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 #define OHCI_SCHED_ENABLES \
  40         (OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
  41
  42 static void dl_done_list (struct ohci_hcd *);
  43 static void finish_unlinks (struct ohci_hcd *, u16);
  44
  45 #ifdef  CONFIG_PM
  46 static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
  47 __releases(ohci->lock)
  48 __acquires(ohci->lock)
  49 {
  50         int                     status = 0;
  51
  52         ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
  53         switch (ohci->hc_control & OHCI_CTRL_HCFS) {
  54         case OHCI_USB_RESUME:
  55                 ohci_dbg (ohci, "resume/suspend?\n");
  56                 ohci->hc_control &= ~OHCI_CTRL_HCFS;
  57                 ohci->hc_control |= OHCI_USB_RESET;
  58                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
  59                 (void) ohci_readl (ohci, &ohci->regs->control);
  60                 /* FALL THROUGH */
  61         case OHCI_USB_RESET:
  62                 status = -EBUSY;
  63                 ohci_dbg (ohci, "needs reinit!\n");
  64                 goto done;
  65         case OHCI_USB_SUSPEND:
  66                 if (!ohci->autostop) {
  67                         ohci_dbg (ohci, "already suspended\n");
  68                         goto done;
  69                 }
  70         }
  71         ohci_dbg (ohci, "%s root hub\n",
  72                         autostop ? "auto-stop" : "suspend");
  73
  74         /* First stop any processing */
  75         if (!autostop && (ohci->hc_control & OHCI_SCHED_ENABLES)) {
  76                 ohci->hc_control &= ~OHCI_SCHED_ENABLES;
  77                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
  78                 ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
  79                 ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
  80
  81                 /* sched disables take effect on the next frame,
  82                  * then the last WDH could take 6+ msec
  83                  */
  84                 ohci_dbg (ohci, "stopping schedules ...\n");
  85                 ohci->autostop = 0;
  86                 spin_unlock_irq (&ohci->lock);
  87                 msleep (8);
  88                 spin_lock_irq (&ohci->lock);
  89         }
  90         dl_done_list (ohci);
  91         finish_unlinks (ohci, ohci_frame_no(ohci));
  92
  93         /* maybe resume can wake root hub */
  94         if (ohci_to_hcd(ohci)->self.root_hub->do_remote_wakeup || autostop) {
  95                 ohci->hc_control |= OHCI_CTRL_RWE;
  96         } else {
  97                 ohci_writel(ohci, OHCI_INTR_RHSC | OHCI_INTR_RD,
  98                                 &ohci->regs->intrdisable);
  99                 ohci->hc_control &= ~OHCI_CTRL_RWE;
 100         }
 101
 102         /* Suspend hub ... this is the "global (to this bus) suspend" mode,
 103          * which doesn't imply ports will first be individually suspended.
