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 #include <linux/usb/of.h> 15 16 #include "hub.h" 17 18 static int usb_port_block_power_off; 19 20 static const struct attribute_group *port_dev_group[]; 21 22 static ssize_t early_stop_show(struct device *dev, 23 struct device_attribute *attr, char *buf) 24 { 25 struct usb_port *port_dev = to_usb_port(dev); 26 27 return sysfs_emit(buf, "%s\n", port_dev->early_stop ? "yes" : "no"); 28 } 29 30 static ssize_t early_stop_store(struct device *dev, struct device_attribute *attr, 31 const char *buf, size_t count) 32 { 33 struct usb_port *port_dev = to_usb_port(dev); 34 bool value; 35 36 if (kstrtobool(buf, &value)) 37 return -EINVAL; 38 39 if (value) 40 port_dev->early_stop = 1; 41 else 42 port_dev->early_stop = 0; 43 44 return count; 45 } 46 static DEVICE_ATTR_RW(early_stop); 47 48 static ssize_t disable_show(struct device *dev, 49 struct device_attribute *attr, char *buf) 50 { 51 struct usb_port *port_dev = to_usb_port(dev); 52 struct usb_device *hdev = to_usb_device(dev->parent->parent); 53 struct usb_hub *hub = usb_hub_to_struct_hub(hdev); 54 struct usb_interface *intf = to_usb_interface(hub->intfdev); 55 int port1 = port_dev->portnum; 56 u16 portstatus, unused; 57 bool disabled; 58 int rc; 59 60 rc = usb_autopm_get_interface(intf); 61 if (rc < 0) 62 return rc; 63 64 usb_lock_device(hdev); 65 if (hub->disconnected) { 66 rc = -ENODEV; 67 goto out_hdev_lock; 68 } 69 70 usb_hub_port_status(hub, port1, &portstatus, &unused); 71 disabled = !usb_port_is_power_on(hub, portstatus); 72 73 out_hdev_lock: 74 usb_unlock_device(hdev); 75 usb_autopm_put_interface(intf); 76 77 if (rc) 78 return rc; 79 80 return sysfs_emit(buf, "%s\n", disabled ? "1" : "0"); 81 } 82 83 static ssize_t disable_store(struct device *dev, struct device_attribute *attr, 84 const char *buf, size_t count) 85 { 86 struct usb_port *port_dev = to_usb_port(dev); 87 struct usb_device *hdev = to_usb_device(dev->parent->parent); 88 struct usb_hub *hub = usb_hub_to_struct_hub(hdev); 89 struct usb_interface *intf = to_usb_interface(hub->intfdev); 90 int port1 = port_dev->portnum; 91 bool disabled; 92 int rc; 93 94 rc = kstrtobool(buf, &disabled); 95 if (rc) 96 return rc; 97 98 rc = usb_autopm_get_interface(intf); 99 if (rc < 0) 100 return rc; 101 102 usb_lock_device(hdev); 103 if (hub->disconnected) { 104 rc = -ENODEV; 105 goto out_hdev_lock; 106 } 107 108 if (disabled && port_dev->child) 109 usb_disconnect(&port_dev->child); 110 111 rc = usb_hub_set_port_power(hdev, hub, port1, !disabled); 112 113 if (disabled) { 114 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION); 115 if (!port_dev->is_superspeed) 116 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE); 117 } 118 119 if (!rc) 120 rc = count; 121 122 out_hdev_lock: 123 usb_unlock_device(hdev); 124 usb_autopm_put_interface(intf); 125 126 return rc; 127 } 128 static DEVICE_ATTR_RW(disable); 129 130 static ssize_t location_show(struct device *dev, 131 struct device_attribute *attr, char *buf) 132 { 133 struct usb_port *port_dev = to_usb_port(dev); 134 135 return sprintf(buf, "0x%08x\n", port_dev->location); 136 } 137 static DEVICE_ATTR_RO(location); 138 139 static ssize_t connect_type_show(struct device *dev, 140 struct device_attribute *attr, char *buf) 141 { 142 struct usb_port *port_dev = to_usb_port(dev); 143 char *result; 144 145 switch (port_dev->connect_type) { 146 case USB_PORT_CONNECT_TYPE_HOT_PLUG: 147 result = "hotplug"; 148 break; 149 case USB_PORT_CONNECT_TYPE_HARD_WIRED: 150 result = "hardwired"; 151 break; 152 case USB_PORT_NOT_USED: 153 result = "not used"; 154 break; 155 default: 156 result = "unknown"; 157 break; 158 } 159 160 return sprintf(buf, "%s\n", result); 161 } 162 static