git.oblomov.eu Git - linux-2.6/blob - drivers/usb/host/ohci-hub.c

   1 /*
   2  * OHCI HCD (Host Controller Driver) for USB.
   3  *
   4  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
   5  * (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
   6  *
   7  * This file is licenced under GPL
   8  */
   9
  10 /*-------------------------------------------------------------------------*/
  11
  12 /*
  13  * OHCI Root Hub ... the nonsharable stuff
  14  */
  15
  16 #define dbg_port(hc,label,num,value) \
  17         ohci_dbg (hc, \
  18                 "%s roothub.portstatus [%d] " \
  19                 "= 0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
  20                 label, num, temp, \
  21                 (temp & RH_PS_PRSC) ? " PRSC" : "", \
  22                 (temp & RH_PS_OCIC) ? " OCIC" : "", \
  23                 (temp & RH_PS_PSSC) ? " PSSC" : "", \
  24                 (temp & RH_PS_PESC) ? " PESC" : "", \
  25                 (temp & RH_PS_CSC) ? " CSC" : "", \
  26                 \
  27                 (temp & RH_PS_LSDA) ? " LSDA" : "", \
  28                 (temp & RH_PS_PPS) ? " PPS" : "", \
  29                 (temp & RH_PS_PRS) ? " PRS" : "", \
  30                 (temp & RH_PS_POCI) ? " POCI" : "", \
  31                 (temp & RH_PS_PSS) ? " PSS" : "", \
  32                 \
  33                 (temp & RH_PS_PES) ? " PES" : "", \
  34                 (temp & RH_PS_CCS) ? " CCS" : "" \
  35                 );
  36
  37 /*-------------------------------------------------------------------------*/
  38
  39 /* hcd->hub_irq_enable() */
  40 static void ohci_rhsc_enable (struct usb_hcd *hcd)
  41 {
  42         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
  43
  44         ohci_writel (ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
  45 }
  46
  47 #define OHCI_SCHED_ENABLES \
  48         (OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
  49
  50 static void dl_done_list (struct ohci_hcd *);
  51 static void finish_unlinks (struct ohci_hcd *, u16);
  52
  53 static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
  54 __releases(ohci->lock)
  55 __acquires(ohci->lock)
  56 {
  57         int                     status = 0;
  58
  59         ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
  60         switch (ohci->hc_control & OHCI_CTRL_HCFS) {
  61         case OHCI_USB_RESUME:
  62                 ohci_dbg (ohci, "resume/suspend?\n");
  63                 ohci->hc_control &= ~OHCI_CTRL_HCFS;
  64                 ohci->hc_control |= OHCI_USB_RESET;
  65                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
  66                 (void) ohci_readl (ohci, &ohci->regs->control);
  67                 /* FALL THROUGH */
  68         case OHCI_USB_RESET:
  69                 status = -EBUSY;
  70                 ohci_dbg (ohci, "needs reinit!\n");
  71                 goto done;
  72         case OHCI_USB_SUSPEND:
  73                 if (!ohci->autostop) {
  74                         ohci_dbg (ohci, "already suspended\n");
  75                         goto done;
  76                 }
  77         }
  78         ohci_dbg (ohci, "%s root hub\n",
  79                         autostop ? "auto-stop" : "suspend");
  80
  81         /* First stop any processing */
  82         if (!autostop && (ohci->hc_control & OHCI_SCHED_ENABLES)) {
  83                 ohci->hc_control &= ~OHCI_SCHED_ENABLES;
  84                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
  85                 ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
  86                 ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
  87
  88                 /* sched disables take effect on the next frame,
  89                  * then the last WDH could take 6+ msec
  90                  */
  91                 ohci_dbg (ohci, "stopping schedules ...\n");
  92                 ohci->autostop = 0;
  93                 spin_unlock_irq (&ohci->lock);
  94                 msleep (8);
  95                 spin_lock_irq (&ohci->lock);
  96         }
  97         dl_done_list (ohci);
  98         finish_unlinks (ohci, ohci_frame_no(ohci));
  99
 100         /* maybe resume can wake root hub */
 101         if (device_may_wakeup(&ohci_to_hcd(ohci)->self.root_hub->dev) ||
 102                         autostop)
 103                 ohci->hc_control |= OHCI_CTRL_RWE;
 104         else {
 105                 ohci_writel (ohci, OHCI_INTR_RHSC, &ohci->regs->intrdisable);
 106                 ohci->hc_control &= ~OHCI_CTRL_RWE;
 107         }
 108
 109         /* Suspend hub ... this is the "global (to this bus) suspend" mode,
 110          * which doesn't imply ports will first be individually suspended.
