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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dock.c - ACPI dock station driver
4 *
5 * Copyright (C) 2006, 2014, Intel Corp.
6 * Author: Kristen Carlson Accardi <[email protected]>
7 * Rafael J. Wysocki <[email protected]>
8 */
9
10#include <linux/kernel.h>
11#include <linux/moduleparam.h>
12#include <linux/slab.h>
13#include <linux/init.h>
14#include <linux/types.h>
15#include <linux/notifier.h>
16#include <linux/platform_device.h>
17#include <linux/jiffies.h>
18#include <linux/stddef.h>
19#include <linux/acpi.h>
20
21#include "internal.h"
22
23static bool immediate_undock = 1;
24module_param(immediate_undock, bool, 0644);
25MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
26 "undock immediately when the undock button is pressed, 0 will cause"
27 " the driver to wait for userspace to write the undock sysfs file "
28 " before undocking");
29
30struct dock_station {
31 acpi_handle handle;
32 unsigned long last_dock_time;
33 u32 flags;
34 struct list_head dependent_devices;
35
36 struct list_head sibling;
37 struct platform_device *dock_device;
38};
39static LIST_HEAD(dock_stations);
40static int dock_station_count;
41
42struct dock_dependent_device {
43 struct list_head list;
44 struct acpi_device *adev;
45};
46
47#define DOCK_DOCKING 0x00000001
48#define DOCK_UNDOCKING 0x00000002
49#define DOCK_IS_DOCK 0x00000010
50#define DOCK_IS_ATA 0x00000020
51#define DOCK_IS_BAT 0x00000040
52#define DOCK_EVENT 3
53#define UNDOCK_EVENT 2
54
55enum dock_callback_type {
56 DOCK_CALL_HANDLER,
57 DOCK_CALL_FIXUP,
58 DOCK_CALL_UEVENT,
59};
60
61/*****************************************************************************
62 * Dock Dependent device functions *
63 *****************************************************************************/
64/**
65 * add_dock_dependent_device - associate a device with the dock station
66 * @ds: Dock station.
67 * @adev: Dependent ACPI device object.
68 *
69 * Add the dependent device to the dock's dependent device list.
70 */
71static int add_dock_dependent_device(struct dock_station *ds,
72 struct acpi_device *adev)
73{
74 struct dock_dependent_device *dd;
75
76 dd = kzalloc_obj(*dd);
77 if (!dd)
78 return -ENOMEM;
79
80 dd->adev = adev;
81 INIT_LIST_HEAD(&dd->list);
82 list_add_tail(&dd->list, &ds->dependent_devices);
83
84 return 0;
85}
86
87static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
88 enum dock_callback_type cb_type)
89{
90 struct acpi_device *adev = dd->adev;
91 acpi_hp_fixup fixup = NULL;
92 acpi_hp_uevent uevent = NULL;
93 acpi_hp_notify notify = NULL;
94
95 acpi_lock_hp_context();
96
97 if (adev->hp) {
98 if (cb_type == DOCK_CALL_FIXUP)
99 fixup = adev->hp->fixup;
100 else if (cb_type == DOCK_CALL_UEVENT)
101 uevent = adev->hp->uevent;
102 else
103 notify = adev->hp->notify;
104 }
105
106 acpi_unlock_hp_context();
107
108 if (fixup)
109 fixup(adev);
110 else if (uevent)
111 uevent(adev, event);
112 else if (notify)
113 notify(adev, event);
114}
115
116static struct dock_station *find_dock_station(acpi_handle handle)
117{
118 struct dock_station *ds;
119
120 list_for_each_entry(ds, &dock_stations, sibling)
121 if (ds->handle == handle)
122 return ds;
123
124 return NULL;
125}
126
127/**
128 * find_dock_dependent_device - get a device dependent on this dock
129 * @ds: the dock station
130 * @adev: ACPI device object to find.
131 *
132 * iterate over the dependent device list for this dock. If the
133 * dependent device matches the handle, return.
