drivers/usb/core/hcd.c

   1 /*
   2  * (C) Copyright Linus Torvalds 1999
   3  * (C) Copyright Johannes Erdfelt 1999-2001
   4  * (C) Copyright Andreas Gal 1999
   5  * (C) Copyright Gregory P. Smith 1999
   6  * (C) Copyright Deti Fliegl 1999
   7  * (C) Copyright Randy Dunlap 2000
   8  * (C) Copyright David Brownell 2000-2002
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by the
  12  * Free Software Foundation; either version 2 of the License, or (at your
  13  * option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18  * for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/version.h>
  27 #include <linux/kernel.h>
  28 #include <linux/slab.h>
  29 #include <linux/completion.h>
  30 #include <linux/utsname.h>
  31 #include <linux/mm.h>
  32 #include <asm/io.h>
  33 #include <asm/scatterlist.h>
  34 #include <linux/device.h>
  35 #include <linux/dma-mapping.h>
  36 #include <linux/mutex.h>
  37 #include <asm/irq.h>
  38 #include <asm/byteorder.h>
  39 #include <linux/platform_device.h>
  40 #include <linux/workqueue.h>
  41
  42 #include <linux/usb.h>
  43
  44 #include "usb.h"
  45 #include "hcd.h"
  46 #include "hub.h"
  47
  48
  49 /*-------------------------------------------------------------------------*/
  50
  51 /*
  52  * USB Host Controller Driver framework
  53  *
  54  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
  55  * HCD-specific behaviors/bugs.
  56  *
  57  * This does error checks, tracks devices and urbs, and delegates to a
  58  * "hc_driver" only for code (and data) that really needs to know about
  59  * hardware differences.  That includes root hub registers, i/o queues,
  60  * and so on ... but as little else as possible.
  61  *
  62  * Shared code includes most of the "root hub" code (these are emulated,
  63  * though each HC's hardware works differently) and PCI glue, plus request
  64  * tracking overhead.  The HCD code should only block on spinlocks or on
  65  * hardware handshaking; blocking on software events (such as other kernel
  66  * threads releasing resources, or completing actions) is all generic.
  67  *
  68  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
  69  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
  70  * only by the hub driver ... and that neither should be seen or used by
  71  * usb client device drivers.
  72  *
  73  * Contributors of ideas or unattributed patches include: David Brownell,
  74  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
  75  *
  76  * HISTORY:
  77  * 2002-02-21   Pull in most of the usb_bus support from usb.c; some
  78  *              associated cleanup.  "usb_hcd" still != "usb_bus".
  79  * 2001-12-12   Initial patch version for Linux 2.5.1 kernel.
  80  */
  81
  82 /*-------------------------------------------------------------------------*/
  83
  84 /* host controllers we manage */
  85 LIST_HEAD (usb_bus_list);
  86 EXPORT_SYMBOL_GPL (usb_bus_list);
  87
  88 /* used when allocating bus numbers */
  89 #define USB_MAXBUS              64
  90 struct usb_busmap {
  91         unsigned long busmap [USB_MAXBUS / (8*sizeof (unsigned long))];
  92 };
  93 static struct usb_busmap busmap;
  94
  95 /* used when updating list of hcds */
  96 DEFINE_MUTEX(usb_bus_list_lock);        /* exported only for usbfs */
  97 EXPORT_SYMBOL_GPL (usb_bus_list_lock);
  98
  99 /* used for controlling access to virtual root hubs */
 100 static DEFINE_SPINLOCK(hcd_root_hub_lock);
 101
 102 /* used when updating an endpoint's URB list */
 103 static DEFINE_SPINLOCK(hcd_urb_list_lock);
 104
 105 /* wait queue for synchronous unlinks */
 106 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
 107
 108 static inline int is_root_hub(struct usb_device *udev)
 109 {
 110         return (udev->parent == NULL);
 111 }
 112
 113 /*-------------------------------------------------------------------------*/
 114
 115 /*
 116  * Sharable chunks of root hub code.
 117  */
 118
 119 /*-------------------------------------------------------------------------*/
 120
 121 #define KERNEL_REL      ((LINUX_VERSION_CODE >> 16) & 0x0ff)
 122 #define KERNEL_VER      ((LINUX_VERSION_CODE >> 8) & 0x0ff)
 123
 124 /* usb 2.0 root hub device descriptor */
 125 static const u8 usb2_rh_dev_descriptor [18] = {
 126         0x12,       /*  __u8  bLength; */
 127         0x01,       /*  __u8  bDescriptorType; Device */
 128         0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
 129
 130         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 131         0x00,       /*  __u8  bDeviceSubClass; */
 132         0x01,       /*  __u8  bDeviceProtocol; [ usb 2.0 single TT ]*/
 133         0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
 134
 135         0x00, 0x00, /*  __le16 idVendor; */
 136         0x00, 0x00, /*  __le16 idProduct; */
 137         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 138
 139         0x03,       /*  __u8  iManufacturer; */
 140         0x02,       /*  __u8  iProduct; */
 141         0x01,       /*  __u8  iSerialNumber; */
 142         0x01        /*  __u8  bNumConfigurations; */
 143 };
 144
 145 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
 146
 147 /* usb 1.1 root hub device descriptor */
 148 static const u8 usb11_rh_dev_descriptor [18] = {
 149         0x12,       /*  __u8  bLength; */
 150         0x01,       /*  __u8  bDescriptorType; Device */
 151         0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
 152
 153         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 154         0x00,       /*  __u8  bDeviceSubClass; */
 155         0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
 156         0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
 157
 158         0x00, 0x00, /*  __le16 idVendor; */
 159         0x00, 0x00, /*  __le16 idProduct; */
 160         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 161
 162         0x03,       /*  __u8  iManufacturer; */
 163         0x02,       /*  __u8  iProduct; */
 164         0x01,       /*  __u8  iSerialNumber; */
 165         0x01        /*  __u8  bNumConfigurations; */
 166 };
 167
 168
 169 /*-------------------------------------------------------------------------*/
 170
 171 /* Configuration descriptors for our root hubs */
 172
 173 static const u8 fs_rh_config_descriptor [] = {
 174
 175         /* one configuration */
 176         0x09,       /*  __u8  bLength; */
 177         0x02,       /*  __u8  bDescriptorType; Configuration */
 178         0x19, 0x00, /*  __le16 wTotalLength; */
 179         0x01,       /*  __u8  bNumInterfaces; (1) */
 180         0x01,       /*  __u8  bConfigurationValue; */
 181         0x00,       /*  __u8  iConfiguration; */
 182         0xc0,       /*  __u8  bmAttributes;
 183                                  Bit 7: must be set,
 184                                      6: Self-powered,
 185                                      5: Remote wakeup,
 186                                      4..0: resvd */
 187         0x00,       /*  __u8  MaxPower; */
 188
 189         /* USB 1.1:
 190          * USB 2.0, single TT organization (mandatory):
 191          *      one interface, protocol 0
 192          *
 193          * USB 2.0, multiple TT organization (optional):
 194          *      two interfaces, protocols 1 (like single TT)
 195          *      and 2 (multiple TT mode) ... config is
 196          *      sometimes settable
 197          *      NOT IMPLEMENTED
 198          */
 199
 200         /* one interface */
 201         0x09,       /*  __u8  if_bLength; */
 202         0x04,       /*  __u8  if_bDescriptorType; Interface */
 203         0x00,       /*  __u8  if_bInterfaceNumber; */
 204         0x00,       /*  __u8  if_bAlternateSetting; */
 205         0x01,       /*  __u8  if_bNumEndpoints; */
 206         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
 207         0x00,       /*  __u8  if_bInterfaceSubClass; */
 208         0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
 209         0x00,       /*  __u8  if_iInterface; */
 210
 211         /* one endpoint (status change endpoint) */
 212         0x07,       /*  __u8  ep_bLength; */
 213         0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
 214         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 215         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 216         0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
 217         0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
 218 };
 219
 220 static const u8 hs_rh_config_descriptor [] = {
 221
 222         /* one configuration */
 223         0x09,       /*  __u8  bLength; */
 224         0x02,       /*  __u8  bDescriptorType; Configuration */
 225         0x19, 0x00, /*  __le16 wTotalLength; */
 226         0x01,       /*  __u8  bNumInterfaces; (1) */
 227         0x01,       /*  __u8  bConfigurationValue; */
 228         0x00,       /*  __u8  iConfiguration; */
 229         0xc0,       /*  __u8  bmAttributes;
 230                                  Bit 7: must be set,
 231                                      6: Self-powered,
 232                                      5: Remote wakeup,
 233                                      4..0: resvd */
 234         0x00,       /*  __u8  MaxPower; */
 235
 236         /* USB 1.1:
 237          * USB 2.0, single TT organization (mandatory):
 238          *      one interface, protocol 0
 239          *
 240          * USB 2.0, multiple TT organization (optional):
 241          *      two interfaces, protocols 1 (like single TT)
 242          *      and 2 (multiple TT mode) ... config is
 243          *      sometimes settable
 244          *      NOT IMPLEMENTED
 245          */
 246
 247         /* one interface */
 248         0x09,       /*  __u8  if_bLength; */
 249         0x04,       /*  __u8  if_bDescriptorType; Interface */
 250         0x00,       /*  __u8  if_bInterfaceNumber; */
 251         0x00,       /*  __u8  if_bAlternateSetting; */
 252         0x01,       /*  __u8  if_bNumEndpoints; */
 253         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
 254         0x00,       /*  __u8  if_bInterfaceSubClass; */
 255         0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
 256         0x00,       /*  __u8  if_iInterface; */
 257
 258         /* one endpoint (status change endpoint) */
 259         0x07,       /*  __u8  ep_bLength; */
 260         0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
 261         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 262         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 263                     /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
 264                      * see hub.c:hub_configure() for details. */
 265         (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
 266         0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
 267 };
 268
 269 /*-------------------------------------------------------------------------*/
 270
 271 /*
 272  * helper routine for returning string descriptors in UTF-16LE
 273  * input can actually be ISO-8859-1; ASCII is its 7-bit subset
 274  */
 275 static int ascii2utf (char *s, u8 *utf, int utfmax)
 276 {
 277         int retval;
 278
 279         for (retval = 0; *s && utfmax > 1; utfmax -= 2, retval += 2) {
 280                 *utf++ = *s++;
 281                 *utf++ = 0;
 282         }
 283         if (utfmax > 0) {
 284                 *utf = *s;
 285                 ++retval;
 286         }
 287         return retval;
 288 }
 289
 290 /*
 291  * rh_string - provides manufacturer, product and serial strings for root hub
 292  * @id: the string ID number (1: serial number, 2: product, 3: vendor)
 293  * @hcd: the host controller for this root hub
 294  * @type: string describing our driver
 295  * @data: return packet in UTF-16 LE
 296  * @len: length of the return packet
 297  *
 298  * Produces either a manufacturer, product or serial number string for the
 299  * virtual root hub device.
