drivers/acpi/dock.c

   1 /*
   2  *  dock.c - ACPI dock station driver
   3  *
   4  *  Copyright (C) 2006, 2014, Intel Corp.
   5  *  Author: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
   6  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or (at
  13  *  your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful, but
  16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *  General Public License for more details.
  19  *
  20  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/types.h>
  28 #include <linux/notifier.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/stddef.h>
  32 #include <linux/acpi.h>
  33
  34 #include "internal.h"
  35
  36 #define ACPI_DOCK_DRIVER_DESCRIPTION "ACPI Dock Station Driver"
  37
  38 ACPI_MODULE_NAME("dock");
  39 MODULE_AUTHOR("Kristen Carlson Accardi");
  40 MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_DESCRIPTION);
  41 MODULE_LICENSE("GPL");
  42
  43 static bool immediate_undock = 1;
  44 module_param(immediate_undock, bool, 0644);
  45 MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
  46         "undock immediately when the undock button is pressed, 0 will cause"
  47         " the driver to wait for userspace to write the undock sysfs file "
  48         " before undocking");
  49
  50 struct dock_station {
  51         acpi_handle handle;
  52         unsigned long last_dock_time;
  53         u32 flags;
  54         struct list_head dependent_devices;
  55
  56         struct list_head sibling;
  57         struct platform_device *dock_device;
  58 };
  59 static LIST_HEAD(dock_stations);
  60 static int dock_station_count;
  61
  62 struct dock_dependent_device {
  63         struct list_head list;
  64         struct acpi_device *adev;
  65 };
  66
  67 #define DOCK_DOCKING    0x00000001
  68 #define DOCK_UNDOCKING  0x00000002
  69 #define DOCK_IS_DOCK    0x00000010
  70 #define DOCK_IS_ATA     0x00000020
  71 #define DOCK_IS_BAT     0x00000040
  72 #define DOCK_EVENT      3
  73 #define UNDOCK_EVENT    2
  74
  75 enum dock_callback_type {
  76         DOCK_CALL_HANDLER,
  77         DOCK_CALL_FIXUP,
  78         DOCK_CALL_UEVENT,
  79 };
  80
  81 /*****************************************************************************
  82  *                         Dock Dependent device functions                   *
  83  *****************************************************************************/
  84 /**
  85  * add_dock_dependent_device - associate a device with the dock station
  86  * @ds: Dock station.
  87  * @adev: Dependent ACPI device object.
  88  *
  89  * Add the dependent device to the dock's dependent device list.
  90  */
  91 static int add_dock_dependent_device(struct dock_station *ds,
  92                                      struct acpi_device *adev)
  93 {
  94         struct dock_dependent_device *dd;
  95
  96         dd = kzalloc(sizeof(*dd), GFP_KERNEL);
  97         if (!dd)
  98                 return -ENOMEM;
  99
 100         dd->adev = adev;
 101         INIT_LIST_HEAD(&dd->list);
 102         list_add_tail(&dd->list, &ds->dependent_devices);
 103
 104         return 0;
 105 }
 106
 107 static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
 108                                enum dock_callback_type cb_type)
 109 {
 110         struct acpi_device *adev = dd->adev;
 111
 112         acpi_lock_hp_context();
 113
 114         if (!adev->hp)
 115                 goto out;
 116
 117         if (cb_type == DOCK_CALL_FIXUP) {
 118                 void (*fixup)(struct acpi_device *);
 119
 120                 fixup = adev->hp->fixup;
 121                 if (fixup) {
 122                         acpi_unlock_hp_context();
 123                         fixup(adev);
 124                         return;
 125                 }
 126         } else if (cb_type == DOCK_CALL_UEVENT) {
 127                 void (*uevent)(struct acpi_device *, u32);
 128
 129                 uevent = adev->hp->uevent;
 130                 if (uevent) {
 131                         acpi_unlock_hp_context();
 132                         uevent(adev, event);
 133                         return;
 134                 }
 135         } else {
 136                 int (*notify)(struct acpi_device *, u32);
 137
 138                 notify = adev->hp->notify;
 139                 if (notify) {
 140                         acpi_unlock_hp_context();
 141                         notify(adev, event);
 142                         return;
 143                 }
 144         }
 145
 146  out:
 147         acpi_unlock_hp_context();
 148 }
 149
 150 static struct dock_station *find_dock_station(acpi_handle handle)
 151 {
 152         struct dock_station *ds;
 153
 154         list_for_each_entry(ds, &dock_stations, sibling)
 155                 if (ds->handle == handle)
 156                         return ds;
 157
 158         return NULL;
 159 }
 160
 161 /**
 162  * find_dock_dependent_device - get a device dependent on this dock
 163  * @ds: the dock station
 164  * @adev: ACPI device object to find.
