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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * usb port device code
4 *
5 * Copyright (C) 2012 Intel Corp
6 *
7 * Author: Lan Tianyu <tianyu.lan@intel.com>
8 */
9
10#include <linux/kstrtox.h>
11#include <linux/slab.h>
12#include <linux/pm_qos.h>
13#include <linux/component.h>
14
15#include "hub.h"
16
17static int usb_port_block_power_off;
18
19static const struct attribute_group *port_dev_group[];
20
21static ssize_t early_stop_show(struct device *dev,
22 struct device_attribute *attr, char *buf)
23{
24 struct usb_port *port_dev = to_usb_port(dev);
25
26 return sysfs_emit(buf, "%s\n", port_dev->early_stop ? "yes" : "no");
27}
28
29static ssize_t early_stop_store(struct device *dev, struct device_attribute *attr,
30 const char *buf, size_t count)
31{
32 struct usb_port *port_dev = to_usb_port(dev);
33 bool value;
34
35 if (kstrtobool(buf, &value))
36 return -EINVAL;
37
38 if (value)
39 port_dev->early_stop = 1;
40 else
41 port_dev->early_stop = 0;
42
43 return count;
44}
45static DEVICE_ATTR_RW(early_stop);
46
47static ssize_t disable_show(struct device *dev,
48 struct device_attribute *attr, char *buf)
49{
50 struct usb_port *port_dev = to_usb_port(dev);
51 struct usb_device *hdev = to_usb_device(dev->parent->parent);
52 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
53 struct usb_interface *intf = to_usb_interface(hub->intfdev);
54 int port1 = port_dev->portnum;
55 u16 portstatus, unused;
56 bool disabled;
57 int rc;
58
59 rc = usb_autopm_get_interface(intf);
60 if (rc < 0)
61 return rc;
62
63 usb_lock_device(hdev);
64 if (hub->disconnected) {
65 rc = -ENODEV;
66 goto out_hdev_lock;
67 }
68
69 usb_hub_port_status(hub, port1, &portstatus, &unused);
70 disabled = !usb_port_is_power_on(hub, portstatus);
71
72out_hdev_lock:
73 usb_unlock_device(hdev);
74 usb_autopm_put_interface(intf);
75
76 if (rc)
77 return rc;
78
79 return sysfs_emit(buf, "%s\n", disabled ? "1" : "0");
80}
81
82static ssize_t disable_store(struct device *dev, struct device_attribute *attr,
83 const char *buf, size_t count)
84{
85 struct usb_port *port_dev = to_usb_port(dev);
86 struct usb_device *hdev = to_usb_device(dev->parent->parent);
87 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
88 struct usb_interface *intf = to_usb_interface(hub->intfdev);
89 int port1 = port_dev->portnum;
90 bool disabled;
91 int rc;
92
93 rc = kstrtobool(buf, &disabled);
94 if (rc)
95 return rc;
96
97 rc = usb_autopm_get_interface(intf);
98 if (rc < 0)
99 return rc;
100
101 usb_lock_device(hdev);
102 if (hub->disconnected) {
103 rc = -ENODEV;
104 goto out_hdev_lock;
105 }
106
107 if (disabled && port_dev->child)
108 usb_disconnect(&port_dev->child);
109
110 rc = usb_hub_set_port_power(hdev, hub, port1, !disabled);
111
112 if (disabled) {
113 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
114 if (!port_dev->is_superspeed)
115 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
116 }
117
118 if (!rc)
119 rc = count;
120
121out_hdev_lock:
122 usb_unlock_device(hdev);
123 usb_autopm_put_interface(intf);
124
125 return rc;
126}
127static DEVICE_ATTR_RW(disable);
128
129static ssize_t location_show(struct device *dev,
130 struct device_attribute *attr, char *buf)
131{
132 struct usb_port *port_dev = to_usb_port(dev);
133
134 return sprintf(buf, "0x%08x\n", port_dev->location);
135}
136static DEVICE_ATTR_RO(location);
137
138static ssize_t connect_type_show(struct device *dev,
139 struct device_attribute *attr, char *buf)
140{
141 struct usb_port *port_dev = to_usb_port(dev);
142 char *result;
143
144 switch (port_dev->connect_type) {
145 case USB_PORT_CONNECT_TYPE_HOT_PLUG:
146 result = "hotplug";
147 break;
148 case USB_PORT_CONNECT_TYPE_HARD_WIRED:
149 result = "hardwired";
150 break;
151 case USB_PORT_NOT_USED:
152 result = "not used";
153 break;
154 default:
155 result = "unknown";
156 break;
157 }
158
159 return sprintf(buf, "%s\n", result);
160}
161static DEVICE_ATTR_RO(connect_type);
162
163static ssize_t state_show(struct device *dev,
164 struct device_attribute *attr, char *buf)
165{
166 struct usb_port *port_dev = to_usb_port(dev);
167 enum usb_device_state state = READ_ONCE(port_dev->state);
168
169 return sysfs_emit(buf, "%s\n", usb_state_string(state));
170}
171static DEVICE_ATTR_RO(state);
172
173static ssize_t over_current_count_show(struct device *dev,
174 struct device_attribute *attr, char *buf)
175{
176 struct usb_port *port_dev = to_usb_port(dev);
177
178 return sprintf(buf, "%u\n", port_dev->over_current_count);
