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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/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 location_show(struct device *dev,
20 struct device_attribute *attr, char *buf)
21{
22 struct usb_port *port_dev = to_usb_port(dev);
23
24 return sprintf(buf, "0x%08x\n", port_dev->location);
25}
26static DEVICE_ATTR_RO(location);
27
28static ssize_t connect_type_show(struct device *dev,
29 struct device_attribute *attr, char *buf)
30{
31 struct usb_port *port_dev = to_usb_port(dev);
32 char *result;
33
34 switch (port_dev->connect_type) {
35 case USB_PORT_CONNECT_TYPE_HOT_PLUG:
36 result = "hotplug";
37 break;
38 case USB_PORT_CONNECT_TYPE_HARD_WIRED:
39 result = "hardwired";
40 break;
41 case USB_PORT_NOT_USED:
42 result = "not used";
43 break;
44 default:
45 result = "unknown";
46 break;
47 }
48
49 return sprintf(buf, "%s\n", result);
50}
51static DEVICE_ATTR_RO(connect_type);
52
53static ssize_t over_current_count_show(struct device *dev,
54 struct device_attribute *attr, char *buf)
55{
56 struct usb_port *port_dev = to_usb_port(dev);
57
58 return sprintf(buf, "%u\n", port_dev->over_current_count);
59}
60static DEVICE_ATTR_RO(over_current_count);
61
62static ssize_t quirks_show(struct device *dev,
63 struct device_attribute *attr, char *buf)
64{
65 struct usb_port *port_dev = to_usb_port(dev);
66
67 return sprintf(buf, "%08x\n", port_dev->quirks);
68}
69
70static ssize_t quirks_store(struct device *dev, struct device_attribute *attr,
71 const char *buf, size_t count)
72{
73 struct usb_port *port_dev = to_usb_port(dev);
74 u32 value;
75
76 if (kstrtou32(buf, 16, &value))
77 return -EINVAL;
78
79 port_dev->quirks = value;
80 return count;
81}
82static DEVICE_ATTR_RW(quirks);
83
84static ssize_t usb3_lpm_permit_show(struct device *dev,
85 struct device_attribute *attr, char *buf)
86{
87 struct usb_port *port_dev = to_usb_port(dev);
88 const char *p;
89
90 if (port_dev->usb3_lpm_u1_permit) {
91 if (port_dev->usb3_lpm_u2_permit)
92 p = "u1_u2";
93 else
94 p = "u1";
95 } else {
96 if (port_dev->usb3_lpm_u2_permit)
97 p = "u2";
98 else
99 p = "0";
100 }
101
102 return sprintf(buf, "%s\n", p);
103}
104
105static ssize_t usb3_lpm_permit_store(struct device *dev,
106 struct device_attribute *attr,
107 const char *buf, size_t count)
108{
109 struct usb_port *port_dev = to_usb_port(dev);
110 struct usb_device *udev = port_dev->child;
111 struct usb_hcd *hcd;
112
113 if (!strncmp(buf, "u1_u2", 5)) {
114 port_dev->usb3_lpm_u1_permit = 1;
115 port_dev->usb3_lpm_u2_permit = 1;
116
117 } else if (!strncmp(buf, "u1", 2)) {
118 port_dev->usb3_lpm_u1_permit = 1;
119 port_dev->usb3_lpm_u2_permit = 0;
120
121 } else if (!strncmp(buf, "u2", 2)) {
122 port_dev->usb3_lpm_u1_permit = 0;
123 port_dev->usb3_lpm_u2_permit = 1;
124
125 } else if (!strncmp(buf, "0", 1)) {
126 port_dev->usb3_lpm_u1_permit = 0;
127 port_dev->usb3_lpm_u2_permit = 0;
128 } else
129 return -EINVAL;
130
131 /* If device is connected to the port, disable or enable lpm
132 * to make new u1 u2 setting take effect immediately.
