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                         (void) ohci_init (ohci);
 180                         status = ohci_restart (ohci);
 181
 182                         usb_root_hub_lost_power(hcd->self.root_hub);
 183
 184                         spin_lock_irq (&ohci->lock);
 185                 }
 186                 return status;
 187         }
 188         if (status != -EINPROGRESS)
 189                 return status;
 190         if (autostopped)
 191                 goto skip_resume;
 192         spin_unlock_irq (&ohci->lock);
 193
 194         /* Some controllers (lucent erratum) need extra-long delays */
 195         msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
 196
 197         temp = ohci_readl (ohci, &ohci->regs->control);
 198         temp &= OHCI_CTRL_HCFS;
 199         if (temp != OHCI_USB_RESUME) {
 200                 ohci_err (ohci, "controller won't resume\n");
 201                 spin_lock_irq(&ohci->lock);
 202                 return -EBUSY;
 203         }
 204
 205         /* disable old schedule state, reinit from scratch */
 206         ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
 207         ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
 208         ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
 209         ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
 210         ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
 211         ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
 212
 213         /* Sometimes PCI D3 suspend trashes frame timings ... */
 214         periodic_reinit (ohci);
 215
 216         /* the following code is executed with ohci->lock held and
 217          * irqs disabled if and only if autostopped is true
 218          */
 219
 220 skip_resume:
 221         /* interrupts might have been disabled */
 222         ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
 223         if (ohci->ed_rm_list)
 224                 ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
 225
 226         /* Then re-enable operations */
 227         ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
 228         (void) ohci_readl (ohci, &ohci->regs->control);
 229         if (!autostopped)
 230                 msleep (3);
 231
 232         temp = ohci->hc_control;
 233         temp &= OHCI_CTRL_RWC;
 234         temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
 235         ohci->hc_control = temp;
 236         ohci_writel (ohci, temp, &ohci->regs->control);
 237         (void) ohci_readl (ohci, &ohci->regs->control);
 238
 239         /* TRSMRCY */
 240         if (!autostopped) {
 241                 msleep (10);
 242                 spin_lock_irq (&ohci->lock);
 243         }
 244         /* now ohci->lock is always held and irqs are always disabled */
 245
 246         /* keep it alive for more than ~5x suspend + resume costs */
 247         ohci->next_statechange = jiffies + STATECHANGE_DELAY;
 248
 249         /* maybe turn schedules back on */
 250         enables = 0;
 251         temp = 0;
 252         if (!ohci->ed_rm_list) {
 253                 if (ohci->ed_controltail) {
 254                         ohci_writel (ohci,
 255                                         find_head (ohci->ed_controltail)->dma,
 256                                         &ohci->regs->ed_controlhead);
 257                         enables |= OHCI_CTRL_CLE;
 258                         temp |= OHCI_CLF;
 259                 }
 260                 if (ohci->ed_bulktail) {
 261                         ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
 262                                 &ohci->regs->ed_bulkhead);
 263                         enables |= OHCI_CTRL_BLE;
 264                         temp |= OHCI_BLF;
 265                 }
 266         }
 267         if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
 268                 enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
 269         if (enables) {
 270                 ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
 271                 ohci->hc_control |= enables;
 272                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 273                 if (temp)
 274                         ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
 275                 (void) ohci_readl (ohci, &ohci->regs->control);
 276         }
 277
 278         ohci->rh_state = OHCI_RH_RUNNING;
 279         return 0;
 280 }
 281
 282 static int ohci_bus_suspend (struct usb_hcd *hcd)
 283 {
 284         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
 285         int                     rc;
 286
 287         spin_lock_irq (&ohci->lock);
 288
 289         if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
 290                 rc = -ESHUTDOWN;
 291         else
 292                 rc = ohci_rh_suspend (ohci, 0);
 293         spin_unlock_irq (&ohci->lock);
 294         return rc;
 295 }
 296
 297 static int ohci_bus_resume (struct usb_hcd *hcd)
 298 {
 299         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
 300         int                     rc;
 301
 302         if (time_before (jiffies, ohci->next_statechange))
 303                 msleep(5);
 304
 305         spin_lock_irq (&ohci->lock);
 306
 307         if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
 308                 rc = -ESHUTDOWN;
 309         else
 310                 rc = ohci_rh_resume (ohci);
 311         spin_unlock_irq (&ohci->lock);
 312
 313         /* poll until we know a device is connected or we autostop */
 314         if (rc == 0)
 315                 usb_hcd_poll_rh_status(hcd);
 316         return rc;
 317 }
 318
 319 /* Carry out polling-, autostop-, and autoresume-related state changes */
 320 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
 321                 int any_connected, int rhsc_status)
 322 {
 323         int     poll_rh = 1;
 324         int     rhsc_enable;
 325
 326         /* Some broken controllers never turn off RHSC in the interrupt
 327          * status register.  For their sake we won't re-enable RHSC
 328          * interrupts if the interrupt bit is already active.