179}
180static DEVICE_ATTR_RO(over_current_count);
181
182static ssize_t quirks_show(struct device *dev,
183 struct device_attribute *attr, char *buf)
184{
185 struct usb_port *port_dev = to_usb_port(dev);
186
187 return sprintf(buf, "%08x\n", port_dev->quirks);
188}
189
190static ssize_t quirks_store(struct device *dev, struct device_attribute *attr,
191 const char *buf, size_t count)
192{
193 struct usb_port *port_dev = to_usb_port(dev);
194 u32 value;
195
196 if (kstrtou32(buf, 16, &value))
197 return -EINVAL;
198
199 port_dev->quirks = value;
200 return count;
201}
202static DEVICE_ATTR_RW(quirks);
203
204static ssize_t usb3_lpm_permit_show(struct device *dev,
205 struct device_attribute *attr, char *buf)
206{
207 struct usb_port *port_dev = to_usb_port(dev);
208 const char *p;
209
210 if (port_dev->usb3_lpm_u1_permit) {
211 if (port_dev->usb3_lpm_u2_permit)
212 p = "u1_u2";
213 else
214 p = "u1";
215 } else {
216 if (port_dev->usb3_lpm_u2_permit)
217 p = "u2";
218 else
219 p = "0";
220 }
221
222 return sprintf(buf, "%s\n", p);
223}
224
225static ssize_t usb3_lpm_permit_store(struct device *dev,
226 struct device_attribute *attr,
227 const char *buf, size_t count)
228{
229 struct usb_port *port_dev = to_usb_port(dev);
230 struct usb_device *udev = port_dev->child;
231 struct usb_hcd *hcd;
232
233 if (!strncmp(buf, "u1_u2", 5)) {
234 port_dev->usb3_lpm_u1_permit = 1;
235 port_dev->usb3_lpm_u2_permit = 1;
236
237 } else if (!strncmp(buf, "u1", 2)) {
238 port_dev->usb3_lpm_u1_permit = 1;
239 port_dev->usb3_lpm_u2_permit = 0;
240
241 } else if (!strncmp(buf, "u2", 2)) {
242 port_dev->usb3_lpm_u1_permit = 0;
243 port_dev->usb3_lpm_u2_permit = 1;
244
245 } else if (!strncmp(buf, "0", 1)) {
246 port_dev->usb3_lpm_u1_permit = 0;
247 port_dev->usb3_lpm_u2_permit = 0;
248 } else
249 return -EINVAL;
250
251 /* If device is connected to the port, disable or enable lpm
252 * to make new u1 u2 setting take effect immediately.
253 */
254 if (udev) {
255 hcd = bus_to_hcd(udev->bus);
256 if (!hcd)
257 return -EINVAL;
258 usb_lock_device(udev);
259 mutex_lock(hcd->bandwidth_mutex);
260 if (!usb_disable_lpm(udev))
261 usb_enable_lpm(udev);
262 mutex_unlock(hcd->bandwidth_mutex);
263 usb_unlock_device(udev);
264 }
265
266 return count;
267}
268static DEVICE_ATTR_RW(usb3_lpm_permit);
269
270static struct attribute *port_dev_attrs[] = {
271 &dev_attr_connect_type.attr,
272 &dev_attr_state.attr,
273 &dev_attr_location.attr,
274 &dev_attr_quirks.attr,
275 &dev_attr_over_current_count.attr,
276 &dev_attr_disable.attr,
277 &dev_attr_early_stop.attr,
278 NULL,
279};
280
281static const struct attribute_group port_dev_attr_grp = {
282 .attrs = port_dev_attrs,
283};
284
285static const struct attribute_group *port_dev_group[] = {
286 &port_dev_attr_grp,
287 NULL,
288};
289
290static struct attribute *port_dev_usb3_attrs[] = {
291 &dev_attr_usb3_lpm_permit.attr,
292 NULL,
293};
294
295static const struct attribute_group port_dev_usb3_attr_grp = {
296 .attrs = port_dev_usb3_attrs,
297};
298
299static const struct attribute_group *port_dev_usb3_group[] = {
300 &port_dev_attr_grp,
301 &port_dev_usb3_attr_grp,
302 NULL,
303};
304
305static void usb_port_device_release(struct device *dev)
306{
307 struct usb_port *port_dev = to_usb_port(dev);
308
309 kfree(port_dev->req);
310 kfree(port_dev);
311}
312
313#ifdef CONFIG_PM
314static int usb_port_runtime_resume(struct device *dev)
315{
316 struct usb_port *port_dev = to_usb_port(dev);
317 struct usb_device *hdev = to_usb_device(dev->parent->parent);
318 struct usb_interface *intf = to_usb_interface(dev->parent);
319 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
320 struct usb_device *udev = port_dev->child;
321 struct usb_port *peer = port_dev->peer;
322 int port1 = port_dev->portnum;
323 int retval;
324
325 if (!hub)
326 return -EINVAL;
327 if (hub->in_reset) {
328 set_bit(port1, hub->power_bits);
329 return 0;
330 }
331
332 /*
333 * Power on our usb3 peer before this usb2 port to prevent a usb3
334 * device from degrading to its usb2 connection
335 */
336 if (!port_dev->is_superspeed && peer)
337 pm_runtime_get_sync(&peer->dev);
338
339 retval = usb_autopm_get_interface(intf);
340 if (retval < 0)
341 return retval;
342
343 retval = usb_hub_set_port_power(hdev, hub, port1, true);
344 msleep(hub_power_on_good_delay(hub));
345 if (udev && !retval) {
346 /*
347 * Our preference is to simply wait for the port to reconnect,
348 * as that is the lowest latency method to restart the port.
