summaryrefslogtreecommitdiffstats
path: root/drivers/usb/core/port.c
blob: 4a21431953953d5b52b467a107a04c5f8198cf19 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * usb port device code
 *
 * Copyright (C) 2012 Intel Corp
 *
 * Author: Lan Tianyu <tianyu.lan@intel.com>
 */

#include <linux/slab.h>
#include <linux/pm_qos.h>

#include "hub.h"

static int usb_port_block_power_off;

static const struct attribute_group *port_dev_group[];

static ssize_t connect_type_show(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	struct usb_port *port_dev = to_usb_port(dev);
	char *result;

	switch (port_dev->connect_type) {
	case USB_PORT_CONNECT_TYPE_HOT_PLUG:
		result = "hotplug";
		break;
	case USB_PORT_CONNECT_TYPE_HARD_WIRED:
		result = "hardwired";
		break;
	case USB_PORT_NOT_USED:
		result = "not used";
		break;
	default:
		result = "unknown";
		break;
	}

	return sprintf(buf, "%s\n", result);
}
static DEVICE_ATTR_RO(connect_type);

static ssize_t over_current_count_show(struct device *dev,
				       struct device_attribute *attr, char *buf)
{
	struct usb_port *port_dev = to_usb_port(dev);

	return sprintf(buf, "%u\n", port_dev->over_current_count);
}
static DEVICE_ATTR_RO(over_current_count);

static ssize_t quirks_show(struct device *dev,
			   struct device_attribute *attr, char *buf)
{
	struct usb_port *port_dev = to_usb_port(dev);

	return sprintf(buf, "%08x\n", port_dev->quirks);
}

static ssize_t quirks_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct usb_port *port_dev = to_usb_port(dev);
	u32 value;

	if (kstrtou32(buf, 16, &value))
		return -EINVAL;

	port_dev->quirks = value;
	return count;
}
static DEVICE_ATTR_RW(quirks);

static ssize_t usb3_lpm_permit_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct usb_port *port_dev = to_usb_port(dev);
	const char *p;

	if (port_dev->usb3_lpm_u1_permit) {
		if (port_dev->usb3_lpm_u2_permit)
			p = "u1_u2";
		else
			p = "u1";
	} else {
		if (port_dev->usb3_lpm_u2_permit)
			p = "u2";
		else
			p = "0";
	}

	return sprintf(buf, "%s\n", p);
}

static ssize_t usb3_lpm_permit_store(struct device *dev,
			       struct device_attribute *attr,
			       const char *buf, size_t count)
{
	struct usb_port *port_dev = to_usb_port(dev);
	struct usb_device *udev = port_dev->child;
	struct usb_hcd *hcd;

	if (!strncmp(buf, "u1_u2", 5)) {
		port_dev->usb3_lpm_u1_permit = 1;
		port_dev->usb3_lpm_u2_permit = 1;

	} else if (!strncmp(buf, "u1", 2)) {
		port_dev->usb3_lpm_u1_permit = 1;
		port_dev->usb3_lpm_u2_permit = 0;

	} else if (!strncmp(buf, "u2", 2)) {
		port_dev->usb3_lpm_u1_permit = 0;
		port_dev->usb3_lpm_u2_permit = 1;

	} else if (!strncmp(buf, "0", 1)) {
		port_dev->usb3_lpm_u1_permit = 0;
		port_dev->usb3_lpm_u2_permit = 0;
	} else
		return -EINVAL;

	/* If device is connected to the port, disable or enable lpm
	 * to make new u1 u2 setting take effect immediately.
	 */
	if (udev) {
		hcd = bus_to_hcd(udev->bus);
		if (!hcd)
			return -EINVAL;
		usb_lock_device(udev);
		mutex_lock(hcd->bandwidth_mutex);
		if (!usb_disable_lpm(udev))
			usb_enable_lpm(udev);
		mutex_unlock(hcd->bandwidth_mutex);
		usb_unlock_device(udev);
	}

	return count;
}
static DEVICE_ATTR_RW(usb3_lpm_permit);

static struct attribute *port_dev_attrs[] = {
	&dev_attr_connect_type.attr,
	&dev_attr_quirks.attr,
	&dev_attr_over_current_count.attr,
	NULL,
};

static struct attribute_group port_dev_attr_grp = {
	.attrs = port_dev_attrs,
};