134 */
135static struct dock_dependent_device *
136find_dock_dependent_device(struct dock_station *ds, struct acpi_device *adev)
137{
138 struct dock_dependent_device *dd;
139
140 list_for_each_entry(dd, &ds->dependent_devices, list)
141 if (adev == dd->adev)
142 return dd;
143
144 return NULL;
145}
146
147void register_dock_dependent_device(struct acpi_device *adev,
148 acpi_handle dshandle)
149{
150 struct dock_station *ds = find_dock_station(dshandle);
151
152 if (ds && !find_dock_dependent_device(ds, adev))
153 add_dock_dependent_device(ds, adev);
154}
155
156/*****************************************************************************
157 * Dock functions *
158 *****************************************************************************/
159
160/**
161 * is_dock_device - see if a device is on a dock station
162 * @adev: ACPI device object to check.
163 *
164 * If this device is either the dock station itself,
165 * or is a device dependent on the dock station, then it
166 * is a dock device
167 */
168int is_dock_device(struct acpi_device *adev)
169{
170 struct dock_station *dock_station;
171
172 if (!dock_station_count)
173 return 0;
174
175 if (acpi_dock_match(adev->handle))
176 return 1;
177
178 list_for_each_entry(dock_station, &dock_stations, sibling)
179 if (find_dock_dependent_device(dock_station, adev))
180 return 1;
181
182 return 0;
183}
184EXPORT_SYMBOL_GPL(is_dock_device);
185
186/**
187 * dock_present - see if the dock station is present.
188 * @ds: the dock station
189 *
190 * execute the _STA method. note that present does not
191 * imply that we are docked.
192 */
193static int dock_present(struct dock_station *ds)
194{
195 unsigned long long sta;
196 acpi_status status;
197
198 if (ds) {
199 status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
200 if (ACPI_SUCCESS(status) && sta)
201 return 1;
202 }
203 return 0;
204}
205
206/**
207 * hot_remove_dock_devices - Remove dock station devices.
208 * @ds: Dock station.
209 */
210static void hot_remove_dock_devices(struct dock_station *ds)
211{
212 struct dock_dependent_device *dd;
213
214 /*
215 * Walk the list in reverse order so that devices that have been added
216 * last are removed first (in case there are some indirect dependencies
217 * between them).
218 */
219 list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
220 dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST,
221 DOCK_CALL_HANDLER);
222
223 list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
224 acpi_bus_trim(dd->adev);
225}
226
227/**
228 * hotplug_dock_devices - Insert devices on a dock station.
229 * @ds: the dock station
230 * @event: either bus check or device check request
231 *
232 * Some devices on the dock station need to have drivers called
233 * to perform hotplug operations after a dock event has occurred.
234 * Traverse the list of dock devices that have registered a
235 * hotplug handler, and call the handler.
236 */
237static void hotplug_dock_devices(struct dock_station *ds, u32 event)
238{
239 struct dock_dependent_device *dd;
240
241 /* Call driver specific post-dock fixups. */
242 list_for_each_entry(dd, &ds->dependent_devices, list)
243 dock_hotplug_event(dd, event, DOCK_CALL_FIXUP);
244
245 /* Call driver specific hotplug functions. */
246 list_for_each_entry(dd, &ds->dependent_devices, list)
247 dock_hotplug_event(dd, event, DOCK_CALL_HANDLER);
248
249 /*
250 * Check if all devices have been enumerated already. If not, run
251 * acpi_bus_scan() for them and that will cause scan handlers to be
252 * attached to device objects or acpi_drivers to be stopped/started if
253 * they are present.
