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                 ohci->rh_state = OHCI_RH_SUSPENDED;
 115         }
 116
 117 done:
 118         return status;
 119 }
 120
 121 static inline struct ed *find_head (struct ed *ed)
 122 {
 123         /* for bulk and control lists */
 124         while (ed->ed_prev)
 125                 ed = ed->ed_prev;
 126         return ed;
 127 }
 128
 129 /* caller has locked the root hub */
 130 static int ohci_rh_resume (struct ohci_hcd *ohci)
 131 __releases(ohci->lock)
 132 __acquires(ohci->lock)
 133 {
 134         struct usb_hcd          *hcd = ohci_to_hcd (ohci);
 135         u32                     temp, enables;
 136         int                     status = -EINPROGRESS;
 137         int                     autostopped = ohci->autostop;
 138
 139         ohci->autostop = 0;
 140         ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
 141
 142         if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
 143                 /* this can happen after resuming a swsusp snapshot */
 144                 if (ohci->rh_state != OHCI_RH_RUNNING) {
 145                         ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
 146                                         ohci->hc_control);
 147                         status = -EBUSY;
 148                 /* this happens when pmcore resumes HC then root */
 149                 } else {
 150                         ohci_dbg (ohci, "duplicate resume\n");
 151                         status = 0;
 152                 }
 153         } else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
 154         case OHCI_USB_SUSPEND:
 155                 ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
 156                 ohci->hc_control |= OHCI_USB_RESUME;
 157                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 158                 (void) ohci_readl (ohci, &ohci->regs->control);
 159                 ohci_dbg (ohci, "%s root hub\n",
 160                                 autostopped ? "auto-start" : "resume");
 161                 break;
 162         case OHCI_USB_RESUME:
 163                 /* HCFS changes sometime after INTR_RD */
 164                 ohci_dbg(ohci, "%swakeup root hub\n",
 165                                 autostopped ? "auto-" : "");
 166                 break;
 167         case OHCI_USB_OPER:
 168                 /* this can happen after resuming a swsusp snapshot */
 169                 ohci_dbg (ohci, "snapshot resume? reinit\n");
 170                 status = -EBUSY;
 171                 break;
 172         default:                /* RESET, we lost power */
 173                 ohci_dbg (ohci, "lost power\n");
 174                 status = -EBUSY;
 175         }
 176         if (status == -EBUSY) {
 177                 if (!autostopped) {
 178                         spin_unlock_irq (&ohci->lock);
 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         ohci->rh_state = OHCI_RH_RUNNING;
 278         return 0;
 279 }
 280
 281 static int ohci_bus_suspend (struct usb_hcd *hcd)
 282 {
 283         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
 284         int                     rc;
 285
 286         spin_lock_irq (&ohci->lock);
 287
 288         if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
 289                 rc = -ESHUTDOWN;
 290         else
 291                 rc = ohci_rh_suspend (ohci, 0);
 292         spin_unlock_irq (&ohci->lock);
 293         return rc;
 294 }
 295
 296 static int ohci_bus_resume (struct usb_hcd *hcd)
 297 {
 298         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
 299         int                     rc;
 300
 301         if (time_before (jiffies, ohci->next_statechange))
 302                 msleep(5);
 303
 304         spin_lock_irq (&ohci->lock);
 305
 306         if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
 307                 rc = -ESHUTDOWN;
 308         else
 309                 rc = ohci_rh_resume (ohci);
 310         spin_unlock_irq (&ohci->lock);
 311
 312         /* poll until we know a device is connected or we autostop */
 313         if (rc == 0)
 314                 usb_hcd_poll_rh_status(hcd);
 315         return rc;
 316 }
 317
 318 /* Carry out polling-, autostop-, and autoresume-related state changes */
 319 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
 320                 int any_connected, int rhsc_status)
 321 {
 322         int     poll_rh = 1;
 323         int     rhsc_enable;
 324
 325         /* Some broken controllers never turn off RHSC in the interrupt
 326          * status register.  For their sake we won't re-enable RHSC
 327          * interrupts if the interrupt bit is already active.