 104          */
 105         ohci->hc_control &= ~OHCI_CTRL_HCFS;
 106         ohci->hc_control |= OHCI_USB_SUSPEND;
 107         ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 108         (void) ohci_readl (ohci, &ohci->regs->control);
 109
 110         /* no resumes until devices finish suspending */
 111         if (!autostop) {
 112                 ohci->next_statechange = jiffies + msecs_to_jiffies (5);
 113                 ohci->autostop = 0;
 114         }
 115
 116 done:
 117         return status;
 118 }
 119
 120 static inline struct ed *find_head (struct ed *ed)
 121 {
 122         /* for bulk and control lists */
 123         while (ed->ed_prev)
 124                 ed = ed->ed_prev;
 125         return ed;
 126 }
 127
 128 /* caller has locked the root hub */
 129 static int ohci_rh_resume (struct ohci_hcd *ohci)
 130 __releases(ohci->lock)
 131 __acquires(ohci->lock)
 132 {
 133         struct usb_hcd          *hcd = ohci_to_hcd (ohci);
 134         u32                     temp, enables;
 135         int                     status = -EINPROGRESS;
 136         int                     autostopped = ohci->autostop;
 137
 138         ohci->autostop = 0;
 139         ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
 140
 141         if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
 142                 /* this can happen after resuming a swsusp snapshot */
 143                 if (hcd->state == HC_STATE_RESUMING) {
 144                         ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
 145                                         ohci->hc_control);
 146                         status = -EBUSY;
 147                 /* this happens when pmcore resumes HC then root */
 148                 } else {
 149                         ohci_dbg (ohci, "duplicate resume\n");
 150                         status = 0;
 151                 }
 152         } else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
 153         case OHCI_USB_SUSPEND:
 154                 ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
 155                 ohci->hc_control |= OHCI_USB_RESUME;
 156                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 157                 (void) ohci_readl (ohci, &ohci->regs->control);
 158                 ohci_dbg (ohci, "%s root hub\n",
 159                                 autostopped ? "auto-start" : "resume");
 160                 break;
 161         case OHCI_USB_RESUME:
 162                 /* HCFS changes sometime after INTR_RD */
 163                 ohci_dbg(ohci, "%swakeup root hub\n",
 164                                 autostopped ? "auto-" : "");
 165                 break;
 166         case OHCI_USB_OPER:
 167                 /* this can happen after resuming a swsusp snapshot */
 168                 ohci_dbg (ohci, "snapshot resume? reinit\n");
 169                 status = -EBUSY;
 170                 break;
 171         default:                /* RESET, we lost power */
 172                 ohci_dbg (ohci, "lost power\n");
 173                 status = -EBUSY;
 174         }
 175         if (status == -EBUSY) {
 176                 if (!autostopped) {
 177                         spin_unlock_irq (&ohci->lock);
 178                         (void) ohci_init (ohci);
 179                         status = ohci_restart (ohci);
 180
 181                         usb_root_hub_lost_power(hcd->self.root_hub);
 182
 183                         spin_lock_irq (&ohci->lock);
 184                 }
 185                 return status;
 186         }
 187         if (status != -EINPROGRESS)
 188                 return status;
 189         if (autostopped)
 190                 goto skip_resume;
 191         spin_unlock_irq (&ohci->lock);
 192
 193         /* Some controllers (lucent erratum) need extra-long delays */
 194         msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
 195
 196         temp = ohci_readl (ohci, &ohci->regs->control);
 197         temp &= OHCI_CTRL_HCFS;
 198         if (temp != OHCI_USB_RESUME) {
 199                 ohci_err (ohci, "controller won't resume\n");
 200                 spin_lock_irq(&ohci->lock);
 201                 return -EBUSY;
 202         }
 203
 204         /* disable old schedule state, reinit from scratch */
 205         ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
 206         ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
 207         ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
 208         ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
 209         ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
 210         ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
 211
 212         /* Sometimes PCI D3 suspend trashes frame timings ... */
 213         periodic_reinit (ohci);
 214
 215         /* the following code is executed with ohci->lock held and
 216          * irqs disabled if and only if autostopped is true
 217          */
 218
 219 skip_resume:
 220         /* interrupts might have been disabled */
 221         ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
 222         if (ohci->ed_rm_list)
 223                 ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
 224
 225         /* Then re-enable operations */
 226         ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
 227         (void) ohci_readl (ohci, &ohci->regs->control);
 228         if (!autostopped)
 229                 msleep (3);
 230
 231         temp = ohci->hc_control;
 232         temp &= OHCI_CTRL_RWC;
 233         temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