254 */
255 list_for_each_entry(dd, &ds->dependent_devices, list) {
256 struct acpi_device *adev = dd->adev;
257
258 if (!acpi_device_enumerated(adev)) {
259 int ret = acpi_bus_scan(adev->handle);
260
261 if (ret)
262 dev_dbg(&adev->dev, "scan error %d\n", -ret);
263 }
264 }
265}
266
267static void dock_event(struct dock_station *ds, u32 event, int num)
268{
269 struct device *dev = &ds->dock_device->dev;
270 char event_string[13];
271 char *envp[] = { event_string, NULL };
272 struct dock_dependent_device *dd;
273
274 if (num == UNDOCK_EVENT)
275 sprintf(event_string, "EVENT=undock");
276 else
277 sprintf(event_string, "EVENT=dock");
278
279 /*
280 * Indicate that the status of the dock station has
281 * changed.
282 */
283 if (num == DOCK_EVENT)
284 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
285
286 list_for_each_entry(dd, &ds->dependent_devices, list)
287 dock_hotplug_event(dd, event, DOCK_CALL_UEVENT);
288
289 if (num != DOCK_EVENT)
290 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
291}
292
293/**
294 * handle_dock - handle a dock event
295 * @ds: the dock station
296 * @dock: to dock, or undock - that is the question
297 *
298 * Execute the _DCK method in response to an acpi event
299 */
300static void handle_dock(struct dock_station *ds, int dock)
301{
302 acpi_status status;
303 struct acpi_object_list arg_list;
304 union acpi_object arg;
305 unsigned long long value;
306
307 acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking");
308
309 /* _DCK method has one argument */
310 arg_list.count = 1;
311 arg_list.pointer = &arg;
312 arg.type = ACPI_TYPE_INTEGER;
313 arg.integer.value = dock;
314 status = acpi_evaluate_integer(ds->handle, "_DCK", &arg_list, &value);
315 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
316 acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n",
317 status);
318}
319
320static inline void dock(struct dock_station *ds)
321{
322 handle_dock(ds, 1);
323}
324
325static inline void undock(struct dock_station *ds)
326{
327 handle_dock(ds, 0);
328}
329
330static inline void begin_dock(struct dock_station *ds)
331{
332 ds->flags |= DOCK_DOCKING;
333}
334
335static inline void complete_dock(struct dock_station *ds)
336{
337 ds->flags &= ~(DOCK_DOCKING);
338 ds->last_dock_time = jiffies;
339}
340
341static inline void begin_undock(struct dock_station *ds)
342{
343 ds->flags |= DOCK_UNDOCKING;
344}
345
346static inline void complete_undock(struct dock_station *ds)
347{
348 ds->flags &= ~(DOCK_UNDOCKING);
349}
350
351/**
352 * dock_in_progress - see if we are in the middle of handling a dock event
353 * @ds: the dock station
354 *
355 * Sometimes while docking, false dock events can be sent to the driver
356 * because good connections aren't made or some other reason. Ignore these
357 * if we are in the middle of doing something.
358 */
359static int dock_in_progress(struct dock_station *ds)
360{
361 if ((ds->flags & DOCK_DOCKING) ||
362 time_before(jiffies, (ds->last_dock_time + HZ)))
363 return 1;
364 return 0;
365}
366
367/**
368 * handle_eject_request - handle an undock request checking for error conditions
369 * @ds: The dock station to undock.
370 * @event: The ACPI event number associated with the undock request.
371 *
372 * Check to make sure the dock device is still present, then undock and
373 * hotremove all the devices that may need removing.
374 */
375static int handle_eject_request(struct dock_station *ds, u32 event)
376{
377 if (dock_in_progress(ds))
378 return -EBUSY;
379
380 /*
381 * here we need to generate the undock
382 * event prior to actually doing the undock
383 * so that the device struct still exists.
384 * Also, even send the dock event if the
385 * device is not present anymore
386 */
387 dock_event(ds, event, UNDOCK_EVENT);
388
389 hot_remove_dock_devices(ds);
390 undock(ds);
391 acpi_evaluate_lck(ds->handle, 0);
392 acpi_evaluate_ej0(ds->handle);
393 if (dock_present(ds)) {
394 acpi_handle_err(ds->handle, "Unable to undock!\n");
395 return -EBUSY;
396 }
397 complete_undock(ds);
398 return 0;
399}
400
401/**
402 * dock_notify - Handle ACPI dock notification.