349 * However, there are cases where toggling port power results in
350 * the host port and the device port getting out of sync causing
351 * a link training live lock. Upon timeout, flag the port as
352 * needing warm reset recovery (to be performed later by
353 * usb_port_resume() as requested via usb_wakeup_notification())
354 */
355 if (hub_port_debounce_be_connected(hub, port1) < 0) {
356 dev_dbg(&port_dev->dev, "reconnect timeout\n");
357 if (hub_is_superspeed(hdev))
358 set_bit(port1, hub->warm_reset_bits);
359 }
360
361 /* Force the child awake to revalidate after the power loss. */
362 if (!test_and_set_bit(port1, hub->child_usage_bits)) {
363 pm_runtime_get_noresume(&port_dev->dev);
364 pm_request_resume(&udev->dev);
365 }
366 }
367
368 usb_autopm_put_interface(intf);
369
370 return retval;
371}
372
373static int usb_port_runtime_suspend(struct device *dev)
374{
375 struct usb_port *port_dev = to_usb_port(dev);
376 struct usb_device *hdev = to_usb_device(dev->parent->parent);
377 struct usb_interface *intf = to_usb_interface(dev->parent);
378 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
379 struct usb_port *peer = port_dev->peer;
380 int port1 = port_dev->portnum;
381 int retval;
382
383 if (!hub)
384 return -EINVAL;
385 if (hub->in_reset)
386 return -EBUSY;
387
388 if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
389 == PM_QOS_FLAGS_ALL)
390 return -EAGAIN;
391
392 if (usb_port_block_power_off)
393 return -EBUSY;
394
395 retval = usb_autopm_get_interface(intf);
396 if (retval < 0)
397 return retval;
398
399 retval = usb_hub_set_port_power(hdev, hub, port1, false);
400 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
401 if (!port_dev->is_superspeed)
402 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
403 usb_autopm_put_interface(intf);
404
405 /*
406 * Our peer usb3 port may now be able to suspend, so
407 * asynchronously queue a suspend request to observe that this
408 * usb2 port is now off.
409 */
410 if (!port_dev->is_superspeed && peer)
411 pm_runtime_put(&peer->dev);
412
413 return retval;
414}
415#endif
416
417static void usb_port_shutdown(struct device *dev)
418{
419 struct usb_port *port_dev = to_usb_port(dev);
420
421 if (port_dev->child)
422 usb_disable_usb2_hardware_lpm(port_dev->child);
423}
424
425static const struct dev_pm_ops usb_port_pm_ops = {
426#ifdef CONFIG_PM
427 .runtime_suspend = usb_port_runtime_suspend,
428 .runtime_resume = usb_port_runtime_resume,
429#endif
430};
431
432struct device_type usb_port_device_type = {
433 .name = "usb_port",
434 .release = usb_port_device_release,
435 .pm = &usb_port_pm_ops,
436};
437
438static struct device_driver usb_port_driver = {
439 .name = "usb",
440 .owner = THIS_MODULE,
441 .shutdown = usb_port_shutdown,
442};
443
444static int link_peers(struct usb_port *left, struct usb_port *right)
445{
446 struct usb_port *ss_port, *hs_port;
447 int rc;
448
449 if (left->peer == right && right->peer == left)
450 return 0;
451
452 if (left->peer || right->peer) {
453 struct usb_port *lpeer = left->peer;
454 struct usb_port *rpeer = right->peer;
455 char *method;
456
457 if (left->location && left->location == right->location)
458 method = "location";
459 else
460 method = "default";
461
462 pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
463 dev_name(&left->dev), dev_name(&right->dev), method,
464 dev_name(&left->dev),
465 lpeer ? dev_name(&lpeer->dev) : "none",
466 dev_name(&right->dev),
467 rpeer ? dev_name(&rpeer->dev) : "none");
468 return -EBUSY;
469 }
470
471 rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
472 if (rc)
473 return rc;
474 rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
475 if (rc) {
476 sysfs_remove_link(&left->dev.kobj, "peer");
477 return rc;
478 }
479
480 /*
481 * We need to wake the HiSpeed port to make sure we don't race
482 * setting ->peer with usb_port_runtime_suspend(). Otherwise we
483 * may miss a suspend event for the SuperSpeed port.
484 */
485 if (left->is_superspeed) {
486 ss_port = left;
487 WARN_ON(right->is_superspeed);
488 hs_port = right;
489 } else {
490 ss_port = right;
491 WARN_ON(!right->is_superspeed);
492 hs_port = left;
493 }
494 pm_runtime_get_sync(&hs_port->dev);
495
496 left->peer = right;
497 right->peer = left;
498
499 /*
500 * The SuperSpeed reference is dropped when the HiSpeed port in
501 * this relationship suspends, i.e. when it is safe to allow a
502 * SuperSpeed connection to drop since there is no risk of a
503 * device degrading to its powered-off HiSpeed connection.
504 *
505 * Also, drop the HiSpeed ref taken above.
