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/slab.h>
  11 #include <linux/pm_qos.h>
  12
  13 #include "hub.h"
  14
  15 static int usb_port_block_power_off;
  16
  17 static const struct attribute_group *port_dev_group[];
  18
  19 static 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 }
  26 static DEVICE_ATTR_RO(location);
  27
  28 static 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 }
  51 static DEVICE_ATTR_RO(connect_type);
  52
  53 static 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 }
  60 static DEVICE_ATTR_RO(over_current_count);
  61
  62 static 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
  70 static 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 }
  82 static DEVICE_ATTR_RW(quirks);
  83
  84 static 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
 105 static 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 }
 148 static DEVICE_ATTR_RW(usb3_lpm_permit);
 149
 150 static 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
 158 static struct attribute_group port_dev_attr_grp = {
 159         .attrs = port_dev_attrs,
 160 };
 161
 162 static const struct attribute_group *port_dev_group[] = {
 163         &port_dev_attr_grp,
 164         NULL,
 165 };
 166
 167 static struct attribute *port_dev_usb3_attrs[] = {
 168         &dev_attr_usb3_lpm_permit.attr,
 169         NULL,
 170 };
 171
 172 static struct attribute_group port_dev_usb3_attr_grp = {
 173         .attrs = port_dev_usb3_attrs,
 174 };
 175
 176 static const struct attribute_group *port_dev_usb3_group[] = {
 177         &port_dev_attr_grp,
 178         &port_dev_usb3_attr_grp,
 179         NULL,
 180 };
 181
 182 static 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
 191 static 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
 247 static 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
 288 static 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
 296 static 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
 303 struct device_type usb_port_device_type = {
 304         .name =         "usb_port",
 305         .release =      usb_port_device_release,
 306         .pm =           &usb_port_pm_ops,
 307 };
 308
 309 static struct device_driver usb_port_driver = {
 310         .name = "usb",
 311         .owner = THIS_MODULE,
 312         .shutdown = usb_port_shutdown,
 313 };
 314
 315 static 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
 384 static 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
 399 static 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  */
 439 static 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  */
 472 static 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
 525 int 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
 608 void 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 }