 111          */
 112         ohci->hc_control &= ~OHCI_CTRL_HCFS;
 113         ohci->hc_control |= OHCI_USB_SUSPEND;
 114         ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 115         (void) ohci_readl (ohci, &ohci->regs->control);
 116
 117         /* no resumes until devices finish suspending */
 118         if (!autostop) {
 119                 ohci->next_statechange = jiffies + msecs_to_jiffies (5);
 120                 ohci->autostop = 0;
 121         }
 122
 123 done:
 124         return status;
 125 }
 126
 127 static inline struct ed *find_head (struct ed *ed)
 128 {
 129         /* for bulk and control lists */
 130         while (ed->ed_prev)
 131                 ed = ed->ed_prev;
 132         return ed;
 133 }
 134
 135 static int ohci_restart (struct ohci_hcd *ohci);
 136
 137 /* caller has locked the root hub */
 138 static int ohci_rh_resume (struct ohci_hcd *ohci)
 139 __releases(ohci->lock)
 140 __acquires(ohci->lock)
 141 {
 142         struct usb_hcd          *hcd = ohci_to_hcd (ohci);
 143         u32                     temp, enables;
 144         int                     status = -EINPROGRESS;
 145         int                     autostopped = ohci->autostop;
 146
 147         ohci->autostop = 0;
 148         ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
 149
 150         if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
 151                 /* this can happen after resuming a swsusp snapshot */
 152                 if (hcd->state == HC_STATE_RESUMING) {
 153                         ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
 154                                         ohci->hc_control);
 155                         status = -EBUSY;
 156                 /* this happens when pmcore resumes HC then root */
 157                 } else {
 158                         ohci_dbg (ohci, "duplicate resume\n");
 159                         status = 0;
 160                 }
 161         } else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
 162         case OHCI_USB_SUSPEND:
 163                 ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
 164                 ohci->hc_control |= OHCI_USB_RESUME;
 165                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 166                 (void) ohci_readl (ohci, &ohci->regs->control);
 167                 ohci_dbg (ohci, "%s root hub\n",
 168                                 autostopped ? "auto-start" : "resume");
 169                 break;
 170         case OHCI_USB_RESUME:
 171                 /* HCFS changes sometime after INTR_RD */
 172                 ohci_info (ohci, "wakeup\n");
 173                 break;
 174         case OHCI_USB_OPER:
 175                 /* this can happen after resuming a swsusp snapshot */
 176                 ohci_dbg (ohci, "snapshot resume? reinit\n");
 177                 status = -EBUSY;
 178                 break;
 179         default:                /* RESET, we lost power */
 180                 ohci_dbg (ohci, "lost power\n");
 181                 status = -EBUSY;
 182         }
 183 #ifdef  CONFIG_PM
 184         if (status == -EBUSY) {
 185                 if (!autostopped) {
 186                         spin_unlock_irq (&ohci->lock);
 187                         (void) ohci_init (ohci);
 188                         status = ohci_restart (ohci);
 189                         spin_lock_irq (&ohci->lock);
 190                 }
 191                 return status;
 192         }
 193 #endif
 194         if (status != -EINPROGRESS)
 195                 return status;
 196         if (autostopped)
 197                 goto skip_resume;
 198         spin_unlock_irq (&ohci->lock);
 199
 200         temp = ohci->num_ports;
 201         while (temp--) {
 202                 u32 stat = ohci_readl (ohci,
 203                                        &ohci->regs->roothub.portstatus [temp]);
 204
 205                 /* force global, not selective, resume */
 206                 if (!(stat & RH_PS_PSS))
 207                         continue;
 208                 ohci_writel (ohci, RH_PS_POCI,
 209                                 &ohci->regs->roothub.portstatus [temp]);
 210         }
 211
 212         /* Some controllers (lucent erratum) need extra-long delays */
 213         msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
 214
 215         temp = ohci_readl (ohci, &ohci->regs->control);
 216         temp &= OHCI_CTRL_HCFS;
 217         if (temp != OHCI_USB_RESUME) {
 218                 ohci_err (ohci, "controller won't resume\n");
