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  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/slab.h>
  30 #include <linux/init.h>
  31 #include <linux/types.h>
  32 #include <linux/notifier.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/jiffies.h>
  35 #include <linux/stddef.h>
  36 #include <linux/acpi.h>
  37
  38 #include "internal.h"
  39
  40 #define ACPI_DOCK_DRIVER_DESCRIPTION "ACPI Dock Station Driver"
  41
  42 ACPI_MODULE_NAME("dock");
  43 MODULE_AUTHOR("Kristen Carlson Accardi");
  44 MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_DESCRIPTION);
  45 MODULE_LICENSE("GPL");
  46
  47 static bool immediate_undock = 1;
  48 module_param(immediate_undock, bool, 0644);
  49 MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
  50         "undock immediately when the undock button is pressed, 0 will cause"
  51         " the driver to wait for userspace to write the undock sysfs file "
  52         " before undocking");
  53
  54 struct dock_station {
  55         acpi_handle handle;
  56         unsigned long last_dock_time;
  57         u32 flags;
  58         struct list_head dependent_devices;
  59
  60         struct list_head sibling;
  61         struct platform_device *dock_device;
  62 };
  63 static LIST_HEAD(dock_stations);
  64 static int dock_station_count;
  65
  66 struct dock_dependent_device {
  67         struct list_head list;
  68         struct acpi_device *adev;
  69 };
  70
  71 #define DOCK_DOCKING    0x00000001
  72 #define DOCK_UNDOCKING  0x00000002
  73 #define DOCK_IS_DOCK    0x00000010
  74 #define DOCK_IS_ATA     0x00000020
  75 #define DOCK_IS_BAT     0x00000040
  76 #define DOCK_EVENT      3
  77 #define UNDOCK_EVENT    2
  78
  79 enum dock_callback_type {
  80         DOCK_CALL_HANDLER,
  81         DOCK_CALL_FIXUP,
  82         DOCK_CALL_UEVENT,
  83 };
  84
  85 /*****************************************************************************
  86  *                         Dock Dependent device functions                   *
  87  *****************************************************************************/
  88 /**
  89  * add_dock_dependent_device - associate a device with the dock station
  90  * @ds: Dock station.
  91  * @adev: Dependent ACPI device object.
  92  *
  93  * Add the dependent device to the dock's dependent device list.
  94  */
  95 static int add_dock_dependent_device(struct dock_station *ds,
  96                                      struct acpi_device *adev)
  97 {
  98         struct dock_dependent_device *dd;
  99
 100         dd = kzalloc(sizeof(*dd), GFP_KERNEL);
 101         if (!dd)
 102                 return -ENOMEM;
 103
 104         dd->adev = adev;
 105         INIT_LIST_HEAD(&dd->list);
 106         list_add_tail(&dd->list, &ds->dependent_devices);
 107
 108         return 0;
 109 }
 110
 111 static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
 112                                enum dock_callback_type cb_type)
 113 {
 114         struct acpi_device *adev = dd->adev;
 115
 116         acpi_lock_hp_context();
 117
 118         if (!adev->hp)
 119                 goto out;
 120
 121         if (cb_type == DOCK_CALL_FIXUP) {
 122                 void (*fixup)(struct acpi_device *);
 123
 124                 fixup = adev->hp->fixup;
 125                 if (fixup) {
 126                         acpi_unlock_hp_context();
 127                         fixup(adev);
 128                         return;
 129                 }
 130         } else if (cb_type == DOCK_CALL_UEVENT) {
 131                 void (*uevent)(struct acpi_device *, u32);
 132
 133                 uevent = adev->hp->uevent;
 134                 if (uevent) {
 135                         acpi_unlock_hp_context();
 136                         uevent(adev, event);
 137                         return;
 138                 }
 139         } else {
 140                 int (*notify)(struct acpi_device *, u32);
 141
 142                 notify = adev->hp->notify;
 143                 if (notify) {
 144                         acpi_unlock_hp_context();
 145                         notify(adev, event);
 146                         return;
 147                 }
 148         }
 149
 150  out:
 151         acpi_unlock_hp_context();
 152 }
 153
 154 static struct dock_station *find_dock_station(acpi_handle handle)
 155 {
 156         struct dock_station *ds;
 157
 158         list_for_each_entry(ds, &dock_stations, sibling)
 159                 if (ds->handle == handle)
 160                         return ds;
 161
 162         return NULL;
 163 }
 164
 165 /**
 166  * find_dock_dependent_device - get a device dependent on this dock
 167  * @ds: the dock station
 168  * @adev: ACPI device object to find.