DEVICE_ATTR_RO(connect_type); 163 164 static ssize_t state_show(struct device *dev, 165 struct device_attribute *attr, char *buf) 166 { 167 struct usb_port *port_dev = to_usb_port(dev); 168 enum usb_device_state state = READ_ONCE(port_dev->state); 169 170 return sysfs_emit(buf, "%s\n", usb_state_string(state)); 171 } 172 static DEVICE_ATTR_RO(state); 173 174 static ssize_t over_current_count_show(struct device *dev, 175 struct device_attribute *attr, char *buf) 176 { 177 struct usb_port *port_dev = to_usb_port(dev); 178 179 return sprintf(buf, "%u\n", port_dev->over_current_count); 180 } 181 static DEVICE_ATTR_RO(over_current_count); 182 183 static ssize_t quirks_show(struct device *dev, 184 struct device_attribute *attr, char *buf) 185 { 186 struct usb_port *port_dev = to_usb_port(dev); 187 188 return sprintf(buf, "%08x\n", port_dev->quirks); 189 } 190 191 static ssize_t quirks_store(struct device *dev, struct device_attribute *attr, 192 const char *buf, size_t count) 193 { 194 struct usb_port *port_dev = to_usb_port(dev); 195 u32 value; 196 197 if (kstrtou32(buf, 16, &value)) 198 return -EINVAL; 199 200 port_dev->quirks = value; 201 return count; 202 } 203 static DEVICE_ATTR_RW(quirks); 204 205 static ssize_t usb3_lpm_permit_show(struct device *dev, 206 struct device_attribute *attr, char *buf) 207 { 208 struct usb_port *port_dev = to_usb_port(dev); 209 const char *p; 210 211 if (port_dev->usb3_lpm_u1_permit) { 212 if (port_dev->usb3_lpm_u2_permit) 213 p = "u1_u2"; 214 else 215 p = "u1"; 216 } else { 217 if (port_dev->usb3_lpm_u2_permit) 218 p = "u2"; 219 else 220 p = "0"; 221 } 222 223 return sprintf(buf, "%s\n", p); 224 } 225 226 static ssize_t usb3_lpm_permit_store(struct device *dev, 227 struct device_attribute *attr, 228 const char *buf, size_t count) 229 { 230 struct usb_port *port_dev = to_usb_port(dev); 231 struct usb_device *udev = port_dev->child; 232 struct usb_hcd *hcd; 233 234 if (!strncmp(buf, "u1_u2", 5)) { 235 port_dev->usb3_lpm_u1_permit = 1; 236 port_dev->usb3_lpm_u2_permit = 1; 237 238 } else if (!strncmp(buf, "u1", 2)) { 239 port_dev->usb3_lpm_u1_permit = 1; 240 port_dev->usb3_lpm_u2_permit = 0; 241 242 } else if (!strncmp(buf, "u2", 2)) { 243 port_dev->usb3_lpm_u1_permit = 0; 244 port_dev->usb3_lpm_u2_permit = 1; 245 246 } else if (!strncmp(buf, "0", 1)) { 247 port_dev->usb3_lpm_u1_permit = 0; 248 port_dev->usb3_lpm_u2_permit = 0; 249 } else 250 return -EINVAL; 251 252 /* If device is connected to the port, disable or enable lpm 253 * to make new u1 u2 setting take effect immediately. 254 */ 255 if (udev) { 256 hcd = bus_to_hcd(udev->bus); 257 if (!hcd) 258 return -EINVAL; 259 usb_lock_device(udev); 260 mutex_lock(hcd->bandwidth_mutex); 261 if (!usb_disable_lpm(udev)) 262 usb_enable_lpm(udev); 263 mutex_unlock(hcd->bandwidth_mutex); 264 usb_unlock_device(udev); 265 } 266 267 return count; 268 } 269 static DEVICE_ATTR_RW(usb3_lpm_permit); 270 271 static struct attribute *port_dev_attrs[] = { 272 &dev_attr_connect_type.attr, 273 &dev_attr_state.attr, 274 &dev_attr_location.attr, 275 &dev_attr_quirks.attr, 276 &dev_attr_over_current_count.attr, 277 &dev_attr_disable.attr, 278 &dev_attr_early_stop.attr, 279 NULL, 280 }; 281 282 static const struct attribute_group port_dev_attr_grp = { 283 .attrs = port_dev_attrs, 284 }; 285 286 static const struct attribute_group *port_dev_group[] = { 287 &port_dev_attr_grp, 288 NULL, 289 }; 290 291 static struct attribute *port_dev_usb3_attrs[] = { 292 &dev_attr_usb3_lpm_permit.attr, 293 NULL, 294 }; 295 296 static const struct attribute_group port_dev_usb3_attr_grp = { 297 .attrs = port_dev_usb3_attrs, 298 }; 299 300 static const struct attribute_group *port_dev_usb3_group[] = { 301 &port_dev_attr_grp, 302 &port_dev_usb3_attr_grp, 303 NULL, 304 }; 305 306 static void usb_port_device_release(struct device *dev) 307 { 308 struct usb_port *port_dev = to_usb_port(dev); 309 310 kfree(port_dev->req); 311 kfree(port_dev); 312 } 313 314 #ifdef CONFIG_PM 315 static int usb_port_runtime_resume(struct device *dev) 316 { 317 struct usb_port *port_dev = to_usb_port(dev); 318 struct usb_device *hdev = to_usb_device(dev->parent->parent); 319 struct usb_interface *intf = to_usb_interface(dev->parent); 320 struct usb_hub *hub = usb_hub_to_struct_hub(hdev); 321 struct usb_device *udev = port_dev->child; 322 struct usb_port *peer = port_dev->peer; 323 int port1 = port_dev->portnum; 324 int retval; 325 326 if (!hub) 327 return -EINVAL; 328 if (hub->in_reset) { 329 set_bit(port1, hub->power_bits); 330 return 0; 331 } 332 333 /* 334 * Power on our usb3 peer before this usb2 port to prevent a usb3 335 * device from degrading to its usb2 connection 336 */ 337 if (!port_dev->is_superspeed && peer) 338 pm_runtime_get_sync(&peer->dev); 339 340 retval = usb_autopm_get_interface(intf); 341 if (retval < 0) 342 return retval; 343 344 retval = usb_hub_set_port_power(hdev, hub, port1, true); 345 msleep(hub_power_on_good_delay(hub)); 346 if (udev && !retval) { 347 /* 348 * Our preference is to simply wait for the port to reconnect, 349 * as that is the lowest latency method to restart the port. 350 * However, there are cases where toggling port power results in 351 * the host port and the device port getting out of sync causing 352 * a link training live lock. Upon timeout, flag the port as 353 * needing warm reset recovery (to be performed later by 354 * usb_port_resume() as requested via usb_wakeup_notification()) 355 */ 356 if (hub_port_debounce_be_connected(hub, port1) < 0) { 357 dev_dbg(&port_dev->dev, "reconnect timeout\n"); 358 if (hub_is_superspeed(hdev)) 359 set_bit(port1, hub->warm_reset_bits); 360 } 361 362 /* Force the child awake to revalidate after the power loss. */ 363 if (!test_and_set_bit(port1, hub->child_usage_bits)) { 364 pm_runtime_get_noresume(&port_dev->dev); 365 pm_request_resume(&udev->dev); 366 } 367 } 368 369 usb_autopm_put_interface(intf); 370 371 return retval; 372 } 373 374 static int usb_port_runtime_suspend(struct device *dev) 375 { 376 struct usb_port *port_dev = to_usb_port(dev); 377 struct usb_device *hdev = to_usb_device(dev->parent->parent); 378 struct usb_interface *intf = to_usb_interface(dev->parent); 379 struct usb_hub *hub = usb_hub_to_struct_hub(hdev); 380 struct usb_port *peer = port_dev->peer; 381 int port1 = port_dev->portnum; 382 int retval; 383 384 if (!hub) 385 return -EINVAL; 386 if (hub->in_reset) 387 return -EBUSY; 388 389 if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF) 390 == PM_QOS_FLAGS_ALL) 391 return -EAGAIN; 392 393 if (usb_port_block_power_off) 394 return -EBUSY; 395 396 retval = usb_autopm_get_interface(intf); 397 if (retval < 0) 398 return retval; 399 400 retval = usb_hub_set_port_power(hdev, hub, port1, false); 401 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION); 402 if (!port_dev->is_superspeed) 403 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE); 404 usb_autopm_put_interface(intf); 405 406 /* 407 * Our peer usb3 port may now be able to suspend, so 408 * asynchronously queue a suspend request to observe that this 409 * usb2 port is now off. 410 */ 411 if (!port_dev->is_superspeed && peer) 412 pm_runtime_put(&peer->dev); 413 414 return retval; 415 } 416 #endif 417 418 static void usb_port_shutdown(struct device *dev) 419 { 420 struct usb_port *port_dev = to_usb_port(dev); 421 422 if (port_dev->child) 423 usb_disable_usb2_hardware_lpm(port_dev->child); 424 } 425 426 static const struct dev_pm_ops usb_port_pm_ops = { 427 #ifdef