 219                 return -EBUSY;
 220         }
 221
 222         /* disable old schedule state, reinit from scratch */
 223         ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
 224         ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
 225         ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
 226         ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
 227         ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
 228         ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
 229
 230         /* Sometimes PCI D3 suspend trashes frame timings ... */
 231         periodic_reinit (ohci);
 232
 233         /* the following code is executed with ohci->lock held and
 234          * irqs disabled if and only if autostopped is true
 235          */
 236
 237 skip_resume:
 238         /* interrupts might have been disabled */
 239         ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
 240         if (ohci->ed_rm_list)
 241                 ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
 242
 243         /* Then re-enable operations */
 244         ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
 245         (void) ohci_readl (ohci, &ohci->regs->control);
 246         if (!autostopped)
 247                 msleep (3);
 248
 249         temp = ohci->hc_control;
 250         temp &= OHCI_CTRL_RWC;
 251         temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
 252         ohci->hc_control = temp;
 253         ohci_writel (ohci, temp, &ohci->regs->control);
 254         (void) ohci_readl (ohci, &ohci->regs->control);
 255
 256         /* TRSMRCY */
 257         if (!autostopped) {
 258                 msleep (10);
 259                 spin_lock_irq (&ohci->lock);
 260         }
 261         /* now ohci->lock is always held and irqs are always disabled */
 262
 263         /* keep it alive for more than ~5x suspend + resume costs */
 264         ohci->next_statechange = jiffies + STATECHANGE_DELAY;
 265
 266         /* maybe turn schedules back on */
 267         enables = 0;
 268         temp = 0;
 269         if (!ohci->ed_rm_list) {
 270                 if (ohci->ed_controltail) {
 271                         ohci_writel (ohci,
 272                                         find_head (ohci->ed_controltail)->dma,
 273                                         &ohci->regs->ed_controlhead);
 274                         enables |= OHCI_CTRL_CLE;
 275                         temp |= OHCI_CLF;
 276                 }
 277                 if (ohci->ed_bulktail) {
 278                         ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
 279                                 &ohci->regs->ed_bulkhead);
 280                         enables |= OHCI_CTRL_BLE;
 281                         temp |= OHCI_BLF;
 282                 }
 283         }
 284         if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
 285                 enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
 286         if (enables) {
 287                 ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
 288                 ohci->hc_control |= enables;
 289                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 290                 if (temp)
 291                         ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
 292                 (void) ohci_readl (ohci, &ohci->regs->control);
 293         }
 294
 295         return 0;
 296 }
 297
 298 #ifdef  CONFIG_PM
 299
 300 static int ohci_bus_suspend (struct usb_hcd *hcd)
 301 {
 302         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
 303         int                     rc;
 304
 305         spin_lock_irq (&ohci->lock);
 306
 307         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
 308                 rc = -ESHUTDOWN;
 309         else
 310                 rc = ohci_rh_suspend (ohci, 0);
 311         spin_unlock_irq (&ohci->lock);
 312         return rc;
 313 }
 314
 315 static int ohci_bus_resume (struct usb_hcd *hcd)
 316 {
 317         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
 318         int                     rc;
 319
 320         if (time_before (jiffies, ohci->next_statechange))
 321                 msleep(5);
 322
 323         spin_lock_irq (&ohci->lock);
 324
 325         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
 326                 rc = -ESHUTDOWN;
 327         else
 328                 rc = ohci_rh_resume (ohci);
 329         spin_unlock_irq (&ohci->lock);
 330
 331         /* poll until we know a device is connected or we autostop */
 332         if (rc == 0)
