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
36ACPI_MODULE_NAME("dock");
37
38static bool immediate_undock = 1;
39module_param(immediate_undock, bool, 0644);
40MODULE_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
45struct 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};
54static LIST_HEAD(dock_stations);
55static int dock_station_count;
56
57struct 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
70enum 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 */
86static 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
102static 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
145static 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 */
164static struct dock_dependent_device *
165find_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
176void 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 */
197int 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}
213EXPORT_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 */
222static 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 */
239static 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 */
265static 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
294static 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 */
327static 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
347static inline void dock(struct dock_station *ds)
348{
349 handle_dock(ds, 1);
350}
351
352static inline void undock(struct dock_station *ds)
353{
354 handle_dock(ds, 0);
355}
356
357static inline void begin_dock(struct dock_station *ds)
358{
359 ds->flags |= DOCK_DOCKING;
360}
361
362static inline void complete_dock(struct dock_station *ds)
363{
364 ds->flags &= ~(DOCK_DOCKING);
365 ds->last_dock_time = jiffies;
366}
367
368static inline void begin_undock(struct dock_station *ds)
369{
370 ds->flags |= DOCK_UNDOCKING;
371}
372
373static 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 */
386static 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 */
400static 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 */
435int 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 */
501static 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}
510static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
511
512/*
513 * show_flags - read method for flags file in sysfs
514 */
515static 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}
522static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
523
524/*
525 * write_undock - write method for "undock" file in sysfs
526 */
527static 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}
542static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
543
544/*
545 * show_dock_uid - read method for "uid" file in sysfs
546 */
547static 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}
559static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
560
561static 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}
578static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
579
580static 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
589static 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 */
599void 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
652err_rmgroup:
653 sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
654
655err_unregister:
656 platform_device_unregister(dd);
657 acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
658}
659