 165  *
 166  * iterate over the dependent device list for this dock.  If the
 167  * dependent device matches the handle, return.
 168  */
 169 static struct dock_dependent_device *
 170 find_dock_dependent_device(struct dock_station *ds, struct acpi_device *adev)
 171 {
 172         struct dock_dependent_device *dd;
 173
 174         list_for_each_entry(dd, &ds->dependent_devices, list)
 175                 if (adev == dd->adev)
 176                         return dd;
 177
 178         return NULL;
 179 }
 180
 181 void register_dock_dependent_device(struct acpi_device *adev,
 182                                     acpi_handle dshandle)
 183 {
 184         struct dock_station *ds = find_dock_station(dshandle);
 185
 186         if (ds && !find_dock_dependent_device(ds, adev))
 187                 add_dock_dependent_device(ds, adev);
 188 }
 189
 190 /*****************************************************************************
 191  *                         Dock functions                                    *
 192  *****************************************************************************/
 193
 194 /**
 195  * is_dock_device - see if a device is on a dock station
 196  * @adev: ACPI device object to check.
 197  *
 198  * If this device is either the dock station itself,
 199  * or is a device dependent on the dock station, then it
 200  * is a dock device
 201  */
 202 int is_dock_device(struct acpi_device *adev)
 203 {
 204         struct dock_station *dock_station;
 205
 206         if (!dock_station_count)
 207                 return 0;
 208
 209         if (acpi_dock_match(adev->handle))
 210                 return 1;
 211
 212         list_for_each_entry(dock_station, &dock_stations, sibling)
 213                 if (find_dock_dependent_device(dock_station, adev))
 214                         return 1;
 215
 216         return 0;
 217 }
 218 EXPORT_SYMBOL_GPL(is_dock_device);
 219
 220 /**
 221  * dock_present - see if the dock station is present.
 222  * @ds: the dock station
 223  *
 224  * execute the _STA method.  note that present does not
 225  * imply that we are docked.
 226  */
 227 static int dock_present(struct dock_station *ds)
 228 {
 229         unsigned long long sta;
 230         acpi_status status;
 231
 232         if (ds) {
 233                 status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
 234                 if (ACPI_SUCCESS(status) && sta)
 235                         return 1;
 236         }
 237         return 0;
 238 }
 239
 240 /**
 241  * hot_remove_dock_devices - Remove dock station devices.
 242  * @ds: Dock station.
 243  */
 244 static void hot_remove_dock_devices(struct dock_station *ds)
 245 {
 246         struct dock_dependent_device *dd;
 247
 248         /*
 249          * Walk the list in reverse order so that devices that have been added
 250          * last are removed first (in case there are some indirect dependencies
 251          * between them).
 252          */
 253         list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
 254                 dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST, false);
 255
 256         list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
 257                 acpi_bus_trim(dd->adev);
 258 }
 259
 260 /**
 261  * hotplug_dock_devices - Insert devices on a dock station.
 262  * @ds: the dock station
 263  * @event: either bus check or device check request
 264  *
 265  * Some devices on the dock station need to have drivers called
 266  * to perform hotplug operations after a dock event has occurred.
 267  * Traverse the list of dock devices that have registered a
 268  * hotplug handler, and call the handler.
 269  */
 270 static void hotplug_dock_devices(struct dock_station *ds, u32 event)
 271 {
 272         struct dock_dependent_device *dd;
 273
 274         /* Call driver specific post-dock fixups. */
 275         list_for_each_entry(dd, &ds->dependent_devices, list)
 276                 dock_hotplug_event(dd, event, DOCK_CALL_FIXUP);
 277
 278         /* Call driver specific hotplug functions. */
 279         list_for_each_entry(dd, &ds->dependent_devices, list)
 280                 dock_hotplug_event(dd, event, DOCK_CALL_HANDLER);
 281
 282         /*
 283          * Check if all devices have been enumerated already.  If not, run
 284          * acpi_bus_scan() for them and that will cause scan handlers to be
 285          * attached to device objects or acpi_drivers to be stopped/started if
 286          * they are present.