 234         ohci->hc_control = temp;
 235         ohci_writel (ohci, temp, &ohci->regs->control);
 236         (void) ohci_readl (ohci, &ohci->regs->control);
 237
 238         /* TRSMRCY */
 239         if (!autostopped) {
 240                 msleep (10);
 241                 spin_lock_irq (&ohci->lock);
 242         }
 243         /* now ohci->lock is always held and irqs are always disabled */
 244
 245         /* keep it alive for more than ~5x suspend + resume costs */
 246         ohci->next_statechange = jiffies + STATECHANGE_DELAY;
 247
 248         /* maybe turn schedules back on */
 249         enables = 0;
 250         temp = 0;
 251         if (!ohci->ed_rm_list) {
 252                 if (ohci->ed_controltail) {
 253                         ohci_writel (ohci,
 254                                         find_head (ohci->ed_controltail)->dma,
 255                                         &ohci->regs->ed_controlhead);
 256                         enables |= OHCI_CTRL_CLE;
 257                         temp |= OHCI_CLF;
 258                 }
 259                 if (ohci->ed_bulktail) {
 260                         ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
 261                                 &ohci->regs->ed_bulkhead);
 262                         enables |= OHCI_CTRL_BLE;
 263                         temp |= OHCI_BLF;
 264                 }
 265         }
 266         if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
 267                 enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
 268         if (enables) {
 269                 ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
 270                 ohci->hc_control |= enables;
 271                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 272                 if (temp)
 273                         ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
 274                 (void) ohci_readl (ohci, &ohci->regs->control);
 275         }
 276
 277         return 0;
 278 }
 279
 280 static int ohci_bus_suspend (struct usb_hcd *hcd)
 281 {
 282         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
 283         int                     rc;
 284
 285         spin_lock_irq (&ohci->lock);
 286
 287         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
 288                 rc = -ESHUTDOWN;
 289         else
 290                 rc = ohci_rh_suspend (ohci, 0);
 291         spin_unlock_irq (&ohci->lock);
 292         return rc;
 293 }
 294
 295 static int ohci_bus_resume (struct usb_hcd *hcd)
 296 {
 297         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
 298         int                     rc;
 299
 300         if (time_before (jiffies, ohci->next_statechange))
 301                 msleep(5);
 302
 303         spin_lock_irq (&ohci->lock);
 304
 305         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
 306                 rc = -ESHUTDOWN;
 307         else
 308                 rc = ohci_rh_resume (ohci);
 309         spin_unlock_irq (&ohci->lock);
 310
 311         /* poll until we know a device is connected or we autostop */
 312         if (rc == 0)
 313                 usb_hcd_poll_rh_status(hcd);
 314         return rc;
 315 }
 316
 317 /* Carry out the final steps of resuming the controller device */
 318 static void ohci_finish_controller_resume(struct usb_hcd *hcd)
 319 {
 320         struct ohci_hcd         *ohci = hcd_to_ohci(hcd);
 321         int                     port;
 322         bool                    need_reinit = false;
 323
 324         /* See if the controller is already running or has been reset */
 325         ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
 326         if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
 327                 need_reinit = true;
 328         } else {
 329                 switch (ohci->hc_control & OHCI_CTRL_HCFS) {
 330                 case OHCI_USB_OPER:
 331                 case OHCI_USB_RESET:
 332                         need_reinit = true;
 333                 }
 334         }
 335
 336         /* If needed, reinitialize and suspend the root hub */
 337         if (need_reinit) {
 338                 spin_lock_irq(&ohci->lock);
 339                 hcd->state = HC_STATE_RESUMING;
 340                 ohci_rh_resume(ohci);
 341                 hcd->state = HC_STATE_QUIESCING;
 342                 ohci_rh_suspend(ohci, 0);
 343                 hcd->state = HC_STATE_SUSPENDED;
 344                 spin_unlock_irq(&ohci->lock);
 345         }
 346
 347         /* Normally just turn on port power and enable interrupts */
 348         else {
 349                 ohci_dbg(ohci, "powerup ports\n");
 350                 for (port = 0; port < ohci->num_ports; port++)
 351                         ohci_writel(ohci, RH_PS_PPS,
 352                                         &ohci->regs->roothub.portstatus[port]);
 353
 354                 ohci_writel(ohci, OHCI_INTR_MIE, &ohci->regs->intrenable);
 355                 ohci_readl(ohci, &ohci->regs->intrenable);
 356                 msleep(20);
 357         }
 358 }
 359
 360 /* Carry out polling-, autostop-, and autoresume-related state changes */
 361 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
 362                 int any_connected)
 363 {
 364         int     poll_rh = 1;
 365         int     rhsc;
 366
 367         rhsc = ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC;
 368         switch (ohci->hc_control & OHCI_CTRL_HCFS) {
 369
 370         case OHCI_USB_OPER:
 371                 /* If no status changes are pending, enable status-change
 372                  * interrupts.