 333                 usb_hcd_poll_rh_status(hcd);
 334         return rc;
 335 }
 336
 337 #endif  /* CONFIG_PM */
 338
 339 /*-------------------------------------------------------------------------*/
 340
 341 /* build "status change" packet (one or two bytes) from HC registers */
 342
 343 static int
 344 ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
 345 {
 346         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 347         int             i, changed = 0, length = 1;
 348         int             any_connected = 0, rhsc_enabled = 1;
 349         unsigned long   flags;
 350
 351         spin_lock_irqsave (&ohci->lock, flags);
 352
 353         /* undocumented erratum seen on at least rev D */
 354         if ((ohci->flags & OHCI_QUIRK_AMD756)
 355                         && (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
 356                 ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
 357                           ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
 358                 /* retry later; "should not happen" */
 359                 goto done;
 360         }
 361
 362         /* init status */
 363         if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
 364                 buf [0] = changed = 1;
 365         else
 366                 buf [0] = 0;
 367         if (ohci->num_ports > 7) {
 368                 buf [1] = 0;
 369                 length++;
 370         }
 371
 372         /* look at each port */
 373         for (i = 0; i < ohci->num_ports; i++) {
 374                 u32     status = roothub_portstatus (ohci, i);
 375
 376                 /* can't autostop if ports are connected */
 377                 any_connected |= (status & RH_PS_CCS);
 378
 379                 if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
 380                                 | RH_PS_OCIC | RH_PS_PRSC)) {
 381                         changed = 1;
 382                         if (i < 7)
 383                             buf [0] |= 1 << (i + 1);
 384                         else
 385                             buf [1] |= 1 << (i - 7);
 386                 }
 387         }
 388
 389         /* NOTE:  vendors didn't always make the same implementation
 390          * choices for RHSC.  Sometimes it triggers on an edge (like
 391          * setting and maybe clearing a port status change bit); and
 392          * it's level-triggered on other silicon, active until khubd
 393          * clears all active port status change bits.  If it's still
 394          * set (level-triggered) we must disable it and rely on
 395          * polling until khubd re-enables it.
 396          */
 397         if (ohci_readl (ohci, &ohci->regs->intrstatus) & OHCI_INTR_RHSC) {
 398                 ohci_writel (ohci, OHCI_INTR_RHSC, &ohci->regs->intrdisable);
 399                 (void) ohci_readl (ohci, &ohci->regs->intrdisable);
 400                 rhsc_enabled = 0;
 401         }
 402         hcd->poll_rh = 1;
 403
 404         /* carry out appropriate state changes */
 405         switch (ohci->hc_control & OHCI_CTRL_HCFS) {
 406
 407         case OHCI_USB_OPER:
 408                 /* keep on polling until we know a device is connected
 409                  * and RHSC is enabled */
 410                 if (!ohci->autostop) {
 411                         if (any_connected) {
 412                                 if (rhsc_enabled)
 413                                         hcd->poll_rh = 0;
 414                         } else {
 415                                 ohci->autostop = 1;
 416                                 ohci->next_statechange = jiffies + HZ;
 417                         }
 418
 419                 /* if no devices have been attached for one second, autostop */
 420                 } else {
 421                         if (changed || any_connected) {
 422                                 ohci->autostop = 0;
 423                                 ohci->next_statechange = jiffies +
 424                                                 STATECHANGE_DELAY;
 425                         } else if (time_after_eq (jiffies,
 426                                                 ohci->next_statechange)
 427                                         && !ohci->ed_rm_list
 428                                         && !(ohci->hc_control &
 429                                                 OHCI_SCHED_ENABLES)) {
 430                                 ohci_rh_suspend (ohci, 1);
 431                         }
 432                 }
 433                 break;