 287          */
 288         list_for_each_entry(dd, &ds->dependent_devices, list) {
 289                 struct acpi_device *adev = dd->adev;
 290
 291                 if (!acpi_device_enumerated(adev)) {
 292                         int ret = acpi_bus_scan(adev->handle);
 293                         if (ret)
 294                                 dev_dbg(&adev->dev, "scan error %d\n", -ret);
 295                 }
 296         }
 297 }
 298
 299 static void dock_event(struct dock_station *ds, u32 event, int num)
 300 {
 301         struct device *dev = &ds->dock_device->dev;
 302         char event_string[13];
 303         char *envp[] = { event_string, NULL };
 304         struct dock_dependent_device *dd;
 305
 306         if (num == UNDOCK_EVENT)
 307                 sprintf(event_string, "EVENT=undock");
 308         else
 309                 sprintf(event_string, "EVENT=dock");
 310
 311         /*
 312          * Indicate that the status of the dock station has
 313          * changed.
 314          */
 315         if (num == DOCK_EVENT)
 316                 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 317
 318         list_for_each_entry(dd, &ds->dependent_devices, list)
 319                 dock_hotplug_event(dd, event, DOCK_CALL_UEVENT);
 320
 321         if (num != DOCK_EVENT)
 322                 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 323 }
 324
 325 /**
 326  * handle_dock - handle a dock event
 327  * @ds: the dock station
 328  * @dock: to dock, or undock - that is the question
 329  *
 330  * Execute the _DCK method in response to an acpi event
 331  */
 332 static void handle_dock(struct dock_station *ds, int dock)
 333 {
 334         acpi_status status;
 335         struct acpi_object_list arg_list;
 336         union acpi_object arg;
 337         unsigned long long value;
 338
 339         acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking");
 340
 341         /* _DCK method has one argument */
 342         arg_list.count = 1;
 343         arg_list.pointer = &arg;
 344         arg.type = ACPI_TYPE_INTEGER;
 345         arg.integer.value = dock;
 346         status = acpi_evaluate_integer(ds->handle, "_DCK", &arg_list, &value);
 347         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
 348                 acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n",
 349                                 status);
 350 }
 351
 352 static inline void dock(struct dock_station *ds)
 353 {
 354         handle_dock(ds, 1);
 355 }
 356
 357 static inline void undock(struct dock_station *ds)
 358 {
 359         handle_dock(ds, 0);
 360 }
 361
 362 static inline void begin_dock(struct dock_station *ds)
 363 {
 364         ds->flags |= DOCK_DOCKING;
 365 }
 366
 367 static inline void complete_dock(struct dock_station *ds)
 368 {
 369         ds->flags &= ~(DOCK_DOCKING);
 370         ds->last_dock_time = jiffies;
 371 }
 372
 373 static inline void begin_undock(struct dock_station *ds)
 374 {
 375         ds->flags |= DOCK_UNDOCKING;
 376 }
 377
 378 static inline void complete_undock(struct dock_station *ds)
 379 {
 380         ds->flags &= ~(DOCK_UNDOCKING);
 381 }
 382
 383 /**
 384  * dock_in_progress - see if we are in the middle of handling a dock event
 385  * @ds: the dock station
 386  *
 387  * Sometimes while docking, false dock events can be sent to the driver
 388  * because good connections aren't made or some other reason.  Ignore these
 389  * if we are in the middle of doing something.
 390  */
 391 static int dock_in_progress(struct dock_station *ds)
 392 {
 393         if ((ds->flags & DOCK_DOCKING) ||
 394             time_before(jiffies, (ds->last_dock_time + HZ)))
 395                 return 1;
 396         return 0;
 397 }
 398
 399 /**
 400  * handle_eject_request - handle an undock request checking for error conditions
 401  *
 402  * Check to make sure the dock device is still present, then undock and
 403  * hotremove all the devices that may need removing.
 404  */
 405 static int handle_eject_request(struct dock_station *ds, u32 event)
 406 {
 407         if (dock_in_progress(ds))
 408                 return -EBUSY;
 409
 410         /*
 411          * here we need to generate the undock
 412          * event prior to actually doing the undock
 413          * so that the device struct still exists.