 373                  */
 374                 if (!rhsc && !changed) {
 375                         rhsc = OHCI_INTR_RHSC;
 376                         ohci_writel(ohci, rhsc, &ohci->regs->intrenable);
 377                 }
 378
 379                 /* Keep on polling until we know a device is connected
 380                  * and RHSC is enabled, or until we autostop.
 381                  */
 382                 if (!ohci->autostop) {
 383                         if (any_connected ||
 384                                         !device_may_wakeup(&ohci_to_hcd(ohci)
 385                                                 ->self.root_hub->dev)) {
 386                                 if (rhsc)
 387                                         poll_rh = 0;
 388                         } else {
 389                                 ohci->autostop = 1;
 390                                 ohci->next_statechange = jiffies + HZ;
 391                         }
 392
 393                 /* if no devices have been attached for one second, autostop */
 394                 } else {
 395                         if (changed || any_connected) {
 396                                 ohci->autostop = 0;
 397                                 ohci->next_statechange = jiffies +
 398                                                 STATECHANGE_DELAY;
 399                         } else if (rhsc && time_after_eq(jiffies,
 400                                                 ohci->next_statechange)
 401                                         && !ohci->ed_rm_list
 402                                         && !(ohci->hc_control &
 403                                                 OHCI_SCHED_ENABLES)) {
 404                                 ohci_rh_suspend(ohci, 1);
 405                                 poll_rh = 0;
 406                         }
 407                 }
 408                 break;
 409
 410         /* if there is a port change, autostart or ask to be resumed */
 411         case OHCI_USB_SUSPEND:
 412         case OHCI_USB_RESUME:
 413                 if (changed) {
 414                         if (ohci->autostop)
 415                                 ohci_rh_resume(ohci);
 416                         else
 417                                 usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
 418                 } else {
 419                         if (!rhsc && (ohci->autostop ||
 420                                         ohci_to_hcd(ohci)->self.root_hub->
 421                                                 do_remote_wakeup))
 422                                 ohci_writel(ohci, OHCI_INTR_RHSC,
 423                                                 &ohci->regs->intrenable);
 424
 425                         /* everything is idle, no need for polling */
 426                         poll_rh = 0;
 427                 }
 428                 break;
 429         }
 430         return poll_rh;
 431 }
 432
 433 #else   /* CONFIG_PM */
 434
 435 static inline int ohci_rh_resume(struct ohci_hcd *ohci)
 436 {
 437         return 0;
 438 }
 439
 440 /* Carry out polling-related state changes.
 441  * autostop isn't used when CONFIG_PM is turned off.
