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 struct attribute *port_dev_attrs[] = {
  54         &dev_attr_connect_type.attr,
  55         NULL,
  56 };
  57
  58 static struct attribute_group port_dev_attr_grp = {
  59         .attrs = port_dev_attrs,
  60 };
  61
  62 static const struct attribute_group *port_dev_group[] = {
  63         &port_dev_attr_grp,
  64         NULL,
  65 };
  66
  67 static void usb_port_device_release(struct device *dev)
  68 {
  69         struct usb_port *port_dev = to_usb_port(dev);
  70
  71         kfree(port_dev->req);
  72         kfree(port_dev);
  73 }
  74
  75 #ifdef CONFIG_PM_RUNTIME
  76 static int usb_port_runtime_resume(struct device *dev)
  77 {
  78         struct usb_port *port_dev = to_usb_port(dev);
  79         struct usb_device *hdev = to_usb_device(dev->parent->parent);
  80         struct usb_interface *intf = to_usb_interface(dev->parent);
  81         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
  82         struct usb_device *udev = port_dev->child;
  83         struct usb_port *peer = port_dev->peer;
  84         int port1 = port_dev->portnum;
  85         int retval;
  86
  87         if (!hub)
  88                 return -EINVAL;
  89         if (hub->in_reset) {
  90                 set_bit(port1, hub->power_bits);
  91                 return 0;
  92         }
  93
  94         /*
  95          * Power on our usb3 peer before this usb2 port to prevent a usb3
  96          * device from degrading to its usb2 connection
  97          */
  98         if (!port_dev->is_superspeed && peer)
  99                 pm_runtime_get_sync(&peer->dev);
 100
 101         usb_autopm_get_interface(intf);
 102         retval = usb_hub_set_port_power(hdev, hub, port1, true);
 103         msleep(hub_power_on_good_delay(hub));
 104         if (udev && !retval) {
 105                 /*
 106                  * Attempt to wait for usb hub port to be reconnected in order
 107                  * to make the resume procedure successful.  The device may have
 108                  * disconnected while the port was powered off, so ignore the
 109                  * return status.
 110                  */
 111                 retval = hub_port_debounce_be_connected(hub, port1);
 112                 if (retval < 0)
 113                         dev_dbg(&port_dev->dev, "can't get reconnection after setting port  power on, status %d\n",
 114                                         retval);
 115                 retval = 0;
 116
 117                 /* Force the child awake to revalidate after the power loss. */
 118                 if (!test_and_set_bit(port1, hub->child_usage_bits)) {
 119                         pm_runtime_get_noresume(&port_dev->dev);
 120                         pm_request_resume(&udev->dev);
 121                 }
 122         }
 123
 124         usb_autopm_put_interface(intf);
 125
 126         return retval;
 127 }
 128
 129 static int usb_port_runtime_suspend(struct device *dev)
 130 {
 131         struct usb_port *port_dev = to_usb_port(dev);
 132         struct usb_device *hdev = to_usb_device(dev->parent->parent);
 133         struct usb_interface *intf = to_usb_interface(dev->parent);
 134         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
 135         struct usb_port *peer = port_dev->peer;
 136         int port1 = port_dev->portnum;
 137         int retval;
 138
 139         if (!hub)
 140                 return -EINVAL;
 141         if (hub->in_reset)
 142                 return -EBUSY;
 143
 144         if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
 145                         == PM_QOS_FLAGS_ALL)
 146                 return -EAGAIN;
 147
 148         if (usb_port_block_power_off)
 149                 return -EBUSY;
 150
 151         usb_autopm_get_interface(intf);
 152         retval = usb_hub_set_port_power(hdev, hub, port1, false);
 153         usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
 154         if (!port_dev->is_superspeed)
 155                 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
 156         usb_autopm_put_interface(intf);
 157
 158         /*
 159          * Our peer usb3 port may now be able to suspend, so
 160          * asynchronously queue a suspend request to observe that this
 161          * usb2 port is now off.