 329          */
 330         rhsc_enable = ohci_readl(ohci, &ohci->regs->intrenable) &
 331                         OHCI_INTR_RHSC;
 332
 333         switch (ohci->hc_control & OHCI_CTRL_HCFS) {
 334         case OHCI_USB_OPER:
 335                 /* If no status changes are pending, enable RHSC interrupts. */
 336                 if (!rhsc_enable && !rhsc_status && !changed) {
 337                         rhsc_enable = OHCI_INTR_RHSC;
 338                         ohci_writel(ohci, rhsc_enable, &ohci->regs->intrenable);
 339                 }
 340
 341                 /* Keep on polling until we know a device is connected
 342                  * and RHSC is enabled, or until we autostop.
 343                  */
 344                 if (!ohci->autostop) {
 345                         if (any_connected ||
 346                                         !device_may_wakeup(&ohci_to_hcd(ohci)
 347                                                 ->self.root_hub->dev)) {
 348                                 if (rhsc_enable)
 349                                         poll_rh = 0;
 350                         } else {
 351                                 ohci->autostop = 1;
 352                                 ohci->next_statechange = jiffies + HZ;
 353                         }
 354
 355                 /* if no devices have been attached for one second, autostop */
 356                 } else {
 357                         if (changed || any_connected) {
 358                                 ohci->autostop = 0;
 359                                 ohci->next_statechange = jiffies +
 360                                                 STATECHANGE_DELAY;
 361                         } else if (time_after_eq(jiffies,
 362                                                 ohci->next_statechange)
 363                                         && !ohci->ed_rm_list
 364                                         && !(ohci->hc_control &
 365                                                 OHCI_SCHED_ENABLES)) {
 366                                 ohci_rh_suspend(ohci, 1);
 367                                 if (rhsc_enable)
 368                                         poll_rh = 0;
 369                         }
 370                 }
 371                 break;
 372
 373         case OHCI_USB_SUSPEND:
 374         case OHCI_USB_RESUME:
 375                 /* if there is a port change, autostart or ask to be resumed */
 376                 if (changed) {
 377                         if (ohci->autostop)
 378                                 ohci_rh_resume(ohci);
 379                         else
 380                                 usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
 381
 382                 /* If remote wakeup is disabled, stop polling */
 383                 } else if (!ohci->autostop &&
 384                                 !ohci_to_hcd(ohci)->self.root_hub->
 385                                         do_remote_wakeup) {
 386                         poll_rh = 0;
 387
 388                 } else {
 389                         /* If no status changes are pending,
 390                          * enable RHSC interrupts
 391                          */
 392                         if (!rhsc_enable && !rhsc_status) {
 393                                 rhsc_enable = OHCI_INTR_RHSC;
 394                                 ohci_writel(ohci, rhsc_enable,
 395                                                 &ohci->regs->intrenable);
 396                         }
 397                         /* Keep polling until RHSC is enabled */
 398                         if (rhsc_enable)
 399                                 poll_rh = 0;
 400                 }
 401                 break;
 402         }
 403         return poll_rh;
 404 }
 405
 406 #else   /* CONFIG_PM */
 407
 408 static inline int ohci_rh_resume(struct ohci_hcd *ohci)
 409 {
 410         return 0;
 411 }
 412
 413 /* Carry out polling-related state changes.
 414  * autostop isn't used when CONFIG_PM is turned off.
