_bus_scan() for them and that will cause scan handlers to be 266 * attached to device objects or acpi_drivers to be stopped/started if 267 * they are present. 268 */ 269 list_for_each_entry(dd, &ds->dependent_devices, list) { 270 struct acpi_device *adev = dd->adev; 271 272 if (!acpi_device_enumerated(adev)) { 273 int ret = acpi_bus_scan(adev->handle); 274 if (ret) 275 dev_dbg(&adev->dev, "scan error %d\n", -ret); 276 } 277 } 278} 279 280static void dock_event(struct dock_station *ds, u32 event, int num) 281{ 282 struct device *dev = &ds->dock_device->dev; 283 char event_string[13]; 284 char *envp[] = { event_string, NULL }; 285 struct dock_dependent_device *dd; 286 287 if (num == UNDOCK_EVENT) 288 sprintf(event_string, "EVENT=undock"); 289 else 290 sprintf(event_string, "EVENT=dock"); 291 292 /* 293 * Indicate that the status of the dock station has 294 * changed. 295 */ 296 if (num == DOCK_EVENT) 297 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp); 298 299 list_for_each_entry(dd, &ds->dependent_devices, list) 300 dock_hotplug_event(dd, event, DOCK_CALL_UEVENT); 301 302 if (num != DOCK_EVENT) 303 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp); 304} 305 306/** 307 * handle_dock - handle a dock event 308 * @ds: the dock station 309 * @dock: to dock, or undock - that is the question 310 * 311 * Execute the _DCK method in response to an acpi event 312 */ 313static void handle_dock(struct dock_station *ds, int dock) 314{ 315 acpi_status status; 316 struct acpi_object_list arg_list; 317 union acpi_object arg; 318 unsigned long long value; 319 320 acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking"); 321 322 /* _DCK method has one argument */ 323 arg_list.count = 1; 324 arg_list.pointer = &arg; 325 arg.type = ACPI_TYPE_INTEGER; 326 arg.integer.value = dock; 327 status = acpi_evaluate_integer(ds->handle, "_DCK", &arg_list, &value); 328 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) 329 acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n", 330 status); 331} 332 333static inline void dock(struct dock_station *ds) 334{ 335 handle_dock(ds, 1); 336} 337 338static inline void undock(struct dock_station *ds) 339{ 340 handle_dock(ds, 0); 341} 342 343static inline void begin_dock(struct dock_station *ds) 344{ 345 ds->flags |= DOCK_DOCKING; 346} 347 348static inline void complete_dock(struct dock_station *ds) 349{ 350 ds->flags &= ~(DOCK_DOCKING); 351 ds->last_dock_time = jiffies; 352} 353 354static inline void begin_undock(struct dock_station *ds) 355{ 356 ds->flags |= DOCK_UNDOCKING; 357} 358 359static inline void complete_undock(struct dock_station *ds) 360{ 361 ds->flags &= ~(DOCK_UNDOCKING); 362} 363 364/** 365 * dock_in_progress - see if we are in the middle of handling a dock event 366 * @ds: the dock station 367 * 368 * Sometimes while docking, false dock events can be sent to the driver 369 * because good connections aren't made or some other reason. Ignore these 370 * if we are in the middle of doing something. 371 */ 372static int dock_in_progress(struct dock_station *ds) 373{ 374 if ((ds->flags & DOCK_DOCKING) || 375 time_before(jiffies, (ds->last_dock_time + HZ))) 376 return 1; 377 return 0; 378} 379 380/** 381 * handle_eject_request - handle an undock request checking for error conditions 382 * 383 * Check to make sure the dock device is still present, then undock and 384 * hotremove all the devices that may need removing. 385 */ 386static int handle_eject_request(struct dock_station *ds, u32 event) 387{ 388 if (dock_in_progress(ds)) 389 return -EBUSY; 390 391 /* 392 * here we need to generate the undock 393 * event prior to actually doing the undock 394 * so that the device struct still exists. 