aboutsummaryrefslogtreecommitdiff
path: root/drivers/acpi/dock.c
blob: 24e076f44d23827874c4d476ba8323d55dfa993c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  dock.c - ACPI dock station driver
 *
 *  Copyright (C) 2006, 2014, Intel Corp.
 *  Author: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
 *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 */

#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/notifier.h>
#include <linux/platform_device.h>
#include <linux/jiffies.h>
#include <linux/stddef.h>
#include <linux/acpi.h>

#include "internal.h"

static bool immediate_undock = 1;
module_param(immediate_undock, bool, 0644);
MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
	"undock immediately when the undock button is pressed, 0 will cause"
	" the driver to wait for userspace to write the undock sysfs file "
	" before undocking");

struct dock_station {
	acpi_handle handle;
	unsigned long last_dock_time;
	u32 flags;
	struct list_head dependent_devices;

	struct list_head sibling;
	struct platform_device *dock_device;
};
static LIST_HEAD(dock_stations);
static int dock_station_count;

struct dock_dependent_device {
	struct list_head list;
	struct acpi_device *adev;
};

#define DOCK_DOCKING	0x00000001
#define DOCK_UNDOCKING  0x00000002
#define DOCK_IS_DOCK	0x00000010
#define DOCK_IS_ATA	0x00000020
#define DOCK_IS_BAT	0x00000040
#define DOCK_EVENT	3
#define UNDOCK_EVENT	2

enum dock_callback_type {
	DOCK_CALL_HANDLER,
	DOCK_CALL_FIXUP,
	DOCK_CALL_UEVENT,
};

/*****************************************************************************
 *                         Dock Dependent device functions                   *
 *****************************************************************************/
/**
 * add_dock_dependent_device - associate a device with the dock station
 * @ds: Dock station.
 * @adev: Dependent ACPI device object.
 *
 * Add the dependent device to the dock's dependent device list.
 */
static int add_dock_dependent_device(struct dock_station *ds,
				     struct acpi_device *adev)
{
	struct dock_dependent_device *dd;

	dd = kzalloc(sizeof(*dd), GFP_KERNEL);
	if (!dd)
		return -ENOMEM;

	dd->adev = adev;
	INIT_LIST_HEAD(&dd->list);
	list_add_tail(&dd->list, &ds->dependent_devices);

	return 0;
}

static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
			       enum dock_callback_type cb_type)
{
	struct acpi_device *adev = dd->adev;

	acpi_lock_hp_context();

	if (!adev->hp)
		goto out;

	if (cb_type == DOCK_CALL_FIXUP) {
		void (*fixup)(struct acpi_device *);

		fixup = adev->hp->fixup;
		if (fixup) {
			acpi_unlock_hp_context();
			fixup(adev);
			return;
		}
	} else if (cb_type == DOCK_CALL_UEVENT) {
		void (*uevent)(struct acpi_device *, u32);

		uevent = adev->hp->uevent;
		if (uevent) {
			acpi_unlock_hp_context();
			uevent(adev, event);
			return;
		}
	} else {
		int (*notify)(struct acpi_device *, u32);

		notify = adev->hp->notify;
		if (notify) {
			acpi_unlock_hp_context();
			notify(adev, event);
			return;
		}
	}

 out:
	acpi_unlock_hp_context();
}

static struct dock_station *find_dock_station(acpi_handle handle)
{
	struct dock_station *ds;

	list_for_each_entry(ds, &dock_stations, sibling)
		if (ds->handle == handle)
			return ds;

	return NULL;
}

/**
 * find_dock_dependent_device - get a device dependent on this dock
 * @ds: the dock station
 * @adev: ACPI device object to find.
 *
 * iterate over the dependent device list for this dock.  If the
 * dependent device matches the handle, return.
 */
static struct dock_dependent_device *
find_dock_dependent_device(struct dock_station *ds, struct acpi_device *adev)
{
	struct dock_dependent_device *dd;

	list_for_each_entry(dd, &ds->dependent_devices, list)
		if (adev == dd->adev)
			return dd;

	return NULL;
}

void register_dock_dependent_device(struct acpi_device *adev,
				    acpi_handle dshandle)
{
	struct dock_station *ds = find_dock_station(dshandle);

	if (ds && !find_dock_dependent_device(ds, adev))
		add_dock_dependent_device(ds, adev);
}

/*****************************************************************************
 *                         Dock functions                                    *
 *****************************************************************************/