CONFIG_PM 428 .runtime_suspend = usb_port_runtime_suspend, 429 .runtime_resume = usb_port_runtime_resume, 430 #endif 431 }; 432 433 const struct device_type usb_port_device_type = { 434 .name = "usb_port", 435 .release = usb_port_device_release, 436 .pm = &usb_port_pm_ops, 437 }; 438 439 static struct device_driver usb_port_driver = { 440 .name = "usb", 441 .owner = THIS_MODULE, 442 .shutdown = usb_port_shutdown, 443 }; 444 445 static int link_peers(struct usb_port *left, struct usb_port *right) 446 { 447 struct usb_port *ss_port, *hs_port; 448 int rc; 449 450 if (left->peer == right && right->peer == left) 451 return 0; 452 453 if (left->peer || right->peer) { 454 struct usb_port *lpeer = left->peer; 455 struct usb_port *rpeer = right->peer; 456 char *method; 457 458 if (left->location && left->location == right->location) 459 method = "location"; 460 else 461 method = "default"; 462 463 pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n", 464 dev_name(&left->dev), dev_name(&right->dev), method, 465 dev_name(&left->dev), 466 lpeer ? dev_name(&lpeer->dev) : "none", 467 dev_name(&right->dev), 468 rpeer ? dev_name(&rpeer->dev) : "none"); 469 return -EBUSY; 470 } 471 472 rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer"); 473 if (rc) 474 return rc; 475 rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer"); 476 if (rc) { 477 sysfs_remove_link(&left->dev.kobj, "peer"); 478 return rc; 479 } 480 481 /* 482 * We need to wake the HiSpeed port to make sure we don't race 483 * setting ->peer with usb_port_runtime_suspend(). Otherwise we 484 * may miss a suspend event for the SuperSpeed port. 485 */ 486 if (left->is_superspeed) { 487 ss_port = left; 488 WARN_ON(right->is_superspeed); 489 hs_port = right; 490 } else { 491 ss_port = right; 492 WARN_ON(!right->is_superspeed); 493 hs_port = left; 494 } 495 pm_runtime_get_sync(&hs_port->dev); 496 497 left->peer = right; 498 right->peer = left; 499 500 /* 501 * The SuperSpeed reference is dropped when the HiSpeed port in 502 * this relationship suspends, i.e. when it is safe to allow a 503 * SuperSpeed connection to drop since there is no risk of a 504 * device degrading to its powered-off HiSpeed connection. 505 * 506 * Also, drop the HiSpeed ref taken above. 507 */ 508 pm_runtime_get_sync(&ss_port->dev); 509 pm_runtime_put(&hs_port->dev); 510 511 return 0; 512 } 513 514 static void link_peers_report(struct usb_port *left, struct usb_port *right) 515 { 516 int rc; 517 518 rc = link_peers(left, right); 519 if (rc == 0) { 520 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev)); 521 } else { 522 dev_dbg(&left->dev, "failed to peer to %s (%d)\n", 523 dev_name(&right->dev), rc); 524 pr_warn_once("usb: port power management may be unreliable\n"); 525 usb_port_block_power_off = 1; 526 } 527 } 528 529 static void unlink_peers(struct usb_port *left, struct usb_port *right) 530 { 531 struct usb_port *ss_port, *hs_port; 532 533 WARN(right->peer != left || left->peer != right, 534 "%s and %s are not peers?\n", 535 dev_name(&left->dev), dev_name(&right->dev)); 536 537 /* 538 * We wake the HiSpeed port to make sure we don't race its 539 * usb_port_runtime_resume() event which takes a SuperSpeed ref 540 * when ->peer is !NULL. 541 */ 542 if (left->is_superspeed) { 543 ss_port = left; 544 hs_port = right; 545 } else { 546 ss_port = right; 547 hs_port = left; 548 } 549 550 pm_runtime_get_sync(&hs_port->dev); 551 552 sysfs_remove_link(&left->dev.kobj, "peer"); 553 right->peer = NULL; 554 sysfs_remove_link(&right->dev.kobj, "peer"); 555 left->peer = NULL; 556 557 /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */ 558 pm_runtime_put(&ss_port->dev); 559 560 /* Drop the ref taken above */ 561 pm_runtime_put(&hs_port->dev); 