506 */
507 pm_runtime_get_sync(&ss_port->dev);
508 pm_runtime_put(&hs_port->dev);
509
510 return 0;
511}
512
513static void link_peers_report(struct usb_port *left, struct usb_port *right)
514{
515 int rc;
516
517 rc = link_peers(left, right);
518 if (rc == 0) {
519 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
520 } else {
521 dev_dbg(&left->dev, "failed to peer to %s (%d)\n",
522 dev_name(&right->dev), rc);
523 pr_warn_once("usb: port power management may be unreliable\n");
524 usb_port_block_power_off = 1;
525 }
526}
527
528static void unlink_peers(struct usb_port *left, struct usb_port *right)
529{
530 struct usb_port *ss_port, *hs_port;
531
532 WARN(right->peer != left || left->peer != right,
533 "%s and %s are not peers?\n",
534 dev_name(&left->dev), dev_name(&right->dev));
535
536 /*
537 * We wake the HiSpeed port to make sure we don't race its
538 * usb_port_runtime_resume() event which takes a SuperSpeed ref
539 * when ->peer is !NULL.
540 */
541 if (left->is_superspeed) {
542 ss_port = left;
543 hs_port = right;
544 } else {
545 ss_port = right;
546 hs_port = left;
547 }
548
549 pm_runtime_get_sync(&hs_port->dev);
550
551 sysfs_remove_link(&left->dev.kobj, "peer");
552 right->peer = NULL;
553 sysfs_remove_link(&right->dev.kobj, "peer");
554 left->peer = NULL;
555
556 /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
557 pm_runtime_put(&ss_port->dev);
558
559 /* Drop the ref taken above */
560 pm_runtime_put(&hs_port->dev);
561}
562
563/*
564 * For each usb hub device in the system check to see if it is in the
565 * peer domain of the given port_dev, and if it is check to see if it
566 * has a port that matches the given port by location
567 */
568static int match_location(struct usb_device *peer_hdev, void *p)
569{
570 int port1;
571 struct usb_hcd *hcd, *peer_hcd;
572 struct usb_port *port_dev = p, *peer;
573 struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
574 struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
575
576 if (!peer_hub || port_dev->connect_type == USB_PORT_NOT_USED)
577 return 0;
578
579 hcd = bus_to_hcd(hdev->bus);
580 peer_hcd = bus_to_hcd(peer_hdev->bus);
581 /* peer_hcd is provisional until we verify it against the known peer */
582 if (peer_hcd != hcd->shared_hcd)
583 return 0;
584
585 for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
586 peer = peer_hub->ports[port1 - 1];
587 if (peer && peer->connect_type != USB_PORT_NOT_USED &&
588 peer->location == port_dev->location) {
589 link_peers_report(port_dev, peer);
590 return 1; /* done */
591 }
592 }
593
594 return 0;
595}
596
597/*
598 * Find the peer port either via explicit platform firmware "location"
599 * data, the peer hcd for root hubs, or the upstream peer relationship
600 * for all other hubs.
601 */
602static void find_and_link_peer(struct usb_hub *hub, int port1)
603{
604 struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
605 struct usb_device *hdev = hub->hdev;
606 struct usb_device *peer_hdev;
607 struct usb_hub *peer_hub;
608
609 /*
610 * If location data is available then we can only peer this port
611 * by a location match, not the default peer (lest we create a
612 * situation where we need to go back and undo a default peering
613 * when the port is later peered by location data)
614 */
615 if (port_dev->location) {
616 /* we link the peer in match_location() if found */
617 usb_for_each_dev(port_dev, match_location);
618 return;
619 } else if (!hdev->parent) {
620 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
621 struct usb_hcd *peer_hcd = hcd->shared_hcd;
622
623 if (!peer_hcd)
624 return;
625
626 peer_hdev = peer_hcd->self.root_hub;
627 } else {
628 struct usb_port *upstream;
629 struct usb_device *parent = hdev->parent;
630 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
631
632 if (!parent_hub)
633 return;
634
635 upstream = parent_hub->ports[hdev->portnum - 1];
636 if (!upstream || !upstream->peer)
637 return;
638
639 peer_hdev = upstream->peer->child;
640 }
641
642 peer_hub = usb_hub_to_struct_hub(peer_hdev);
643 if (!peer_hub || port1 > peer_hdev->maxchild)
644 return;
645
646 /*
647 * we found a valid default peer, last check is to make sure it
648 * does not have location data
649 */
650 peer = peer_hub->ports[port1 - 1];
651 if (peer && peer->location == 0)
652 link_peers_report(port_dev, peer);
653}
654
655static int connector_bind(struct device *dev, struct device *connector, void *data)
656{
657 struct usb_port *port_dev = to_usb_port(dev);
658 int ret;
659
660 ret = sysfs_create_link(&dev->kobj, &connector->kobj, "connector");
661 if (ret)
662 return ret;
663
664 ret = sysfs_create_link(&connector->kobj, &dev->kobj, dev_name(dev));
665 if (ret) {
666 sysfs_remove_link(&dev->kobj, "connector");
667 return ret;
668 }
669
670 port_dev->connector = data;
671
672 /*
673 * If there is already USB device connected to the port, letting the
674 * Type-C connector know about it immediately.