 300  */
 301 static int rh_string (
 302         int             id,
 303         struct usb_hcd  *hcd,
 304         u8              *data,
 305         int             len
 306 ) {
 307         char buf [100];
 308
 309         // language ids
 310         if (id == 0) {
 311                 buf[0] = 4;    buf[1] = 3;      /* 4 bytes string data */
 312                 buf[2] = 0x09; buf[3] = 0x04;   /* MSFT-speak for "en-us" */
 313                 len = min (len, 4);
 314                 memcpy (data, buf, len);
 315                 return len;
 316
 317         // serial number
 318         } else if (id == 1) {
 319                 strlcpy (buf, hcd->self.bus_name, sizeof buf);
 320
 321         // product description
 322         } else if (id == 2) {
 323                 strlcpy (buf, hcd->product_desc, sizeof buf);
 324
 325         // id 3 == vendor description
 326         } else if (id == 3) {
 327                 snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
 328                         init_utsname()->release, hcd->driver->description);
 329
 330         // unsupported IDs --> "protocol stall"
 331         } else
 332                 return -EPIPE;
 333
 334         switch (len) {          /* All cases fall through */
 335         default:
 336                 len = 2 + ascii2utf (buf, data + 2, len - 2);
 337         case 2:
 338                 data [1] = 3;   /* type == string */
 339         case 1:
 340                 data [0] = 2 * (strlen (buf) + 1);
 341         case 0:
 342                 ;               /* Compiler wants a statement here */
 343         }
 344         return len;
 345 }
 346
 347
 348 /* Root hub control transfers execute synchronously */
 349 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
 350 {
 351         struct usb_ctrlrequest *cmd;
 352         u16             typeReq, wValue, wIndex, wLength;
 353         u8              *ubuf = urb->transfer_buffer;
 354         u8              tbuf [sizeof (struct usb_hub_descriptor)]
 355                 __attribute__((aligned(4)));
 356         const u8        *bufp = tbuf;
 357         int             len = 0;
 358         int             patch_wakeup = 0;
 359         int             status = 0;
 360         int             n;
 361
 362         might_sleep();
 363
 364         cmd = (struct usb_ctrlrequest *) urb->setup_packet;
 365         typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
 366         wValue   = le16_to_cpu (cmd->wValue);
 367         wIndex   = le16_to_cpu (cmd->wIndex);
 368         wLength  = le16_to_cpu (cmd->wLength);
 369
 370         if (wLength > urb->transfer_buffer_length)
 371                 goto error;
 372
 373         urb->actual_length = 0;
 374         switch (typeReq) {
 375
 376         /* DEVICE REQUESTS */
 377
 378         /* The root hub's remote wakeup enable bit is implemented using
 379          * driver model wakeup flags.  If this system supports wakeup
 380          * through USB, userspace may change the default "allow wakeup"
 381          * policy through sysfs or these calls.
 382          *
 383          * Most root hubs support wakeup from downstream devices, for
 384          * runtime power management (disabling USB clocks and reducing
 385          * VBUS power usage).  However, not all of them do so; silicon,
 386          * board, and BIOS bugs here are not uncommon, so these can't
 387          * be treated quite like external hubs.
 388          *
 389          * Likewise, not all root hubs will pass wakeup events upstream,
 390          * to wake up the whole system.  So don't assume root hub and
 391          * controller capabilities are identical.
 392          */
 393
 394         case DeviceRequest | USB_REQ_GET_STATUS:
 395                 tbuf [0] = (device_may_wakeup(&hcd->self.root_hub->dev)
 396                                         << USB_DEVICE_REMOTE_WAKEUP)
 397                                 | (1 << USB_DEVICE_SELF_POWERED);
 398                 tbuf [1] = 0;
 399                 len = 2;
 400                 break;
 401         case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
 402                 if (wValue == USB_DEVICE_REMOTE_WAKEUP)
 403                         device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
 404                 else
 405                         goto error;
 406                 break;
 407         case DeviceOutRequest | USB_REQ_SET_FEATURE:
 408                 if (device_can_wakeup(&hcd->self.root_hub->dev)
 409                                 && wValue == USB_DEVICE_REMOTE_WAKEUP)
 410                         device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
 411                 else
 412                         goto error;
 413                 break;
 414         case DeviceRequest | USB_REQ_GET_CONFIGURATION:
 415                 tbuf [0] = 1;
 416                 len = 1;
 417                         /* FALLTHROUGH */
 418         case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
 419                 break;
 420         case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
 421                 switch (wValue & 0xff00) {
 422                 case USB_DT_DEVICE << 8:
 423                         if (hcd->driver->flags & HCD_USB2)
 424                                 bufp = usb2_rh_dev_descriptor;
 425                         else if (hcd->driver->flags & HCD_USB11)
 426                                 bufp = usb11_rh_dev_descriptor;
 427                         else
 428                                 goto error;
 429                         len = 18;
 430                         break;
 431                 case USB_DT_CONFIG << 8:
 432                         if (hcd->driver->flags & HCD_USB2) {
 433                                 bufp = hs_rh_config_descriptor;
 434                                 len = sizeof hs_rh_config_descriptor;
 435                         } else {
 436                                 bufp = fs_rh_config_descriptor;
 437                                 len = sizeof fs_rh_config_descriptor;
 438                         }
 439                         if (device_can_wakeup(&hcd->self.root_hub->dev))
 440                                 patch_wakeup = 1;
 441                         break;
 442                 case USB_DT_STRING << 8:
 443                         n = rh_string (wValue & 0xff, hcd, ubuf, wLength);
 444                         if (n < 0)
 445                                 goto error;
 446                         urb->actual_length = n;
 447                         break;
 448                 default:
 449                         goto error;
 450                 }
 451                 break;
 452         case DeviceRequest | USB_REQ_GET_INTERFACE:
 453                 tbuf [0] = 0;
 454                 len = 1;
 455                         /* FALLTHROUGH */
 456         case DeviceOutRequest | USB_REQ_SET_INTERFACE:
 457                 break;
 458         case DeviceOutRequest | USB_REQ_SET_ADDRESS:
 459                 // wValue == urb->dev->devaddr
 460                 dev_dbg (hcd->self.controller, "root hub device address %d\n",
 461                         wValue);
 462                 break;
 463
 464         /* INTERFACE REQUESTS (no defined feature/status flags) */
 465
 466         /* ENDPOINT REQUESTS */
 467
 468         case EndpointRequest | USB_REQ_GET_STATUS:
 469                 // ENDPOINT_HALT flag
 470                 tbuf [0] = 0;
 471                 tbuf [1] = 0;
 472                 len = 2;
 473                         /* FALLTHROUGH */
 474         case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
 475         case EndpointOutRequest | USB_REQ_SET_FEATURE:
 476                 dev_dbg (hcd->self.controller, "no endpoint features yet\n");
 477                 break;
 478
 479         /* CLASS REQUESTS (and errors) */
 480
 481         default:
 482                 /* non-generic request */
 483                 switch (typeReq) {
 484                 case GetHubStatus:
 485                 case GetPortStatus:
 486                         len = 4;
 487                         break;
 488                 case GetHubDescriptor:
 489                         len = sizeof (struct usb_hub_descriptor);
 490                         break;
 491                 }
 492                 status = hcd->driver->hub_control (hcd,
 493                         typeReq, wValue, wIndex,
 494                         tbuf, wLength);
 495                 break;
 496 error:
 497                 /* "protocol stall" on error */
 498                 status = -EPIPE;
 499         }
 500
 501         if (status) {
 502                 len = 0;
 503                 if (status != -EPIPE) {
 504                         dev_dbg (hcd->self.controller,
 505                                 "CTRL: TypeReq=0x%x val=0x%x "
 506                                 "idx=0x%x len=%d ==> %d\n",
 507                                 typeReq, wValue, wIndex,
 508                                 wLength, status);
 509                 }
 510         }
 511         if (len) {
 512                 if (urb->transfer_buffer_length < len)
 513                         len = urb->transfer_buffer_length;
 514                 urb->actual_length = len;
 515                 // always USB_DIR_IN, toward host
 516                 memcpy (ubuf, bufp, len);
 517
 518                 /* report whether RH hardware supports remote wakeup */
 519                 if (patch_wakeup &&
 520                                 len > offsetof (struct usb_config_descriptor,
 521                                                 bmAttributes))
 522                         ((struct usb_config_descriptor *)ubuf)->bmAttributes
 523                                 |= USB_CONFIG_ATT_WAKEUP;
 524         }
 525
 526         /* any errors get returned through the urb completion */
 527         spin_lock_irq(&hcd_root_hub_lock);
 528         spin_lock(&urb->lock);
 529         if (urb->status == -EINPROGRESS)
 530                 urb->status = status;
 531         spin_unlock(&urb->lock);
 532
 533         /* This peculiar use of spinlocks echoes what real HC drivers do.
 534          * Avoiding calls to local_irq_disable/enable makes the code
 535          * RT-friendly.
 536          */
 537         spin_unlock(&hcd_root_hub_lock);
 538         usb_hcd_giveback_urb(hcd, urb);
 539         spin_lock(&hcd_root_hub_lock);
 540
 541         spin_unlock_irq(&hcd_root_hub_lock);
 542         return 0;
 543 }
 544
 545 /*-------------------------------------------------------------------------*/
 546
 547 /*
 548  * Root Hub interrupt transfers are polled using a timer if the
 549  * driver requests it; otherwise the driver is responsible for
 550  * calling usb_hcd_poll_rh_status() when an event occurs.
 551  *
 552  * Completions are called in_interrupt(), but they may or may not
 553  * be in_irq().
 554  */
 555 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
 556 {
 557         struct urb      *urb;
 558         int             length;
 559         unsigned long   flags;
 560         char            buffer[4];      /* Any root hubs with > 31 ports? */
 561
 562         if (unlikely(!hcd->rh_registered))
 563                 return;
 564         if (!hcd->uses_new_polling && !hcd->status_urb)
 565                 return;
 566
 567         length = hcd->driver->hub_status_data(hcd, buffer);
 568         if (length > 0) {
 569
 570                 /* try to complete the status urb */
 571                 spin_lock_irqsave(&hcd_root_hub_lock, flags);
 572                 urb = hcd->status_urb;
 573                 if (urb) {
 574                         spin_lock(&urb->lock);
 575                         if (urb->status == -EINPROGRESS) {
 576                                 hcd->poll_pending = 0;
 577                                 hcd->status_urb = NULL;
 578                                 urb->status = 0;
 579                                 urb->hcpriv = NULL;
 580                                 urb->actual_length = length;
 581                                 memcpy(urb->transfer_buffer, buffer, length);
 582                         } else          /* urb has been unlinked */
 583                                 length = 0;
 584                         spin_unlock(&urb->lock);
 585
 586                         spin_unlock(&hcd_root_hub_lock);
 587                         usb_hcd_giveback_urb(hcd, urb);
 588                         spin_lock(&hcd_root_hub_lock);
 589                 } else
 590                         length = 0;
 591
 592                 if (length <= 0)
 593                         hcd->poll_pending = 1;
 594                 spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
 595         }
 596
 597         /* The USB 2.0 spec says 256 ms.  This is close enough and won't
 598          * exceed that limit if HZ is 100. The math is more clunky than
 599          * maybe expected, this is to make sure that all timers for USB devices
 600          * fire at the same time to give the CPU a break inbetween */
 601         if (hcd->uses_new_polling ? hcd->poll_rh :
 602                         (length == 0 && hcd->status_urb != NULL))
 603                 mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
 604 }
 605 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
 606
 607 /* timer callback */
 608 static void rh_timer_func (unsigned long _hcd)
 609 {
 610         usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
 611 }
 612
 613 /*-------------------------------------------------------------------------*/
 614
 615 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
 616 {
 617         int             retval;
 618         unsigned long   flags;
 619         int             len = 1 + (urb->dev->maxchild / 8);
 620
 621         spin_lock_irqsave (&hcd_root_hub_lock, flags);
 622         if (urb->status != -EINPROGRESS)        /* already unlinked */
 623                 retval = urb->status;
 624         else if (hcd->status_urb || urb->transfer_buffer_length < len) {
 625                 dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
 626                 retval = -EINVAL;
 627         } else {
 628                 hcd->status_urb = urb;
 629                 urb->hcpriv = hcd;      /* indicate it's queued */
 630
 631                 if (!hcd->uses_new_polling)
 632                         mod_timer (&hcd->rh_timer,
 633                                 (jiffies/(HZ/4) + 1) * (HZ/4));
 634
 635                 /* If a status change has already occurred, report it ASAP */
 636                 else if (hcd->poll_pending)
 637                         mod_timer (&hcd->rh_timer, jiffies);
 638                 retval = 0;
 639         }
 640         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
 641         return retval;
 642 }
 643
 644 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
 645 {
 646         if (usb_endpoint_xfer_int(&urb->ep->desc))
 647                 return rh_queue_status (hcd, urb);
 648         if (usb_endpoint_xfer_control(&urb->ep->desc))
 649                 return rh_call_control (hcd, urb);
 650         return -EINVAL;
 651 }
 652
 653 /*-------------------------------------------------------------------------*/
 654
 655 /* Unlinks of root-hub control URBs are legal, but they don't do anything
 656  * since these URBs always execute synchronously.