 328          */
 329         rhsc_enable = ohci_readl(ohci, &ohci->regs->intrenable) &
 330                         OHCI_INTR_RHSC;
 331
 332         switch (ohci->hc_control & OHCI_CTRL_HCFS) {
 333         case OHCI_USB_OPER:
 334                 /* If no status changes are pending, enable RHSC interrupts. */
 335                 if (!rhsc_enable && !rhsc_status && !changed) {
 336                         rhsc_enable = OHCI_INTR_RHSC;
 337                         ohci_writel(ohci, rhsc_enable, &ohci->regs->intrenable);
 338                 }
 339
 340                 /* Keep on polling until we know a device is connected
 341                  * and RHSC is enabled, or until we autostop.
 342                  */
 343                 if (!ohci->autostop) {
 344                         if (any_connected ||
 345                                         !device_may_wakeup(&ohci_to_hcd(ohci)
 346                                                 ->self.root_hub->dev)) {
 347                                 if (rhsc_enable)
 348                                         poll_rh = 0;
 349                         } else {
 350                                 ohci->autostop = 1;
 351                                 ohci->next_statechange = jiffies + HZ;
 352                         }
 353
 354                 /* if no devices have been attached for one second, autostop */
 355                 } else {
 356                         if (changed || any_connected) {
 357                                 ohci->autostop = 0;
 358                                 ohci->next_statechange = jiffies +
 359                                                 STATECHANGE_DELAY;
 360                         } else if (time_after_eq(jiffies,
 361                                                 ohci->next_statechange)
 362                                         && !ohci->ed_rm_list
 363                                         && !(ohci->hc_control &
 364                                                 OHCI_SCHED_ENABLES)) {
 365                                 ohci_rh_suspend(ohci, 1);
 366                                 if (rhsc_enable)
 367                                         poll_rh = 0;
 368                         }
 369                 }
 370                 break;
 371
 372         case OHCI_USB_SUSPEND:
 373         case OHCI_USB_RESUME:
 374                 /* if there is a port change, autostart or ask to be resumed */
 375                 if (changed) {
 376                         if (ohci->autostop)
 377                                 ohci_rh_resume(ohci);
 378                         else
 379                                 usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
 380
 381                 /* If remote wakeup is disabled, stop polling */
 382                 } else if (!ohci->autostop &&
 383                                 !ohci_to_hcd(ohci)->self.root_hub->
 384                                         do_remote_wakeup) {
 385                         poll_rh = 0;
 386
 387                 } else {
 388                         /* If no status changes are pending,
 389                          * enable RHSC interrupts
 390                          */
 391                         if (!rhsc_enable && !rhsc_status) {
 392                                 rhsc_enable = OHCI_INTR_RHSC;
 393                                 ohci_writel(ohci, rhsc_enable,
 394                                                 &ohci->regs->intrenable);
 395                         }
 396                         /* Keep polling until RHSC is enabled */
 397                         if (rhsc_enable)
 398                                 poll_rh = 0;
 399                 }
 400                 break;
 401         }
 402         return poll_rh;
 403 }
 404
 405 #else   /* CONFIG_PM */
 406
 407 static inline int ohci_rh_resume(struct ohci_hcd *ohci)
 408 {
 409         return 0;
 410 }
 411
 412 /* Carry out polling-related state changes.
 413  * autostop isn't used when CONFIG_PM is turned off.
 414  */
 415 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
 416                 int any_connected, int rhsc_status)
 417 {
 418         /* If RHSC is enabled, don't poll */
 419         if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
 420                 return 0;
 421
 422         /* If status changes are pending, continue polling.
 423          * Conversely, if no status changes are pending but the RHSC
 424          * status bit was set, then RHSC may be broken so continue polling.