 442  */
 443 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
 444                 int any_connected)
 445 {
 446         /* If RHSC is enabled, don't poll */
 447         if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
 448                 return 0;
 449
 450         /* If no status changes are pending, enable status-change interrupts */
 451         if (!changed) {
 452                 ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
 453                 return 0;
 454         }
 455         return 1;
 456 }
 457
 458 #endif  /* CONFIG_PM */
 459
 460 /*-------------------------------------------------------------------------*/
 461
 462 /* build "status change" packet (one or two bytes) from HC registers */
 463
 464 static int
 465 ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
 466 {
 467         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 468         int             i, changed = 0, length = 1;
 469         int             any_connected = 0;
 470         unsigned long   flags;
 471
 472         spin_lock_irqsave (&ohci->lock, flags);
 473         if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
 474                 goto done;
 475
 476         /* undocumented erratum seen on at least rev D */
 477         if ((ohci->flags & OHCI_QUIRK_AMD756)
 478                         && (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
 479                 ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
 480                           ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
 481                 /* retry later; "should not happen" */
 482                 goto done;
 483         }
 484
 485         /* init status */
 486         if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
 487                 buf [0] = changed = 1;
 488         else
 489                 buf [0] = 0;
 490         if (ohci->num_ports > 7) {
 491                 buf [1] = 0;
 492                 length++;
 493         }
 494
 495         /* Some broken controllers never turn off RHCS in the interrupt
 496          * status register.  For their sake we won't re-enable RHSC
 497          * interrupts if the flag is already set.
 498          */
 499         if (ohci_readl(ohci, &ohci->regs->intrstatus) & OHCI_INTR_RHSC)
 500                 changed = 1;
 501
 502         /* look at each port */
 503         for (i = 0; i < ohci->num_ports; i++) {
 504                 u32     status = roothub_portstatus (ohci, i);
 505
 506                 /* can't autostop if ports are connected */
 507                 any_connected |= (status & RH_PS_CCS);
 508
 509                 if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
 510                                 | RH_PS_OCIC | RH_PS_PRSC)) {
 511                         changed = 1;
 512                         if (i < 7)
 513                             buf [0] |= 1 << (i + 1);
 514                         else
 515                             buf [1] |= 1 << (i - 7);
 516                 }
 517         }
 518
 519         hcd->poll_rh = ohci_root_hub_state_changes(ohci, changed,
 520                         any_connected);
 521
 522 done:
 523         spin_unlock_irqrestore (&ohci->lock, flags);
 524
 525         return changed ? length : 0;
 526 }
 527
 528 /*-------------------------------------------------------------------------*/
 529
 530 static void
 531 ohci_hub_descriptor (
 532         struct ohci_hcd                 *ohci,
 533         struct usb_hub_descriptor       *desc
 534 ) {
 535         u32             rh = roothub_a (ohci);
 536         u16             temp;
 537
 538         desc->bDescriptorType = 0x29;
 539         desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
 540         desc->bHubContrCurrent = 0;
 541
 542         desc->bNbrPorts = ohci->num_ports;
 543         temp = 1 + (ohci->num_ports / 8);
 544         desc->bDescLength = 7 + 2 * temp;
 545
 546         temp = 0;
 547         if (rh & RH_A_NPS)              /* no power switching? */
 548             temp |= 0x0002;
 549         if (rh & RH_A_PSM)              /* per-port power switching? */
 550             temp |= 0x0001;
 551         if (rh & RH_A_NOCP)             /* no overcurrent reporting? */
 552             temp |= 0x0010;
 553         else if (rh & RH_A_OCPM)        /* per-port overcurrent reporting? */
 554             temp |= 0x0008;
 555         desc->wHubCharacteristics = (__force __u16)cpu_to_hc16(ohci, temp);
 556
 557         /* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
 558         rh = roothub_b (ohci);
 559         memset(desc->bitmap, 0xff, sizeof(desc->bitmap));
 560         desc->bitmap [0] = rh & RH_B_DR;
 561         if (ohci->num_ports > 7) {
 562                 desc->bitmap [1] = (rh & RH_B_DR) >> 8;
 563                 desc->bitmap [2] = 0xff;
 564         } else
 565                 desc->bitmap [1] = 0xff;
 566 }
 567
 568 /*-------------------------------------------------------------------------*/
 569
 570 #ifdef  CONFIG_USB_OTG
 571
 572 static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
 573 {
 574         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 575         u32                     status;
 576
 577         if (!port)
 578                 return -EINVAL;
 579         port--;
 580
 581         /* start port reset before HNP protocol times out */
 582         status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
 583         if (!(status & RH_PS_CCS))
 584                 return -ENODEV;
 585
 586         /* khubd will finish the reset later */
 587         ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
 588         return 0;
 589 }
 590
 591 #else
 592
 593 #define ohci_start_port_reset           NULL
 594
 595 #endif
 596
 597 /*-------------------------------------------------------------------------*/
 598
 599
 600 /* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
 601  * not necessarily continuous ... to guard against resume signaling.