 657  */
 658 static int usb_rh_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
 659 {
 660         unsigned long   flags;
 661
 662         spin_lock_irqsave(&hcd_root_hub_lock, flags);
 663         if (usb_endpoint_num(&urb->ep->desc) == 0) {    /* Control URB */
 664                 ;       /* Do nothing */
 665
 666         } else {                                /* Status URB */
 667                 if (!hcd->uses_new_polling)
 668                         del_timer (&hcd->rh_timer);
 669                 if (urb == hcd->status_urb) {
 670                         hcd->status_urb = NULL;
 671                         urb->hcpriv = NULL;
 672
 673                         spin_unlock(&hcd_root_hub_lock);
 674                         usb_hcd_giveback_urb(hcd, urb);
 675                         spin_lock(&hcd_root_hub_lock);
 676                 }
 677         }
 678         spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
 679         return 0;
 680 }
 681
 682
 683
 684 /*
 685  * Show & store the current value of authorized_default
 686  */
 687 static ssize_t usb_host_authorized_default_show(struct device *dev,
 688                                                 struct device_attribute *attr,
 689                                                 char *buf)
 690 {
 691         struct usb_device *rh_usb_dev = to_usb_device(dev);
 692         struct usb_bus *usb_bus = rh_usb_dev->bus;
 693         struct usb_hcd *usb_hcd;
 694
 695         if (usb_bus == NULL)    /* FIXME: not sure if this case is possible */
 696                 return -ENODEV;
 697         usb_hcd = bus_to_hcd(usb_bus);
 698         return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
 699 }
 700
 701 static ssize_t usb_host_authorized_default_store(struct device *dev,
 702                                                  struct device_attribute *attr,
 703                                                  const char *buf, size_t size)
 704 {
 705         ssize_t result;
 706         unsigned val;
 707         struct usb_device *rh_usb_dev = to_usb_device(dev);
 708         struct usb_bus *usb_bus = rh_usb_dev->bus;
 709         struct usb_hcd *usb_hcd;
 710
 711         if (usb_bus == NULL)    /* FIXME: not sure if this case is possible */
 712                 return -ENODEV;
 713         usb_hcd = bus_to_hcd(usb_bus);
 714         result = sscanf(buf, "%u\n", &val);
 715         if (result == 1) {
 716                 usb_hcd->authorized_default = val? 1 : 0;
 717                 result = size;
 718         }
 719         else
 720                 result = -EINVAL;
 721         return result;
 722 }
 723
 724 static DEVICE_ATTR(authorized_default, 0644,
 725             usb_host_authorized_default_show,
 726             usb_host_authorized_default_store);
 727
 728
 729 /* Group all the USB bus attributes */
 730 static struct attribute *usb_bus_attrs[] = {
 731                 &dev_attr_authorized_default.attr,
 732                 NULL,
 733 };
 734
 735 static struct attribute_group usb_bus_attr_group = {
 736         .name = NULL,   /* we want them in the same directory */
 737         .attrs = usb_bus_attrs,
 738 };
 739
 740
 741
 742 /*-------------------------------------------------------------------------*/
 743
 744 static struct class *usb_host_class;
 745
 746 int usb_host_init(void)
 747 {
 748         int retval = 0;
 749
 750         usb_host_class = class_create(THIS_MODULE, "usb_host");
 751         if (IS_ERR(usb_host_class))
 752                 retval = PTR_ERR(usb_host_class);
 753         return retval;
 754 }
 755
 756 void usb_host_cleanup(void)
 757 {
 758         class_destroy(usb_host_class);
 759 }
 760
 761 /**
 762  * usb_bus_init - shared initialization code
 763  * @bus: the bus structure being initialized
 764  *
 765  * This code is used to initialize a usb_bus structure, memory for which is
 766  * separately managed.
 767  */
 768 static void usb_bus_init (struct usb_bus *bus)
 769 {
 770         memset (&bus->devmap, 0, sizeof(struct usb_devmap));
 771
 772         bus->devnum_next = 1;
 773
 774         bus->root_hub = NULL;
 775         bus->busnum = -1;
 776         bus->bandwidth_allocated = 0;
 777         bus->bandwidth_int_reqs  = 0;
 778         bus->bandwidth_isoc_reqs = 0;
 779
 780         INIT_LIST_HEAD (&bus->bus_list);
 781 }
 782
 783 /*-------------------------------------------------------------------------*/
 784
 785 /**
 786  * usb_register_bus - registers the USB host controller with the usb core
 787  * @bus: pointer to the bus to register
 788  * Context: !in_interrupt()
 789  *
 790  * Assigns a bus number, and links the controller into usbcore data
 791  * structures so that it can be seen by scanning the bus list.
 792  */
 793 static int usb_register_bus(struct usb_bus *bus)
 794 {
 795         int result = -E2BIG;
 796         int busnum;
 797
 798         mutex_lock(&usb_bus_list_lock);
 799         busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1);
 800         if (busnum >= USB_MAXBUS) {
 801                 printk (KERN_ERR "%s: too many buses\n", usbcore_name);
 802                 goto error_find_busnum;
 803         }
 804         set_bit (busnum, busmap.busmap);
 805         bus->busnum = busnum;
 806         bus->class_dev = class_device_create(usb_host_class, NULL, MKDEV(0,0),
 807                                              bus->controller, "usb_host%d",
 808                                              busnum);
 809         result = PTR_ERR(bus->class_dev);
 810         if (IS_ERR(bus->class_dev))
 811                 goto error_create_class_dev;
 812         class_set_devdata(bus->class_dev, bus);
 813
 814         /* Add it to the local list of buses */
 815         list_add (&bus->bus_list, &usb_bus_list);
 816         mutex_unlock(&usb_bus_list_lock);
 817
 818         usb_notify_add_bus(bus);
 819
 820         dev_info (bus->controller, "new USB bus registered, assigned bus "
 821                   "number %d\n", bus->busnum);
 822         return 0;
 823
 824 error_create_class_dev:
 825         clear_bit(busnum, busmap.busmap);
 826 error_find_busnum:
 827         mutex_unlock(&usb_bus_list_lock);
 828         return result;
 829 }
 830
 831 /**
 832  * usb_deregister_bus - deregisters the USB host controller
 833  * @bus: pointer to the bus to deregister
 834  * Context: !in_interrupt()
 835  *
 836  * Recycles the bus number, and unlinks the controller from usbcore data
 837  * structures so that it won't be seen by scanning the bus list.
 838  */
 839 static void usb_deregister_bus (struct usb_bus *bus)
 840 {
 841         dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
 842
 843         /*
 844          * NOTE: make sure that all the devices are removed by the
 845          * controller code, as well as having it call this when cleaning
 846          * itself up
 847          */
 848         mutex_lock(&usb_bus_list_lock);
 849         list_del (&bus->bus_list);
 850         mutex_unlock(&usb_bus_list_lock);
 851
 852         usb_notify_remove_bus(bus);
 853
 854         clear_bit (bus->busnum, busmap.busmap);
 855
 856         class_device_unregister(bus->class_dev);
 857 }
 858
 859 /**
 860  * register_root_hub - called by usb_add_hcd() to register a root hub
 861  * @hcd: host controller for this root hub
 862  *
 863  * This function registers the root hub with the USB subsystem.  It sets up
 864  * the device properly in the device tree and then calls usb_new_device()
 865  * to register the usb device.  It also assigns the root hub's USB address
 866  * (always 1).
 867  */
 868 static int register_root_hub(struct usb_hcd *hcd)
 869 {
 870         struct device *parent_dev = hcd->self.controller;
 871         struct usb_device *usb_dev = hcd->self.root_hub;
 872         const int devnum = 1;
 873         int retval;
 874
 875         usb_dev->devnum = devnum;
 876         usb_dev->bus->devnum_next = devnum + 1;
 877         memset (&usb_dev->bus->devmap.devicemap, 0,
 878                         sizeof usb_dev->bus->devmap.devicemap);
 879         set_bit (devnum, usb_dev->bus->devmap.devicemap);
 880         usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
 881
 882         mutex_lock(&usb_bus_list_lock);
 883
 884         usb_dev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
 885         retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
 886         if (retval != sizeof usb_dev->descriptor) {
 887                 mutex_unlock(&usb_bus_list_lock);
 888                 dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
 889                                 usb_dev->dev.bus_id, retval);
 890                 return (retval < 0) ? retval : -EMSGSIZE;
 891         }
 892
 893         retval = usb_new_device (usb_dev);
 894         if (retval) {
 895                 dev_err (parent_dev, "can't register root hub for %s, %d\n",
 896                                 usb_dev->dev.bus_id, retval);
 897         }
 898         mutex_unlock(&usb_bus_list_lock);
 899
 900         if (retval == 0) {
 901                 spin_lock_irq (&hcd_root_hub_lock);
 902                 hcd->rh_registered = 1;
 903                 spin_unlock_irq (&hcd_root_hub_lock);
 904
 905                 /* Did the HC die before the root hub was registered? */
 906                 if (hcd->state == HC_STATE_HALT)
 907                         usb_hc_died (hcd);      /* This time clean up */
 908         }
 909
 910         return retval;
 911 }
 912
 913 void usb_enable_root_hub_irq (struct usb_bus *bus)
 914 {
 915         struct usb_hcd *hcd;
 916
 917         hcd = container_of (bus, struct usb_hcd, self);
 918         if (hcd->driver->hub_irq_enable && hcd->state != HC_STATE_HALT)
 919                 hcd->driver->hub_irq_enable (hcd);
 920 }
 921
 922
 923 /*-------------------------------------------------------------------------*/
 924
 925 /**
 926  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
 927  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
 928  * @is_input: true iff the transaction sends data to the host
 929  * @isoc: true for isochronous transactions, false for interrupt ones
 930  * @bytecount: how many bytes in the transaction.