403 * @adev: Dock station's ACPI device object.
404 * @event: Event code.
405 *
406 * If we are notified to dock, then check to see if the dock is
407 * present and then dock. Notify all drivers of the dock event,
408 * and then hotplug and devices that may need hotplugging.
409 */
410int dock_notify(struct acpi_device *adev, u32 event)
411{
412 acpi_handle handle = adev->handle;
413 struct dock_station *ds = find_dock_station(handle);
414 int surprise_removal = 0;
415
416 if (!ds)
417 return -ENODEV;
418
419 /*
420 * According to acpi spec 3.0a, if a DEVICE_CHECK notification
421 * is sent and _DCK is present, it is assumed to mean an undock
422 * request.
423 */
424 if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
425 event = ACPI_NOTIFY_EJECT_REQUEST;
426
427 /*
428 * dock station: BUS_CHECK - docked or surprise removal
429 * DEVICE_CHECK - undocked
430 * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
431 *
432 * To simplify event handling, dock dependent device handler always
433 * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
434 * ACPI_NOTIFY_EJECT_REQUEST for removal
435 */
436 switch (event) {
437 case ACPI_NOTIFY_BUS_CHECK:
438 case ACPI_NOTIFY_DEVICE_CHECK:
439 if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) {
440 begin_dock(ds);
441 dock(ds);
442 if (!dock_present(ds)) {
443 acpi_handle_err(handle, "Unable to dock!\n");
444 complete_dock(ds);
445 break;
446 }
447 hotplug_dock_devices(ds, event);
448 complete_dock(ds);
449 dock_event(ds, event, DOCK_EVENT);
450 acpi_evaluate_lck(ds->handle, 1);
451 acpi_update_all_gpes();
452 break;
453 }
454 if (dock_present(ds) || dock_in_progress(ds))
455 break;
456 /* This is a surprise removal */
457 surprise_removal = 1;
458 event = ACPI_NOTIFY_EJECT_REQUEST;
459 /* Fall back */
460 fallthrough;
461 case ACPI_NOTIFY_EJECT_REQUEST:
462 begin_undock(ds);
463 if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
464 || surprise_removal)
465 handle_eject_request(ds, event);
466 else
467 dock_event(ds, event, UNDOCK_EVENT);
468 break;
469 }
470 return 0;
471}
472
473/*
474 * show_docked - read method for "docked" file in sysfs
475 */
476static ssize_t docked_show(struct device *dev,
477 struct device_attribute *attr, char *buf)
478{
479 struct dock_station *dock_station = dev->platform_data;
480 struct acpi_device *adev = acpi_fetch_acpi_dev(dock_station->handle);
481
482 return sysfs_emit(buf, "%u\n", acpi_device_enumerated(adev));
483}
484static DEVICE_ATTR_RO(docked);
485
486/*
487 * show_flags - read method for flags file in sysfs
488 */
489static ssize_t flags_show(struct device *dev,
490 struct device_attribute *attr, char *buf)
491{
492 struct dock_station *dock_station = dev->platform_data;
493
494 return sysfs_emit(buf, "%d\n", dock_station->flags);
495
496}
497static DEVICE_ATTR_RO(flags);
498
499/*
500 * write_undock - write method for "undock" file in sysfs
501 */
502static ssize_t undock_store(struct device *dev, struct device_attribute *attr,
503 const char *buf, size_t count)
504{
505 int ret;
506 struct dock_station *dock_station = dev->platform_data;
507
508 if (!count)
509 return -EINVAL;
510
511 acpi_scan_lock_acquire();
512 begin_undock(dock_station);
513 ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
514 acpi_scan_lock_release();
515 return ret ? ret : count;
516}