 415  */
 416 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
 417                 int any_connected, int rhsc_status)
 418 {
 419         /* If RHSC is enabled, don't poll */
 420         if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
 421                 return 0;
 422
 423         /* If status changes are pending, continue polling.
 424          * Conversely, if no status changes are pending but the RHSC
 425          * status bit was set, then RHSC may be broken so continue polling.
 426          */
 427         if (changed || rhsc_status)
 428                 return 1;
 429
 430         /* It's safe to re-enable RHSC interrupts */
 431         ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
 432         return 0;
 433 }
 434
 435 #endif  /* CONFIG_PM */
 436
 437 /*-------------------------------------------------------------------------*/
 438
 439 /* build "status change" packet (one or two bytes) from HC registers */
 440
 441 static int
 442 ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
 443 {
 444         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 445         int             i, changed = 0, length = 1;
 446         int             any_connected = 0;
 447         int             rhsc_status;
 448         unsigned long   flags;
 449
 450         spin_lock_irqsave (&ohci->lock, flags);
 451         if (!HCD_HW_ACCESSIBLE(hcd))
 452                 goto done;
 453
 454         /* undocumented erratum seen on at least rev D */
 455         if ((ohci->flags & OHCI_QUIRK_AMD756)
 456                         && (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
 457                 ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
 458                           ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
 459                 /* retry later; "should not happen" */
 460                 goto done;
 461         }
 462
 463         /* init status */
 464         if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
 465                 buf [0] = changed = 1;
 466         else
 467                 buf [0] = 0;
 468         if (ohci->num_ports > 7) {
 469                 buf [1] = 0;
 470                 length++;
 471         }
 472
 473         /* Clear the RHSC status flag before reading the port statuses */
 474         ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrstatus);
 475         rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
 476                         OHCI_INTR_RHSC;
 477
 478         /* look at each port */
 479         for (i = 0; i < ohci->num_ports; i++) {
 480                 u32     status = roothub_portstatus (ohci, i);
 481
 482                 /* can't autostop if ports are connected */
 483                 any_connected |= (status & RH_PS_CCS);
 484
 485                 if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
 486                                 | RH_PS_OCIC | RH_PS_PRSC)) {
 487                         changed = 1;
 488                         if (i < 7)
 489                             buf [0] |= 1 << (i + 1);
 490                         else
 491                             buf [1] |= 1 << (i - 7);
 492                 }
 493         }
 494
 495         if (ohci_root_hub_state_changes(ohci, changed,
 496                         any_connected, rhsc_status))
 497                 set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 498         else
 499                 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 500
 501
 502 done:
 503         spin_unlock_irqrestore (&ohci->lock, flags);
 504
 505         return changed ? length : 0;
 506 }
 507
 508 /*-------------------------------------------------------------------------*/
 509
 510 static void
 511 ohci_hub_descriptor (
 512         struct ohci_hcd                 *ohci,
 513         struct usb_hub_descriptor       *desc
 514 ) {
 515         u32             rh = roothub_a (ohci);
 516         u16             temp;
 517
 518         desc->bDescriptorType = 0x29;
 519         desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
 520         desc->bHubContrCurrent = 0;
 521
 522         desc->bNbrPorts = ohci->num_ports;
 523         temp = 1 + (ohci->num_ports / 8);
 524         desc->bDescLength = 7 + 2 * temp;
 525
 526         temp = 0;
 527         if (rh & RH_A_NPS)              /* no power switching? */
 528             temp |= 0x0002;
 529         if (rh & RH_A_PSM)              /* per-port power switching? */
 530             temp |= 0x0001;
 531         if (rh & RH_A_NOCP)             /* no overcurrent reporting? */
