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1/*
2 * usb port device code
3 *
4 * Copyright (C) 2012 Intel Corp
5 *
6 * Author: Lan Tianyu <tianyu.lan@intel.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * for more details.
16 *
17 */
18
19#include <linux/slab.h>
20#include <linux/pm_qos.h>
21
22#include "hub.h"
23
24static int usb_port_block_power_off;
25
26static const struct attribute_group *port_dev_group[];
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 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 NULL,
122};
123
124static struct attribute_group port_dev_attr_grp = {
125 .attrs = port_dev_attrs,
126};
127
128static const struct attribute_group *port_dev_group[] = {
129 &port_dev_attr_grp,
130 NULL,
131};
132
133static struct attribute *port_dev_usb3_attrs[] = {
134 &dev_attr_usb3_lpm_permit.attr,
135 NULL,
136};
137
138static struct attribute_group port_dev_usb3_attr_grp = {
139 .attrs = port_dev_usb3_attrs,
140};
141
142static const struct attribute_group *port_dev_usb3_group[] = {
143 &port_dev_attr_grp,
144 &port_dev_usb3_attr_grp,
145 NULL,
146};
147
148static void usb_port_device_release(struct device *dev)
149{
150 struct usb_port *port_dev = to_usb_port(dev);
151
152 kfree(port_dev->req);
153 kfree(port_dev);
154}
155
156#ifdef CONFIG_PM
157static int usb_port_runtime_resume(struct device *dev)
158{
159 struct usb_port *port_dev = to_usb_port(dev);
160 struct usb_device *hdev = to_usb_device(dev->parent->parent);
161 struct usb_interface *intf = to_usb_interface(dev->parent);
162 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
163 struct usb_device *udev = port_dev->child;
164 struct usb_port *peer = port_dev->peer;
165 int port1 = port_dev->portnum;
166 int retval;
167
168 if (!hub)
169 return -EINVAL;
170 if (hub->in_reset) {
171 set_bit(port1, hub->power_bits);
172 return 0;
173 }
174
175 /*
176 * Power on our usb3 peer before this usb2 port to prevent a usb3
177 * device from degrading to its usb2 connection
178 */
179 if (!port_dev->is_superspeed && peer)
180 pm_runtime_get_sync(&peer->dev);
181
182 usb_autopm_get_interface(intf);
183 retval = usb_hub_set_port_power(hdev, hub, port1, true);
184 msleep(hub_power_on_good_delay(hub));
185 if (udev && !retval) {
186 /*
187 * Our preference is to simply wait for the port to reconnect,
188 * as that is the lowest latency method to restart the port.
189 * However, there are cases where toggling port power results in
190 * the host port and the device port getting out of sync causing
191 * a link training live lock. Upon timeout, flag the port as
192 * needing warm reset recovery (to be performed later by
193 * usb_port_resume() as requested via usb_wakeup_notification())
194 */
195 if (hub_port_debounce_be_connected(hub, port1) < 0) {
196 dev_dbg(&port_dev->dev, "reconnect timeout\n");
197 if (hub_is_superspeed(hdev))
198 set_bit(port1, hub->warm_reset_bits);
199 }
200
201 /* Force the child awake to revalidate after the power loss. */
202 if (!test_and_set_bit(port1, hub->child_usage_bits)) {
203 pm_runtime_get_noresume(&port_dev->dev);
204 pm_request_resume(&udev->dev);
205 }
206 }
207
208 usb_autopm_put_interface(intf);
209
210 return retval;
211}
212
213static int usb_port_runtime_suspend(struct device *dev)
214{
215 struct usb_port *port_dev = to_usb_port(dev);
216 struct usb_device *hdev = to_usb_device(dev->parent->parent);
217 struct usb_interface *intf = to_usb_interface(dev->parent);
218 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
219 struct usb_port *peer = port_dev->peer;
220 int port1 = port_dev->portnum;
221 int retval;
222
223 if (!hub)
224 return -EINVAL;
225 if (hub->in_reset)
226 return -EBUSY;
227
228 if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
229 == PM_QOS_FLAGS_ALL)
230 return -EAGAIN;
231
232 if (usb_port_block_power_off)
233 return -EBUSY;
234
235 usb_autopm_get_interface(intf);
236 retval = usb_hub_set_port_power(hdev, hub, port1, false);
237 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
238 if (!port_dev->is_superspeed)
239 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
240 usb_autopm_put_interface(intf);
241
242 /*
243 * Our peer usb3 port may now be able to suspend, so
244 * asynchronously queue a suspend request to observe that this
245 * usb2 port is now off.