static const struct attribute_group *port_dev_group[] = {
	&port_dev_attr_grp,
	NULL,
};

static struct attribute *port_dev_usb3_attrs[] = {
	&dev_attr_usb3_lpm_permit.attr,
	NULL,
};

static struct attribute_group port_dev_usb3_attr_grp = {
	.attrs = port_dev_usb3_attrs,
};

static const struct attribute_group *port_dev_usb3_group[] = {
	&port_dev_attr_grp,
	&port_dev_usb3_attr_grp,
	NULL,
};

static void usb_port_device_release(struct device *dev)
{
	struct usb_port *port_dev = to_usb_port(dev);

	kfree(port_dev->req);
	kfree(port_dev);
}

#ifdef CONFIG_PM
static int usb_port_runtime_resume(struct device *dev)
{
	struct usb_port *port_dev = to_usb_port(dev);
	struct usb_device *hdev = to_usb_device(dev->parent->parent);
	struct usb_interface *intf = to_usb_interface(dev->parent);
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
	struct usb_device *udev = port_dev->child;
	struct usb_port *peer = port_dev->peer;
	int port1 = port_dev->portnum;
	int retval;

	if (!hub)
		return -EINVAL;
	if (hub->in_reset) {
		set_bit(port1, hub->power_bits);
		return 0;
	}

	/*
	 * Power on our usb3 peer before this usb2 port to prevent a usb3
	 * device from degrading to its usb2 connection
	 */
	if (!port_dev->is_superspeed && peer)
		pm_runtime_get_sync(&peer->dev);

	usb_autopm_get_interface(intf);
	retval = usb_hub_set_port_power(hdev, hub, port1, true);
	msleep(hub_power_on_good_delay(hub));
	if (udev && !retval) {
		/*
		 * Our preference is to simply wait for the port to reconnect,
		 * as that is the lowest latency method to restart the port.
		 * However, there are cases where toggling port power results in
		 * the host port and the device port getting out of sync causing
		 * a link training live lock.  Upon timeout, flag the port as
		 * needing warm reset recovery (to be performed later by
		 * usb_port_resume() as requested via usb_wakeup_notification())
		 */
		if (hub_port_debounce_be_connected(hub, port1) < 0) {
			dev_dbg(&port_dev->dev, "reconnect timeout\n");
			if (hub_is_superspeed(hdev))
				set_bit(port1, hub->warm_reset_bits);
		}

		/* Force the child awake to revalidate after the power loss. */
		if (!test_and_set_bit(port1, hub->child_usage_bits)) {
			pm_runtime_get_noresume(&port_dev->dev);
			pm_request_resume(&udev->dev);
		}
	}

	usb_autopm_put_interface(intf);

	return retval;
}

static int usb_port_runtime_suspend(struct device *dev)
{
	struct usb_port *port_dev = to_usb_port(dev);
	struct usb_device *hdev = to_usb_device(dev->parent->parent);
	struct usb_interface *intf = to_usb_interface(dev->parent);
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
	struct usb_port *peer = port_dev->peer;
	int port1 = port_dev->portnum;
	int retval;

	if (!hub)
		return -EINVAL;
	if (hub->in_reset)
		return -EBUSY;

	if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
			== PM_QOS_FLAGS_ALL)
		return -EAGAIN;

	if (usb_port_block_power_off)
		return -EBUSY;

	usb_autopm_get_interface(intf);
	retval = usb_hub_set_port_power(hdev, hub, port1, false);
	usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
	if (!port_dev->is_superspeed)
		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
	usb_autopm_put_interface(intf);

	/*
	 * Our peer usb3 port may now be able to suspend, so
	 * asynchronously queue a suspend request to observe that this
	 * usb2 port is now off.
	 */
	if (!port_dev->is_superspeed && peer)
		pm_runtime_put(&peer->dev);

	return retval;
}
#endif

static const struct dev_pm_ops usb_port_pm_ops = {
#ifdef CONFIG_PM
	.runtime_suspend =	usb_port_runtime_suspend,
	.runtime_resume =	usb_port_runtime_resume,
#endif
};

struct device_type usb_port_device_type = {
	.name =		"usb_port",
	.release =	usb_port_device_release,
	.pm =		&usb_port_pm_ops,
};

