drivers/usb/core/port.c

   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
  24 static int usb_port_block_power_off;
  25
  26 static const struct attribute_group *port_dev_group[];
  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 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
  74 static 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 }
 117 static DEVICE_ATTR_RW(usb3_lpm_permit);
 118
 119 static struct attribute *port_dev_attrs[] = {
 120         &dev_attr_connect_type.attr,
 121         NULL,
 122 };
 123
 124 static struct attribute_group port_dev_attr_grp = {
 125         .attrs = port_dev_attrs,
 126 };
 127
 128 static const struct attribute_group *port_dev_group[] = {
 129         &port_dev_attr_grp,
 130         NULL,
 131 };
 132
 133 static struct attribute *port_dev_usb3_attrs[] = {
 134         &dev_attr_usb3_lpm_permit.attr,
 135         NULL,
 136 };
 137
 138 static struct attribute_group port_dev_usb3_attr_grp = {
 139         .attrs = port_dev_usb3_attrs,
 140 };
 141
 142 static const struct attribute_group *port_dev_usb3_group[] = {
 143         &port_dev_attr_grp,
 144         &port_dev_usb3_attr_grp,
 145         NULL,
 146 };
 147
 148 static 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
 157 static 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
 213 static 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
 253 static int usb_port_prepare(struct device *dev)
 254 {
 255         return 1;
 256 }
 257 #endif
 258
 259 static const struct dev_pm_ops usb_port_pm_ops = {
 260 #ifdef CONFIG_PM
 261         .runtime_suspend =      usb_port_runtime_suspend,
 262         .runtime_resume =       usb_port_runtime_resume,
 263         .prepare =              usb_port_prepare,
 264 #endif
 265 };
 266
 267 struct device_type usb_port_device_type = {
 268         .name =         "usb_port",
 269         .release =      usb_port_device_release,
 270         .pm =           &usb_port_pm_ops,
 271 };
 272
 273 static struct device_driver usb_port_driver = {
 274         .name = "usb",
 275         .owner = THIS_MODULE,
 276 };
 277
 278 static int link_peers(struct usb_port *left, struct usb_port *right)
 279 {
 280         struct usb_port *ss_port, *hs_port;
 281         int rc;
 282
 283         if (left->peer == right && right->peer == left)
 284                 return 0;
 285
 286         if (left->peer || right->peer) {
 287                 struct usb_port *lpeer = left->peer;
 288                 struct usb_port *rpeer = right->peer;
 289                 char *method;
 290
 291                 if (left->location && left->location == right->location)
 292                         method = "location";
 293                 else
 294                         method = "default";
 295
 296                 pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
 297                         dev_name(&left->dev), dev_name(&right->dev), method,
 298                         dev_name(&left->dev),
 299                         lpeer ? dev_name(&lpeer->dev) : "none",
 300                         dev_name(&right->dev),
 301                         rpeer ? dev_name(&rpeer->dev) : "none");
 302                 return -EBUSY;
 303         }
 304
 305         rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
 306         if (rc)
 307                 return rc;
 308         rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
 309         if (rc) {
 310                 sysfs_remove_link(&left->dev.kobj, "peer");
 311                 return rc;
 312         }
 313
 314         /*
 315          * We need to wake the HiSpeed port to make sure we don't race
 316          * setting ->peer with usb_port_runtime_suspend().  Otherwise we
 317          * may miss a suspend event for the SuperSpeed port.
 318          */
 319         if (left->is_superspeed) {
 320                 ss_port = left;
 321                 WARN_ON(right->is_superspeed);
 322                 hs_port = right;
 323         } else {
 324                 ss_port = right;
 325                 WARN_ON(!right->is_superspeed);
 326                 hs_port = left;
 327         }
 328         pm_runtime_get_sync(&hs_port->dev);
 329
 330         left->peer = right;
 331         right->peer = left;
 332
 333         /*
 334          * The SuperSpeed reference is dropped when the HiSpeed port in
 335          * this relationship suspends, i.e. when it is safe to allow a
 336          * SuperSpeed connection to drop since there is no risk of a
 337          * device degrading to its powered-off HiSpeed connection.