/**
 * is_dock_device - see if a device is on a dock station
 * @adev: ACPI device object to check.
 *
 * If this device is either the dock station itself,
 * or is a device dependent on the dock station, then it
 * is a dock device
 */
int is_dock_device(struct acpi_device *adev)
{
	struct dock_station *dock_station;

	if (!dock_station_count)
		return 0;

	if (acpi_dock_match(adev->handle))
		return 1;

	list_for_each_entry(dock_station, &dock_stations, sibling)
		if (find_dock_dependent_device(dock_station, adev))
			return 1;

	return 0;
}
EXPORT_SYMBOL_GPL(is_dock_device);

/**
 * dock_present - see if the dock station is present.
 * @ds: the dock station
 *
 * execute the _STA method.  note that present does not
 * imply that we are docked.
 */
static int dock_present(struct dock_station *ds)
{
	unsigned long long sta;
	acpi_status status;

	if (ds) {
		status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
		if (ACPI_SUCCESS(status) && sta)
			return 1;
	}
	return 0;
}

/**
 * hot_remove_dock_devices - Remove dock station devices.
 * @ds: Dock station.
 */
static void hot_remove_dock_devices(struct dock_station *ds)
{
	struct dock_dependent_device *dd;

	/*
	 * Walk the list in reverse order so that devices that have been added
	 * last are removed first (in case there are some indirect dependencies
	 * between them).
	 */
	list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
		dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST,
				   DOCK_CALL_HANDLER);

	list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
		acpi_bus_trim(dd->adev);
}

/**
 * hotplug_dock_devices - Insert devices on a dock station.
 * @ds: the dock station
 * @event: either bus check or device check request
 *
 * Some devices on the dock station need to have drivers called
 * to perform hotplug operations after a dock event has occurred.
 * Traverse the list of dock devices that have registered a
 * hotplug handler, and call the handler.
 */
static void hotplug_dock_devices(struct dock_station *ds, u32 event)
{
	struct dock_dependent_device *dd;

	/* Call driver specific post-dock fixups. */
	list_for_each_entry(dd, &ds->dependent_devices, list)
		dock_hotplug_event(dd, event, DOCK_CALL_FIXUP);

	/* Call driver specific hotplug functions. */
	list_for_each_entry(dd, &ds->dependent_devices, list)
		dock_hotplug_event(dd, event, DOCK_CALL_HANDLER);

	/*
	 * Check if all devices have been enumerated already.  If not, run
	 * acpi_bus_scan() for them and that will cause scan handlers to be
	 * attached to device objects or acpi_drivers to be stopped/started if
	 * they are present.
	 */
	list_for_each_entry(dd, &ds->dependent_devices, list) {
		struct acpi_device *adev = dd->adev;

		if (!acpi_device_enumerated(adev)) {
			int ret = acpi_bus_scan(adev->handle);
			if (ret)
				dev_dbg(&adev->dev, "scan error %d\n", -ret);
		}
	}
}

static void dock_event(struct dock_station *ds, u32 event, int num)
{
	struct device *dev = &ds->dock_device->dev;
	char event_string[13];
	char *envp[] = { event_string, NULL };
	struct dock_dependent_device *dd;

	if (num == UNDOCK_EVENT)
		sprintf(event_string, "EVENT=undock");
	else
		sprintf(event_string, "EVENT=dock");

	/*
	 * Indicate that the status of the dock station has
	 * changed.
	 */
	if (num == DOCK_EVENT)
		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);

	list_for_each_entry(dd, &ds->dependent_devices, list)
		dock_hotplug_event(dd, event, DOCK_CALL_UEVENT);

	if (num != DOCK_EVENT)
		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
}

/**
 * handle_dock - handle a dock event
 * @ds: the dock station
 * @dock: to dock, or undock - that is the question
 *
 * Execute the _DCK method in response to an acpi event
 */
static void handle_dock(struct dock_station *ds, int dock)
{
	acpi_status status;
	struct acpi_object_list arg_list;
	union acpi_object arg;
	unsigned long long value;

	acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking");