 169  *
 170  * iterate over the dependent device list for this dock.  If the
 171  * dependent device matches the handle, return.
 172  */
 173 static struct dock_dependent_device *
 174 find_dock_dependent_device(struct dock_station *ds, struct acpi_device *adev)
 175 {
 176         struct dock_dependent_device *dd;
 177
 178         list_for_each_entry(dd, &ds->dependent_devices, list)
 179                 if (adev == dd->adev)
 180                         return dd;
 181
 182         return NULL;
 183 }
 184
 185 void register_dock_dependent_device(struct acpi_device *adev,
 186                                     acpi_handle dshandle)
 187 {
 188         struct dock_station *ds = find_dock_station(dshandle);
 189
 190         if (ds && !find_dock_dependent_device(ds, adev))
 191                 add_dock_dependent_device(ds, adev);
 192 }
 193
 194 /*****************************************************************************
 195  *                         Dock functions                                    *
 196  *****************************************************************************/
 197
 198 /**
 199  * is_dock_device - see if a device is on a dock station
 200  * @adev: ACPI device object to check.
 201  *
 202  * If this device is either the dock station itself,
 203  * or is a device dependent on the dock station, then it
 204  * is a dock device
 205  */
 206 int is_dock_device(struct acpi_device *adev)
 207 {
 208         struct dock_station *dock_station;
 209
 210         if (!dock_station_count)
 211                 return 0;
 212
 213         if (acpi_dock_match(adev->handle))
 214                 return 1;
 215
 216         list_for_each_entry(dock_station, &dock_stations, sibling)
 217                 if (find_dock_dependent_device(dock_station, adev))
 218                         return 1;
 219
 220         return 0;
 221 }
 222 EXPORT_SYMBOL_GPL(is_dock_device);
 223
 224 /**
 225  * dock_present - see if the dock station is present.
 226  * @ds: the dock station
 227  *
 228  * execute the _STA method.  note that present does not
 229  * imply that we are docked.
 230  */
 231 static int dock_present(struct dock_station *ds)
 232 {
 233         unsigned long long sta;
 234         acpi_status status;
 235
 236         if (ds) {
 237                 status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
 238                 if (ACPI_SUCCESS(status) && sta)
 239                         return 1;
 240         }
 241         return 0;
 242 }
 243
 244 /**
 245  * hot_remove_dock_devices - Remove dock station devices.
 246  * @ds: Dock station.
 247  */
 248 static void hot_remove_dock_devices(struct dock_station *ds)
 249 {
 250         struct dock_dependent_device *dd;
 251
 252         /*
 253          * Walk the list in reverse order so that devices that have been added
 254          * last are removed first (in case there are some indirect dependencies
 255          * between them).
 256          */
 257         list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
 258                 dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST, false);
 259
 260         list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
 261                 acpi_bus_trim(dd->adev);
 262 }
 263
 264 /**
 265  * hotplug_dock_devices - Insert devices on a dock station.
 266  * @ds: the dock station
 267  * @event: either bus check or device check request
 268  *
 269  * Some devices on the dock station need to have drivers called
 270  * to perform hotplug operations after a dock event has occurred.
 271  * Traverse the list of dock devices that have registered a
 272  * hotplug handler, and call the handler.
 273  */
 274 static void hotplug_dock_devices(struct dock_station *ds, u32 event)
 275 {
 276         struct dock_dependent_device *dd;
 277
 278         /* Call driver specific post-dock fixups. */
 279         list_for_each_entry(dd, &ds->dependent_devices, list)
 280                 dock_hotplug_event(dd, event, DOCK_CALL_FIXUP);
 281
 282         /* Call driver specific hotplug functions. */
 283         list_for_each_entry(dd, &ds->dependent_devices, list)
 284                 dock_hotplug_event(dd, event, DOCK_CALL_HANDLER);
 285
 286         /*
 287          * Check if all devices have been enumerated already.  If not, run
 288          * acpi_bus_scan() for them and that will cause scan handlers to be
 289          * attached to device objects or acpi_drivers to be stopped/started if
 290          * they are present.