 425          */
 426         if (changed || rhsc_status)
 427                 return 1;
 428
 429         /* It's safe to re-enable RHSC interrupts */
 430         ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
 431         return 0;
 432 }
 433
 434 #endif  /* CONFIG_PM */
 435
 436 /*-------------------------------------------------------------------------*/
 437
 438 /* build "status change" packet (one or two bytes) from HC registers */
 439
 440 static int
 441 ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
 442 {
 443         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 444         int             i, changed = 0, length = 1;
 445         int             any_connected = 0;
 446         int             rhsc_status;
 447         unsigned long   flags;
 448
 449         spin_lock_irqsave (&ohci->lock, flags);
 450         if (!HCD_HW_ACCESSIBLE(hcd))
 451                 goto done;
 452
 453         /* undocumented erratum seen on at least rev D */
 454         if ((ohci->flags & OHCI_QUIRK_AMD756)
 455                         && (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
 456                 ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
 457                           ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
 458                 /* retry later; "should not happen" */
 459                 goto done;
 460         }
 461
 462         /* init status */
 463         if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
 464                 buf [0] = changed = 1;
 465         else
 466                 buf [0] = 0;
 467         if (ohci->num_ports > 7) {
 468                 buf [1] = 0;
 469                 length++;
 470         }
 471
 472         /* Clear the RHSC status flag before reading the port statuses */
 473         ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrstatus);
 474         rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
 475                         OHCI_INTR_RHSC;
 476
 477         /* look at each port */
 478         for (i = 0; i < ohci->num_ports; i++) {
 479                 u32     status = roothub_portstatus (ohci, i);
 480
 481                 /* can't autostop if ports are connected */
 482                 any_connected |= (status & RH_PS_CCS);
 483
 484                 if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
 485                                 | RH_PS_OCIC | RH_PS_PRSC)) {
 486                         changed = 1;
 487                         if (i < 7)
 488                             buf [0] |= 1 << (i + 1);
 489                         else
 490                             buf [1] |= 1 << (i - 7);
 491                 }
 492         }
 493
 494         if (ohci_root_hub_state_changes(ohci, changed,
 495                         any_connected, rhsc_status))
 496                 set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 497         else
 498                 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 499
 500
 501 done:
 502         spin_unlock_irqrestore (&ohci->lock, flags);
 503
 504         return changed ? length : 0;
 505 }
 506
 507 /*-------------------------------------------------------------------------*/
 508
 509 static void
 510 ohci_hub_descriptor (
 511         struct ohci_hcd                 *ohci,
 512         struct usb_hub_descriptor       *desc
 513 ) {
 514         u32             rh = roothub_a (ohci);
 515         u16             temp;
 516
 517         desc->bDescriptorType = 0x29;
 518         desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
 519         desc->bHubContrCurrent = 0;
 520
 521         desc->bNbrPorts = ohci->num_ports;
 522         temp = 1 + (ohci->num_ports / 8);
 523         desc->bDescLength = 7 + 2 * temp;
 524
 525         temp = 0;
 526         if (rh & RH_A_NPS)              /* no power switching? */
 527             temp |= 0x0002;
 528         if (rh & RH_A_PSM)              /* per-port power switching? */
 529             temp |= 0x0001;
 530         if (rh & RH_A_NOCP)             /* no overcurrent reporting? */
 531             temp |= 0x0010;
 532         else if (rh & RH_A_OCPM)        /* per-port overcurrent reporting? */
 533             temp |= 0x0008;
 534         desc->wHubCharacteristics = (__force __u16)cpu_to_hc16(ohci, temp);
 535
 536         /* ports removable, and usb 1.0 legacy PortPwrCtrlMask */
 537         rh = roothub_b (ohci);
 538         memset(desc->u.hs.DeviceRemovable, 0xff,
 539                         sizeof(desc->u.hs.DeviceRemovable));
 540         desc->u.hs.DeviceRemovable[0] = rh & RH_B_DR;
 541         if (ohci->num_ports > 7) {
 542                 desc->u.hs.DeviceRemovable[1] = (rh & RH_B_DR) >> 8;
 543                 desc->u.hs.DeviceRemovable[2] = 0xff;
 544         } else
 545                 desc->u.hs.DeviceRemovable[1] = 0xff;
 546 }
 547
 548 /*-------------------------------------------------------------------------*/
 549
 550 #ifdef  CONFIG_USB_OTG
 551
 552 static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
 553 {
 554         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 555         u32                     status;
 556
 557         if (!port)
 558                 return -EINVAL;
 559         port--;
 560
 561         /* start port reset before HNP protocol times out */
 562         status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
 563         if (!(status & RH_PS_CCS))
 564                 return -ENODEV;
 565
 566         /* khubd will finish the reset later */
 567         ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
 568         return 0;
 569 }
 570
 571 #else
 572
 573 #define ohci_start_port_reset           NULL
 574
 575 #endif
 576
 577 /*-------------------------------------------------------------------------*/
 578
 579
 580 /* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
 581  * not necessarily continuous ... to guard against resume signaling.