	/* _DCK method has one argument */
	arg_list.count = 1;
	arg_list.pointer = &arg;
	arg.type = ACPI_TYPE_INTEGER;
	arg.integer.value = dock;
	status = acpi_evaluate_integer(ds->handle, "_DCK", &arg_list, &value);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
		acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n",
				status);
}

static inline void dock(struct dock_station *ds)
{
	handle_dock(ds, 1);
}

static inline void undock(struct dock_station *ds)
{
	handle_dock(ds, 0);
}

static inline void begin_dock(struct dock_station *ds)
{
	ds->flags |= DOCK_DOCKING;
}

static inline void complete_dock(struct dock_station *ds)
{
	ds->flags &= ~(DOCK_DOCKING);
	ds->last_dock_time = jiffies;
}

static inline void begin_undock(struct dock_station *ds)
{
	ds->flags |= DOCK_UNDOCKING;
}

static inline void complete_undock(struct dock_station *ds)
{
	ds->flags &= ~(DOCK_UNDOCKING);
}

/**
 * dock_in_progress - see if we are in the middle of handling a dock event
 * @ds: the dock station
 *
 * Sometimes while docking, false dock events can be sent to the driver
 * because good connections aren't made or some other reason.  Ignore these
 * if we are in the middle of doing something.
 */
static int dock_in_progress(struct dock_station *ds)
{
	if ((ds->flags & DOCK_DOCKING) ||
	    time_before(jiffies, (ds->last_dock_time + HZ)))
		return 1;
	return 0;
}

/**
 * handle_eject_request - handle an undock request checking for error conditions
 *
 * Check to make sure the dock device is still present, then undock and
 * hotremove all the devices that may need removing.
 */
static int handle_eject_request(struct dock_station *ds, u32 event)
{
	if (dock_in_progress(ds))
		return -EBUSY;

	/*
	 * here we need to generate the undock
	 * event prior to actually doing the undock
	 * so that the device struct still exists.
	 * Also, even send the dock event if the
	 * device is not present anymore
	 */
	dock_event(ds, event, UNDOCK_EVENT);

	hot_remove_dock_devices(ds);
	undock(ds);
	acpi_evaluate_lck(ds->handle, 0);
	acpi_evaluate_ej0(ds->handle);
	if (dock_present(ds)) {
		acpi_handle_err(ds->handle, "Unable to undock!\n");
		return -EBUSY;
	}
	complete_undock(ds);
	return 0;
}

/**
 * dock_notify - Handle ACPI dock notification.
 * @adev: Dock station's ACPI device object.
 * @event: Event code.
 *
 * If we are notified to dock, then check to see if the dock is
 * present and then dock.  Notify all drivers of the dock event,
 * and then hotplug and devices that may need hotplugging.
 */
int dock_notify(struct acpi_device *adev, u32 event)
{
	acpi_handle handle = adev->handle;
	struct dock_station *ds = find_dock_station(handle);
	int surprise_removal = 0;

	if (!ds)
		return -ENODEV;

	/*
	 * According to acpi spec 3.0a, if a DEVICE_CHECK notification
	 * is sent and _DCK is present, it is assumed to mean an undock
	 * request.
	 */
	if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
		event = ACPI_NOTIFY_EJECT_REQUEST;

	/*
	 * dock station: BUS_CHECK - docked or surprise removal
	 *		 DEVICE_CHECK - undocked
	 * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
	 *
	 * To simplify event handling, dock dependent device handler always
	 * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
	 * ACPI_NOTIFY_EJECT_REQUEST for removal
	 */
	switch (event) {
	case ACPI_NOTIFY_BUS_CHECK:
	case ACPI_NOTIFY_DEVICE_CHECK:
		if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) {
			begin_dock(ds);
			dock(ds);
			if (!dock_present(ds)) {
				acpi_handle_err(handle, "Unable to dock!\n");
				complete_dock(ds);
				break;
			}
			hotplug_dock_devices(ds, event);
			complete_dock(ds);
			dock_event(ds, event, DOCK_EVENT);
			acpi_evaluate_lck(ds->handle, 1);
			acpi_update_all_gpes();
			break;
		}
		if (dock_present(ds) || dock_in_progress(ds))
			break;
		/* This is a surprise removal */
		surprise_removal = 1;
		event = ACPI_NOTIFY_EJECT_REQUEST;
		/* Fall back */
		fallthrough;
	case ACPI_NOTIFY_EJECT_REQUEST:
		begin_undock(ds);
		if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
		   || surprise_removal)
			handle_eject_request(ds, event);
		else
			dock_event(ds, event, UNDOCK_EVENT);
		break;
	}
	return 0;
}