517static DEVICE_ATTR_WO(undock);
518
519/*
520 * show_dock_uid - read method for "uid" file in sysfs
521 */
522static ssize_t uid_show(struct device *dev,
523 struct device_attribute *attr, char *buf)
524{
525 unsigned long long lbuf;
526 struct dock_station *dock_station = dev->platform_data;
527
528 acpi_status status = acpi_evaluate_integer(dock_station->handle,
529 "_UID", NULL, &lbuf);
530 if (ACPI_FAILURE(status))
531 return 0;
532
533 return sysfs_emit(buf, "%llx\n", lbuf);
534}
535static DEVICE_ATTR_RO(uid);
536
537static ssize_t type_show(struct device *dev,
538 struct device_attribute *attr, char *buf)
539{
540 struct dock_station *dock_station = dev->platform_data;
541 char *type;
542
543 if (dock_station->flags & DOCK_IS_DOCK)
544 type = "dock_station";
545 else if (dock_station->flags & DOCK_IS_ATA)
546 type = "ata_bay";
547 else if (dock_station->flags & DOCK_IS_BAT)
548 type = "battery_bay";
549 else
550 type = "unknown";
551
552 return sysfs_emit(buf, "%s\n", type);
553}
554static DEVICE_ATTR_RO(type);
555
556static struct attribute *dock_attributes[] = {
557 &dev_attr_docked.attr,
558 &dev_attr_flags.attr,
559 &dev_attr_undock.attr,
560 &dev_attr_uid.attr,
561 &dev_attr_type.attr,
562 NULL
563};
564
565static const struct attribute_group dock_attribute_group = {
566 .attrs = dock_attributes
567};
568
569/**
570 * acpi_dock_add - Add a new dock station
571 * @adev: Dock station ACPI device object.
572 *
573 * allocated and initialize a new dock station device.
574 */
575void acpi_dock_add(struct acpi_device *adev)
576{
577 struct dock_station *dock_station, ds = { NULL, };
578 struct platform_device_info pdevinfo;
579 acpi_handle handle = adev->handle;
580 struct platform_device *dd;
581 int ret;
582
583 memset(&pdevinfo, 0, sizeof(pdevinfo));
584 pdevinfo.name = "dock";
585 pdevinfo.id = dock_station_count;
586 pdevinfo.fwnode = acpi_fwnode_handle(adev);
587 pdevinfo.data = &ds;
588 pdevinfo.size_data = sizeof(ds);
589 dd = platform_device_register_full(&pdevinfo);
590 if (IS_ERR(dd))
591 return;
592
593 dock_station = dd->dev.platform_data;
594
595 dock_station->handle = handle;
596 dock_station->dock_device = dd;
597 dock_station->last_dock_time = jiffies - HZ;
598
599 INIT_LIST_HEAD(&dock_station->sibling);
600 INIT_LIST_HEAD(&dock_station->dependent_devices);
601
602 /* we want the dock device to send uevents */
603 dev_set_uevent_suppress(&dd->dev, 0);
604
605 if (acpi_dock_match(handle))
606 dock_station->flags |= DOCK_IS_DOCK;
607 if (acpi_ata_match(handle))
608 dock_station->flags |= DOCK_IS_ATA;
609 if (acpi_device_is_battery(adev))
610 dock_station->flags |= DOCK_IS_BAT;
611
612 ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
613 if (ret)
614 goto err_unregister;
615
616 /* add the dock station as a device dependent on itself */
617 ret = add_dock_dependent_device(dock_station, adev);
618 if (ret)
619 goto err_rmgroup;
620
621 dock_station_count++;
622 list_add(&dock_station->sibling, &dock_stations);
623 adev->flags.is_dock_station = true;
624 dev_info(&adev->dev, "ACPI dock station (docks/bays count: %d)\n",
625 dock_station_count);
626 return;
627
628err_rmgroup:
629 sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
630
631err_unregister:
632 platform_device_unregister(dd);
633 acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
634}