 582  */
 583 #define PORT_RESET_MSEC         50
 584
 585 /* this timer value might be vendor-specific ... */
 586 #define PORT_RESET_HW_MSEC      10
 587
 588 /* wrap-aware logic morphed from <linux/jiffies.h> */
 589 #define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
 590
 591 /* called from some task, normally khubd */
 592 static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
 593 {
 594         __hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
 595         u32     temp = 0;
 596         u16     now = ohci_readl(ohci, &ohci->regs->fmnumber);
 597         u16     reset_done = now + PORT_RESET_MSEC;
 598         int     limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
 599
 600         /* build a "continuous enough" reset signal, with up to
 601          * 3msec gap between pulses.  scheduler HZ==100 must work;
 602          * this might need to be deadline-scheduled.
 603          */
 604         do {
 605                 int limit_2;
 606
 607                 /* spin until any current reset finishes */
 608                 limit_2 = PORT_RESET_HW_MSEC * 2;
 609                 while (--limit_2 >= 0) {
 610                         temp = ohci_readl (ohci, portstat);
 611                         /* handle e.g. CardBus eject */
 612                         if (temp == ~(u32)0)
 613                                 return -ESHUTDOWN;
 614                         if (!(temp & RH_PS_PRS))
 615                                 break;
 616                         udelay (500);
 617                 }
 618
 619                 /* timeout (a hardware error) has been observed when
 620                  * EHCI sets CF while this driver is resetting a port;
 621                  * presumably other disconnect paths might do it too.
 622                  */
 623                 if (limit_2 < 0) {
 624                         ohci_dbg(ohci,
 625                                 "port[%d] reset timeout, stat %08x\n",
 626                                 port, temp);
 627                         break;
 628                 }
 629
 630                 if (!(temp & RH_PS_CCS))
 631                         break;
 632                 if (temp & RH_PS_PRSC)
 633                         ohci_writel (ohci, RH_PS_PRSC, portstat);
 634
 635                 /* start the next reset, sleep till it's probably done */
 636                 ohci_writel (ohci, RH_PS_PRS, portstat);
 637                 msleep(PORT_RESET_HW_MSEC);
 638                 now = ohci_readl(ohci, &ohci->regs->fmnumber);
 639         } while (tick_before(now, reset_done) && --limit_1 >= 0);
 640
 641         /* caller synchronizes using PRSC ... and handles PRS
 642          * still being set when this returns.