/*
 * show_docked - read method for "docked" file in sysfs
 */
static ssize_t show_docked(struct device *dev,
			   struct device_attribute *attr, char *buf)
{
	struct dock_station *dock_station = dev->platform_data;
	struct acpi_device *adev = NULL;

	acpi_bus_get_device(dock_station->handle, &adev);
	return snprintf(buf, PAGE_SIZE, "%u\n", acpi_device_enumerated(adev));
}
static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);

/*
 * show_flags - read method for flags file in sysfs
 */
static ssize_t show_flags(struct device *dev,
			  struct device_attribute *attr, char *buf)
{
	struct dock_station *dock_station = dev->platform_data;
	return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);

}
static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);

/*
 * write_undock - write method for "undock" file in sysfs
 */
static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
			   const char *buf, size_t count)
{
	int ret;
	struct dock_station *dock_station = dev->platform_data;

	if (!count)
		return -EINVAL;

	acpi_scan_lock_acquire();
	begin_undock(dock_station);
	ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
	acpi_scan_lock_release();
	return ret ? ret: count;
}
static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);

/*
 * show_dock_uid - read method for "uid" file in sysfs
 */
static ssize_t show_dock_uid(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	unsigned long long lbuf;
	struct dock_station *dock_station = dev->platform_data;
	acpi_status status = acpi_evaluate_integer(dock_station->handle,
					"_UID", NULL, &lbuf);
	if (ACPI_FAILURE(status))
	    return 0;

	return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf);
}
static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);

static ssize_t show_dock_type(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct dock_station *dock_station = dev->platform_data;
	char *type;

	if (dock_station->flags & DOCK_IS_DOCK)
		type = "dock_station";
	else if (dock_station->flags & DOCK_IS_ATA)
		type = "ata_bay";
	else if (dock_station->flags & DOCK_IS_BAT)
		type = "battery_bay";
	else
		type = "unknown";

	return snprintf(buf, PAGE_SIZE, "%s\n", type);
}
static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);

static struct attribute *dock_attributes[] = {
	&dev_attr_docked.attr,
	&dev_attr_flags.attr,
	&dev_attr_undock.attr,
	&dev_attr_uid.attr,
	&dev_attr_type.attr,
	NULL
};

static const struct attribute_group dock_attribute_group = {
	.attrs = dock_attributes
};

/**
 * acpi_dock_add - Add a new dock station
 * @adev: Dock station ACPI device object.
 *
 * allocated and initialize a new dock station device.
 */
void acpi_dock_add(struct acpi_device *adev)
{
	struct dock_station *dock_station, ds = { NULL, };
	struct platform_device_info pdevinfo;
	acpi_handle handle = adev->handle;
	struct platform_device *dd;
	int ret;

	memset(&pdevinfo, 0, sizeof(pdevinfo));
	pdevinfo.name = "dock";
	pdevinfo.id = dock_station_count;
	pdevinfo.fwnode = acpi_fwnode_handle(adev);
	pdevinfo.data = &ds;
	pdevinfo.size_data = sizeof(ds);
	dd = platform_device_register_full(&pdevinfo);
	if (IS_ERR(dd))
		return;

	dock_station = dd->dev.platform_data;

	dock_station->handle = handle;
	dock_station->dock_device = dd;
	dock_station->last_dock_time = jiffies - HZ;

	INIT_LIST_HEAD(&dock_station->sibling);
	INIT_LIST_HEAD(&dock_station->dependent_devices);

	/* we want the dock device to send uevents */
	dev_set_uevent_suppress(&dd->dev, 0);

	if (acpi_dock_match(handle))
		dock_station->flags |= DOCK_IS_DOCK;
	if (acpi_ata_match(handle))
		dock_station->flags |= DOCK_IS_ATA;
	if (acpi_device_is_battery(adev))
		dock_station->flags |= DOCK_IS_BAT;

	ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
	if (ret)
		goto err_unregister;

	/* add the dock station as a device dependent on itself */
	ret = add_dock_dependent_device(dock_station, adev);
	if (ret)
		goto err_rmgroup;

	dock_station_count++;
	list_add(&dock_station->sibling, &dock_stations);
	adev->flags.is_dock_station = true;
	dev_info(&adev->dev, "ACPI dock station (docks/bays count: %d)\n",
		 dock_station_count);
	return;

err_rmgroup:
	sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);

err_unregister:
	platform_device_unregister(dd);
	acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
}