 434
 435         /* if there is a port change, autostart or ask to be resumed */
 436         case OHCI_USB_SUSPEND:
 437         case OHCI_USB_RESUME:
 438                 if (changed) {
 439                         if (ohci->autostop)
 440                                 ohci_rh_resume (ohci);
 441                         else
 442                                 usb_hcd_resume_root_hub (hcd);
 443                 } else {
 444                         /* everything is idle, no need for polling */
 445                         hcd->poll_rh = 0;
 446                 }
 447                 break;
 448         }
 449
 450 done:
 451         spin_unlock_irqrestore (&ohci->lock, flags);
 452
 453         return changed ? length : 0;
 454 }
 455
 456 /*-------------------------------------------------------------------------*/
 457
 458 static void
 459 ohci_hub_descriptor (
 460         struct ohci_hcd                 *ohci,
 461         struct usb_hub_descriptor       *desc
 462 ) {
 463         u32             rh = roothub_a (ohci);
 464         u16             temp;
 465
 466         desc->bDescriptorType = 0x29;
 467         desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
 468         desc->bHubContrCurrent = 0;
 469
 470         desc->bNbrPorts = ohci->num_ports;
 471         temp = 1 + (ohci->num_ports / 8);
 472         desc->bDescLength = 7 + 2 * temp;
 473
 474         temp = 0;
 475         if (rh & RH_A_NPS)              /* no power switching? */
 476             temp |= 0x0002;
 477         if (rh & RH_A_PSM)              /* per-port power switching? */
 478             temp |= 0x0001;
 479         if (rh & RH_A_NOCP)             /* no overcurrent reporting? */
 480             temp |= 0x0010;
 481         else if (rh & RH_A_OCPM)        /* per-port overcurrent reporting? */
 482             temp |= 0x0008;
 483         desc->wHubCharacteristics = (__force __u16)cpu_to_hc16(ohci, temp);
 484
 485         /* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
 486         rh = roothub_b (ohci);
 487         memset(desc->bitmap, 0xff, sizeof(desc->bitmap));
 488         desc->bitmap [0] = rh & RH_B_DR;
 489         if (ohci->num_ports > 7) {
 490                 desc->bitmap [1] = (rh & RH_B_DR) >> 8;
 491                 desc->bitmap [2] = 0xff;
 492         } else
 493                 desc->bitmap [1] = 0xff;
 494 }
 495
 496 /*-------------------------------------------------------------------------*/
 497
 498 #ifdef  CONFIG_USB_OTG
 499
 500 static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
 501 {
 502         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 503         u32                     status;
 504
 505         if (!port)
 506                 return -EINVAL;
 507         port--;
 508
 509         /* start port reset before HNP protocol times out */
 510         status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
 511         if (!(status & RH_PS_CCS))
 512                 return -ENODEV;
 513
 514         /* khubd will finish the reset later */
 515         ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
 516         return 0;
 517 }
 518
 519 static void start_hnp(struct ohci_hcd *ohci);
 520
 521 #else
 522
 523 #define ohci_start_port_reset           NULL
 524
 525 #endif
 526
 527 /*-------------------------------------------------------------------------*/
 528
 529
 530 /* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
 531  * not necessarily continuous ... to guard against resume signaling.
 532  * The short timeout is safe for non-root hubs, and is backward-compatible
 533  * with earlier Linux hosts.
 534  */
 535 #ifdef  CONFIG_USB_SUSPEND
 536 #define PORT_RESET_MSEC         50
 537 #else
 538 #define PORT_RESET_MSEC         10
 539 #endif
 540
 541 /* this timer value might be vendor-specific ... */
 542 #define PORT_RESET_HW_MSEC      10
 543
 544 /* wrap-aware logic morphed from <linux/jiffies.h> */
 545 #define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
 546
 547 /* called from some task, normally khubd */
 548 static inline void root_port_reset (struct ohci_hcd *ohci, unsigned port)
 549 {
 550         __hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
 551         u32     temp;
 552         u16     now = ohci_readl(ohci, &ohci->regs->fmnumber);
 553         u16     reset_done = now + PORT_RESET_MSEC;
 554
 555         /* build a "continuous enough" reset signal, with up to
 556          * 3msec gap between pulses.  scheduler HZ==100 must work;
 557          * this might need to be deadline-scheduled.