675 */
676 if (port_dev->child)
677 typec_attach(port_dev->connector, &port_dev->child->dev);
678
679 return 0;
680}
681
682static void connector_unbind(struct device *dev, struct device *connector, void *data)
683{
684 struct usb_port *port_dev = to_usb_port(dev);
685
686 sysfs_remove_link(&connector->kobj, dev_name(dev));
687 sysfs_remove_link(&dev->kobj, "connector");
688 port_dev->connector = NULL;
689}
690
691static const struct component_ops connector_ops = {
692 .bind = connector_bind,
693 .unbind = connector_unbind,
694};
695
696int usb_hub_create_port_device(struct usb_hub *hub, int port1)
697{
698 struct usb_port *port_dev;
699 struct usb_device *hdev = hub->hdev;
700 int retval;
701
702 port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
703 if (!port_dev)
704 return -ENOMEM;
705
706 port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
707 if (!port_dev->req) {
708 kfree(port_dev);
709 return -ENOMEM;
710 }
711
712 hub->ports[port1 - 1] = port_dev;
713 port_dev->portnum = port1;
714 set_bit(port1, hub->power_bits);
715 port_dev->dev.parent = hub->intfdev;
716 if (hub_is_superspeed(hdev)) {
717 port_dev->is_superspeed = 1;
718 port_dev->usb3_lpm_u1_permit = 1;
719 port_dev->usb3_lpm_u2_permit = 1;
720 port_dev->dev.groups = port_dev_usb3_group;
721 } else
722 port_dev->dev.groups = port_dev_group;
723 port_dev->dev.type = &usb_port_device_type;
724 port_dev->dev.driver = &usb_port_driver;
725 dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
726 port1);
727 mutex_init(&port_dev->status_lock);
728 retval = device_register(&port_dev->dev);
729 if (retval) {
730 put_device(&port_dev->dev);
731 return retval;
732 }
733
734 port_dev->state_kn = sysfs_get_dirent(port_dev->dev.kobj.sd, "state");
735 if (!port_dev->state_kn) {
736 dev_err(&port_dev->dev, "failed to sysfs_get_dirent 'state'\n");
737 retval = -ENODEV;
738 goto err_unregister;
739 }
740
741 /* Set default policy of port-poweroff disabled. */
742 retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
743 DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
744 if (retval < 0) {
745 goto err_put_kn;
746 }
747
748 retval = component_add(&port_dev->dev, &connector_ops);
749 if (retval) {
750 dev_warn(&port_dev->dev, "failed to add component\n");
751 goto err_put_kn;
752 }
753
754 find_and_link_peer(hub, port1);
755
756 /*
757 * Enable runtime pm and hold a refernce that hub_configure()
758 * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
759 * and the hub has been fully registered (hdev->maxchild set).
760 */
761 pm_runtime_set_active(&port_dev->dev);
762 pm_runtime_get_noresume(&port_dev->dev);
763 pm_runtime_enable(&port_dev->dev);
764 device_enable_async_suspend(&port_dev->dev);
765
766 /*
767 * Keep hidden the ability to enable port-poweroff if the hub
768 * does not support power switching.
769 */
770 if (!hub_is_port_power_switchable(hub))
771 return 0;
772
773 /* Attempt to let userspace take over the policy. */
774 retval = dev_pm_qos_expose_flags(&port_dev->dev,
775 PM_QOS_FLAG_NO_POWER_OFF);
776 if (retval < 0) {
777 dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
778 return 0;
779 }
780
781 /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
782 retval = dev_pm_qos_remove_request(port_dev->req);
783 if (retval >= 0) {
784 kfree(port_dev->req);
785 port_dev->req = NULL;
786 }
787 return 0;
788
789err_put_kn:
790 sysfs_put(port_dev->state_kn);
791err_unregister:
792 device_unregister(&port_dev->dev);
793
794 return retval;
795}
796
797void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
798{
799 struct usb_port *port_dev = hub->ports[port1 - 1];
800 struct usb_port *peer;
801
802 peer = port_dev->peer;
803 if (peer)
804 unlink_peers(port_dev, peer);
805 component_del(&port_dev->dev, &connector_ops);
806 sysfs_put(port_dev->state_kn);
807 device_unregister(&port_dev->dev);
808}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * usb port device code
4 *
5 * Copyright (C) 2012 Intel Corp
6 *
7 * Author: Lan Tianyu <tianyu.lan@intel.com>
8 */
9
10#include <linux/slab.h>
11#include <linux/pm_qos.h>
12
13#include "hub.h"
14
15static int usb_port_block_power_off;
16
17static const struct attribute_group *port_dev_group[];
18
19static ssize_t connect_type_show(struct device *dev,
20 struct device_attribute *attr, char *buf)
21{
22 struct usb_port *port_dev = to_usb_port(dev);
23 char *result;
24
25 switch (port_dev->connect_type) {
26 case USB_PORT_CONNECT_TYPE_HOT_PLUG:
27 result = "hotplug";
28 break;
29 case USB_PORT_CONNECT_TYPE_HARD_WIRED:
30 result = "hardwired";
31 break;
32 case USB_PORT_NOT_USED:
33 result = "not used";
34 break;
35 default:
36 result = "unknown";
37 break;
38 }
39
40 return sprintf(buf, "%s\n", result);
41}
42static DEVICE_ATTR_RO(connect_type);
43
44static ssize_t over_current_count_show(struct device *dev,
45 struct device_attribute *attr, char *buf)
46{
47 struct usb_port *port_dev = to_usb_port(dev);
48
49 return sprintf(buf, "%u\n", port_dev->over_current_count);
50}
51static DEVICE_ATTR_RO(over_current_count);
52
53static ssize_t usb3_lpm_permit_show(struct device *dev,
54 struct device_attribute *attr, char *buf)
55{
56 struct usb_port *port_dev = to_usb_port(dev);
57 const char *p;
58
59 if (port_dev->usb3_lpm_u1_permit) {
60 if (port_dev->usb3_lpm_u2_permit)
61 p = "u1_u2";
62 else
63 p = "u1";
64 } else {
65 if (port_dev->usb3_lpm_u2_permit)
66 p = "u2";
67 else
68 p = "0";
69 }
70
71 return sprintf(buf, "%s\n", p);
72}
73
74static ssize_t usb3_lpm_permit_store(struct device *dev,
75 struct device_attribute *attr,
76 const char *buf, size_t count)
77{
78 struct usb_port *port_dev = to_usb_port(dev);
79 struct usb_device *udev = port_dev->child;
80 struct usb_hcd *hcd;
81
82 if (!strncmp(buf, "u1_u2", 5)) {
83 port_dev->usb3_lpm_u1_permit = 1;
84 port_dev->usb3_lpm_u2_permit = 1;
85
86 } else if (!strncmp(buf, "u1", 2)) {
87 port_dev->usb3_lpm_u1_permit = 1;
88 port_dev->usb3_lpm_u2_permit = 0;
89
90 } else if (!strncmp(buf, "u2", 2)) {
91 port_dev->usb3_lpm_u1_permit = 0;
92 port_dev->usb3_lpm_u2_permit = 1;
93
94 } else if (!strncmp(buf, "0", 1)) {
95 port_dev->usb3_lpm_u1_permit = 0;
96 port_dev->usb3_lpm_u2_permit = 0;
97 } else
98 return -EINVAL;
99
100 /* If device is connected to the port, disable or enable lpm
101 * to make new u1 u2 setting take effect immediately.