 291          */
 292         list_for_each_entry(dd, &ds->dependent_devices, list) {
 293                 struct acpi_device *adev = dd->adev;
 294
 295                 if (!acpi_device_enumerated(adev)) {
 296                         int ret = acpi_bus_scan(adev->handle);
 297                         if (ret)
 298                                 dev_dbg(&adev->dev, "scan error %d\n", -ret);
 299                 }
 300         }
 301 }
 302
 303 static void dock_event(struct dock_station *ds, u32 event, int num)
 304 {
 305         struct device *dev = &ds->dock_device->dev;
 306         char event_string[13];
 307         char *envp[] = { event_string, NULL };
 308         struct dock_dependent_device *dd;
 309
 310         if (num == UNDOCK_EVENT)
 311                 sprintf(event_string, "EVENT=undock");
 312         else
 313                 sprintf(event_string, "EVENT=dock");
 314
 315         /*
 316          * Indicate that the status of the dock station has
 317          * changed.
 318          */
 319         if (num == DOCK_EVENT)
 320                 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 321
 322         list_for_each_entry(dd, &ds->dependent_devices, list)
 323                 dock_hotplug_event(dd, event, DOCK_CALL_UEVENT);
 324
 325         if (num != DOCK_EVENT)
 326                 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 327 }
 328
 329 /**
 330  * handle_dock - handle a dock event
 331  * @ds: the dock station
 332  * @dock: to dock, or undock - that is the question
 333  *
 334  * Execute the _DCK method in response to an acpi event
 335  */
 336 static void handle_dock(struct dock_station *ds, int dock)
 337 {
 338         acpi_status status;
 339         struct acpi_object_list arg_list;
 340         union acpi_object arg;
 341         unsigned long long value;
 342
 343         acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking");
 344
 345         /* _DCK method has one argument */
 346         arg_list.count = 1;
 347         arg_list.pointer = &arg;
 348         arg.type = ACPI_TYPE_INTEGER;
 349         arg.integer.value = dock;
 350         status = acpi_evaluate_integer(ds->handle, "_DCK", &arg_list, &value);
 351         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
 352                 acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n",
 353                                 status);
 354 }
 355
 356 static inline void dock(struct dock_station *ds)
 357 {
 358         handle_dock(ds, 1);
 359 }
 360
 361 static inline void undock(struct dock_station *ds)
 362 {
 363         handle_dock(ds, 0);
 364 }
 365
 366 static inline void begin_dock(struct dock_station *ds)
 367 {
 368         ds->flags |= DOCK_DOCKING;
 369 }
 370
 371 static inline void complete_dock(struct dock_station *ds)
 372 {
 373         ds->flags &= ~(DOCK_DOCKING);
 374         ds->last_dock_time = jiffies;
 375 }
 376
 377 static inline void begin_undock(struct dock_station *ds)
 378 {
 379         ds->flags |= DOCK_UNDOCKING;
 380 }
 381
 382 static inline void complete_undock(struct dock_station *ds)
 383 {
 384         ds->flags &= ~(DOCK_UNDOCKING);
 385 }
 386
 387 /**
 388  * dock_in_progress - see if we are in the middle of handling a dock event
 389  * @ds: the dock station
 390  *
 391  * Sometimes while docking, false dock events can be sent to the driver
 392  * because good connections aren't made or some other reason.  Ignore these
 393  * if we are in the middle of doing something.
 394  */
 395 static int dock_in_progress(struct dock_station *ds)
 396 {
 397         if ((ds->flags & DOCK_DOCKING) ||
 398             time_before(jiffies, (ds->last_dock_time + HZ)))
 399                 return 1;
 400         return 0;
 401 }
 402
 403 /**
 404  * handle_eject_request - handle an undock request checking for error conditions
 405  *
 406  * Check to make sure the dock device is still present, then undock and
 407  * hotremove all the devices that may need removing.
 408  */
 409 static int handle_eject_request(struct dock_station *ds, u32 event)
 410 {
 411         if (dock_in_progress(ds))
 412                 return -EBUSY;
 413
 414         /*
 415          * here we need to generate the undock
 416          * event prior to actually doing the undock
 417          * so that the device struct still exists.
