drivers/acpi/dock.c

   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
  23 static bool immediate_undock = 1;
  24 module_param(immediate_undock, bool, 0644);
  25 MODULE_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
  30 struct 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 };
  39 static LIST_HEAD(dock_stations);
  40 static int dock_station_count;
  41
  42 struct 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
  55 enum 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  */
  71 static 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
  87 static 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
 130 static 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  */
 149 static struct dock_dependent_device *
 150 find_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
 161 void 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  */
 182 int 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 }
 198 EXPORT_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  */
 207 static 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  */
 224 static 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  */
 251 static 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
 280 static 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  */
 313 static 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
 333 static inline void dock(struct dock_station *ds)
 334 {
 335         handle_dock(ds, 1);
 336 }
 337
 338 static inline void undock(struct dock_station *ds)
 339 {
 340         handle_dock(ds, 0);
 341 }
 342
 343 static inline void begin_dock(struct dock_station *ds)
 344 {
 345         ds->flags |= DOCK_DOCKING;
 346 }
 347
 348 static inline void complete_dock(struct dock_station *ds)
 349 {
 350         ds->flags &= ~(DOCK_DOCKING);
 351         ds->last_dock_time = jiffies;
 352 }
 353
 354 static inline void begin_undock(struct dock_station *ds)
 355 {
 356         ds->flags |= DOCK_UNDOCKING;
 357 }
 358
 359 static 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  */
 372 static 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  */
 386 static 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  */
 421 int 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  */
 487 static ssize_t show_docked(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 }
 496 static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
 497
 498 /*
 499  * show_flags - read method for flags file in sysfs
 500  */
 501 static ssize_t show_flags(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 }
 508 static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
 509
 510 /*
 511  * write_undock - write method for "undock" file in sysfs
 512  */
 513 static ssize_t write_undock(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 }
 528 static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
 529
 530 /*
 531  * show_dock_uid - read method for "uid" file in sysfs
 532  */
 533 static ssize_t show_dock_uid(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 }
 545 static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
 546
 547 static ssize_t show_dock_type(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 }
 564 static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
 565
 566 static 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
 575 static 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  */
 585 void 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
 638 err_rmgroup:
 639         sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
 640
 641 err_unregister:
 642         platform_device_unregister(dd);
 643         acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
 644 }