102 */
103 if (udev) {
104 hcd = bus_to_hcd(udev->bus);
105 if (!hcd)
106 return -EINVAL;
107 usb_lock_device(udev);
108 mutex_lock(hcd->bandwidth_mutex);
109 if (!usb_disable_lpm(udev))
110 usb_enable_lpm(udev);
111 mutex_unlock(hcd->bandwidth_mutex);
112 usb_unlock_device(udev);
113 }
114
115 return count;
116}
117static DEVICE_ATTR_RW(usb3_lpm_permit);
118
119static struct attribute *port_dev_attrs[] = {
120 &dev_attr_connect_type.attr,
121 &dev_attr_over_current_count.attr,
122 NULL,
123};
124
125static struct attribute_group port_dev_attr_grp = {
126 .attrs = port_dev_attrs,
127};
128
129static const struct attribute_group *port_dev_group[] = {
130 &port_dev_attr_grp,
131 NULL,
132};
133
134static struct attribute *port_dev_usb3_attrs[] = {
135 &dev_attr_usb3_lpm_permit.attr,
136 NULL,
137};
138
139static struct attribute_group port_dev_usb3_attr_grp = {
140 .attrs = port_dev_usb3_attrs,
141};
142
143static const struct attribute_group *port_dev_usb3_group[] = {
144 &port_dev_attr_grp,
145 &port_dev_usb3_attr_grp,
146 NULL,
147};
148
149static void usb_port_device_release(struct device *dev)
150{
151 struct usb_port *port_dev = to_usb_port(dev);
152
153 kfree(port_dev->req);
154 kfree(port_dev);
155}
156
157#ifdef CONFIG_PM
158static int usb_port_runtime_resume(struct device *dev)
159{
160 struct usb_port *port_dev = to_usb_port(dev);
161 struct usb_device *hdev = to_usb_device(dev->parent->parent);
162 struct usb_interface *intf = to_usb_interface(dev->parent);
163 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
164 struct usb_device *udev = port_dev->child;
165 struct usb_port *peer = port_dev->peer;
166 int port1 = port_dev->portnum;
167 int retval;
168
169 if (!hub)
170 return -EINVAL;
171 if (hub->in_reset) {
172 set_bit(port1, hub->power_bits);
173 return 0;
174 }
175
176 /*
177 * Power on our usb3 peer before this usb2 port to prevent a usb3
178 * device from degrading to its usb2 connection
179 */
180 if (!port_dev->is_superspeed && peer)
181 pm_runtime_get_sync(&peer->dev);
182
183 usb_autopm_get_interface(intf);
184 retval = usb_hub_set_port_power(hdev, hub, port1, true);
185 msleep(hub_power_on_good_delay(hub));
186 if (udev && !retval) {
187 /*
188 * Our preference is to simply wait for the port to reconnect,
189 * as that is the lowest latency method to restart the port.
190 * However, there are cases where toggling port power results in
191 * the host port and the device port getting out of sync causing
192 * a link training live lock. Upon timeout, flag the port as
193 * needing warm reset recovery (to be performed later by
194 * usb_port_resume() as requested via usb_wakeup_notification())
195 */
196 if (hub_port_debounce_be_connected(hub, port1) < 0) {
197 dev_dbg(&port_dev->dev, "reconnect timeout\n");
198 if (hub_is_superspeed(hdev))
199 set_bit(port1, hub->warm_reset_bits);
200 }
201
202 /* Force the child awake to revalidate after the power loss. */
203 if (!test_and_set_bit(port1, hub->child_usage_bits)) {
204 pm_runtime_get_noresume(&port_dev->dev);
205 pm_request_resume(&udev->dev);
206 }
207 }
208
209 usb_autopm_put_interface(intf);
210
211 return retval;
212}
213
214static int usb_port_runtime_suspend(struct device *dev)
215{
216 struct usb_port *port_dev = to_usb_port(dev);
217 struct usb_device *hdev = to_usb_device(dev->parent->parent);
218 struct usb_interface *intf = to_usb_interface(dev->parent);
219 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
220 struct usb_port *peer = port_dev->peer;
221 int port1 = port_dev->portnum;
222 int retval;
223
224 if (!hub)
225 return -EINVAL;
226 if (hub->in_reset)
227 return -EBUSY;
228
229 if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
230 == PM_QOS_FLAGS_ALL)
231 return -EAGAIN;
232
233 if (usb_port_block_power_off)
234 return -EBUSY;
235
236 usb_autopm_get_interface(intf);
237 retval = usb_hub_set_port_power(hdev, hub, port1, false);
238 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
239 if (!port_dev->is_superspeed)
240 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
241 usb_autopm_put_interface(intf);
242
243 /*
244 * Our peer usb3 port may now be able to suspend, so
245 * asynchronously queue a suspend request to observe that this
246 * usb2 port is now off.