562 } 563 564 /* 565 * For each usb hub device in the system check to see if it is in the 566 * peer domain of the given port_dev, and if it is check to see if it 567 * has a port that matches the given port by location 568 */ 569 static int match_location(struct usb_device *peer_hdev, void *p) 570 { 571 int port1; 572 struct usb_hcd *hcd, *peer_hcd; 573 struct usb_port *port_dev = p, *peer; 574 struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev); 575 struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent); 576 577 if (!peer_hub || port_dev->connect_type == USB_PORT_NOT_USED) 578 return 0; 579 580 hcd = bus_to_hcd(hdev->bus); 581 peer_hcd = bus_to_hcd(peer_hdev->bus); 582 /* peer_hcd is provisional until we verify it against the known peer */ 583 if (peer_hcd != hcd->shared_hcd) 584 return 0; 585 586 for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) { 587 peer = peer_hub->ports[port1 - 1]; 588 if (peer && peer->connect_type != USB_PORT_NOT_USED && 589 peer->location == port_dev->location) { 590 link_peers_report(port_dev, peer); 591 return 1; /* done */ 592 } 593 } 594 595 return 0; 596 } 597 598 /* 599 * Find the peer port either via explicit platform firmware "location" 600 * data, the peer hcd for root hubs, or the upstream peer relationship 601 * for all other hubs. 602 */ 603 static void find_and_link_peer(struct usb_hub *hub, int port1) 604 { 605 struct usb_port *port_dev = hub->ports[port1 - 1], *peer; 606 struct usb_device *hdev = hub->hdev; 607 struct usb_device *peer_hdev; 608 struct usb_hub *peer_hub; 609 610 /* 611 * If location data is available then we can only peer this port 612 * by a location match, not the default peer (lest we create a 613 * situation where we need to go back and undo a default peering 614 * when the port is later peered by location data) 615 */ 616 if (port_dev->location) { 617 /* we link the peer in match_location() if found */ 618 usb_for_each_dev(port_dev, match_location); 619 return; 620 } else if (!hdev->parent) { 621 struct usb_hcd *hcd = bus_to_hcd(hdev->bus); 622 struct usb_hcd *peer_hcd = hcd->shared_hcd; 623 624 if (!peer_hcd) 625 return; 626 627 peer_hdev = peer_hcd->self.root_hub; 628 } else { 629 struct usb_port *upstream; 630 struct usb_device *parent = hdev->parent; 631 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent); 632 633 if (!parent_hub) 634 return; 635 636 upstream = parent_hub->ports[hdev->portnum - 1]; 637 if (!upstream || !upstream->peer) 638 return; 639 640 peer_hdev = upstream->peer->child; 641 } 642 643 peer_hub = usb_hub_to_struct_hub(peer_hdev); 644 if (!peer_hub || port1 > peer_hdev->maxchild) 645 return; 646 647 /* 648 * we found a valid default peer, last check is to make sure it 649 * does not have location data 650 */ 651 peer = peer_hub->ports[port1 - 1]; 652 if (peer && peer->location == 0) 653 link_peers_report(port_dev, peer); 654 } 655 656 static int connector_bind(struct device *dev, struct device *connector, void *data) 657 { 658 struct usb_port *port_dev = to_usb_port(dev); 659 int ret; 660 661 ret = sysfs_create_link(&dev->kobj, &connector->kobj, "connector"); 662 if (ret) 663 return ret; 664 665 ret = sysfs_create_link(&connector->kobj, &dev->kobj, dev_name(dev)); 666 if (ret) { 667 sysfs_remove_link(&dev->kobj, "connector"); 668 return ret; 669 } 670 671 port_dev->connector = data; 672 673 /* 674 * If there is already USB device connected to the port, letting the 675 * Type-C connector know about it immediately. 