133 */
134 if (udev) {
135 hcd = bus_to_hcd(udev->bus);
136 if (!hcd)
137 return -EINVAL;
138 usb_lock_device(udev);
139 mutex_lock(hcd->bandwidth_mutex);
140 if (!usb_disable_lpm(udev))
141 usb_enable_lpm(udev);
142 mutex_unlock(hcd->bandwidth_mutex);
143 usb_unlock_device(udev);
144 }
145
146 return count;
147}
148static DEVICE_ATTR_RW(usb3_lpm_permit);
149
150static struct attribute *port_dev_attrs[] = {
151 &dev_attr_connect_type.attr,
152 &dev_attr_location.attr,
153 &dev_attr_quirks.attr,
154 &dev_attr_over_current_count.attr,
155 NULL,
156};
157
158static struct attribute_group port_dev_attr_grp = {
159 .attrs = port_dev_attrs,
160};
161
162static const struct attribute_group *port_dev_group[] = {
163 &port_dev_attr_grp,
164 NULL,
165};
166
167static struct attribute *port_dev_usb3_attrs[] = {
168 &dev_attr_usb3_lpm_permit.attr,
169 NULL,
170};
171
172static struct attribute_group port_dev_usb3_attr_grp = {
173 .attrs = port_dev_usb3_attrs,
174};
175
176static const struct attribute_group *port_dev_usb3_group[] = {
177 &port_dev_attr_grp,
178 &port_dev_usb3_attr_grp,
179 NULL,
180};
181
182static void usb_port_device_release(struct device *dev)
183{
184 struct usb_port *port_dev = to_usb_port(dev);
185
186 kfree(port_dev->req);
187 kfree(port_dev);
188}
189
190#ifdef CONFIG_PM
191static int usb_port_runtime_resume(struct device *dev)
192{
193 struct usb_port *port_dev = to_usb_port(dev);
194 struct usb_device *hdev = to_usb_device(dev->parent->parent);
195 struct usb_interface *intf = to_usb_interface(dev->parent);
196 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
197 struct usb_device *udev = port_dev->child;
198 struct usb_port *peer = port_dev->peer;
199 int port1 = port_dev->portnum;
200 int retval;
201
202 if (!hub)
203 return -EINVAL;
204 if (hub->in_reset) {
205 set_bit(port1, hub->power_bits);
206 return 0;
207 }
208
209 /*
210 * Power on our usb3 peer before this usb2 port to prevent a usb3
211 * device from degrading to its usb2 connection
212 */
213 if (!port_dev->is_superspeed && peer)
214 pm_runtime_get_sync(&peer->dev);
215
216 retval = usb_autopm_get_interface(intf);
217 if (retval < 0)
218 return retval;
219
220 retval = usb_hub_set_port_power(hdev, hub, port1, true);
221 msleep(hub_power_on_good_delay(hub));
222 if (udev && !retval) {
223 /*
224 * Our preference is to simply wait for the port to reconnect,
225 * as that is the lowest latency method to restart the port.
226 * However, there are cases where toggling port power results in
227 * the host port and the device port getting out of sync causing
228 * a link training live lock. Upon timeout, flag the port as
229 * needing warm reset recovery (to be performed later by
230 * usb_port_resume() as requested via usb_wakeup_notification())
231 */
232 if (hub_port_debounce_be_connected(hub, port1) < 0) {
233 dev_dbg(&port_dev->dev, "reconnect timeout\n");
234 if (hub_is_superspeed(hdev))
235 set_bit(port1, hub->warm_reset_bits);
236 }
237
238 /* Force the child awake to revalidate after the power loss. */
239 if (!test_and_set_bit(port1, hub->child_usage_bits)) {
240 pm_runtime_get_noresume(&port_dev->dev);
241 pm_request_resume(&udev->dev);
242 }
243 }
244
245 usb_autopm_put_interface(intf);
246
247 return retval;
248}
249
250static int usb_port_runtime_suspend(struct device *dev)
251{
252 struct usb_port *port_dev = to_usb_port(dev);
253 struct usb_device *hdev = to_usb_device(dev->parent->parent);
254 struct usb_interface *intf = to_usb_interface(dev->parent);
255 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
256 struct usb_port *peer = port_dev->peer;
257 int port1 = port_dev->portnum;
258 int retval;
259
260 if (!hub)
261 return -EINVAL;
262 if (hub->in_reset)
263 return -EBUSY;
264
265 if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
266 == PM_QOS_FLAGS_ALL)
267 return -EAGAIN;
268
269 if (usb_port_block_power_off)
270 return -EBUSY;
271
272 retval = usb_autopm_get_interface(intf);
273 if (retval < 0)
274 return retval;
275
276 retval = usb_hub_set_port_power(hdev, hub, port1, false);
277 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
278 if (!port_dev->is_superspeed)
279 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
280 usb_autopm_put_interface(intf);
281
282 /*
283 * Our peer usb3 port may now be able to suspend, so
284 * asynchronously queue a suspend request to observe that this
285 * usb2 port is now off.