 931  *
 932  * Returns approximate bus time in nanoseconds for a periodic transaction.
 933  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
 934  * scheduled in software, this function is only used for such scheduling.
 935  */
 936 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
 937 {
 938         unsigned long   tmp;
 939
 940         switch (speed) {
 941         case USB_SPEED_LOW:     /* INTR only */
 942                 if (is_input) {
 943                         tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
 944                         return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
 945                 } else {
 946                         tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
 947                         return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
 948                 }
 949         case USB_SPEED_FULL:    /* ISOC or INTR */
 950                 if (isoc) {
 951                         tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
 952                         return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp);
 953                 } else {
 954                         tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
 955                         return (9107L + BW_HOST_DELAY + tmp);
 956                 }
 957         case USB_SPEED_HIGH:    /* ISOC or INTR */
 958                 // FIXME adjust for input vs output
 959                 if (isoc)
 960                         tmp = HS_NSECS_ISO (bytecount);
 961                 else
 962                         tmp = HS_NSECS (bytecount);
 963                 return tmp;
 964         default:
 965                 pr_debug ("%s: bogus device speed!\n", usbcore_name);
 966                 return -1;
 967         }
 968 }
 969 EXPORT_SYMBOL (usb_calc_bus_time);
 970
 971
 972 /*-------------------------------------------------------------------------*/
 973
 974 /*
 975  * Generic HC operations.
 976  */
 977
 978 /*-------------------------------------------------------------------------*/
 979
 980 static int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
 981 {
 982         unsigned long   flags;
 983         int             rc = 0;
 984
 985         spin_lock_irqsave(&hcd_urb_list_lock, flags);
 986
 987         /* Check that the URB isn't being killed */
 988         if (unlikely(urb->reject)) {
 989                 rc = -EPERM;
 990                 goto done;
 991         }
 992
 993         if (unlikely(!urb->ep->enabled)) {
 994                 rc = -ENOENT;
 995                 goto done;
 996         }
 997
 998         /*
 999          * Check the host controller's state and add the URB to the
1000          * endpoint's queue.
1001          */
1002         switch (hcd->state) {
1003         case HC_STATE_RUNNING:
1004         case HC_STATE_RESUMING:
1005                 list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1006                 break;
1007         default:
1008                 rc = -ESHUTDOWN;
1009                 goto done;
1010         }
1011  done:
1012         spin_unlock_irqrestore(&hcd_urb_list_lock, flags);
1013         return rc;
1014 }
1015
1016 static int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1017                 int status)
1018 {
1019         unsigned long           flags;
1020         struct list_head        *tmp;
1021         int                     rc = 0;
1022
1023         /*
1024          * we contend for urb->status with the hcd core,
1025          * which changes it while returning the urb.
1026          *
1027          * Caller guaranteed that the urb pointer hasn't been freed, and
1028          * that it was submitted.  But as a rule it can't know whether or
1029          * not it's already been unlinked ... so we respect the reversed
1030          * lock sequence needed for the usb_hcd_giveback_urb() code paths
1031          * (urb lock, then hcd_urb_list_lock) in case some other CPU is now
1032          * unlinking it.
1033          */
1034         spin_lock_irqsave(&urb->lock, flags);
1035         spin_lock(&hcd_urb_list_lock);
1036
1037         /* insist the urb is still queued */
1038         list_for_each(tmp, &urb->ep->urb_list) {
1039                 if (tmp == &urb->urb_list)
1040                         break;
1041         }
1042         if (tmp != &urb->urb_list) {
1043                 rc = -EIDRM;
1044                 goto done;
1045         }
1046
1047         /* Any status except -EINPROGRESS means something already started to
1048          * unlink this URB from the hardware.  So there's no more work to do.
1049          */
1050         if (urb->status != -EINPROGRESS) {
1051                 rc = -EBUSY;
1052                 goto done;
1053         }
1054         urb->status = status;
1055
1056         /* IRQ setup can easily be broken so that USB controllers
1057          * never get completion IRQs ... maybe even the ones we need to
1058          * finish unlinking the initial failed usb_set_address()
1059          * or device descriptor fetch.
1060          */
1061         if (!test_bit(HCD_FLAG_SAW_IRQ, &hcd->flags) &&
1062                         !is_root_hub(urb->dev)) {
1063                 dev_warn(hcd->self.controller, "Unlink after no-IRQ?  "
1064                         "Controller is probably using the wrong IRQ.\n");
1065                 set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
1066         }
1067
1068  done:
1069         spin_unlock(&hcd_urb_list_lock);
1070         spin_unlock_irqrestore (&urb->lock, flags);
1071         return rc;
1072 }
1073
1074 static void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1075 {
1076         unsigned long           flags;
1077
1078         /* clear all state linking urb to this dev (and hcd) */
1079         spin_lock_irqsave(&hcd_urb_list_lock, flags);
1080         list_del_init(&urb->urb_list);
1081         spin_unlock_irqrestore(&hcd_urb_list_lock, flags);
1082 }
1083
1084 static void map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1085 {
1086         /* Map the URB's buffers for DMA access.
1087          * Lower level HCD code should use *_dma exclusively,
1088          * unless it uses pio or talks to another transport.
1089          */
1090         if (hcd->self.uses_dma && !is_root_hub(urb->dev)) {
1091                 if (usb_endpoint_xfer_control(&urb->ep->desc)
1092                         && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
1093                         urb->setup_dma = dma_map_single (
1094                                         hcd->self.controller,
1095                                         urb->setup_packet,
1096                                         sizeof (struct usb_ctrlrequest),
1097                                         DMA_TO_DEVICE);
1098                 if (urb->transfer_buffer_length != 0
1099                         && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP))
1100                         urb->transfer_dma = dma_map_single (
1101                                         hcd->self.controller,
1102                                         urb->transfer_buffer,
1103                                         urb->transfer_buffer_length,
1104                                         usb_urb_dir_in(urb)
1105                                             ? DMA_FROM_DEVICE
1106                                             : DMA_TO_DEVICE);
1107         }
1108 }
1109
1110 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1111 {
1112         if (hcd->self.uses_dma && !is_root_hub(urb->dev)) {
1113                 if (usb_endpoint_xfer_control(&urb->ep->desc)
1114                         && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
1115                         dma_unmap_single(hcd->self.controller, urb->setup_dma,
1116                                         sizeof(struct usb_ctrlrequest),
1117                                         DMA_TO_DEVICE);
1118                 if (urb->transfer_buffer_length != 0
1119                         && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP))
1120                         dma_unmap_single(hcd->self.controller,
1121                                         urb->transfer_dma,
1122                                         urb->transfer_buffer_length,
1123                                         usb_urb_dir_in(urb)
1124                                             ? DMA_FROM_DEVICE
1125                                             : DMA_TO_DEVICE);
1126         }
1127 }
1128
1129 /*-------------------------------------------------------------------------*/
1130
1131 /* may be called in any context with a valid urb->dev usecount
1132  * caller surrenders "ownership" of urb
1133  * expects usb_submit_urb() to have sanity checked and conditioned all
1134  * inputs in the urb
1135  */
1136 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1137 {
1138         int                     status;
1139         struct usb_hcd          *hcd = bus_to_hcd(urb->dev->bus);
1140
1141         /* increment urb's reference count as part of giving it to the HCD
1142          * (which will control it).  HCD guarantees that it either returns
1143          * an error or calls giveback(), but not both.
1144          */
1145         usb_get_urb(urb);
1146         atomic_inc(&urb->use_count);
1147         usbmon_urb_submit(&hcd->self, urb);
1148
1149         /* NOTE requirements on root-hub callers (usbfs and the hub
1150          * driver, for now):  URBs' urb->transfer_buffer must be
1151          * valid and usb_buffer_{sync,unmap}() not be needed, since
1152          * they could clobber root hub response data.  Also, control
1153          * URBs must be submitted in process context with interrupts
1154          * enabled.