 162          */
 163         if (!port_dev->is_superspeed && peer)
 164                 pm_runtime_put(&peer->dev);
 165
 166         return retval;
 167 }
 168 #endif
 169
 170 static const struct dev_pm_ops usb_port_pm_ops = {
 171 #ifdef CONFIG_PM_RUNTIME
 172         .runtime_suspend =      usb_port_runtime_suspend,
 173         .runtime_resume =       usb_port_runtime_resume,
 174 #endif
 175 };
 176
 177 struct device_type usb_port_device_type = {
 178         .name =         "usb_port",
 179         .release =      usb_port_device_release,
 180         .pm =           &usb_port_pm_ops,
 181 };
 182
 183 static struct device_driver usb_port_driver = {
 184         .name = "usb",
 185         .owner = THIS_MODULE,
 186 };
 187
 188 static int link_peers(struct usb_port *left, struct usb_port *right)
 189 {
 190         struct usb_port *ss_port, *hs_port;
 191         int rc;
 192
 193         if (left->peer == right && right->peer == left)
 194                 return 0;
 195
 196         if (left->peer || right->peer) {
 197                 struct usb_port *lpeer = left->peer;
 198                 struct usb_port *rpeer = right->peer;
 199                 char *method;
 200
 201                 if (left->location && left->location == right->location)
 202                         method = "location";
 203                 else
 204                         method = "default";
 205
 206                 pr_warn("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
 207                         dev_name(&left->dev), dev_name(&right->dev), method,
 208                         dev_name(&left->dev),
 209                         lpeer ? dev_name(&lpeer->dev) : "none",
 210                         dev_name(&right->dev),
 211                         rpeer ? dev_name(&rpeer->dev) : "none");
 212                 return -EBUSY;
 213         }
 214
 215         rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
 216         if (rc)
 217                 return rc;
 218         rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
 219         if (rc) {
 220                 sysfs_remove_link(&left->dev.kobj, "peer");
 221                 return rc;
 222         }
 223
 224         /*
 225          * We need to wake the HiSpeed port to make sure we don't race
 226          * setting ->peer with usb_port_runtime_suspend().  Otherwise we
 227          * may miss a suspend event for the SuperSpeed port.
 228          */
 229         if (left->is_superspeed) {
 230                 ss_port = left;
 231                 WARN_ON(right->is_superspeed);
 232                 hs_port = right;
 233         } else {
 234                 ss_port = right;
 235                 WARN_ON(!right->is_superspeed);
 236                 hs_port = left;
 237         }
 238         pm_runtime_get_sync(&hs_port->dev);
 239
 240         left->peer = right;
 241         right->peer = left;
 242
 243         /*
 244          * The SuperSpeed reference is dropped when the HiSpeed port in
 245          * this relationship suspends, i.e. when it is safe to allow a
 246          * SuperSpeed connection to drop since there is no risk of a
 247          * device degrading to its powered-off HiSpeed connection.
 248          *
 249          * Also, drop the HiSpeed ref taken above.
 250          */
 251         pm_runtime_get_sync(&ss_port->dev);
 252         pm_runtime_put(&hs_port->dev);
 253
 254         return 0;
 255 }
 256
 257 static void link_peers_report(struct usb_port *left, struct usb_port *right)
 258 {
 259         int rc;
 260
 261         rc = link_peers(left, right);
 262         if (rc == 0) {
 263                 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
 264         } else {
 265                 dev_warn(&left->dev, "failed to peer to %s (%d)\n",
 266                                 dev_name(&right->dev), rc);
 267                 pr_warn_once("usb: port power management may be unreliable\n");
 268                 usb_port_block_power_off = 1;
 269         }
 270 }
 271
 272 static void unlink_peers(struct usb_port *left, struct usb_port *right)
 273 {
 274         struct usb_port *ss_port, *hs_port;
 275
 276         WARN(right->peer != left || left->peer != right,
 277                         "%s and %s are not peers?\n",
 278                         dev_name(&left->dev), dev_name(&right->dev));
 279
 280         /*
 281          * We wake the HiSpeed port to make sure we don't race its
 282          * usb_port_runtime_resume() event which takes a SuperSpeed ref
 283          * when ->peer is !NULL.
 284          */
 285         if (left->is_superspeed) {
 286                 ss_port = left;
 287                 hs_port = right;
 288         } else {
 289                 ss_port = right;
 290                 hs_port = left;
 291         }
 292
 293         pm_runtime_get_sync(&hs_port->dev);
 294
 295         sysfs_remove_link(&left->dev.kobj, "peer");
 296         right->peer = NULL;
 297         sysfs_remove_link(&right->dev.kobj, "peer");
 298         left->peer = NULL;
 299
 300         /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
 301         pm_runtime_put(&ss_port->dev);
 302
 303         /* Drop the ref taken above */
 304         pm_runtime_put(&hs_port->dev);
 305 }
 306
 307 /*
 308  * For each usb hub device in the system check to see if it is in the
 309  * peer domain of the given port_dev, and if it is check to see if it
 310  * has a port that matches the given port by location
 311  */
 312 static int match_location(struct usb_device *peer_hdev, void *p)
 313 {
 314         int port1;
 315         struct usb_hcd *hcd, *peer_hcd;
 316         struct usb_port *port_dev = p, *peer;
 317         struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
 318         struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
 319
 320         if (!peer_hub)
 321                 return 0;
 322
 323         hcd = bus_to_hcd(hdev->bus);
 324         peer_hcd = bus_to_hcd(peer_hdev->bus);
 325         /* peer_hcd is provisional until we verify it against the known peer */
 326         if (peer_hcd != hcd->shared_hcd)
 327                 return 0;
 328
 329         for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
 330                 peer = peer_hub->ports[port1 - 1];
 331                 if (peer && peer->location == port_dev->location) {
 332                         link_peers_report(port_dev, peer);
 333                         return 1; /* done */
 334                 }
 335         }
 336
 337         return 0;
 338 }
 339
 340 /*
 341  * Find the peer port either via explicit platform firmware "location"
 342  * data, the peer hcd for root hubs, or the upstream peer relationship
 343  * for all other hubs.