 532             temp |= 0x0010;
 533         else if (rh & RH_A_OCPM)        /* per-port overcurrent reporting? */
 534             temp |= 0x0008;
 535         desc->wHubCharacteristics = (__force __u16)cpu_to_hc16(ohci, temp);
 536
 537         /* ports removable, and usb 1.0 legacy PortPwrCtrlMask */
 538         rh = roothub_b (ohci);
 539         memset(desc->u.hs.DeviceRemovable, 0xff,
 540                         sizeof(desc->u.hs.DeviceRemovable));
 541         desc->u.hs.DeviceRemovable[0] = rh & RH_B_DR;
 542         if (ohci->num_ports > 7) {
 543                 desc->u.hs.DeviceRemovable[1] = (rh & RH_B_DR) >> 8;
 544                 desc->u.hs.DeviceRemovable[2] = 0xff;
 545         } else
 546                 desc->u.hs.DeviceRemovable[1] = 0xff;
 547 }
 548
 549 /*-------------------------------------------------------------------------*/
 550
 551 #ifdef  CONFIG_USB_OTG
 552
 553 static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
 554 {
 555         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 556         u32                     status;
 557
 558         if (!port)
 559                 return -EINVAL;
 560         port--;
 561
 562         /* start port reset before HNP protocol times out */
 563         status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
 564         if (!(status & RH_PS_CCS))
 565                 return -ENODEV;
 566
 567         /* khubd will finish the reset later */
 568         ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
 569         return 0;
 570 }
 571
 572 #else
 573
 574 #define ohci_start_port_reset           NULL
 575
 576 #endif
 577
 578 /*-------------------------------------------------------------------------*/
 579
 580
 581 /* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
 582  * not necessarily continuous ... to guard against resume signaling.
 583  */
 584 #define PORT_RESET_MSEC         50
 585
 586 /* this timer value might be vendor-specific ... */
 587 #define PORT_RESET_HW_MSEC      10
 588
 589 /* wrap-aware logic morphed from <linux/jiffies.h> */
 590 #define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
 591
 592 /* called from some task, normally khubd */
 593 static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
 594 {
 595         __hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
 596         u32     temp = 0;
 597         u16     now = ohci_readl(ohci, &ohci->regs->fmnumber);
 598         u16     reset_done = now + PORT_RESET_MSEC;
 599         int     limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
 600
 601         /* build a "continuous enough" reset signal, with up to
 602          * 3msec gap between pulses.  scheduler HZ==100 must work;
 603          * this might need to be deadline-scheduled.
 604          */
 605         do {
 606                 int limit_2;
 607
 608                 /* spin until any current reset finishes */
 609                 limit_2 = PORT_RESET_HW_MSEC * 2;
 610                 while (--limit_2 >= 0) {
 611                         temp = ohci_readl (ohci, portstat);
 612                         /* handle e.g. CardBus eject */
 613                         if (temp == ~(u32)0)
 614                                 return -ESHUTDOWN;
 615                         if (!(temp & RH_PS_PRS))
 616                                 break;
 617                         udelay (500);
 618                 }
 619
 620                 /* timeout (a hardware error) has been observed when
 621                  * EHCI sets CF while this driver is resetting a port;
 622                  * presumably other disconnect paths might do it too.
 623                  */
 624                 if (limit_2 < 0) {
 625                         ohci_dbg(ohci,
 626                                 "port[%d] reset timeout, stat %08x\n",
 627                                 port, temp);
 628                         break;
 629                 }
 630
 631                 if (!(temp & RH_PS_CCS))
 632                         break;
 633                 if (temp & RH_PS_PRSC)
 634                         ohci_writel (ohci, RH_PS_PRSC, portstat);
 635
 636                 /* start the next reset, sleep till it's probably done */
 637                 ohci_writel (ohci, RH_PS_PRS, portstat);
 638                 msleep(PORT_RESET_HW_MSEC);
 639                 now = ohci_readl(ohci, &ohci->regs->fmnumber);
 640         } while (tick_before(now, reset_done) && --limit_1 >= 0);
 641
 642         /* caller synchronizes using PRSC ... and handles PRS
 643          * still being set when this returns.