286 */
287 if (!port_dev->is_superspeed && peer)
288 pm_runtime_put(&peer->dev);
289
290 return retval;
291}
292#endif
293
294static void usb_port_shutdown(struct device *dev)
295{
296 struct usb_port *port_dev = to_usb_port(dev);
297
298 if (port_dev->child)
299 usb_disable_usb2_hardware_lpm(port_dev->child);
300}
301
302static const struct dev_pm_ops usb_port_pm_ops = {
303#ifdef CONFIG_PM
304 .runtime_suspend = usb_port_runtime_suspend,
305 .runtime_resume = usb_port_runtime_resume,
306#endif
307};
308
309struct device_type usb_port_device_type = {
310 .name = "usb_port",
311 .release = usb_port_device_release,
312 .pm = &usb_port_pm_ops,
313};
314
315static struct device_driver usb_port_driver = {
316 .name = "usb",
317 .owner = THIS_MODULE,
318 .shutdown = usb_port_shutdown,
319};
320
321static int link_peers(struct usb_port *left, struct usb_port *right)
322{
323 struct usb_port *ss_port, *hs_port;
324 int rc;
325
326 if (left->peer == right && right->peer == left)
327 return 0;
328
329 if (left->peer || right->peer) {
330 struct usb_port *lpeer = left->peer;
331 struct usb_port *rpeer = right->peer;
332 char *method;
333
334 if (left->location && left->location == right->location)
335 method = "location";
336 else
337 method = "default";
338
339 pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
340 dev_name(&left->dev), dev_name(&right->dev), method,
341 dev_name(&left->dev),
342 lpeer ? dev_name(&lpeer->dev) : "none",
343 dev_name(&right->dev),
344 rpeer ? dev_name(&rpeer->dev) : "none");
345 return -EBUSY;
346 }
347
348 rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
349 if (rc)
350 return rc;
351 rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
352 if (rc) {
353 sysfs_remove_link(&left->dev.kobj, "peer");
354 return rc;
355 }
356
357 /*
358 * We need to wake the HiSpeed port to make sure we don't race
359 * setting ->peer with usb_port_runtime_suspend(). Otherwise we
360 * may miss a suspend event for the SuperSpeed port.
361 */
362 if (left->is_superspeed) {
363 ss_port = left;
364 WARN_ON(right->is_superspeed);
365 hs_port = right;
366 } else {
367 ss_port = right;
368 WARN_ON(!right->is_superspeed);
369 hs_port = left;
370 }
371 pm_runtime_get_sync(&hs_port->dev);
372
373 left->peer = right;
374 right->peer = left;
375
376 /*
377 * The SuperSpeed reference is dropped when the HiSpeed port in
378 * this relationship suspends, i.e. when it is safe to allow a
379 * SuperSpeed connection to drop since there is no risk of a
380 * device degrading to its powered-off HiSpeed connection.
381 *
382 * Also, drop the HiSpeed ref taken above.
383 */
384 pm_runtime_get_sync(&ss_port->dev);
385 pm_runtime_put(&hs_port->dev);
386
387 return 0;
388}
389
390static void link_peers_report(struct usb_port *left, struct usb_port *right)
391{
392 int rc;
393
394 rc = link_peers(left, right);
395 if (rc == 0) {
396 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
397 } else {
398 dev_dbg(&left->dev, "failed to peer to %s (%d)\n",
399 dev_name(&right->dev), rc);
400 pr_warn_once("usb: port power management may be unreliable\n");
401 usb_port_block_power_off = 1;
402 }
403}
404
405static void unlink_peers(struct usb_port *left, struct usb_port *right)
406{
407 struct usb_port *ss_port, *hs_port;
408
409 WARN(right->peer != left || left->peer != right,
410 "%s and %s are not peers?\n",
411 dev_name(&left->dev), dev_name(&right->dev));
412
413 /*
414 * We wake the HiSpeed port to make sure we don't race its
415 * usb_port_runtime_resume() event which takes a SuperSpeed ref
416 * when ->peer is !NULL.
417 */
418 if (left->is_superspeed) {
419 ss_port = left;
420 hs_port = right;
421 } else {
422 ss_port = right;
423 hs_port = left;
424 }
425
426 pm_runtime_get_sync(&hs_port->dev);
427
428 sysfs_remove_link(&left->dev.kobj, "peer");
429 right->peer = NULL;
430 sysfs_remove_link(&right->dev.kobj, "peer");
431 left->peer = NULL;
432
433 /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
434 pm_runtime_put(&ss_port->dev);
435
436 /* Drop the ref taken above */
437 pm_runtime_put(&hs_port->dev);
438}
439
440/*
441 * For each usb hub device in the system check to see if it is in the
442 * peer domain of the given port_dev, and if it is check to see if it
443 * has a port that matches the given port by location
444 */
445static int match_location(struct usb_device *peer_hdev, void *p)
446{
447 int port1;
448 struct usb_hcd *hcd, *peer_hcd;
449 struct usb_port *port_dev = p, *peer;
450 struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
451 struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
452
453 if (!peer_hub)
454 return 0;
455
456 hcd = bus_to_hcd(hdev->bus);
457 peer_hcd = bus_to_hcd(peer_hdev->bus);
458 /* peer_hcd is provisional until we verify it against the known peer */
459 if (peer_hcd != hcd->shared_hcd)
460 return 0;
461
462 for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
463 peer = peer_hub->ports[port1 - 1];
464 if (peer && peer->location == port_dev->location) {
465 link_peers_report(port_dev, peer);
466 return 1; /* done */
467 }
468 }
469
470 return 0;
471}
472
473/*
474 * Find the peer port either via explicit platform firmware "location"
475 * data, the peer hcd for root hubs, or the upstream peer relationship
476 * for all other hubs.
