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