 644          */
 645
 646         return 0;
 647 }
 648
 649 static int ohci_hub_control (
 650         struct usb_hcd  *hcd,
 651         u16             typeReq,
 652         u16             wValue,
 653         u16             wIndex,
 654         char            *buf,
 655         u16             wLength
 656 ) {
 657         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
 658         int             ports = ohci->num_ports;
 659         u32             temp;
 660         int             retval = 0;
 661
 662         if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
 663                 return -ESHUTDOWN;
 664
 665         switch (typeReq) {
 666         case ClearHubFeature:
 667                 switch (wValue) {
 668                 case C_HUB_OVER_CURRENT:
 669                         ohci_writel (ohci, RH_HS_OCIC,
 670                                         &ohci->regs->roothub.status);
 671                 case C_HUB_LOCAL_POWER:
 672                         break;
 673                 default:
 674                         goto error;
 675                 }
 676                 break;
 677         case ClearPortFeature:
 678                 if (!wIndex || wIndex > ports)
 679                         goto error;
 680                 wIndex--;
 681
 682                 switch (wValue) {
 683                 case USB_PORT_FEAT_ENABLE:
 684                         temp = RH_PS_CCS;
 685                         break;
 686                 case USB_PORT_FEAT_C_ENABLE:
 687                         temp = RH_PS_PESC;
 688                         break;
 689                 case USB_PORT_FEAT_SUSPEND:
 690                         temp = RH_PS_POCI;
 691                         break;
 692                 case USB_PORT_FEAT_C_SUSPEND:
 693                         temp = RH_PS_PSSC;
 694                         break;
 695                 case USB_PORT_FEAT_POWER:
 696                         temp = RH_PS_LSDA;
 697                         break;
 698                 case USB_PORT_FEAT_C_CONNECTION:
 699                         temp = RH_PS_CSC;
 700                         break;
 701                 case USB_PORT_FEAT_C_OVER_CURRENT:
 702                         temp = RH_PS_OCIC;
 703                         break;
 704                 case USB_PORT_FEAT_C_RESET:
 705                         temp = RH_PS_PRSC;
 706                         break;
 707                 default:
 708                         goto error;
 709                 }
 710                 ohci_writel (ohci, temp,
 711                                 &ohci->regs->roothub.portstatus [wIndex]);
 712                 // ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
 713                 break;
 714         case GetHubDescriptor:
 715                 ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
 716                 break;
 717         case GetHubStatus:
 718                 temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
 719                 put_unaligned_le32(temp, buf);
 720                 break;
 721         case GetPortStatus:
 722                 if (!wIndex || wIndex > ports)
 723                         goto error;
 724                 wIndex--;
 725                 temp = roothub_portstatus (ohci, wIndex);
 726                 put_unaligned_le32(temp, buf);
 727
 728 #ifndef OHCI_VERBOSE_DEBUG
 729         if (*(u16*)(buf+2))     /* only if wPortChange is interesting */
 730 #endif
 731                 dbg_port (ohci, "GetStatus", wIndex, temp);
 732                 break;
 733         case SetHubFeature:
 734                 switch (wValue) {
 735                 case C_HUB_OVER_CURRENT:
 736                         // FIXME:  this can be cleared, yes?
 737                 case C_HUB_LOCAL_POWER:
 738                         break;
 739                 default:
 740                         goto error;
 741                 }
 742                 break;
 743         case SetPortFeature:
 744                 if (!wIndex || wIndex > ports)
 745                         goto error;
 746                 wIndex--;
 747                 switch (wValue) {
 748                 case USB_PORT_FEAT_SUSPEND:
 749 #ifdef  CONFIG_USB_OTG
 750                         if (hcd->self.otg_port == (wIndex + 1)
 751                                         && hcd->self.b_hnp_enable)
 752                                 ohci->start_hnp(ohci);
 753                         else
 754 #endif
 755                         ohci_writel (ohci, RH_PS_PSS,
 756                                 &ohci->regs->roothub.portstatus [wIndex]);
 757                         break;
 758                 case USB_PORT_FEAT_POWER:
 759                         ohci_writel (ohci, RH_PS_PPS,
 760                                 &ohci->regs->roothub.portstatus [wIndex]);
 761                         break;
 762                 case USB_PORT_FEAT_RESET:
 763                         retval = root_port_reset (ohci, wIndex);
 764                         break;
 765                 default:
 766                         goto error;
 767                 }
 768                 break;
 769
 770         default:
 771 error:
 772                 /* "protocol stall" on error */
 773                 retval = -EPIPE;
 774         }
 775         return retval;
 776 }
 777