 418          * Also, even send the dock event if the
 419          * device is not present anymore
 420          */
 421         dock_event(ds, event, UNDOCK_EVENT);
 422
 423         hot_remove_dock_devices(ds);
 424         undock(ds);
 425         acpi_evaluate_lck(ds->handle, 0);
 426         acpi_evaluate_ej0(ds->handle);
 427         if (dock_present(ds)) {
 428                 acpi_handle_err(ds->handle, "Unable to undock!\n");
 429                 return -EBUSY;
 430         }
 431         complete_undock(ds);
 432         return 0;
 433 }
 434
 435 /**
 436  * dock_notify - Handle ACPI dock notification.
 437  * @adev: Dock station's ACPI device object.
 438  * @event: Event code.
 439  *
 440  * If we are notified to dock, then check to see if the dock is
 441  * present and then dock.  Notify all drivers of the dock event,
 442  * and then hotplug and devices that may need hotplugging.
 443  */
 444 int dock_notify(struct acpi_device *adev, u32 event)
 445 {
 446         acpi_handle handle = adev->handle;
 447         struct dock_station *ds = find_dock_station(handle);
 448         int surprise_removal = 0;
 449
 450         if (!ds)
 451                 return -ENODEV;
 452
 453         /*
 454          * According to acpi spec 3.0a, if a DEVICE_CHECK notification
 455          * is sent and _DCK is present, it is assumed to mean an undock
 456          * request.
 457          */
 458         if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
 459                 event = ACPI_NOTIFY_EJECT_REQUEST;
 460
 461         /*
 462          * dock station: BUS_CHECK - docked or surprise removal
 463          *               DEVICE_CHECK - undocked
 464          * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
 465          *
 466          * To simplify event handling, dock dependent device handler always
 467          * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
 468          * ACPI_NOTIFY_EJECT_REQUEST for removal
 469          */
 470         switch (event) {
 471         case ACPI_NOTIFY_BUS_CHECK:
 472         case ACPI_NOTIFY_DEVICE_CHECK:
 473                 if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) {
 474                         begin_dock(ds);
 475                         dock(ds);
 476                         if (!dock_present(ds)) {
 477                                 acpi_handle_err(handle, "Unable to dock!\n");
 478                                 complete_dock(ds);
 479                                 break;
 480                         }
 481                         hotplug_dock_devices(ds, event);
 482                         complete_dock(ds);
 483                         dock_event(ds, event, DOCK_EVENT);
 484                         acpi_evaluate_lck(ds->handle, 1);
 485                         acpi_update_all_gpes();
 486                         break;
 487                 }
 488                 if (dock_present(ds) || dock_in_progress(ds))
 489                         break;
 490                 /* This is a surprise removal */
 491                 surprise_removal = 1;
 492                 event = ACPI_NOTIFY_EJECT_REQUEST;
 493                 /* Fall back */
 494         case ACPI_NOTIFY_EJECT_REQUEST:
 495                 begin_undock(ds);
 496                 if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
 497                    || surprise_removal)
 498                         handle_eject_request(ds, event);
 499                 else
 500                         dock_event(ds, event, UNDOCK_EVENT);
 501                 break;
 502         }
 503         return 0;
 504 }
 505
 506 /*
 507  * show_docked - read method for "docked" file in sysfs
 508  */
 509 static ssize_t show_docked(struct device *dev,
 510                            struct device_attribute *attr, char *buf)
 511 {
 512         struct dock_station *dock_station = dev->platform_data;
 513         struct acpi_device *adev = NULL;
 514
 515         acpi_bus_get_device(dock_station->handle, &adev);
 516         return snprintf(buf, PAGE_SIZE, "%u\n", acpi_device_enumerated(adev));
 517 }
 518 static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
 519
 520 /*
 521  * show_flags - read method for flags file in sysfs
 522  */
 523 static ssize_t show_flags(struct device *dev,
 524                           struct device_attribute *attr, char *buf)
 525 {
 526         struct dock_station *dock_station = dev->platform_data;
 527         return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
 528
 529 }
 530 static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
 531
 532 /*
 533  * write_undock - write method for "undock" file in sysfs
 534  */
 535 static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