 338          *
 339          * Also, drop the HiSpeed ref taken above.
 340          */
 341         pm_runtime_get_sync(&ss_port->dev);
 342         pm_runtime_put(&hs_port->dev);
 343
 344         return 0;
 345 }
 346
 347 static void link_peers_report(struct usb_port *left, struct usb_port *right)
 348 {
 349         int rc;
 350
 351         rc = link_peers(left, right);
 352         if (rc == 0) {
 353                 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
 354         } else {
 355                 dev_dbg(&left->dev, "failed to peer to %s (%d)\n",
 356                                 dev_name(&right->dev), rc);
 357                 pr_warn_once("usb: port power management may be unreliable\n");
 358                 usb_port_block_power_off = 1;
 359         }
 360 }
 361
 362 static void unlink_peers(struct usb_port *left, struct usb_port *right)
 363 {
 364         struct usb_port *ss_port, *hs_port;
 365
 366         WARN(right->peer != left || left->peer != right,
 367                         "%s and %s are not peers?\n",
 368                         dev_name(&left->dev), dev_name(&right->dev));
 369
 370         /*
 371          * We wake the HiSpeed port to make sure we don't race its
 372          * usb_port_runtime_resume() event which takes a SuperSpeed ref
 373          * when ->peer is !NULL.
 374          */
 375         if (left->is_superspeed) {
 376                 ss_port = left;
 377                 hs_port = right;
 378         } else {
 379                 ss_port = right;
 380                 hs_port = left;
 381         }
 382
 383         pm_runtime_get_sync(&hs_port->dev);
 384
 385         sysfs_remove_link(&left->dev.kobj, "peer");
 386         right->peer = NULL;
 387         sysfs_remove_link(&right->dev.kobj, "peer");
 388         left->peer = NULL;
 389
 390         /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
 391         pm_runtime_put(&ss_port->dev);
 392
 393         /* Drop the ref taken above */
 394         pm_runtime_put(&hs_port->dev);
 395 }
 396
 397 /*
 398  * For each usb hub device in the system check to see if it is in the
 399  * peer domain of the given port_dev, and if it is check to see if it
 400  * has a port that matches the given port by location
 401  */
 402 static int match_location(struct usb_device *peer_hdev, void *p)
 403 {
 404         int port1;
 405         struct usb_hcd *hcd, *peer_hcd;
 406         struct usb_port *port_dev = p, *peer;
 407         struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
 408         struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
 409
 410         if (!peer_hub)
 411                 return 0;
 412
 413         hcd = bus_to_hcd(hdev->bus);
 414         peer_hcd = bus_to_hcd(peer_hdev->bus);
 415         /* peer_hcd is provisional until we verify it against the known peer */
 416         if (peer_hcd != hcd->shared_hcd)
 417                 return 0;
 418
 419         for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
 420                 peer = peer_hub->ports[port1 - 1];
 421                 if (peer && peer->location == port_dev->location) {
 422                         link_peers_report(port_dev, peer);
 423                         return 1; /* done */
 424                 }
 425         }
 426
 427         return 0;
 428 }
 429
 430 /*
 431  * Find the peer port either via explicit platform firmware "location"
 432  * data, the peer hcd for root hubs, or the upstream peer relationship
 433  * for all other hubs.