477 */
478static void find_and_link_peer(struct usb_hub *hub, int port1)
479{
480 struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
481 struct usb_device *hdev = hub->hdev;
482 struct usb_device *peer_hdev;
483 struct usb_hub *peer_hub;
484
485 /*
486 * If location data is available then we can only peer this port
487 * by a location match, not the default peer (lest we create a
488 * situation where we need to go back and undo a default peering
489 * when the port is later peered by location data)
490 */
491 if (port_dev->location) {
492 /* we link the peer in match_location() if found */
493 usb_for_each_dev(port_dev, match_location);
494 return;
495 } else if (!hdev->parent) {
496 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
497 struct usb_hcd *peer_hcd = hcd->shared_hcd;
498
499 if (!peer_hcd)
500 return;
501
502 peer_hdev = peer_hcd->self.root_hub;
503 } else {
504 struct usb_port *upstream;
505 struct usb_device *parent = hdev->parent;
506 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
507
508 if (!parent_hub)
509 return;
510
511 upstream = parent_hub->ports[hdev->portnum - 1];
512 if (!upstream || !upstream->peer)
513 return;
514
515 peer_hdev = upstream->peer->child;
516 }
517
518 peer_hub = usb_hub_to_struct_hub(peer_hdev);
519 if (!peer_hub || port1 > peer_hdev->maxchild)
520 return;
521
522 /*
523 * we found a valid default peer, last check is to make sure it
524 * does not have location data
525 */
526 peer = peer_hub->ports[port1 - 1];
527 if (peer && peer->location == 0)
528 link_peers_report(port_dev, peer);
529}
530
531int usb_hub_create_port_device(struct usb_hub *hub, int port1)
532{
533 struct usb_port *port_dev;
534 struct usb_device *hdev = hub->hdev;
535 int retval;
536
537 port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
538 if (!port_dev)
539 return -ENOMEM;
540
541 port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
542 if (!port_dev->req) {
543 kfree(port_dev);
544 return -ENOMEM;
545 }
546
547 hub->ports[port1 - 1] = port_dev;
548 port_dev->portnum = port1;
549 set_bit(port1, hub->power_bits);
550 port_dev->dev.parent = hub->intfdev;
551 if (hub_is_superspeed(hdev)) {
552 port_dev->usb3_lpm_u1_permit = 1;
553 port_dev->usb3_lpm_u2_permit = 1;
554 port_dev->dev.groups = port_dev_usb3_group;
555 } else
556 port_dev->dev.groups = port_dev_group;
557 port_dev->dev.type = &usb_port_device_type;
558 port_dev->dev.driver = &usb_port_driver;
559 if (hub_is_superspeed(hub->hdev))
560 port_dev->is_superspeed = 1;
561 dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
562 port1);
563 mutex_init(&port_dev->status_lock);
564 retval = device_register(&port_dev->dev);
565 if (retval) {
566 put_device(&port_dev->dev);
567 return retval;
568 }
569
570 /* Set default policy of port-poweroff disabled. */
571 retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
572 DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
573 if (retval < 0) {
574 device_unregister(&port_dev->dev);
575 return retval;
576 }
577
578 find_and_link_peer(hub, port1);
579
580 /*
581 * Enable runtime pm and hold a refernce that hub_configure()
582 * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
583 * and the hub has been fully registered (hdev->maxchild set).
584 */
585 pm_runtime_set_active(&port_dev->dev);
586 pm_runtime_get_noresume(&port_dev->dev);
587 pm_runtime_enable(&port_dev->dev);
588 device_enable_async_suspend(&port_dev->dev);
589
590 /*
591 * Keep hidden the ability to enable port-poweroff if the hub
592 * does not support power switching.
593 */
594 if (!hub_is_port_power_switchable(hub))
595 return 0;
596
597 /* Attempt to let userspace take over the policy. */
598 retval = dev_pm_qos_expose_flags(&port_dev->dev,
599 PM_QOS_FLAG_NO_POWER_OFF);
600 if (retval < 0) {
601 dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
602 return 0;
603 }
604
605 /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
606 retval = dev_pm_qos_remove_request(port_dev->req);
607 if (retval >= 0) {
608 kfree(port_dev->req);
609 port_dev->req = NULL;
610 }
611 return 0;
612}
613
614void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
615{
616 struct usb_port *port_dev = hub->ports[port1 - 1];
617 struct usb_port *peer;
618
619 peer = port_dev->peer;
620 if (peer)
621 unlink_peers(port_dev, peer);
622 device_unregister(&port_dev->dev);
623}