 536                            const char *buf, size_t count)
 537 {
 538         int ret;
 539         struct dock_station *dock_station = dev->platform_data;
 540
 541         if (!count)
 542                 return -EINVAL;
 543
 544         acpi_scan_lock_acquire();
 545         begin_undock(dock_station);
 546         ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
 547         acpi_scan_lock_release();
 548         return ret ? ret: count;
 549 }
 550 static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
 551
 552 /*
 553  * show_dock_uid - read method for "uid" file in sysfs
 554  */
 555 static ssize_t show_dock_uid(struct device *dev,
 556                              struct device_attribute *attr, char *buf)
 557 {
 558         unsigned long long lbuf;
 559         struct dock_station *dock_station = dev->platform_data;
 560         acpi_status status = acpi_evaluate_integer(dock_station->handle,
 561                                         "_UID", NULL, &lbuf);
 562         if (ACPI_FAILURE(status))
 563             return 0;
 564
 565         return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf);
 566 }
 567 static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
 568
 569 static ssize_t show_dock_type(struct device *dev,
 570                 struct device_attribute *attr, char *buf)
 571 {
 572         struct dock_station *dock_station = dev->platform_data;
 573         char *type;
 574
 575         if (dock_station->flags & DOCK_IS_DOCK)
 576                 type = "dock_station";
 577         else if (dock_station->flags & DOCK_IS_ATA)
 578                 type = "ata_bay";
 579         else if (dock_station->flags & DOCK_IS_BAT)
 580                 type = "battery_bay";
 581         else
 582                 type = "unknown";
 583
 584         return snprintf(buf, PAGE_SIZE, "%s\n", type);
 585 }
 586 static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
 587
 588 static struct attribute *dock_attributes[] = {
 589         &dev_attr_docked.attr,
 590         &dev_attr_flags.attr,
 591         &dev_attr_undock.attr,
 592         &dev_attr_uid.attr,
 593         &dev_attr_type.attr,
 594         NULL
 595 };
 596
 597 static struct attribute_group dock_attribute_group = {
 598         .attrs = dock_attributes
 599 };
 600
 601 /**
 602  * acpi_dock_add - Add a new dock station
 603  * @adev: Dock station ACPI device object.
 604  *
 605  * allocated and initialize a new dock station device.
 606  */
 607 void acpi_dock_add(struct acpi_device *adev)
 608 {
 609         struct dock_station *dock_station, ds = { NULL, };
 610         struct platform_device_info pdevinfo;
 611         acpi_handle handle = adev->handle;
 612         struct platform_device *dd;
 613         int ret;
 614
 615         memset(&pdevinfo, 0, sizeof(pdevinfo));
 616         pdevinfo.name = "dock";
 617         pdevinfo.id = dock_station_count;
 618         pdevinfo.fwnode = acpi_fwnode_handle(adev);
 619         pdevinfo.data = &ds;
 620         pdevinfo.size_data = sizeof(ds);
 621         dd = platform_device_register_full(&pdevinfo);
 622         if (IS_ERR(dd))
 623                 return;
 624
 625         dock_station = dd->dev.platform_data;
 626
 627         dock_station->handle = handle;
 628         dock_station->dock_device = dd;
 629         dock_station->last_dock_time = jiffies - HZ;
 630
 631         INIT_LIST_HEAD(&dock_station->sibling);
 632         INIT_LIST_HEAD(&dock_station->dependent_devices);
 633
 634         /* we want the dock device to send uevents */
 635         dev_set_uevent_suppress(&dd->dev, 0);
 636
 637         if (acpi_dock_match(handle))
 638                 dock_station->flags |= DOCK_IS_DOCK;
 639         if (acpi_ata_match(handle))
 640                 dock_station->flags |= DOCK_IS_ATA;
 641         if (acpi_device_is_battery(adev))
 642                 dock_station->flags |= DOCK_IS_BAT;
 643
 644         ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
 645         if (ret)
 646                 goto err_unregister;
 647
 648         /* add the dock station as a device dependent on itself */
 649         ret = add_dock_dependent_device(dock_station, adev);
 650         if (ret)
 651                 goto err_rmgroup;
 652
 653         dock_station_count++;
 654         list_add(&dock_station->sibling, &dock_stations);
 655         adev->flags.is_dock_station = true;
 656         dev_info(&adev->dev, "ACPI dock station (docks/bays count: %d)\n",
 657                  dock_station_count);
 658         return;
 659
 660 err_rmgroup:
 661         sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
 662
 663 err_unregister:
 664         platform_device_unregister(dd);
 665         acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
 666 }