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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 usb_autopm_get_interface(intf);
217 retval = usb_hub_set_port_power(hdev, hub, port1, true);
218 msleep(hub_power_on_good_delay(hub));
219 if (udev && !retval) {
220 /*
221 * Our preference is to simply wait for the port to reconnect,
222 * as that is the lowest latency method to restart the port.
223 * However, there are cases where toggling port power results in
224 * the host port and the device port getting out of sync causing
225 * a link training live lock. Upon timeout, flag the port as
226 * needing warm reset recovery (to be performed later by
227 * usb_port_resume() as requested via usb_wakeup_notification())
228 */
229 if (hub_port_debounce_be_connected(hub, port1) < 0) {
230 dev_dbg(&port_dev->dev, "reconnect timeout\n");
231 if (hub_is_superspeed(hdev))
232 set_bit(port1, hub->warm_reset_bits);
233 }
234
235 /* Force the child awake to revalidate after the power loss. */
236 if (!test_and_set_bit(port1, hub->child_usage_bits)) {
237 pm_runtime_get_noresume(&port_dev->dev);
238 pm_request_resume(&udev->dev);
239 }
240 }
241
242 usb_autopm_put_interface(intf);
243
244 return retval;
245}
246
247static int usb_port_runtime_suspend(struct device *dev)
248{
249 struct usb_port *port_dev = to_usb_port(dev);
250 struct usb_device *hdev = to_usb_device(dev->parent->parent);
251 struct usb_interface *intf = to_usb_interface(dev->parent);
252 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
253 struct usb_port *peer = port_dev->peer;
254 int port1 = port_dev->portnum;
255 int retval;
256
257 if (!hub)
258 return -EINVAL;
259 if (hub->in_reset)
260 return -EBUSY;
261
262 if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
263 == PM_QOS_FLAGS_ALL)
264 return -EAGAIN;
265
266 if (usb_port_block_power_off)
267 return -EBUSY;
268
269 usb_autopm_get_interface(intf);
270 retval = usb_hub_set_port_power(hdev, hub, port1, false);
271 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
272 if (!port_dev->is_superspeed)
273 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
274 usb_autopm_put_interface(intf);
275
276 /*
277 * Our peer usb3 port may now be able to suspend, so
278 * asynchronously queue a suspend request to observe that this
279 * usb2 port is now off.
280 */
281 if (!port_dev->is_superspeed && peer)
282 pm_runtime_put(&peer->dev);
283
284 return retval;
285}
286#endif
287
288static void usb_port_shutdown(struct device *dev)
289{
290 struct usb_port *port_dev = to_usb_port(dev);
291
292 if (port_dev->child)
293 usb_disable_usb2_hardware_lpm(port_dev->child);
294}
295
296static const struct dev_pm_ops usb_port_pm_ops = {
297#ifdef CONFIG_PM
298 .runtime_suspend = usb_port_runtime_suspend,
299 .runtime_resume = usb_port_runtime_resume,
300#endif
301};
302
303struct device_type usb_port_device_type = {
304 .name = "usb_port",
305 .release = usb_port_device_release,
306 .pm = &usb_port_pm_ops,
307};
308
309static struct device_driver usb_port_driver = {
310 .name = "usb",
311 .owner = THIS_MODULE,
312 .shutdown = usb_port_shutdown,
313};
314
315static int link_peers(struct usb_port *left, struct usb_port *right)
316{
317 struct usb_port *ss_port, *hs_port;
318 int rc;
319
320 if (left->peer == right && right->peer == left)
321 return 0;
322
323 if (left->peer || right->peer) {
324 struct usb_port *lpeer = left->peer;
325 struct usb_port *rpeer = right->peer;
326 char *method;
327
328 if (left->location && left->location == right->location)
329 method = "location";
330 else
331 method = "default";
332
333 pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
334 dev_name(&left->dev), dev_name(&right->dev), method,
335 dev_name(&left->dev),
336 lpeer ? dev_name(&lpeer->dev) : "none",
337 dev_name(&right->dev),
338 rpeer ? dev_name(&rpeer->dev) : "none");
339 return -EBUSY;
340 }
341
342 rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
343 if (rc)
344 return rc;
345 rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
346 if (rc) {
347 sysfs_remove_link(&left->dev.kobj, "peer");
348 return rc;
349 }
350
351 /*
352 * We need to wake the HiSpeed port to make sure we don't race
353 * setting ->peer with usb_port_runtime_suspend(). Otherwise we
354 * may miss a suspend event for the SuperSpeed port.