676 */ 677 if (port_dev->child) 678 typec_attach(port_dev->connector, &port_dev->child->dev); 679 680 return 0; 681 } 682 683 static void connector_unbind(struct device *dev, struct device *connector, void *data) 684 { 685 struct usb_port *port_dev = to_usb_port(dev); 686 687 sysfs_remove_link(&connector->kobj, dev_name(dev)); 688 sysfs_remove_link(&dev->kobj, "connector"); 689 port_dev->connector = NULL; 690 } 691 692 static const struct component_ops connector_ops = { 693 .bind = connector_bind, 694 .unbind = connector_unbind, 695 }; 696 697 int usb_hub_create_port_device(struct usb_hub *hub, int port1) 698 { 699 struct usb_port *port_dev; 700 struct usb_device *hdev = hub->hdev; 701 int retval; 702 703 port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL); 704 if (!port_dev) 705 return -ENOMEM; 706 707 port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL); 708 if (!port_dev->req) { 709 kfree(port_dev); 710 return -ENOMEM; 711 } 712 713 port_dev->connect_type = usb_of_get_connect_type(hdev, port1); 714 hub->ports[port1 - 1] = port_dev; 715 port_dev->portnum = port1; 716 set_bit(port1, hub->power_bits); 717 port_dev->dev.parent = hub->intfdev; 718 if (hub_is_superspeed(hdev)) { 719 port_dev->is_superspeed = 1; 720 port_dev->usb3_lpm_u1_permit = 1; 721 port_dev->usb3_lpm_u2_permit = 1; 722 port_dev->dev.groups = port_dev_usb3_group; 723 } else 724 port_dev->dev.groups = port_dev_group; 725 port_dev->dev.type = &usb_port_device_type; 726 port_dev->dev.driver = &usb_port_driver; 727 dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev), 728 port1); 729 mutex_init(&port_dev->status_lock); 730 retval = device_register(&port_dev->dev); 731 if (retval) { 732 put_device(&port_dev->dev); 733 return retval; 734 } 735 736 port_dev->state_kn = sysfs_get_dirent(port_dev->dev.kobj.sd, "state"); 737 if (!port_dev->state_kn) { 738 dev_err(&port_dev->dev, "failed to sysfs_get_dirent 'state'\n"); 739 retval = -ENODEV; 740 goto err_unregister; 741 } 742 743 /* Set default policy of port-poweroff disabled. */ 744 retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req, 745 DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF); 746 if (retval < 0) { 747 goto err_put_kn; 748 } 749 750 retval = component_add(&port_dev->dev, &connector_ops); 751 if (retval) { 752 dev_warn(&port_dev->dev, "failed to add component\n"); 753 goto err_put_kn; 754 } 755 756 find_and_link_peer(hub, port1); 757 758 /* 759 * Enable runtime pm and hold a refernce that hub_configure() 760 * will drop once the PM_QOS_NO_POWER_OFF flag state has been set 761 * and the hub has been fully registered (hdev->maxchild set). 762 */ 763 pm_runtime_set_active(&port_dev->dev); 764 pm_runtime_get_noresume(&port_dev->dev); 765 pm_runtime_enable(&port_dev->dev); 766 device_enable_async_suspend(&port_dev->dev); 767 768 /* 769 * Keep hidden the ability to enable port-poweroff if the hub 770 * does not support power switching. 771 */ 772 if (!hub_is_port_power_switchable(hub)) 773 return 0; 774 775 /* Attempt to let userspace take over the policy. */ 776 retval = dev_pm_qos_expose_flags(&port_dev->dev, 777 PM_QOS_FLAG_NO_POWER_OFF); 778 if (retval < 0) { 779 dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n"); 780 return 0; 781 } 782 783 /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */ 784 retval = dev_pm_qos_remove_request(port_dev->req); 785 if (retval >= 0) { 786 kfree(port_dev->req); 787 port_dev->req = NULL; 788 } 789 return 0; 790 791 err_put_kn: 792 sysfs_put(port_dev->state_kn); 793 err_unregister: 794 device_unregister(&port_dev->dev); 795 796 return retval; 797 } 798 799 void usb_hub_remove_port_device(struct usb_hub *hub, int port1) 800 { 801 struct usb_port *port_dev = hub->ports[port1 - 1]; 802 struct usb_port *peer; 803 804 peer = port_dev->peer; 805 if (peer) 806 unlink_peers(port_dev, peer); 807 component_del(&port_dev->dev, &connector_ops); 808 sysfs_put(port_dev->state_kn); 809 device_unregister(&port_dev->dev); 810 } 811