static struct device_driver usb_port_driver = {
	.name = "usb",
	.owner = THIS_MODULE,
};

static int link_peers(struct usb_port *left, struct usb_port *right)
{
	struct usb_port *ss_port, *hs_port;
	int rc;

	if (left->peer == right && right->peer == left)
		return 0;

	if (left->peer || right->peer) {
		struct usb_port *lpeer = left->peer;
		struct usb_port *rpeer = right->peer;
		char *method;

		if (left->location && left->location == right->location)
			method = "location";
		else
			method = "default";

		pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
			dev_name(&left->dev), dev_name(&right->dev), method,
			dev_name(&left->dev),
			lpeer ? dev_name(&lpeer->dev) : "none",
			dev_name(&right->dev),
			rpeer ? dev_name(&rpeer->dev) : "none");
		return -EBUSY;
	}

	rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
	if (rc)
		return rc;
	rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
	if (rc) {
		sysfs_remove_link(&left->dev.kobj, "peer");
		return rc;
	}

	/*
	 * We need to wake the HiSpeed port to make sure we don't race
	 * setting ->peer with usb_port_runtime_suspend().  Otherwise we
	 * may miss a suspend event for the SuperSpeed port.
	 */
	if (left->is_superspeed) {
		ss_port = left;
		WARN_ON(right->is_superspeed);
		hs_port = right;
	} else {
		ss_port = right;
		WARN_ON(!right->is_superspeed);
		hs_port = left;
	}
	pm_runtime_get_sync(&hs_port->dev);

	left->peer = right;
	right->peer = left;

	/*
	 * The SuperSpeed reference is dropped when the HiSpeed port in
	 * this relationship suspends, i.e. when it is safe to allow a
	 * SuperSpeed connection to drop since there is no risk of a
	 * device degrading to its powered-off HiSpeed connection.
	 *
	 * Also, drop the HiSpeed ref taken above.
	 */
	pm_runtime_get_sync(&ss_port->dev);
	pm_runtime_put(&hs_port->dev);

	return 0;
}

static void link_peers_report(struct usb_port *left, struct usb_port *right)
{
	int rc;

	rc = link_peers(left, right);
	if (rc == 0) {
		dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
	} else {
		dev_dbg(&left->dev, "failed to peer to %s (%d)\n",
				dev_name(&right->dev), rc);
		pr_warn_once("usb: port power management may be unreliable\n");
		usb_port_block_power_off = 1;
	}
}

static void unlink_peers(struct usb_port *left, struct usb_port *right)
{
	struct usb_port *ss_port, *hs_port;

	WARN(right->peer != left || left->peer != right,
			"%s and %s are not peers?\n",
			dev_name(&left->dev), dev_name(&right->dev));

	/*
	 * We wake the HiSpeed port to make sure we don't race its
	 * usb_port_runtime_resume() event which takes a SuperSpeed ref
	 * when ->peer is !NULL.
	 */
	if (left->is_superspeed) {
		ss_port = left;
		hs_port = right;
	} else {
		ss_port = right;
		hs_port = left;
	}

	pm_runtime_get_sync(&hs_port->dev);

	sysfs_remove_link(&left->dev.kobj, "peer");
	right->peer = NULL;
	sysfs_remove_link(&right->dev.kobj, "peer");
	left->peer = NULL;

	/* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
	pm_runtime_put(&ss_port->dev);

	/* Drop the ref taken above */
	pm_runtime_put(&hs_port->dev);
}

/*
 * For each usb hub device in the system check to see if it is in the
 * peer domain of the given port_dev, and if it is check to see if it
 * has a port that matches the given port by location
 */
static int match_location(struct usb_device *peer_hdev, void *p)
{
	int port1;
	struct usb_hcd *hcd, *peer_hcd;
	struct usb_port *port_dev = p, *peer;
	struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
	struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);

	if (!peer_hub)
		return 0;

	hcd = bus_to_hcd(hdev->bus);
	peer_hcd = bus_to_hcd(peer_hdev->bus);
	/* peer_hcd is provisional until we verify it against the known peer */
	if (peer_hcd != hcd->shared_hcd)
		return 0;

	for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
		peer = peer_hub->ports[port1 - 1];
		if (peer && peer->location == port_dev->location) {
			link_peers_report(port_dev, peer);
			return 1; /* done */
		}
	}

	return 0;
}

/*
 * Find the peer port either via explicit platform firmware "location"
 * data, the peer hcd for root hubs, or the upstream peer relationship
 * for all other hubs.
 */
static void find_and_link_peer(struct usb_hub *hub, int port1)
{
	struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
	struct usb_device *hdev = hub->hdev;
	struct usb_device *peer_hdev;
	struct usb_hub *peer_hub;