355 */
356 if (left->is_superspeed) {
357 ss_port = left;
358 WARN_ON(right->is_superspeed);
359 hs_port = right;
360 } else {
361 ss_port = right;
362 WARN_ON(!right->is_superspeed);
363 hs_port = left;
364 }
365 pm_runtime_get_sync(&hs_port->dev);
366
367 left->peer = right;
368 right->peer = left;
369
370 /*
371 * The SuperSpeed reference is dropped when the HiSpeed port in
372 * this relationship suspends, i.e. when it is safe to allow a
373 * SuperSpeed connection to drop since there is no risk of a
374 * device degrading to its powered-off HiSpeed connection.
375 *
376 * Also, drop the HiSpeed ref taken above.
377 */
378 pm_runtime_get_sync(&ss_port->dev);
379 pm_runtime_put(&hs_port->dev);
380
381 return 0;
382}
383
384static void link_peers_report(struct usb_port *left, struct usb_port *right)
385{
386 int rc;
387
388 rc = link_peers(left, right);
389 if (rc == 0) {
390 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
391 } else {
392 dev_dbg(&left->dev, "failed to peer to %s (%d)\n",
393 dev_name(&right->dev), rc);
394 pr_warn_once("usb: port power management may be unreliable\n");
395 usb_port_block_power_off = 1;
396 }
397}
398
399static void unlink_peers(struct usb_port *left, struct usb_port *right)
400{
401 struct usb_port *ss_port, *hs_port;
402
403 WARN(right->peer != left || left->peer != right,
404 "%s and %s are not peers?\n",
405 dev_name(&left->dev), dev_name(&right->dev));
406
407 /*
408 * We wake the HiSpeed port to make sure we don't race its
409 * usb_port_runtime_resume() event which takes a SuperSpeed ref
410 * when ->peer is !NULL.
411 */
412 if (left->is_superspeed) {
413 ss_port = left;
414 hs_port = right;
415 } else {
416 ss_port = right;
417 hs_port = left;
418 }
419
420 pm_runtime_get_sync(&hs_port->dev);
421
422 sysfs_remove_link(&left->dev.kobj, "peer");
423 right->peer = NULL;
424 sysfs_remove_link(&right->dev.kobj, "peer");
425 left->peer = NULL;
426
427 /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
428 pm_runtime_put(&ss_port->dev);
429
430 /* Drop the ref taken above */
431 pm_runtime_put(&hs_port->dev);
432}
433
434/*
435 * For each usb hub device in the system check to see if it is in the
436 * peer domain of the given port_dev, and if it is check to see if it
437 * has a port that matches the given port by location
438 */
439static int match_location(struct usb_device *peer_hdev, void *p)
440{
441 int port1;
442 struct usb_hcd *hcd, *peer_hcd;
443 struct usb_port *port_dev = p, *peer;
444 struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
445 struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
446
447 if (!peer_hub)
448 return 0;
449
450 hcd = bus_to_hcd(hdev->bus);
451 peer_hcd = bus_to_hcd(peer_hdev->bus);
452 /* peer_hcd is provisional until we verify it against the known peer */
453 if (peer_hcd != hcd->shared_hcd)
454 return 0;
455
456 for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
457 peer = peer_hub->ports[port1 - 1];
458 if (peer && peer->location == port_dev->location) {
459 link_peers_report(port_dev, peer);
460 return 1; /* done */
461 }
462 }
463
464 return 0;
465}
466
467/*
468 * Find the peer port either via explicit platform firmware "location"
469 * data, the peer hcd for root hubs, or the upstream peer relationship
470 * for all other hubs.