 414          * Also, even send the dock event if the
 415          * device is not present anymore
 416          */
 417         dock_event(ds, event, UNDOCK_EVENT);
 418
 419         hot_remove_dock_devices(ds);
 420         undock(ds);
 421         acpi_evaluate_lck(ds->handle, 0);
 422         acpi_evaluate_ej0(ds->handle);
 423         if (dock_present(ds)) {
 424                 acpi_handle_err(ds->handle, "Unable to undock!\n");
 425                 return -EBUSY;
 426         }
 427         complete_undock(ds);
 428         return 0;
 429 }
 430
 431 /**
 432  * dock_notify - Handle ACPI dock notification.
 433  * @adev: Dock station's ACPI device object.
 434  * @event: Event code.
 435  *
 436  * If we are notified to dock, then check to see if the dock is
 437  * present and then dock.  Notify all drivers of the dock event,
 438  * and then hotplug and devices that may need hotplugging.
 439  */
 440 int dock_notify(struct acpi_device *adev, u32 event)
 441 {
 442         acpi_handle handle = adev->handle;
 443         struct dock_station *ds = find_dock_station(handle);
 444         int surprise_removal = 0;
 445
 446         if (!ds)
 447                 return -ENODEV;
 448
 449         /*
 450          * According to acpi spec 3.0a, if a DEVICE_CHECK notification
 451          * is sent and _DCK is present, it is assumed to mean an undock
 452          * request.
 453          */
 454         if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
 455                 event = ACPI_NOTIFY_EJECT_REQUEST;
 456
 457         /*
 458          * dock station: BUS_CHECK - docked or surprise removal
 459          *               DEVICE_CHECK - undocked
 460          * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
 461          *
 462          * To simplify event handling, dock dependent device handler always
 463          * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
 464          * ACPI_NOTIFY_EJECT_REQUEST for removal
 465          */
 466         switch (event) {
 467         case ACPI_NOTIFY_BUS_CHECK:
 468         case ACPI_NOTIFY_DEVICE_CHECK:
 469                 if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) {
 470                         begin_dock(ds);
 471                         dock(ds);
 472                         if (!dock_present(ds)) {
 473                                 acpi_handle_err(handle, "Unable to dock!\n");
 474                                 complete_dock(ds);
 475                                 break;
 476                         }
 477                         hotplug_dock_devices(ds, event);
 478                         complete_dock(ds);
 479                         dock_event(ds, event, DOCK_EVENT);
 480                         acpi_evaluate_lck(ds->handle, 1);
 481                         acpi_update_all_gpes();
 482                         break;
 483                 }
 484                 if (dock_present(ds) || dock_in_progress(ds))
 485                         break;
 486                 /* This is a surprise removal */
 487                 surprise_removal = 1;
 488                 event = ACPI_NOTIFY_EJECT_REQUEST;
 489                 /* Fall back */
 490         case ACPI_NOTIFY_EJECT_REQUEST:
 491                 begin_undock(ds);
 492                 if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
 493                    || surprise_removal)
 494                         handle_eject_request(ds, event);
 495                 else
 496                         dock_event(ds, event, UNDOCK_EVENT);
 497                 break;
 498         }
 499         return 0;
 500 }
 501
 502 /*
 503  * show_docked - read method for "docked" file in sysfs
 504  */
 505 static ssize_t show_docked(struct device *dev,
 506                            struct device_attribute *attr, char *buf)
 507 {
 508         struct dock_station *dock_station = dev->platform_data;
 509         struct acpi_device *adev = NULL;
 510
 511         acpi_bus_get_device(dock_station->handle, &adev);
 512         return snprintf(buf, PAGE_SIZE, "%u\n", acpi_device_enumerated(adev));
 513 }
 514 static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
 515
 516 /*
 517  * show_flags - read method for flags file in sysfs
 518  */
 519 static ssize_t show_flags(struct device *dev,
 520                           struct device_attribute *attr, char *buf)
 521 {
 522         struct dock_station *dock_station = dev->platform_data;
 523         return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
 524
 525 }
 526 static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
 527
 528 /*
 529  * write_undock - write method for "undock" file in sysfs
 530  */
 531 static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