 602  * The short timeout is safe for non-root hubs, and is backward-compatible
 603  * with earlier Linux hosts.
 604  */
 605 #ifdef  CONFIG_USB_SUSPEND
 606 #define PORT_RESET_MSEC         50
 607 #else
 608 #define PORT_RESET_MSEC         10
 609 #endif
 610
 611 /* this timer value might be vendor-specific ... */
 612 #define PORT_RESET_HW_MSEC      10
 613
 614 /* wrap-aware logic morphed from <linux/jiffies.h> */
 615 #define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
 616
 617 /* called from some task, normally khubd */
 618 static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
 619 {
 620         __hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
 621         u32     temp = 0;
 622         u16     now = ohci_readl(ohci, &ohci->regs->fmnumber);
 623         u16     reset_done = now + PORT_RESET_MSEC;
 624         int     limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
 625
 626         /* build a "continuous enough" reset signal, with up to
 627          * 3msec gap between pulses.  scheduler HZ==100 must work;
 628          * this might need to be deadline-scheduled.
 629          */
 630         do {
 631                 int limit_2;
 632
 633                 /* spin until any current reset finishes */
 634                 limit_2 = PORT_RESET_HW_MSEC * 2;
 635                 while (--limit_2 >= 0) {
 636                         temp = ohci_readl (ohci, portstat);
 637                         /* handle e.g. CardBus eject */
 638                         if (temp == ~(u32)0)
 639                                 return -ESHUTDOWN;
 640                         if (!(temp & RH_PS_PRS))
 641                                 break;
 642                         udelay (500);
 643                 }
 644
 645                 /* timeout (a hardware error) has been observed when
 646                  * EHCI sets CF while this driver is resetting a port;
 647                  * presumably other disconnect paths might do it too.
 648                  */
 649                 if (limit_2 < 0) {
 650                         ohci_dbg(ohci,
 651                                 "port[%d] reset timeout, stat %08x\n",
 652                                 port, temp);
 653                         break;
 654                 }
 655
 656                 if (!(temp & RH_PS_CCS))
 657                         break;
 658                 if (temp & RH_PS_PRSC)
 659                         ohci_writel (ohci, RH_PS_PRSC, portstat);
 660
 661                 /* start the next reset, sleep till it's probably done */
 662                 ohci_writel (ohci, RH_PS_PRS, portstat);
 663                 msleep(PORT_RESET_HW_MSEC);
 664                 now = ohci_readl(ohci, &ohci->regs->fmnumber);
 665         } while (tick_before(now, reset_done) && --limit_1 >= 0);
 666
 667         /* caller synchronizes using PRSC ... and handles PRS
 668          * still being set when this returns.