471 */
472static void find_and_link_peer(struct usb_hub *hub, int port1)
473{
474 struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
475 struct usb_device *hdev = hub->hdev;
476 struct usb_device *peer_hdev;
477 struct usb_hub *peer_hub;
478
479 /*
480 * If location data is available then we can only peer this port
481 * by a location match, not the default peer (lest we create a
482 * situation where we need to go back and undo a default peering
483 * when the port is later peered by location data)
484 */
485 if (port_dev->location) {
486 /* we link the peer in match_location() if found */
487 usb_for_each_dev(port_dev, match_location);
488 return;
489 } else if (!hdev->parent) {
490 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
491 struct usb_hcd *peer_hcd = hcd->shared_hcd;
492
493 if (!peer_hcd)
494 return;
495
496 peer_hdev = peer_hcd->self.root_hub;
497 } else {
498 struct usb_port *upstream;
499 struct usb_device *parent = hdev->parent;
500 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
501
502 if (!parent_hub)
503 return;
504
505 upstream = parent_hub->ports[hdev->portnum - 1];
506 if (!upstream || !upstream->peer)
507 return;
508
509 peer_hdev = upstream->peer->child;
510 }
511
512 peer_hub = usb_hub_to_struct_hub(peer_hdev);
513 if (!peer_hub || port1 > peer_hdev->maxchild)
514 return;
515
516 /*
517 * we found a valid default peer, last check is to make sure it
518 * does not have location data
519 */
520 peer = peer_hub->ports[port1 - 1];
521 if (peer && peer->location == 0)
522 link_peers_report(port_dev, peer);
523}
524
525int usb_hub_create_port_device(struct usb_hub *hub, int port1)
526{
527 struct usb_port *port_dev;
528 struct usb_device *hdev = hub->hdev;
529 int retval;
530
531 port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
532 if (!port_dev)
533 return -ENOMEM;
534
535 port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
536 if (!port_dev->req) {
537 kfree(port_dev);
538 return -ENOMEM;
539 }
540
541 hub->ports[port1 - 1] = port_dev;
542 port_dev->portnum = port1;
543 set_bit(port1, hub->power_bits);
544 port_dev->dev.parent = hub->intfdev;
545 if (hub_is_superspeed(hdev)) {
546 port_dev->usb3_lpm_u1_permit = 1;
547 port_dev->usb3_lpm_u2_permit = 1;
548 port_dev->dev.groups = port_dev_usb3_group;
549 } else
550 port_dev->dev.groups = port_dev_group;
551 port_dev->dev.type = &usb_port_device_type;
552 port_dev->dev.driver = &usb_port_driver;
553 if (hub_is_superspeed(hub->hdev))
554 port_dev->is_superspeed = 1;
555 dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
556 port1);
557 mutex_init(&port_dev->status_lock);
558 retval = device_register(&port_dev->dev);
559 if (retval) {
560 put_device(&port_dev->dev);
561 return retval;
562 }
563
564 /* Set default policy of port-poweroff disabled. */
565 retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
566 DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
567 if (retval < 0) {
568 device_unregister(&port_dev->dev);
569 return retval;
570 }
571
572 find_and_link_peer(hub, port1);
573
574 /*
575 * Enable runtime pm and hold a refernce that hub_configure()
576 * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
577 * and the hub has been fully registered (hdev->maxchild set).
578 */
579 pm_runtime_set_active(&port_dev->dev);
580 pm_runtime_get_noresume(&port_dev->dev);
581 pm_runtime_enable(&port_dev->dev);
582 device_enable_async_suspend(&port_dev->dev);
583
584 /*
585 * Keep hidden the ability to enable port-poweroff if the hub
586 * does not support power switching.
587 */
588 if (!hub_is_port_power_switchable(hub))
589 return 0;
590
591 /* Attempt to let userspace take over the policy. */
592 retval = dev_pm_qos_expose_flags(&port_dev->dev,
593 PM_QOS_FLAG_NO_POWER_OFF);
594 if (retval < 0) {
595 dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
596 return 0;
597 }
598
599 /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
600 retval = dev_pm_qos_remove_request(port_dev->req);
601 if (retval >= 0) {
602 kfree(port_dev->req);
603 port_dev->req = NULL;
604 }
605 return 0;
606}
607
608void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
609{
610 struct usb_port *port_dev = hub->ports[port1 - 1];
611 struct usb_port *peer;
612
613 peer = port_dev->peer;
614 if (peer)
615 unlink_peers(port_dev, peer);
616 device_unregister(&port_dev->dev);
617}