 532                            const char *buf, size_t count)
 533 {
 534         int ret;
 535         struct dock_station *dock_station = dev->platform_data;
 536
 537         if (!count)
 538                 return -EINVAL;
 539
 540         acpi_scan_lock_acquire();
 541         begin_undock(dock_station);
 542         ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
 543         acpi_scan_lock_release();
 544         return ret ? ret: count;
 545 }
 546 static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
 547
 548 /*
 549  * show_dock_uid - read method for "uid" file in sysfs
 550  */
 551 static ssize_t show_dock_uid(struct device *dev,
 552                              struct device_attribute *attr, char *buf)
 553 {
 554         unsigned long long lbuf;
 555         struct dock_station *dock_station = dev->platform_data;
 556         acpi_status status = acpi_evaluate_integer(dock_station->handle,
 557                                         "_UID", NULL, &lbuf);
 558         if (ACPI_FAILURE(status))
 559             return 0;
 560
 561         return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf);
 562 }
 563 static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
 564
 565 static ssize_t show_dock_type(struct device *dev,
 566                 struct device_attribute *attr, char *buf)
 567 {
 568         struct dock_station *dock_station = dev->platform_data;
 569         char *type;
 570
 571         if (dock_station->flags & DOCK_IS_DOCK)
 572                 type = "dock_station";
 573         else if (dock_station->flags & DOCK_IS_ATA)
 574                 type = "ata_bay";
 575         else if (dock_station->flags & DOCK_IS_BAT)
 576                 type = "battery_bay";
 577         else
 578                 type = "unknown";
 579
 580         return snprintf(buf, PAGE_SIZE, "%s\n", type);
 581 }
 582 static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
 583
 584 static struct attribute *dock_attributes[] = {
 585         &dev_attr_docked.attr,
 586         &dev_attr_flags.attr,
 587         &dev_attr_undock.attr,
 588         &dev_attr_uid.attr,
 589         &dev_attr_type.attr,
 590         NULL
 591 };
 592
 593 static struct attribute_group dock_attribute_group = {
 594         .attrs = dock_attributes
 595 };
 596
 597 /**
 598  * acpi_dock_add - Add a new dock station
 599  * @adev: Dock station ACPI device object.
 600  *
 601  * allocated and initialize a new dock station device.
 602  */
 603 void acpi_dock_add(struct acpi_device *adev)
 604 {
 605         struct dock_station *dock_station, ds = { NULL, };
 606         struct platform_device_info pdevinfo;
 607         acpi_handle handle = adev->handle;
 608         struct platform_device *dd;
 609         int ret;
 610
 611         memset(&pdevinfo, 0, sizeof(pdevinfo));
 612         pdevinfo.name = "dock";
 613         pdevinfo.id = dock_station_count;
 614         pdevinfo.fwnode = acpi_fwnode_handle(adev);
 615         pdevinfo.data = &ds;
 616         pdevinfo.size_data = sizeof(ds);
 617         dd = platform_device_register_full(&pdevinfo);
 618         if (IS_ERR(dd))
 619                 return;
 620
 621         dock_station = dd->dev.platform_data;
 622
 623         dock_station->handle = handle;
 624         dock_station->dock_device = dd;
 625         dock_station->last_dock_time = jiffies - HZ;
 626
 627         INIT_LIST_HEAD(&dock_station->sibling);
 628         INIT_LIST_HEAD(&dock_station->dependent_devices);
 629
 630         /* we want the dock device to send uevents */
 631         dev_set_uevent_suppress(&dd->dev, 0);
 632
 633         if (acpi_dock_match(handle))
 634                 dock_station->flags |= DOCK_IS_DOCK;
 635         if (acpi_ata_match(handle))
 636                 dock_station->flags |= DOCK_IS_ATA;
 637         if (acpi_device_is_battery(adev))
 638                 dock_station->flags |= DOCK_IS_BAT;
 639
 640         ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
 641         if (ret)
 642                 goto err_unregister;
 643
 644         /* add the dock station as a device dependent on itself */
 645         ret = add_dock_dependent_device(dock_station, adev);
 646         if (ret)
 647                 goto err_rmgroup;
 648
 649         dock_station_count++;
 650         list_add(&dock_station->sibling, &dock_stations);
 651         adev->flags.is_dock_station = true;
 652         dev_info(&adev->dev, "ACPI dock station (docks/bays count: %d)\n",
 653                  dock_station_count);
 654         return;
 655
 656 err_rmgroup:
 657         sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
 658
 659 err_unregister:
 660         platform_device_unregister(dd);
 661         acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
 662 }