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Linux/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 }
663 

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