1155          */
1156         status = usb_hcd_link_urb_to_ep(hcd, urb);
1157         if (!status) {
1158                 map_urb_for_dma(hcd, urb);
1159                 if (is_root_hub(urb->dev))
1160                         status = rh_urb_enqueue(hcd, urb);
1161                 else
1162                         status = hcd->driver->urb_enqueue(hcd, urb->ep, urb,
1163                                         mem_flags);
1164         }
1165
1166         if (unlikely(status)) {
1167                 usbmon_urb_submit_error(&hcd->self, urb, status);
1168                 unmap_urb_for_dma(hcd, urb);
1169                 usb_hcd_unlink_urb_from_ep(hcd, urb);
1170                 INIT_LIST_HEAD(&urb->urb_list);
1171                 atomic_dec(&urb->use_count);
1172                 if (urb->reject)
1173                         wake_up(&usb_kill_urb_queue);
1174                 usb_put_urb(urb);
1175         }
1176         return status;
1177 }
1178
1179 /*-------------------------------------------------------------------------*/
1180
1181 /* this makes the hcd giveback() the urb more quickly, by kicking it
1182  * off hardware queues (which may take a while) and returning it as
1183  * soon as practical.  we've already set up the urb's return status,
1184  * but we can't know if the callback completed already.
1185  */
1186 static int
1187 unlink1 (struct usb_hcd *hcd, struct urb *urb)
1188 {
1189         int             value;
1190
1191         if (is_root_hub(urb->dev))
1192                 value = usb_rh_urb_dequeue (hcd, urb);
1193         else {
1194
1195                 /* The only reason an HCD might fail this call is if
1196                  * it has not yet fully queued the urb to begin with.
1197                  * Such failures should be harmless. */
1198                 value = hcd->driver->urb_dequeue (hcd, urb);
1199         }
1200
1201         if (value != 0)
1202                 dev_dbg (hcd->self.controller, "dequeue %p --> %d\n",
1203                                 urb, value);
1204         return value;
1205 }
1206
1207 /*
1208  * called in any context
1209  *
1210  * caller guarantees urb won't be recycled till both unlink()
1211  * and the urb's completion function return
1212  */
1213 int usb_hcd_unlink_urb (struct urb *urb, int status)
1214 {
1215         struct usb_hcd          *hcd;
1216         int                     retval;
1217
1218         hcd = bus_to_hcd(urb->dev->bus);
1219
1220         retval = usb_hcd_check_unlink_urb(hcd, urb, status);
1221         if (!retval)
1222                 retval = unlink1(hcd, urb);
1223
1224         if (retval == 0)
1225                 retval = -EINPROGRESS;
1226         else if (retval != -EIDRM)
1227                 dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n",
1228                                 urb, retval);
1229         return retval;
1230 }
1231
1232 /*-------------------------------------------------------------------------*/
1233
1234 /**
1235  * usb_hcd_giveback_urb - return URB from HCD to device driver
1236  * @hcd: host controller returning the URB
1237  * @urb: urb being returned to the USB device driver.
1238  * Context: in_interrupt()
1239  *
1240  * This hands the URB from HCD to its USB device driver, using its
1241  * completion function.  The HCD has freed all per-urb resources
1242  * (and is done using urb->hcpriv).  It also released all HCD locks;
1243  * the device driver won't cause problems if it frees, modifies,
1244  * or resubmits this URB.
1245  */
1246 void usb_hcd_giveback_urb (struct usb_hcd *hcd, struct urb *urb)
1247 {
1248         usb_hcd_unlink_urb_from_ep(hcd, urb);
1249         unmap_urb_for_dma(hcd, urb);
1250         usbmon_urb_complete (&hcd->self, urb);
1251         usb_unanchor_urb(urb);
1252
1253         /* pass ownership to the completion handler */
1254         urb->complete (urb);
1255         atomic_dec (&urb->use_count);
1256         if (unlikely (urb->reject))
1257                 wake_up (&usb_kill_urb_queue);
1258         usb_put_urb (urb);
1259 }
1260 EXPORT_SYMBOL (usb_hcd_giveback_urb);
1261
1262 /*-------------------------------------------------------------------------*/
1263
1264 /* disables the endpoint: cancels any pending urbs, then synchronizes with
1265  * the hcd to make sure all endpoint state is gone from hardware, and then
1266  * waits until the endpoint's queue is completely drained. use for
1267  * set_configuration, set_interface, driver removal, physical disconnect.
1268  *
1269  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1270  * type, maxpacket size, toggle, halt status, and scheduling.
1271  */
1272 void usb_hcd_endpoint_disable (struct usb_device *udev,
1273                 struct usb_host_endpoint *ep)
1274 {
1275         struct usb_hcd          *hcd;
1276         struct urb              *urb;
1277
1278         might_sleep();
1279         hcd = bus_to_hcd(udev->bus);
1280
1281         /* ep is already gone from udev->ep_{in,out}[]; no more submits */
1282 rescan:
1283         spin_lock_irq(&hcd_urb_list_lock);
1284         list_for_each_entry (urb, &ep->urb_list, urb_list) {
1285                 int     tmp;
1286                 int     is_in;
1287
1288                 /* the urb may already have been unlinked */
1289                 if (urb->status != -EINPROGRESS)
1290                         continue;
1291                 usb_get_urb (urb);
1292                 is_in = usb_urb_dir_in(urb);
1293                 spin_unlock(&hcd_urb_list_lock);
1294
1295                 spin_lock (&urb->lock);
1296                 tmp = urb->status;
1297                 if (tmp == -EINPROGRESS)
1298                         urb->status = -ESHUTDOWN;
1299                 spin_unlock (&urb->lock);
1300
1301                 /* kick hcd unless it's already returning this */
1302                 if (tmp == -EINPROGRESS) {
1303                         unlink1 (hcd, urb);
1304                         dev_dbg (hcd->self.controller,
1305                                 "shutdown urb %p ep%d%s%s\n",
1306                                 urb, usb_endpoint_num(&ep->desc),
1307                                 is_in ? "in" : "out",
1308                                 ({      char *s;
1309
1310                                         switch (usb_endpoint_type(&ep->desc)) {
1311                                         case USB_ENDPOINT_XFER_CONTROL:
1312                                                 s = ""; break;
1313                                         case USB_ENDPOINT_XFER_BULK:
1314                                                 s = "-bulk"; break;
1315                                         case USB_ENDPOINT_XFER_INT:
1316                                                 s = "-intr"; break;
1317                                         default:
1318                                                 s = "-iso"; break;
1319                                         };
1320                                         s;
1321                                 }));
1322                 }
1323                 usb_put_urb (urb);
1324
1325                 /* list contents may have changed */
1326                 goto rescan;
1327         }
1328         spin_unlock_irq(&hcd_urb_list_lock);
1329
1330         /* synchronize with the hardware, so old configuration state
1331          * clears out immediately (and will be freed).
1332          */
1333         if (hcd->driver->endpoint_disable)
1334                 hcd->driver->endpoint_disable (hcd, ep);
1335
1336         /* Wait until the endpoint queue is completely empty.  Most HCDs
1337          * will have done this already in their endpoint_disable method,
1338          * but some might not.  And there could be root-hub control URBs
1339          * still pending since they aren't affected by the HCDs'
1340          * endpoint_disable methods.