247 */
248 if (!port_dev->is_superspeed && peer)
249 pm_runtime_put(&peer->dev);
250
251 return retval;
252}
253#endif
254
255static const struct dev_pm_ops usb_port_pm_ops = {
256#ifdef CONFIG_PM
257 .runtime_suspend = usb_port_runtime_suspend,
258 .runtime_resume = usb_port_runtime_resume,
259#endif
260};
261
262struct device_type usb_port_device_type = {
263 .name = "usb_port",
264 .release = usb_port_device_release,
265 .pm = &usb_port_pm_ops,
266};
267
268static struct device_driver usb_port_driver = {
269 .name = "usb",
270 .owner = THIS_MODULE,
271};
272
273static int link_peers(struct usb_port *left, struct usb_port *right)
274{
275 struct usb_port *ss_port, *hs_port;
276 int rc;
277
278 if (left->peer == right && right->peer == left)
279 return 0;
280
281 if (left->peer || right->peer) {
282 struct usb_port *lpeer = left->peer;
283 struct usb_port *rpeer = right->peer;
284 char *method;
285
286 if (left->location && left->location == right->location)
287 method = "location";
288 else
289 method = "default";
290
291 pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
292 dev_name(&left->dev), dev_name(&right->dev), method,
293 dev_name(&left->dev),
294 lpeer ? dev_name(&lpeer->dev) : "none",
295 dev_name(&right->dev),
296 rpeer ? dev_name(&rpeer->dev) : "none");
297 return -EBUSY;
298 }
299
300 rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
301 if (rc)
302 return rc;
303 rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
304 if (rc) {
305 sysfs_remove_link(&left->dev.kobj, "peer");
306 return rc;
307 }
308
309 /*
310 * We need to wake the HiSpeed port to make sure we don't race
311 * setting ->peer with usb_port_runtime_suspend(). Otherwise we
312 * may miss a suspend event for the SuperSpeed port.
313 */
314 if (left->is_superspeed) {
315 ss_port = left;
316 WARN_ON(right->is_superspeed);
317 hs_port = right;
318 } else {
319 ss_port = right;
320 WARN_ON(!right->is_superspeed);
321 hs_port = left;
322 }
323 pm_runtime_get_sync(&hs_port->dev);
324
325 left->peer = right;
326 right->peer = left;
327
328 /*
329 * The SuperSpeed reference is dropped when the HiSpeed port in
330 * this relationship suspends, i.e. when it is safe to allow a
331 * SuperSpeed connection to drop since there is no risk of a
332 * device degrading to its powered-off HiSpeed connection.
333 *
334 * Also, drop the HiSpeed ref taken above.
335 */
336 pm_runtime_get_sync(&ss_port->dev);
337 pm_runtime_put(&hs_port->dev);
338
339 return 0;
340}
341
342static void link_peers_report(struct usb_port *left, struct usb_port *right)
343{
344 int rc;
345
346 rc = link_peers(left, right);
347 if (rc == 0) {
348 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
349 } else {
350 dev_dbg(&left->dev, "failed to peer to %s (%d)\n",
351 dev_name(&right->dev), rc);
352 pr_warn_once("usb: port power management may be unreliable\n");
353 usb_port_block_power_off = 1;
354 }
355}
356
357static void unlink_peers(struct usb_port *left, struct usb_port *right)
358{
359 struct usb_port *ss_port, *hs_port;
360
361 WARN(right->peer != left || left->peer != right,
362 "%s and %s are not peers?\n",
363 dev_name(&left->dev), dev_name(&right->dev));
364
365 /*
366 * We wake the HiSpeed port to make sure we don't race its
367 * usb_port_runtime_resume() event which takes a SuperSpeed ref
368 * when ->peer is !NULL.