 558          */
 559         do {
 560                 /* spin until any current reset finishes */
 561                 for (;;) {
 562                         temp = ohci_readl (ohci, portstat);
 563                         if (!(temp & RH_PS_PRS))
 564                                 break;
 565                         udelay (500);
 566                 }
 567
 568                 if (!(temp & RH_PS_CCS))
 569                         break;
 570                 if (temp & RH_PS_PRSC)
 571                         ohci_writel (ohci, RH_PS_PRSC, portstat);
 572
 573                 /* start the next reset, sleep till it's probably done */
 574                 ohci_writel (ohci, RH_PS_PRS, portstat);
 575                 msleep(PORT_RESET_HW_MSEC);
 576                 now = ohci_readl(ohci, &ohci->regs->fmnumber);
 577         } while (tick_before(now, reset_done));
 578         /* caller synchronizes using PRSC */
 579 }
 580
 581 static int ohci_hub_control (
 582         struct usb_hcd  *hcd,
 583         u16             typeReq,
 584         u16             wValue,
 585         u16             wIndex,
 586         char            *buf,
 587         u16             wLength
 588 ) {
 589         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 590         int             ports = hcd_to_bus (hcd)->root_hub->maxchild;
 591         u32             temp;
 592         int             retval = 0;
 593
 594         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
 595                 return -ESHUTDOWN;
 596
 597         switch (typeReq) {
 598         case ClearHubFeature:
 599                 switch (wValue) {
 600                 case C_HUB_OVER_CURRENT:
 601                         ohci_writel (ohci, RH_HS_OCIC,
 602                                         &ohci->regs->roothub.status);
 603                 case C_HUB_LOCAL_POWER:
 604                         break;
 605                 default:
 606                         goto error;
 607                 }
 608                 break;
 609         case ClearPortFeature:
 610                 if (!wIndex || wIndex > ports)
 611                         goto error;
 612                 wIndex--;
 613
 614                 switch (wValue) {
 615                 case USB_PORT_FEAT_ENABLE:
 616                         temp = RH_PS_CCS;
 617                         break;
 618                 case USB_PORT_FEAT_C_ENABLE:
 619                         temp = RH_PS_PESC;
 620                         break;
 621                 case USB_PORT_FEAT_SUSPEND:
 622                         temp = RH_PS_POCI;
 623                         break;
 624                 case USB_PORT_FEAT_C_SUSPEND:
 625                         temp = RH_PS_PSSC;
 626                         break;
 627                 case USB_PORT_FEAT_POWER:
 628                         temp = RH_PS_LSDA;
 629                         break;
 630                 case USB_PORT_FEAT_C_CONNECTION:
 631                         temp = RH_PS_CSC;
 632                         break;
 633                 case USB_PORT_FEAT_C_OVER_CURRENT:
 634                         temp = RH_PS_OCIC;
 635                         break;
 636                 case USB_PORT_FEAT_C_RESET:
 637                         temp = RH_PS_PRSC;
 638                         break;
 639                 default:
 640                         goto error;
 641                 }
 642                 ohci_writel (ohci, temp,
 643                                 &ohci->regs->roothub.portstatus [wIndex]);
 644                 // ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
 645                 break;
 646         case GetHubDescriptor:
 647                 ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
 648                 break;
 649         case GetHubStatus:
 650                 temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
 651                 put_unaligned(cpu_to_le32 (temp), (__le32 *) buf);
 652                 break;
 653         case GetPortStatus:
 654                 if (!wIndex || wIndex > ports)
 655                         goto error;
 656                 wIndex--;
 657                 temp = roothub_portstatus (ohci, wIndex);
 658                 put_unaligned(cpu_to_le32 (temp), (__le32 *) buf);
 659
 660 #ifndef OHCI_VERBOSE_DEBUG
 661         if (*(u16*)(buf+2))     /* only if wPortChange is interesting */
 662 #endif
 663                 dbg_port (ohci, "GetStatus", wIndex, temp);
 664                 break;
 665         case SetHubFeature:
 666                 switch (wValue) {
 667                 case C_HUB_OVER_CURRENT:
 668                         // FIXME:  this can be cleared, yes?
 669                 case C_HUB_LOCAL_POWER:
 670                         break;
 671                 default:
 672                         goto error;
 673                 }
 674                 break;
 675         case SetPortFeature:
 676                 if (!wIndex || wIndex > ports)
 677                         goto error;
 678                 wIndex--;
 679                 switch (wValue) {
 680                 case USB_PORT_FEAT_SUSPEND:
 681 #ifdef  CONFIG_USB_OTG
 682                         if (hcd->self.otg_port == (wIndex + 1)
 683                                         && hcd->self.b_hnp_enable)
 684                                 start_hnp(ohci);
 685                         else
 686 #endif
 687                         ohci_writel (ohci, RH_PS_PSS,
 688                                 &ohci->regs->roothub.portstatus [wIndex]);
 689                         break;
 690                 case USB_PORT_FEAT_POWER:
 691                         ohci_writel (ohci, RH_PS_PPS,
 692                                 &ohci->regs->roothub.portstatus [wIndex]);
 693                         break;
 694                 case USB_PORT_FEAT_RESET:
 695                         root_port_reset (ohci, wIndex);
 696                         break;
 697                 default:
 698                         goto error;
 699                 }
 700                 break;
 701
 702         default:
 703 error:
 704                 /* "protocol stall" on error */
 705                 retval = -EPIPE;
 706         }
 707         return retval;
 708 }
 709