246 */
247 if (!port_dev->is_superspeed && peer)
248 pm_runtime_put(&peer->dev);
249
250 return retval;
251}
252#endif
253
254static const struct dev_pm_ops usb_port_pm_ops = {
255#ifdef CONFIG_PM
256 .runtime_suspend = usb_port_runtime_suspend,
257 .runtime_resume = usb_port_runtime_resume,
258#endif
259};
260
261struct device_type usb_port_device_type = {
262 .name = "usb_port",
263 .release = usb_port_device_release,
264 .pm = &usb_port_pm_ops,
265};
266
267static struct device_driver usb_port_driver = {
268 .name = "usb",
269 .owner = THIS_MODULE,
270};
271
272static int link_peers(struct usb_port *left, struct usb_port *right)
273{
274 struct usb_port *ss_port, *hs_port;
275 int rc;
276
277 if (left->peer == right && right->peer == left)
278 return 0;
279
280 if (left->peer || right->peer) {
281 struct usb_port *lpeer = left->peer;
282 struct usb_port *rpeer = right->peer;
283 char *method;
284
285 if (left->location && left->location == right->location)
286 method = "location";
287 else
288 method = "default";
289
290 pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
291 dev_name(&left->dev), dev_name(&right->dev), method,
292 dev_name(&left->dev),
293 lpeer ? dev_name(&lpeer->dev) : "none",
294 dev_name(&right->dev),
295 rpeer ? dev_name(&rpeer->dev) : "none");
296 return -EBUSY;
297 }
298
299 rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
300 if (rc)
301 return rc;
302 rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
303 if (rc) {
304 sysfs_remove_link(&left->dev.kobj, "peer");
305 return rc;
306 }
307
308 /*
309 * We need to wake the HiSpeed port to make sure we don't race
310 * setting ->peer with usb_port_runtime_suspend(). Otherwise we
311 * may miss a suspend event for the SuperSpeed port.
312 */
313 if (left->is_superspeed) {
314 ss_port = left;
315 WARN_ON(right->is_superspeed);
316 hs_port = right;
317 } else {
318 ss_port = right;
319 WARN_ON(!right->is_superspeed);
320 hs_port = left;
321 }
322 pm_runtime_get_sync(&hs_port->dev);
323
324 left->peer = right;
325 right->peer = left;
326
327 /*
328 * The SuperSpeed reference is dropped when the HiSpeed port in
329 * this relationship suspends, i.e. when it is safe to allow a
330 * SuperSpeed connection to drop since there is no risk of a
331 * device degrading to its powered-off HiSpeed connection.
332 *
333 * Also, drop the HiSpeed ref taken above.
334 */
335 pm_runtime_get_sync(&ss_port->dev);
336 pm_runtime_put(&hs_port->dev);
337
338 return 0;
339}
340
341static void link_peers_report(struct usb_port *left, struct usb_port *right)
342{
343 int rc;
344
345 rc = link_peers(left, right);
346 if (rc == 0) {
347 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
348 } else {
349 dev_dbg(&left->dev, "failed to peer to %s (%d)\n",
350 dev_name(&right->dev), rc);
351 pr_warn_once("usb: port power management may be unreliable\n");
352 usb_port_block_power_off = 1;
353 }
354}
355
356static void unlink_peers(struct usb_port *left, struct usb_port *right)
357{
358 struct usb_port *ss_port, *hs_port;
359
360 WARN(right->peer != left || left->peer != right,
361 "%s and %s are not peers?\n",
362 dev_name(&left->dev), dev_name(&right->dev));
363
364 /*
365 * We wake the HiSpeed port to make sure we don't race its
366 * usb_port_runtime_resume() event which takes a SuperSpeed ref
367 * when ->peer is !NULL.
368 */
369 if (left->is_superspeed) {
370 ss_port = left;
371 hs_port = right;
372 } else {
373 ss_port = right;
374 hs_port = left;
375 }
376
377 pm_runtime_get_sync(&hs_port->dev);
378
379 sysfs_remove_link(&left->dev.kobj, "peer");
380 right->peer = NULL;
381 sysfs_remove_link(&right->dev.kobj, "peer");
382 left->peer = NULL;
383
384 /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
385 pm_runtime_put(&ss_port->dev);
386
387 /* Drop the ref taken above */
388 pm_runtime_put(&hs_port->dev);
389}
390
391/*
392 * For each usb hub device in the system check to see if it is in the
393 * peer domain of the given port_dev, and if it is check to see if it
394 * has a port that matches the given port by location
395 */
396static int match_location(struct usb_device *peer_hdev, void *p)
397{
398 int port1;
399 struct usb_hcd *hcd, *peer_hcd;
400 struct usb_port *port_dev = p, *peer;
401 struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
402 struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
403
404 if (!peer_hub)
405 return 0;
406
407 hcd = bus_to_hcd(hdev->bus);
408 peer_hcd = bus_to_hcd(peer_hdev->bus);
409 /* peer_hcd is provisional until we verify it against the known peer */
410 if (peer_hcd != hcd->shared_hcd)
411 return 0;
412
413 for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
414 peer = peer_hub->ports[port1 - 1];
415 if (peer && peer->location == port_dev->location) {
416 link_peers_report(port_dev, peer);
417 return 1; /* done */
418 }
419 }
420
421 return 0;
422}
423
424/*
425 * Find the peer port either via explicit platform firmware "location"
426 * data, the peer hcd for root hubs, or the upstream peer relationship
427 * for all other hubs.