 434  */
 435 static void find_and_link_peer(struct usb_hub *hub, int port1)
 436 {
 437         struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
 438         struct usb_device *hdev = hub->hdev;
 439         struct usb_device *peer_hdev;
 440         struct usb_hub *peer_hub;
 441
 442         /*
 443          * If location data is available then we can only peer this port
 444          * by a location match, not the default peer (lest we create a
 445          * situation where we need to go back and undo a default peering
 446          * when the port is later peered by location data)
 447          */
 448         if (port_dev->location) {
 449                 /* we link the peer in match_location() if found */
 450                 usb_for_each_dev(port_dev, match_location);
 451                 return;
 452         } else if (!hdev->parent) {
 453                 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
 454                 struct usb_hcd *peer_hcd = hcd->shared_hcd;
 455
 456                 if (!peer_hcd)
 457                         return;
 458
 459                 peer_hdev = peer_hcd->self.root_hub;
 460         } else {
 461                 struct usb_port *upstream;
 462                 struct usb_device *parent = hdev->parent;
 463                 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
 464
 465                 if (!parent_hub)
 466                         return;
 467
 468                 upstream = parent_hub->ports[hdev->portnum - 1];
 469                 if (!upstream || !upstream->peer)
 470                         return;
 471
 472                 peer_hdev = upstream->peer->child;
 473         }
 474
 475         peer_hub = usb_hub_to_struct_hub(peer_hdev);
 476         if (!peer_hub || port1 > peer_hdev->maxchild)
 477                 return;
 478
 479         /*
 480          * we found a valid default peer, last check is to make sure it
 481          * does not have location data
 482          */
 483         peer = peer_hub->ports[port1 - 1];
 484         if (peer && peer->location == 0)
 485                 link_peers_report(port_dev, peer);
 486 }
 487
 488 int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 489 {
 490         struct usb_port *port_dev;
 491         struct usb_device *hdev = hub->hdev;
 492         int retval;
 493
 494         port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
 495         if (!port_dev)
 496                 return -ENOMEM;
 497
 498         port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
 499         if (!port_dev->req) {
 500                 kfree(port_dev);
 501                 return -ENOMEM;
 502         }
 503
 504         hub->ports[port1 - 1] = port_dev;
 505         port_dev->portnum = port1;
 506         set_bit(port1, hub->power_bits);
 507         port_dev->dev.parent = hub->intfdev;
 508         if (hub_is_superspeed(hdev)) {
 509                 port_dev->usb3_lpm_u1_permit = 1;
 510                 port_dev->usb3_lpm_u2_permit = 1;
 511                 port_dev->dev.groups = port_dev_usb3_group;
 512         } else
 513                 port_dev->dev.groups = port_dev_group;
 514         port_dev->dev.type = &usb_port_device_type;
 515         port_dev->dev.driver = &usb_port_driver;
 516         if (hub_is_superspeed(hub->hdev))
 517                 port_dev->is_superspeed = 1;
 518         dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
 519                         port1);
 520         mutex_init(&port_dev->status_lock);
 521         retval = device_register(&port_dev->dev);
 522         if (retval) {
 523                 put_device(&port_dev->dev);
 524                 return retval;
 525         }
 526
 527         /* Set default policy of port-poweroff disabled. */
 528         retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
 529                         DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
 530         if (retval < 0) {
 531                 device_unregister(&port_dev->dev);
 532                 return retval;
 533         }
 534
 535         find_and_link_peer(hub, port1);
 536
 537         /*
 538          * Enable runtime pm and hold a refernce that hub_configure()
 539          * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
 540          * and the hub has been fully registered (hdev->maxchild set).
 541          */
 542         pm_runtime_set_active(&port_dev->dev);
 543         pm_runtime_get_noresume(&port_dev->dev);
 544         pm_runtime_enable(&port_dev->dev);
 545         device_enable_async_suspend(&port_dev->dev);
 546
 547         /*
 548          * Keep hidden the ability to enable port-poweroff if the hub
 549          * does not support power switching.
 550          */
 551         if (!hub_is_port_power_switchable(hub))
 552                 return 0;
 553
 554         /* Attempt to let userspace take over the policy. */
 555         retval = dev_pm_qos_expose_flags(&port_dev->dev,
 556                         PM_QOS_FLAG_NO_POWER_OFF);
 557         if (retval < 0) {
 558                 dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
 559                 return 0;
 560         }
 561
 562         /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
 563         retval = dev_pm_qos_remove_request(port_dev->req);
 564         if (retval >= 0) {
 565                 kfree(port_dev->req);
 566                 port_dev->req = NULL;
 567         }
 568         return 0;
 569 }
 570
 571 void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
 572 {
 573         struct usb_port *port_dev = hub->ports[port1 - 1];
 574         struct usb_port *peer;
 575
 576         peer = port_dev->peer;
 577         if (peer)
 578                 unlink_peers(port_dev, peer);
 579         device_unregister(&port_dev->dev);
 580 }