369 */
370 if (left->is_superspeed) {
371 ss_port = left;
372 hs_port = right;
373 } else {
374 ss_port = right;
375 hs_port = left;
376 }
377
378 pm_runtime_get_sync(&hs_port->dev);
379
380 sysfs_remove_link(&left->dev.kobj, "peer");
381 right->peer = NULL;
382 sysfs_remove_link(&right->dev.kobj, "peer");
383 left->peer = NULL;
384
385 /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
386 pm_runtime_put(&ss_port->dev);
387
388 /* Drop the ref taken above */
389 pm_runtime_put(&hs_port->dev);
390}
391
392/*
393 * For each usb hub device in the system check to see if it is in the
394 * peer domain of the given port_dev, and if it is check to see if it
395 * has a port that matches the given port by location
396 */
397static int match_location(struct usb_device *peer_hdev, void *p)
398{
399 int port1;
400 struct usb_hcd *hcd, *peer_hcd;
401 struct usb_port *port_dev = p, *peer;
402 struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
403 struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
404
405 if (!peer_hub)
406 return 0;
407
408 hcd = bus_to_hcd(hdev->bus);
409 peer_hcd = bus_to_hcd(peer_hdev->bus);
410 /* peer_hcd is provisional until we verify it against the known peer */
411 if (peer_hcd != hcd->shared_hcd)
412 return 0;
413
414 for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
415 peer = peer_hub->ports[port1 - 1];
416 if (peer && peer->location == port_dev->location) {
417 link_peers_report(port_dev, peer);
418 return 1; /* done */
419 }
420 }
421
422 return 0;
423}
424
425/*
426 * Find the peer port either via explicit platform firmware "location"
427 * data, the peer hcd for root hubs, or the upstream peer relationship
428 * for all other hubs.
429 */
430static void find_and_link_peer(struct usb_hub *hub, int port1)
431{
432 struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
433 struct usb_device *hdev = hub->hdev;
434 struct usb_device *peer_hdev;
435 struct usb_hub *peer_hub;
436
437 /*
438 * If location data is available then we can only peer this port
439 * by a location match, not the default peer (lest we create a
440 * situation where we need to go back and undo a default peering
441 * when the port is later peered by location data)
442 */
443 if (port_dev->location) {
444 /* we link the peer in match_location() if found */
445 usb_for_each_dev(port_dev, match_location);
446 return;
447 } else if (!hdev->parent) {
448 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
449 struct usb_hcd *peer_hcd = hcd->shared_hcd;
450
451 if (!peer_hcd)
452 return;
453
454 peer_hdev = peer_hcd->self.root_hub;
455 } else {
456 struct usb_port *upstream;
457 struct usb_device *parent = hdev->parent;
458 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
459
460 if (!parent_hub)
461 return;
462
463 upstream = parent_hub->ports[hdev->portnum - 1];
464 if (!upstream || !upstream->peer)
465 return;
466
467 peer_hdev = upstream->peer->child;
468 }
469
470 peer_hub = usb_hub_to_struct_hub(peer_hdev);
471 if (!peer_hub || port1 > peer_hdev->maxchild)
472 return;
473
474 /*
475 * we found a valid default peer, last check is to make sure it
476 * does not have location data
477 */
478 peer = peer_hub->ports[port1 - 1];
479 if (peer && peer->location == 0)
480 link_peers_report(port_dev, peer);
481}
482
483int usb_hub_create_port_device(struct usb_hub *hub, int port1)
484{
485 struct usb_port *port_dev;
486 struct usb_device *hdev = hub->hdev;
487 int retval;
488
489 port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
490 if (!port_dev)
491 return -ENOMEM;
492
493 port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
494 if (!port_dev->req) {
495 kfree(port_dev);
496 return -ENOMEM;
497 }
498
499 hub->ports[port1 - 1] = port_dev;
500 port_dev->portnum = port1;
501 set_bit(port1, hub->power_bits);
502 port_dev->dev.parent = hub->intfdev;
503 if (hub_is_superspeed(hdev)) {
504 port_dev->usb3_lpm_u1_permit = 1;
505 port_dev->usb3_lpm_u2_permit = 1;
506 port_dev->dev.groups = port_dev_usb3_group;
507 } else
508 port_dev->dev.groups = port_dev_group;
509 port_dev->dev.type = &usb_port_device_type;
510 port_dev->dev.driver = &usb_port_driver;
511 if (hub_is_superspeed(hub->hdev))
512 port_dev->is_superspeed = 1;
513 dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
514 port1);
515 mutex_init(&port_dev->status_lock);
516 retval = device_register(&port_dev->dev);
517 if (retval) {
518 put_device(&port_dev->dev);
519 return retval;
520 }
521
522 /* Set default policy of port-poweroff disabled. */
523 retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
524 DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
525 if (retval < 0) {
526 device_unregister(&port_dev->dev);
527 return retval;
528 }
529
530 find_and_link_peer(hub, port1);
531
532 /*
533 * Enable runtime pm and hold a refernce that hub_configure()
534 * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
535 * and the hub has been fully registered (hdev->maxchild set).
536 */
537 pm_runtime_set_active(&port_dev->dev);
538 pm_runtime_get_noresume(&port_dev->dev);
539 pm_runtime_enable(&port_dev->dev);
540 device_enable_async_suspend(&port_dev->dev);
541
542 /*
543 * Keep hidden the ability to enable port-poweroff if the hub
544 * does not support power switching.
545 */
546 if (!hub_is_port_power_switchable(hub))
547 return 0;
548
549 /* Attempt to let userspace take over the policy. */
550 retval = dev_pm_qos_expose_flags(&port_dev->dev,
551 PM_QOS_FLAG_NO_POWER_OFF);
552 if (retval < 0) {
553 dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
554 return 0;
555 }
556
557 /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
558 retval = dev_pm_qos_remove_request(port_dev->req);
559 if (retval >= 0) {
560 kfree(port_dev->req);
561 port_dev->req = NULL;
562 }
563 return 0;
564}
565
566void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
567{
568 struct usb_port *port_dev = hub->ports[port1 - 1];
569 struct usb_port *peer;
570
571 peer = port_dev->peer;
572 if (peer)
573 unlink_peers(port_dev, peer);
574 device_unregister(&port_dev->dev);
575}