1341          */
1342         while (!list_empty (&ep->urb_list)) {
1343                 spin_lock_irq(&hcd_urb_list_lock);
1344
1345                 /* The list may have changed while we acquired the spinlock */
1346                 urb = NULL;
1347                 if (!list_empty (&ep->urb_list)) {
1348                         urb = list_entry (ep->urb_list.prev, struct urb,
1349                                         urb_list);
1350                         usb_get_urb (urb);
1351                 }
1352                 spin_unlock_irq(&hcd_urb_list_lock);
1353
1354                 if (urb) {
1355                         usb_kill_urb (urb);
1356                         usb_put_urb (urb);
1357                 }
1358         }
1359 }
1360
1361 /*-------------------------------------------------------------------------*/
1362
1363 /* called in any context */
1364 int usb_hcd_get_frame_number (struct usb_device *udev)
1365 {
1366         struct usb_hcd  *hcd = bus_to_hcd(udev->bus);
1367
1368         if (!HC_IS_RUNNING (hcd->state))
1369                 return -ESHUTDOWN;
1370         return hcd->driver->get_frame_number (hcd);
1371 }
1372
1373 /*-------------------------------------------------------------------------*/
1374
1375 #ifdef  CONFIG_PM
1376
1377 int hcd_bus_suspend(struct usb_device *rhdev)
1378 {
1379         struct usb_hcd  *hcd = container_of(rhdev->bus, struct usb_hcd, self);
1380         int             status;
1381         int             old_state = hcd->state;
1382
1383         dev_dbg(&rhdev->dev, "bus %s%s\n",
1384                         rhdev->auto_pm ? "auto-" : "", "suspend");
1385         if (!hcd->driver->bus_suspend) {
1386                 status = -ENOENT;
1387         } else {
1388                 hcd->state = HC_STATE_QUIESCING;
1389                 status = hcd->driver->bus_suspend(hcd);
1390         }
1391         if (status == 0) {
1392                 usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
1393                 hcd->state = HC_STATE_SUSPENDED;
1394         } else {
1395                 hcd->state = old_state;
1396                 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
1397                                 "suspend", status);
1398         }
1399         return status;
1400 }
1401
1402 int hcd_bus_resume(struct usb_device *rhdev)
1403 {
1404         struct usb_hcd  *hcd = container_of(rhdev->bus, struct usb_hcd, self);
1405         int             status;
1406         int             old_state = hcd->state;
1407
1408         dev_dbg(&rhdev->dev, "usb %s%s\n",
1409                         rhdev->auto_pm ? "auto-" : "", "resume");
1410         if (!hcd->driver->bus_resume)
1411                 return -ENOENT;
1412         if (hcd->state == HC_STATE_RUNNING)
1413                 return 0;
1414
1415         hcd->state = HC_STATE_RESUMING;
1416         status = hcd->driver->bus_resume(hcd);
1417         if (status == 0) {
1418                 /* TRSMRCY = 10 msec */
1419                 msleep(10);
1420                 usb_set_device_state(rhdev, rhdev->actconfig
1421                                 ? USB_STATE_CONFIGURED
1422                                 : USB_STATE_ADDRESS);
1423                 hcd->state = HC_STATE_RUNNING;
1424         } else {
1425                 hcd->state = old_state;
1426                 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
1427                                 "resume", status);
1428                 if (status != -ESHUTDOWN)
1429                         usb_hc_died(hcd);
1430         }
1431         return status;
1432 }
1433
1434 /* Workqueue routine for root-hub remote wakeup */
1435 static void hcd_resume_work(struct work_struct *work)
1436 {
1437         struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
1438         struct usb_device *udev = hcd->self.root_hub;
1439
1440         usb_lock_device(udev);
1441         usb_mark_last_busy(udev);
1442         usb_external_resume_device(udev);
1443         usb_unlock_device(udev);
1444 }
1445
1446 /**
1447  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
1448  * @hcd: host controller for this root hub
1449  *
1450  * The USB host controller calls this function when its root hub is
1451  * suspended (with the remote wakeup feature enabled) and a remote
1452  * wakeup request is received.  The routine submits a workqueue request
1453  * to resume the root hub (that is, manage its downstream ports again).
1454  */
1455 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
1456 {
1457         unsigned long flags;
1458
1459         spin_lock_irqsave (&hcd_root_hub_lock, flags);
1460         if (hcd->rh_registered)
1461                 queue_work(ksuspend_usb_wq, &hcd->wakeup_work);
1462         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
1463 }
1464 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
1465
1466 #endif
1467
1468 /*-------------------------------------------------------------------------*/
1469
1470 #ifdef  CONFIG_USB_OTG
1471
1472 /**
1473  * usb_bus_start_enum - start immediate enumeration (for OTG)
1474  * @bus: the bus (must use hcd framework)
1475  * @port_num: 1-based number of port; usually bus->otg_port
1476  * Context: in_interrupt()
1477  *
1478  * Starts enumeration, with an immediate reset followed later by
1479  * khubd identifying and possibly configuring the device.
1480  * This is needed by OTG controller drivers, where it helps meet
1481  * HNP protocol timing requirements for starting a port reset.
1482  */
1483 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
1484 {
1485         struct usb_hcd          *hcd;
1486         int                     status = -EOPNOTSUPP;
1487
1488         /* NOTE: since HNP can't start by grabbing the bus's address0_sem,
1489          * boards with root hubs hooked up to internal devices (instead of
1490          * just the OTG port) may need more attention to resetting...
1491          */
1492         hcd = container_of (bus, struct usb_hcd, self);
1493         if (port_num && hcd->driver->start_port_reset)
1494                 status = hcd->driver->start_port_reset(hcd, port_num);
1495
1496         /* run khubd shortly after (first) root port reset finishes;
1497          * it may issue others, until at least 50 msecs have passed.
1498          */
1499         if (status == 0)
1500                 mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
1501         return status;
1502 }
1503 EXPORT_SYMBOL (usb_bus_start_enum);
1504
1505 #endif
1506
1507 /*-------------------------------------------------------------------------*/
1508
1509 /**
1510  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
1511  * @irq: the IRQ being raised
1512  * @__hcd: pointer to the HCD whose IRQ is being signaled
1513  * @r: saved hardware registers
1514  *
1515  * If the controller isn't HALTed, calls the driver's irq handler.
1516  * Checks whether the controller is now dead.
1517  */
1518 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
1519 {
1520         struct usb_hcd          *hcd = __hcd;
1521         int                     start = hcd->state;
1522
1523         if (unlikely(start == HC_STATE_HALT ||
1524             !test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
1525                 return IRQ_NONE;
1526         if (hcd->driver->irq (hcd) == IRQ_NONE)
1527                 return IRQ_NONE;
1528
1529         set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
1530
1531         if (unlikely(hcd->state == HC_STATE_HALT))
1532                 usb_hc_died (hcd);
1533         return IRQ_HANDLED;
1534 }
1535
1536 /*-------------------------------------------------------------------------*/
1537
1538 /**
1539  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
1540  * @hcd: pointer to the HCD representing the controller
1541  *
1542  * This is called by bus glue to report a USB host controller that died
1543  * while operations may still have been pending.  It's called automatically
1544  * by the PCI glue, so only glue for non-PCI busses should need to call it.
1545  */
1546 void usb_hc_died (struct usb_hcd *hcd)
1547 {
1548         unsigned long flags;
1549
1550         dev_err (hcd->self.controller, "HC died; cleaning up\n");
1551
1552         spin_lock_irqsave (&hcd_root_hub_lock, flags);
1553         if (hcd->rh_registered) {
1554                 hcd->poll_rh = 0;
1555
1556                 /* make khubd clean up old urbs and devices */
1557                 usb_set_device_state (hcd->self.root_hub,
1558                                 USB_STATE_NOTATTACHED);
1559                 usb_kick_khubd (hcd->self.root_hub);
1560         }
1561         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
1562 }
1563 EXPORT_SYMBOL_GPL (usb_hc_died);
1564
1565 /*-------------------------------------------------------------------------*/
1566
1567 /**
1568  * usb_create_hcd - create and initialize an HCD structure
1569  * @driver: HC driver that will use this hcd
1570  * @dev: device for this HC, stored in hcd->self.controller
1571  * @bus_name: value to store in hcd->self.bus_name
1572  * Context: !in_interrupt()
1573  *
1574  * Allocate a struct usb_hcd, with extra space at the end for the
1575  * HC driver's private data.  Initialize the generic members of the
1576  * hcd structure.
1577  *
1578  * If memory is unavailable, returns NULL.
1579  */
1580 struct usb_hcd *usb_create_hcd (const struct hc_driver *driver,
1581                 struct device *dev, char *bus_name)
1582 {
1583         struct usb_hcd *hcd;
1584
1585         hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
1586         if (!hcd) {
1587                 dev_dbg (dev, "hcd alloc failed\n");
1588                 return NULL;
1589         }
1590         dev_set_drvdata(dev, hcd);
1591         kref_init(&hcd->kref);
1592
1593         usb_bus_init(&hcd->self);
1594         hcd->self.controller = dev;
1595         hcd->self.bus_name = bus_name;
1596         hcd->self.uses_dma = (dev->dma_mask != NULL);
1597
1598         init_timer(&hcd->rh_timer);
1599         hcd->rh_timer.function = rh_timer_func;
1600         hcd->rh_timer.data = (unsigned long) hcd;
1601 #ifdef CONFIG_PM
1602         INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
1603 #endif
1604
1605         hcd->driver = driver;
1606         hcd->product_desc = (driver->product_desc) ? driver->product_desc :
1607                         "USB Host Controller";
1608         return hcd;
1609 }
1610 EXPORT_SYMBOL (usb_create_hcd);
1611
1612 static void hcd_release (struct kref *kref)
1613 {
1614         struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
1615
1616         kfree(hcd);
1617 }
1618
1619 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
1620 {
1621         if (hcd)
1622                 kref_get (&hcd->kref);
1623         return hcd;
1624 }
1625 EXPORT_SYMBOL (usb_get_hcd);
1626
1627 void usb_put_hcd (struct usb_hcd *hcd)
1628 {
1629         if (hcd)
1630                 kref_put (&hcd->kref, hcd_release);
1631 }
1632 EXPORT_SYMBOL (usb_put_hcd);
1633
1634 /**
1635  * usb_add_hcd - finish generic HCD structure initialization and register
1636  * @hcd: the usb_hcd structure to initialize
1637  * @irqnum: Interrupt line to allocate
1638  * @irqflags: Interrupt type flags
1639  *
1640  * Finish the remaining parts of generic HCD initialization: allocate the
1641  * buffers of consistent memory, register the bus, request the IRQ line,
1642  * and call the driver's reset() and start() routines.