	/*
	 * If location data is available then we can only peer this port
	 * by a location match, not the default peer (lest we create a
	 * situation where we need to go back and undo a default peering
	 * when the port is later peered by location data)
	 */
	if (port_dev->location) {
		/* we link the peer in match_location() if found */
		usb_for_each_dev(port_dev, match_location);
		return;
	} else if (!hdev->parent) {
		struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
		struct usb_hcd *peer_hcd = hcd->shared_hcd;

		if (!peer_hcd)
			return;

		peer_hdev = peer_hcd->self.root_hub;
	} else {
		struct usb_port *upstream;
		struct usb_device *parent = hdev->parent;
		struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);

		if (!parent_hub)
			return;

		upstream = parent_hub->ports[hdev->portnum - 1];
		if (!upstream || !upstream->peer)
			return;

		peer_hdev = upstream->peer->child;
	}

	peer_hub = usb_hub_to_struct_hub(peer_hdev);
	if (!peer_hub || port1 > peer_hdev->maxchild)
		return;

	/*
	 * we found a valid default peer, last check is to make sure it
	 * does not have location data
	 */
	peer = peer_hub->ports[port1 - 1];
	if (peer && peer->location == 0)
		link_peers_report(port_dev, peer);
}

int usb_hub_create_port_device(struct usb_hub *hub, int port1)
{
	struct usb_port *port_dev;
	struct usb_device *hdev = hub->hdev;
	int retval;

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

	port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
	if (!port_dev->req) {
		kfree(port_dev);
		return -ENOMEM;
	}

	hub->ports[port1 - 1] = port_dev;
	port_dev->portnum = port1;
	set_bit(port1, hub->power_bits);
	port_dev->dev.parent = hub->intfdev;
	if (hub_is_superspeed(hdev)) {
		port_dev->usb3_lpm_u1_permit = 1;
		port_dev->usb3_lpm_u2_permit = 1;
		port_dev->dev.groups = port_dev_usb3_group;
	} else
		port_dev->dev.groups = port_dev_group;
	port_dev->dev.type = &usb_port_device_type;
	port_dev->dev.driver = &usb_port_driver;
	if (hub_is_superspeed(hub->hdev))
		port_dev->is_superspeed = 1;
	dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
			port1);
	mutex_init(&port_dev->status_lock);
	retval = device_register(&port_dev->dev);
	if (retval) {
		put_device(&port_dev->dev);
		return retval;
	}

	/* Set default policy of port-poweroff disabled. */
	retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
			DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
	if (retval < 0) {
		device_unregister(&port_dev->dev);
		return retval;
	}

	find_and_link_peer(hub, port1);

	/*
	 * Enable runtime pm and hold a refernce that hub_configure()
	 * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
	 * and the hub has been fully registered (hdev->maxchild set).
	 */
	pm_runtime_set_active(&port_dev->dev);
	pm_runtime_get_noresume(&port_dev->dev);
	pm_runtime_enable(&port_dev->dev);
	device_enable_async_suspend(&port_dev->dev);

	/*
	 * Keep hidden the ability to enable port-poweroff if the hub
	 * does not support power switching.
	 */
	if (!hub_is_port_power_switchable(hub))
		return 0;

	/* Attempt to let userspace take over the policy. */
	retval = dev_pm_qos_expose_flags(&port_dev->dev,
			PM_QOS_FLAG_NO_POWER_OFF);
	if (retval < 0) {
		dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
		return 0;
	}

	/* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
	retval = dev_pm_qos_remove_request(port_dev->req);
	if (retval >= 0) {
		kfree(port_dev->req);
		port_dev->req = NULL;
	}
	return 0;
}

void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
{
	struct usb_port *port_dev = hub->ports[port1 - 1];
	struct usb_port *peer;

	peer = port_dev->peer;
	if (peer)
		unlink_peers(port_dev, peer);
	device_unregister(&port_dev->dev);
}
OpenPOWER on IntegriCloud