428 */
429static void find_and_link_peer(struct usb_hub *hub, int port1)
430{
431 struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
432 struct usb_device *hdev = hub->hdev;
433 struct usb_device *peer_hdev;
434 struct usb_hub *peer_hub;
435
436 /*
437 * If location data is available then we can only peer this port
438 * by a location match, not the default peer (lest we create a
439 * situation where we need to go back and undo a default peering
440 * when the port is later peered by location data)
441 */
442 if (port_dev->location) {
443 /* we link the peer in match_location() if found */
444 usb_for_each_dev(port_dev, match_location);
445 return;
446 } else if (!hdev->parent) {
447 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
448 struct usb_hcd *peer_hcd = hcd->shared_hcd;
449
450 if (!peer_hcd)
451 return;
452
453 peer_hdev = peer_hcd->self.root_hub;
454 } else {
455 struct usb_port *upstream;
456 struct usb_device *parent = hdev->parent;
457 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
458
459 if (!parent_hub)
460 return;
461
462 upstream = parent_hub->ports[hdev->portnum - 1];
463 if (!upstream || !upstream->peer)
464 return;
465
466 peer_hdev = upstream->peer->child;
467 }
468
469 peer_hub = usb_hub_to_struct_hub(peer_hdev);
470 if (!peer_hub || port1 > peer_hdev->maxchild)
471 return;
472
473 /*
474 * we found a valid default peer, last check is to make sure it
475 * does not have location data
476 */
477 peer = peer_hub->ports[port1 - 1];
478 if (peer && peer->location == 0)
479 link_peers_report(port_dev, peer);
480}
481
482int usb_hub_create_port_device(struct usb_hub *hub, int port1)
483{
484 struct usb_port *port_dev;
485 struct usb_device *hdev = hub->hdev;
486 int retval;
487
488 port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
489 if (!port_dev)
490 return -ENOMEM;
491
492 port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
493 if (!port_dev->req) {
494 kfree(port_dev);
495 return -ENOMEM;
496 }
497
498 hub->ports[port1 - 1] = port_dev;
499 port_dev->portnum = port1;
500 set_bit(port1, hub->power_bits);
501 port_dev->dev.parent = hub->intfdev;
502 if (hub_is_superspeed(hdev)) {
503 port_dev->usb3_lpm_u1_permit = 1;
504 port_dev->usb3_lpm_u2_permit = 1;
505 port_dev->dev.groups = port_dev_usb3_group;
506 } else
507 port_dev->dev.groups = port_dev_group;
508 port_dev->dev.type = &usb_port_device_type;
509 port_dev->dev.driver = &usb_port_driver;
510 if (hub_is_superspeed(hub->hdev))
511 port_dev->is_superspeed = 1;
512 dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
513 port1);
514 mutex_init(&port_dev->status_lock);
515 retval = device_register(&port_dev->dev);
516 if (retval) {
517 put_device(&port_dev->dev);
518 return retval;
519 }
520
521 /* Set default policy of port-poweroff disabled. */
522 retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
523 DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
524 if (retval < 0) {
525 device_unregister(&port_dev->dev);
526 return retval;
527 }
528
529 find_and_link_peer(hub, port1);
530
531 /*
532 * Enable runtime pm and hold a refernce that hub_configure()
533 * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
534 * and the hub has been fully registered (hdev->maxchild set).
535 */
536 pm_runtime_set_active(&port_dev->dev);
537 pm_runtime_get_noresume(&port_dev->dev);
538 pm_runtime_enable(&port_dev->dev);
539 device_enable_async_suspend(&port_dev->dev);
540
541 /*
542 * Keep hidden the ability to enable port-poweroff if the hub
543 * does not support power switching.
544 */
545 if (!hub_is_port_power_switchable(hub))
546 return 0;
547
548 /* Attempt to let userspace take over the policy. */
549 retval = dev_pm_qos_expose_flags(&port_dev->dev,
550 PM_QOS_FLAG_NO_POWER_OFF);
551 if (retval < 0) {
552 dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
553 return 0;
554 }
555
556 /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
557 retval = dev_pm_qos_remove_request(port_dev->req);
558 if (retval >= 0) {
559 kfree(port_dev->req);
560 port_dev->req = NULL;
561 }
562 return 0;
563}
564
565void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
566{
567 struct usb_port *port_dev = hub->ports[port1 - 1];
568 struct usb_port *peer;
569
570 peer = port_dev->peer;
571 if (peer)
572 unlink_peers(port_dev, peer);
573 device_unregister(&port_dev->dev);
574}
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}