1643  */
1644 int usb_add_hcd(struct usb_hcd *hcd,
1645                 unsigned int irqnum, unsigned long irqflags)
1646 {
1647         int retval;
1648         struct usb_device *rhdev;
1649
1650         dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
1651
1652         hcd->authorized_default = hcd->wireless? 0 : 1;
1653         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1654
1655         /* HC is in reset state, but accessible.  Now do the one-time init,
1656          * bottom up so that hcds can customize the root hubs before khubd
1657          * starts talking to them.  (Note, bus id is assigned early too.)
1658          */
1659         if ((retval = hcd_buffer_create(hcd)) != 0) {
1660                 dev_dbg(hcd->self.controller, "pool alloc failed\n");
1661                 return retval;
1662         }
1663
1664         if ((retval = usb_register_bus(&hcd->self)) < 0)
1665                 goto err_register_bus;
1666
1667         if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
1668                 dev_err(hcd->self.controller, "unable to allocate root hub\n");
1669                 retval = -ENOMEM;
1670                 goto err_allocate_root_hub;
1671         }
1672         rhdev->speed = (hcd->driver->flags & HCD_USB2) ? USB_SPEED_HIGH :
1673                         USB_SPEED_FULL;
1674         hcd->self.root_hub = rhdev;
1675
1676         /* wakeup flag init defaults to "everything works" for root hubs,
1677          * but drivers can override it in reset() if needed, along with
1678          * recording the overall controller's system wakeup capability.
1679          */
1680         device_init_wakeup(&rhdev->dev, 1);
1681
1682         /* "reset" is misnamed; its role is now one-time init. the controller
1683          * should already have been reset (and boot firmware kicked off etc).
1684          */
1685         if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
1686                 dev_err(hcd->self.controller, "can't setup\n");
1687                 goto err_hcd_driver_setup;
1688         }
1689
1690         /* NOTE: root hub and controller capabilities may not be the same */
1691         if (device_can_wakeup(hcd->self.controller)
1692                         && device_can_wakeup(&hcd->self.root_hub->dev))
1693                 dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
1694
1695         /* enable irqs just before we start the controller */
1696         if (hcd->driver->irq) {
1697                 snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
1698                                 hcd->driver->description, hcd->self.busnum);
1699                 if ((retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
1700                                 hcd->irq_descr, hcd)) != 0) {
1701                         dev_err(hcd->self.controller,
1702                                         "request interrupt %d failed\n", irqnum);
1703                         goto err_request_irq;
1704                 }
1705                 hcd->irq = irqnum;
1706                 dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
1707                                 (hcd->driver->flags & HCD_MEMORY) ?
1708                                         "io mem" : "io base",
1709                                         (unsigned long long)hcd->rsrc_start);
1710         } else {
1711                 hcd->irq = -1;
1712                 if (hcd->rsrc_start)
1713                         dev_info(hcd->self.controller, "%s 0x%08llx\n",
1714                                         (hcd->driver->flags & HCD_MEMORY) ?
1715                                         "io mem" : "io base",
1716                                         (unsigned long long)hcd->rsrc_start);
1717         }
1718
1719         if ((retval = hcd->driver->start(hcd)) < 0) {
1720                 dev_err(hcd->self.controller, "startup error %d\n", retval);
1721                 goto err_hcd_driver_start;
1722         }
1723
1724         /* starting here, usbcore will pay attention to this root hub */
1725         rhdev->bus_mA = min(500u, hcd->power_budget);
1726         if ((retval = register_root_hub(hcd)) != 0)
1727                 goto err_register_root_hub;
1728
1729         retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
1730         if (retval < 0) {
1731                 printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
1732                        retval);
1733                 goto error_create_attr_group;
1734         }
1735         if (hcd->uses_new_polling && hcd->poll_rh)
1736                 usb_hcd_poll_rh_status(hcd);
1737         return retval;
1738
1739 error_create_attr_group:
1740         mutex_lock(&usb_bus_list_lock);
1741         usb_disconnect(&hcd->self.root_hub);
1742         mutex_unlock(&usb_bus_list_lock);
1743 err_register_root_hub:
1744         hcd->driver->stop(hcd);
1745 err_hcd_driver_start:
1746         if (hcd->irq >= 0)
1747                 free_irq(irqnum, hcd);
1748 err_request_irq:
1749 err_hcd_driver_setup:
1750         hcd->self.root_hub = NULL;
1751         usb_put_dev(rhdev);
1752 err_allocate_root_hub:
1753         usb_deregister_bus(&hcd->self);
1754 err_register_bus:
1755         hcd_buffer_destroy(hcd);
1756         return retval;
1757 }
1758 EXPORT_SYMBOL (usb_add_hcd);
1759
1760 /**
1761  * usb_remove_hcd - shutdown processing for generic HCDs
1762  * @hcd: the usb_hcd structure to remove
1763  * Context: !in_interrupt()
1764  *
1765  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
1766  * invoking the HCD's stop() method.
1767  */
1768 void usb_remove_hcd(struct usb_hcd *hcd)
1769 {
1770         dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
1771
1772         if (HC_IS_RUNNING (hcd->state))
1773                 hcd->state = HC_STATE_QUIESCING;
1774
1775         dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
1776         spin_lock_irq (&hcd_root_hub_lock);
1777         hcd->rh_registered = 0;
1778         spin_unlock_irq (&hcd_root_hub_lock);
1779
1780 #ifdef CONFIG_PM
1781         cancel_work_sync(&hcd->wakeup_work);
1782 #endif
1783
1784         sysfs_remove_group(&hcd->self.root_hub->dev.kobj, &usb_bus_attr_group);
1785         mutex_lock(&usb_bus_list_lock);
1786         usb_disconnect(&hcd->self.root_hub);
1787         mutex_unlock(&usb_bus_list_lock);
1788
1789         hcd->driver->stop(hcd);
1790         hcd->state = HC_STATE_HALT;
1791
1792         hcd->poll_rh = 0;
1793         del_timer_sync(&hcd->rh_timer);
1794
1795         if (hcd->irq >= 0)
1796                 free_irq(hcd->irq, hcd);
1797         usb_deregister_bus(&hcd->self);
1798         hcd_buffer_destroy(hcd);
1799 }
1800 EXPORT_SYMBOL (usb_remove_hcd);
1801
1802 void
1803 usb_hcd_platform_shutdown(struct platform_device* dev)
1804 {
1805         struct usb_hcd *hcd = platform_get_drvdata(dev);
1806
1807         if (hcd->driver->shutdown)
1808                 hcd->driver->shutdown(hcd);
1809 }
1810 EXPORT_SYMBOL (usb_hcd_platform_shutdown);
1811
1812 /*-------------------------------------------------------------------------*/
1813
1814 #if defined(CONFIG_USB_MON)
1815
1816 struct usb_mon_operations *mon_ops;
1817
1818 /*
1819  * The registration is unlocked.
1820  * We do it this way because we do not want to lock in hot paths.
1821  *
1822  * Notice that the code is minimally error-proof. Because usbmon needs
1823  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
1824  */
1825
1826 int usb_mon_register (struct usb_mon_operations *ops)
1827 {
1828
1829         if (mon_ops)
1830                 return -EBUSY;
1831
1832         mon_ops = ops;
1833         mb();
1834         return 0;
1835 }
1836 EXPORT_SYMBOL_GPL (usb_mon_register);
1837
1838 void usb_mon_deregister (void)
1839 {
1840
1841         if (mon_ops == NULL) {
1842                 printk(KERN_ERR "USB: monitor was not registered\n");
1843                 return;
1844         }
1845         mon_ops = NULL;
1846         mb();
1847 }
1848 EXPORT_SYMBOL_GPL (usb_mon_deregister);
1849
1850 #endif /* CONFIG_USB_MON */