395 * Also, even send the dock event if the 396 * device is not present anymore 397 */ 398 dock_event(ds, event, UNDOCK_EVENT); 399 400 hot_remove_dock_devices(ds); 401 undock(ds); 402 acpi_evaluate_lck(ds->handle, 0); 403 acpi_evaluate_ej0(ds->handle); 404 if (dock_present(ds)) { 405 acpi_handle_err(ds->handle, "Unable to undock!\n"); 406 return -EBUSY; 407 } 408 complete_undock(ds); 409 return 0; 410} 411 412/** 413 * dock_notify - Handle ACPI dock notification. 414 * @adev: Dock station's ACPI device object. 415 * @event: Event code. 416 * 417 * If we are notified to dock, then check to see if the dock is 418 * present and then dock. Notify all drivers of the dock event, 419 * and then hotplug and devices that may need hotplugging. 420 */ 421int dock_notify(struct acpi_device *adev, u32 event) 422{ 423 acpi_handle handle = adev->handle; 424 struct dock_station *ds = find_dock_station(handle); 425 int surprise_removal = 0; 426 427 if (!ds) 428 return -ENODEV; 429 430 /* 431 * According to acpi spec 3.0a, if a DEVICE_CHECK notification 432 * is sent and _DCK is present, it is assumed to mean an undock 433 * request. 434 */ 435 if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK) 436 event = ACPI_NOTIFY_EJECT_REQUEST; 437 438 /* 439 * dock station: BUS_CHECK - docked or surprise removal 440 * DEVICE_CHECK - undocked 441 * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal 442 * 443 * To simplify event handling, dock dependent device handler always 444 * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and 445 * ACPI_NOTIFY_EJECT_REQUEST for removal 446 */ 447 switch (event) { 448 case ACPI_NOTIFY_BUS_CHECK: 449 case ACPI_NOTIFY_DEVICE_CHECK: 450 if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) { 451 begin_dock(ds); 452 dock(ds); 453 if (!dock_present(ds)) { 454 acpi_handle_err(handle, "Unable to dock!\n"); 455 complete_dock(ds); 456 break; 457 } 458 hotplug_dock_devices(ds, event); 459 complete_dock(ds); 460 dock_event(ds, event, DOCK_EVENT); 461 acpi_evaluate_lck(ds->handle, 1); 462 acpi_update_all_gpes(); 463 break; 464 } 465 if (dock_present(ds) || dock_in_progress(ds)) 466 break; 467 /* This is a surprise removal */ 468 surprise_removal = 1; 469 event = ACPI_NOTIFY_EJECT_REQUEST; 470 /* Fall back */ 471 fallthrough; 472 case ACPI_NOTIFY_EJECT_REQUEST: 473 begin_undock(ds); 474 if ((immediate_undock && !(ds->flags & DOCK_IS_ATA)) 475 || surprise_removal) 476 handle_eject_request(ds, event); 477 else 478 dock_event(ds, event, UNDOCK_EVENT); 479 break; 480 } 481 return 0; 482} 483 484/* 485 * show_docked - read method for "docked" file in sysfs 486 */ 487static ssize_t docked_show(struct device *dev, 488 struct device_attribute *attr, char *buf) 489{ 490 struct dock_station *dock_station = dev->platform_data; 491 struct acpi_device *adev = NULL; 492 493 acpi_bus_get_device(dock_station->handle, &adev); 494 return snprintf(buf, PAGE_SIZE, "%u\n", acpi_device_enumerated(adev)); 495} 496static DEVICE_ATTR_RO(docked); 497 498/* 499 * show_flags - read method for flags file in sysfs 500 */ 501static ssize_t flags_show(struct device *dev, 502 struct device_attribute *attr, char *buf) 503{ 504 struct dock_station *dock_station = dev->platform_data; 505 return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags); 506 507} 508static DEVICE_ATTR_RO(flags); 509 510/* 511 * write_undock - write method for "undock" file in sysfs 512 */ 513static ssize_t undock_store(struct device *dev, struct device_attribute *attr, 514 const char *buf, size_t count) 515{ 516 int ret; 517 struct dock_station *dock_station = dev->platform_data; 518 519 if (!count) 520 return -EINVAL; 521 522 acpi_scan_lock_acquire(); 523 begin_undock(dock_station); 524 ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST); 525 acpi_scan_lock_release(); 526 return ret ? ret: count; 527} 528static DEVICE_ATTR_WO(undock); 529 530/* 531 * show_dock_uid - read method for "uid" file in sysfs 532 */ 533static ssize_t uid_show(struct device *dev, 534 struct device_attribute *attr, char *buf) 535{ 536 unsigned long long lbuf; 537 struct dock_station *dock_station = dev->platform_data; 538 acpi_status status = acpi_evaluate_integer(dock_station->handle, 539 "_UID", NULL, &lbuf); 540 if (ACPI_FAILURE(status)) 541 return 0; 542 543 return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf); 544} 545static DEVICE_ATTR_RO(uid); 546 547static ssize_t type_show(struct device *dev, 548 struct device_attribute *attr, char *buf) 549{ 550 struct dock_station *dock_station = dev->platform_data; 551 char *type; 552 553 if (dock_station->flags & DOCK_IS_DOCK) 554 type = "dock_station"; 555 else if (dock_station->flags & DOCK_IS_ATA) 556 type = "ata_bay"; 557 else if (dock_station->flags & DOCK_IS_BAT) 558 type = "battery_bay"; 559 else 560 type = "unknown"; 561 562 return snprintf(buf, PAGE_SIZE, "%s\n", type); 563} 564static DEVICE_ATTR_RO(type); 565 566static struct attribute *dock_attributes[] = { 567 &dev_attr_docked.attr, 568 &dev_attr_flags.attr, 569 &dev_attr_undock.attr, 570 &dev_attr_uid.attr, 571 &dev_attr_type.attr, 572 NULL 573}; 574 575static const struct attribute_group dock_attribute_group = { 576 .attrs = dock_attributes 577}; 578 579/** 580 * acpi_dock_add - Add a new dock station 581 * @adev: Dock station ACPI device object. 582 * 583 * allocated and initialize a new dock station device. 584 */ 585void acpi_dock_add(struct acpi_device *adev) 586{ 587 struct dock_station *dock_station, ds = { NULL, }; 588 struct platform_device_info pdevinfo; 589 acpi_handle handle = adev->handle; 590 struct platform_device *dd; 591 int ret; 592 593 memset(&pdevinfo, 0, sizeof(pdevinfo)); 594 pdevinfo.name = "dock"; 595 pdevinfo.id = dock_station_count; 596 pdevinfo.fwnode = acpi_fwnode_handle(adev); 597 pdevinfo.data = &ds; 598 pdevinfo.size_data = sizeof(ds); 599 dd = platform_device_register_full(&pdevinfo); 600 if (IS_ERR(dd)) 601 return; 602 603 dock_station = dd->dev.platform_data; 604 605 dock_station->handle = handle; 606 dock_station->dock_device = dd; 607 dock_station->last_dock_time = jiffies - HZ; 608 609 INIT_LIST_HEAD(&dock_station->sibling); 610 INIT_LIST_HEAD(&dock_station->dependent_devices); 611 612 /* we want the dock device to send uevents */ 613 dev_set_uevent_suppress(&dd->dev, 0); 614 615 if (acpi_dock_match(handle)) 616 dock_station->flags |= DOCK_IS_DOCK; 617 if (acpi_ata_match(handle)) 618 dock_station->flags |= DOCK_IS_ATA; 619 if (acpi_device_is_battery(adev)) 620 dock_station->flags |= DOCK_IS_BAT; 621 622 ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group); 623 if (ret) 624 goto err_unregister; 625 626 /* add the dock station as a device dependent on itself */ 627 ret = add_dock_dependent_device(dock_station, adev); 628 if (ret) 629 goto err_rmgroup; 630 631 dock_station_count++; 632 list_add(&dock_station->sibling, &dock_stations); 633 adev->flags.is_dock_station = true; 634 dev_info(&adev->dev, "ACPI dock station (docks/bays count: %d)\n", 635 dock_station_count); 636 return; 637 638err_rmgroup: 639 sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group); 640 641err_unregister: 642 platform_device_unregister(dd); 643 acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret); 644} 645