 643          */
 644
 645         return 0;
 646 }
 647
 648 static int ohci_hub_control (
 649         struct usb_hcd  *hcd,
 650         u16             typeReq,
 651         u16             wValue,
 652         u16             wIndex,
 653         char            *buf,
 654         u16             wLength
 655 ) {
 656         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 657         int             ports = ohci->num_ports;
 658         u32             temp;
 659         int             retval = 0;
 660
 661         if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
 662                 return -ESHUTDOWN;
 663
 664         switch (typeReq) {
 665         case ClearHubFeature:
 666                 switch (wValue) {
 667                 case C_HUB_OVER_CURRENT:
 668                         ohci_writel (ohci, RH_HS_OCIC,
 669                                         &ohci->regs->roothub.status);
 670                 case C_HUB_LOCAL_POWER:
 671                         break;
 672                 default:
 673                         goto error;
 674                 }
 675                 break;
 676         case ClearPortFeature:
 677                 if (!wIndex || wIndex > ports)
 678                         goto error;
 679                 wIndex--;
 680
 681                 switch (wValue) {
 682                 case USB_PORT_FEAT_ENABLE:
 683                         temp = RH_PS_CCS;
 684                         break;
 685                 case USB_PORT_FEAT_C_ENABLE:
 686                         temp = RH_PS_PESC;
 687                         break;
 688                 case USB_PORT_FEAT_SUSPEND:
 689                         temp = RH_PS_POCI;
 690                         break;
 691                 case USB_PORT_FEAT_C_SUSPEND:
 692                         temp = RH_PS_PSSC;
 693                         break;
 694                 case USB_PORT_FEAT_POWER:
 695                         temp = RH_PS_LSDA;
 696                         break;
 697                 case USB_PORT_FEAT_C_CONNECTION:
 698                         temp = RH_PS_CSC;
 699                         break;
 700                 case USB_PORT_FEAT_C_OVER_CURRENT:
 701                         temp = RH_PS_OCIC;
 702                         break;
 703                 case USB_PORT_FEAT_C_RESET:
 704                         temp = RH_PS_PRSC;
 705                         break;
 706                 default:
 707                         goto error;
 708                 }
 709                 ohci_writel (ohci, temp,
 710                                 &ohci->regs->roothub.portstatus [wIndex]);
 711                 // ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
 712                 break;
 713         case GetHubDescriptor:
 714                 ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
 715                 break;
 716         case GetHubStatus:
 717                 temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
 718                 put_unaligned_le32(temp, buf);
 719                 break;
 720         case GetPortStatus:
 721                 if (!wIndex || wIndex > ports)
 722                         goto error;
 723                 wIndex--;
 724                 temp = roothub_portstatus (ohci, wIndex);
 725                 put_unaligned_le32(temp, buf);
 726
 727 #ifndef OHCI_VERBOSE_DEBUG
 728         if (*(u16*)(buf+2))     /* only if wPortChange is interesting */
 729 #endif
 730                 dbg_port (ohci, "GetStatus", wIndex, temp);
 731                 break;
 732         case SetHubFeature:
 733                 switch (wValue) {
 734                 case C_HUB_OVER_CURRENT:
 735                         // FIXME:  this can be cleared, yes?
 736                 case C_HUB_LOCAL_POWER:
 737                         break;
 738                 default:
 739                         goto error;
 740                 }
 741                 break;
 742         case SetPortFeature:
 743                 if (!wIndex || wIndex > ports)
 744                         goto error;
 745                 wIndex--;
 746                 switch (wValue) {
 747                 case USB_PORT_FEAT_SUSPEND:
 748 #ifdef  CONFIG_USB_OTG
 749                         if (hcd->self.otg_port == (wIndex + 1)
 750                                         && hcd->self.b_hnp_enable)
 751                                 ohci->start_hnp(ohci);
 752                         else
 753 #endif
 754                         ohci_writel (ohci, RH_PS_PSS,
 755                                 &ohci->regs->roothub.portstatus [wIndex]);
 756                         break;
 757                 case USB_PORT_FEAT_POWER:
 758                         ohci_writel (ohci, RH_PS_PPS,
 759                                 &ohci->regs->roothub.portstatus [wIndex]);
 760                         break;
 761                 case USB_PORT_FEAT_RESET:
 762                         retval = root_port_reset (ohci, wIndex);
 763                         break;
 764                 default:
 765                         goto error;
 766                 }
 767                 break;
 768
 769         default:
 770 error:
 771                 /* "protocol stall" on error */
 772                 retval = -EPIPE;
 773         }
 774         return retval;
 775 }
 776