 669          */
 670
 671         return 0;
 672 }
 673
 674 static int ohci_hub_control (
 675         struct usb_hcd  *hcd,
 676         u16             typeReq,
 677         u16             wValue,
 678         u16             wIndex,
 679         char            *buf,
 680         u16             wLength
 681 ) {
 682         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 683         int             ports = hcd_to_bus (hcd)->root_hub->maxchild;
 684         u32             temp;
 685         int             retval = 0;
 686
 687         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
 688                 return -ESHUTDOWN;
 689
 690         switch (typeReq) {
 691         case ClearHubFeature:
 692                 switch (wValue) {
 693                 case C_HUB_OVER_CURRENT:
 694                         ohci_writel (ohci, RH_HS_OCIC,
 695                                         &ohci->regs->roothub.status);
 696                 case C_HUB_LOCAL_POWER:
 697                         break;
 698                 default:
 699                         goto error;
 700                 }
 701                 break;
 702         case ClearPortFeature:
 703                 if (!wIndex || wIndex > ports)
 704                         goto error;
 705                 wIndex--;
 706
 707                 switch (wValue) {
 708                 case USB_PORT_FEAT_ENABLE:
 709                         temp = RH_PS_CCS;
 710                         break;
 711                 case USB_PORT_FEAT_C_ENABLE:
 712                         temp = RH_PS_PESC;
 713                         break;
 714                 case USB_PORT_FEAT_SUSPEND:
 715                         temp = RH_PS_POCI;
 716                         break;
 717                 case USB_PORT_FEAT_C_SUSPEND:
 718                         temp = RH_PS_PSSC;
 719                         break;
 720                 case USB_PORT_FEAT_POWER:
 721                         temp = RH_PS_LSDA;
 722                         break;
 723                 case USB_PORT_FEAT_C_CONNECTION:
 724                         temp = RH_PS_CSC;
 725                         break;
 726                 case USB_PORT_FEAT_C_OVER_CURRENT:
 727                         temp = RH_PS_OCIC;
 728                         break;
 729                 case USB_PORT_FEAT_C_RESET:
 730                         temp = RH_PS_PRSC;
 731                         break;
 732                 default:
 733                         goto error;
 734                 }
 735                 ohci_writel (ohci, temp,
 736                                 &ohci->regs->roothub.portstatus [wIndex]);
 737                 // ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
 738                 break;
 739         case GetHubDescriptor:
 740                 ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
 741                 break;
 742         case GetHubStatus:
 743                 temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
 744                 put_unaligned_le32(temp, buf);
 745                 break;
 746         case GetPortStatus:
 747                 if (!wIndex || wIndex > ports)
 748                         goto error;
 749                 wIndex--;
 750                 temp = roothub_portstatus (ohci, wIndex);
 751                 put_unaligned_le32(temp, buf);
 752
 753 #ifndef OHCI_VERBOSE_DEBUG
 754         if (*(u16*)(buf+2))     /* only if wPortChange is interesting */
 755 #endif
 756                 dbg_port (ohci, "GetStatus", wIndex, temp);
 757                 break;
 758         case SetHubFeature:
 759                 switch (wValue) {
 760                 case C_HUB_OVER_CURRENT:
 761                         // FIXME:  this can be cleared, yes?
 762                 case C_HUB_LOCAL_POWER:
 763                         break;
 764                 default:
 765                         goto error;
 766                 }
 767                 break;
 768         case SetPortFeature:
 769                 if (!wIndex || wIndex > ports)
 770                         goto error;
 771                 wIndex--;
 772                 switch (wValue) {
 773                 case USB_PORT_FEAT_SUSPEND:
 774 #ifdef  CONFIG_USB_OTG
 775                         if (hcd->self.otg_port == (wIndex + 1)
 776                                         && hcd->self.b_hnp_enable)
 777                                 ohci->start_hnp(ohci);
 778                         else
 779 #endif
 780                         ohci_writel (ohci, RH_PS_PSS,
 781                                 &ohci->regs->roothub.portstatus [wIndex]);
 782                         break;
 783                 case USB_PORT_FEAT_POWER:
 784                         ohci_writel (ohci, RH_PS_PPS,
 785                                 &ohci->regs->roothub.portstatus [wIndex]);
 786                         break;
 787                 case USB_PORT_FEAT_RESET:
 788                         retval = root_port_reset (ohci, wIndex);
 789                         break;
 790                 default:
 791                         goto error;
 792                 }
 793                 break;
 794
 795         default:
 796 error:
 797                 /* "protocol stall" on error */
 798                 retval = -EPIPE;
 799         }
 800         return retval;
 801 }
 802