Merge tag 'zonefs-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal...
[sfrench/cifs-2.6.git] / drivers / usb / core / port.c
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
17 static int usb_port_block_power_off;
18
19 static const struct attribute_group *port_dev_group[];
20
21 static 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
29 static 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 }
45 static DEVICE_ATTR_RW(early_stop);
46
47 static 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
72 out_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
82 static 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
121 out_hdev_lock:
122         usb_unlock_device(hdev);
123         usb_autopm_put_interface(intf);
124
125         return rc;
126 }
127 static DEVICE_ATTR_RW(disable);
128
129 static 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 }
136 static DEVICE_ATTR_RO(location);
137
138 static 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 }
161 static DEVICE_ATTR_RO(connect_type);
162
163 static 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 }
171 static DEVICE_ATTR_RO(state);
172
173 static 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 }
180 static DEVICE_ATTR_RO(over_current_count);
181
182 static 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
190 static 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 }
202 static DEVICE_ATTR_RW(quirks);
203
204 static 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
225 static 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 }
268 static DEVICE_ATTR_RW(usb3_lpm_permit);
269
270 static 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
281 static const struct attribute_group port_dev_attr_grp = {
282         .attrs = port_dev_attrs,
283 };
284
285 static const struct attribute_group *port_dev_group[] = {
286         &port_dev_attr_grp,
287         NULL,
288 };
289
290 static struct attribute *port_dev_usb3_attrs[] = {
291         &dev_attr_usb3_lpm_permit.attr,
292         NULL,
293 };
294
295 static const struct attribute_group port_dev_usb3_attr_grp = {
296         .attrs = port_dev_usb3_attrs,
297 };
298
299 static const struct attribute_group *port_dev_usb3_group[] = {
300         &port_dev_attr_grp,
301         &port_dev_usb3_attr_grp,
302         NULL,
303 };
304
305 static 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
314 static 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
373 static 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
417 static 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
425 static 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
432 struct device_type usb_port_device_type = {
433         .name =         "usb_port",
434         .release =      usb_port_device_release,
435         .pm =           &usb_port_pm_ops,
436 };
437
438 static struct device_driver usb_port_driver = {
439         .name = "usb",
440         .owner = THIS_MODULE,
441         .shutdown = usb_port_shutdown,
442 };
443
444 static 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
513 static 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
528 static 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  */
568 static 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  */
602 static 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
655 static 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
682 static 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
691 static const struct component_ops connector_ops = {
692         .bind = connector_bind,
693         .unbind = connector_unbind,
694 };
695
696 int 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
789 err_put_kn:
790         sysfs_put(port_dev->state_kn);
791 err_unregister:
792         device_unregister(&port_dev->dev);
793
794         return retval;
795 }
796
797 void 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 }