 344  */
 345 static void find_and_link_peer(struct usb_hub *hub, int port1)
 346 {
 347         struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
 348         struct usb_device *hdev = hub->hdev;
 349         struct usb_device *peer_hdev;
 350         struct usb_hub *peer_hub;
 351
 352         /*
 353          * If location data is available then we can only peer this port
 354          * by a location match, not the default peer (lest we create a
 355          * situation where we need to go back and undo a default peering
 356          * when the port is later peered by location data)
 357          */
 358         if (port_dev->location) {
 359                 /* we link the peer in match_location() if found */
 360                 usb_for_each_dev(port_dev, match_location);
 361                 return;
 362         } else if (!hdev->parent) {
 363                 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
 364                 struct usb_hcd *peer_hcd = hcd->shared_hcd;
 365
 366                 if (!peer_hcd)
 367                         return;
 368
 369                 peer_hdev = peer_hcd->self.root_hub;
 370         } else {
 371                 struct usb_port *upstream;
 372                 struct usb_device *parent = hdev->parent;
 373                 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
 374
 375                 if (!parent_hub)
 376                         return;
 377
 378                 upstream = parent_hub->ports[hdev->portnum - 1];
 379                 if (!upstream || !upstream->peer)
 380                         return;
 381
 382                 peer_hdev = upstream->peer->child;
 383         }
 384
 385         peer_hub = usb_hub_to_struct_hub(peer_hdev);
 386         if (!peer_hub || port1 > peer_hdev->maxchild)
 387                 return;
 388
 389         /*
 390          * we found a valid default peer, last check is to make sure it
 391          * does not have location data
 392          */
 393         peer = peer_hub->ports[port1 - 1];
 394         if (peer && peer->location == 0)
 395                 link_peers_report(port_dev, peer);
 396 }
 397
 398 int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 399 {
 400         struct usb_port *port_dev;
 401         int retval;
 402
 403         port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
 404         if (!port_dev)
 405                 return -ENOMEM;
 406
 407         port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
 408         if (!port_dev->req) {
 409                 kfree(port_dev);
 410                 return -ENOMEM;
 411         }
 412
 413         hub->ports[port1 - 1] = port_dev;
 414         port_dev->portnum = port1;
 415         set_bit(port1, hub->power_bits);
 416         port_dev->dev.parent = hub->intfdev;
 417         port_dev->dev.groups = port_dev_group;
 418         port_dev->dev.type = &usb_port_device_type;
 419         port_dev->dev.driver = &usb_port_driver;
 420         if (hub_is_superspeed(hub->hdev))
 421                 port_dev->is_superspeed = 1;
 422         dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
 423                         port1);
 424         mutex_init(&port_dev->status_lock);
 425         retval = device_register(&port_dev->dev);
 426         if (retval) {
 427                 put_device(&port_dev->dev);
 428                 return retval;
 429         }
 430
 431         /* Set default policy of port-poweroff disabled. */
 432         retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
 433                         DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
 434         if (retval < 0) {
 435                 device_unregister(&port_dev->dev);
 436                 return retval;
 437         }
 438
 439         find_and_link_peer(hub, port1);
 440
 441         /*
 442          * Enable runtime pm and hold a refernce that hub_configure()
 443          * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
 444          * and the hub has been fully registered (hdev->maxchild set).
 445          */
 446         pm_runtime_set_active(&port_dev->dev);
 447         pm_runtime_get_noresume(&port_dev->dev);
 448         pm_runtime_enable(&port_dev->dev);
 449         device_enable_async_suspend(&port_dev->dev);
 450
 451         /*
 452          * Keep hidden the ability to enable port-poweroff if the hub
 453          * does not support power switching.
 454          */
 455         if (!hub_is_port_power_switchable(hub))
 456                 return 0;
 457
 458         /* Attempt to let userspace take over the policy. */
 459         retval = dev_pm_qos_expose_flags(&port_dev->dev,
 460                         PM_QOS_FLAG_NO_POWER_OFF);
 461         if (retval < 0) {
 462                 dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
 463                 return 0;
 464         }
 465
 466         /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
 467         retval = dev_pm_qos_remove_request(port_dev->req);
 468         if (retval >= 0) {
 469                 kfree(port_dev->req);
 470                 port_dev->req = NULL;
 471         }
 472         return 0;
 473 }
 474
 475 void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
 476 {
 477         struct usb_port *port_dev = hub->ports[port1 - 1];
 478         struct usb_port *peer;
 479
 480         peer = port_dev->peer;
 481         if (peer)
 482                 unlink_peers(port_dev, peer);
 483         device_unregister(&port_dev->dev);
 484 }