drivers/usb/host/ohci-q.c

   1 /*
   2  * OHCI HCD (Host Controller Driver) for USB.
   3  *
   4  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
   5  * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
   6  *
   7  * This file is licenced under the GPL.
   8  */
   9
  10 #include <linux/irq.h>
  11
  12 static void urb_free_priv (struct ohci_hcd *hc, urb_priv_t *urb_priv)
  13 {
  14         int             last = urb_priv->length - 1;
  15
  16         if (last >= 0) {
  17                 int             i;
  18                 struct td       *td;
  19
  20                 for (i = 0; i <= last; i++) {
  21                         td = urb_priv->td [i];
  22                         if (td)
  23                                 td_free (hc, td);
  24                 }
  25         }
  26
  27         list_del (&urb_priv->pending);
  28         kfree (urb_priv);
  29 }
  30
  31 /*-------------------------------------------------------------------------*/
  32
  33 /*
  34  * URB goes back to driver, and isn't reissued.
  35  * It's completely gone from HC data structures.
  36  * PRECONDITION:  ohci lock held, irqs blocked.
  37  */
  38 static void
  39 finish_urb(struct ohci_hcd *ohci, struct urb *urb, int status)
  40 __releases(ohci->lock)
  41 __acquires(ohci->lock)
  42 {
  43         // ASSERT (urb->hcpriv != 0);
  44
  45         urb_free_priv (ohci, urb->hcpriv);
  46         if (likely(status == -EINPROGRESS))
  47                 status = 0;
  48
  49         switch (usb_pipetype (urb->pipe)) {
  50         case PIPE_ISOCHRONOUS:
  51                 ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs--;
  52                 break;
  53         case PIPE_INTERRUPT:
  54                 ohci_to_hcd(ohci)->self.bandwidth_int_reqs--;
  55                 break;
  56         }
  57
  58 #ifdef OHCI_VERBOSE_DEBUG
  59         urb_print(urb, "RET", usb_pipeout (urb->pipe), status);
  60 #endif
  61
  62         /* urb->complete() can reenter this HCD */
  63         usb_hcd_unlink_urb_from_ep(ohci_to_hcd(ohci), urb);
  64         spin_unlock (&ohci->lock);
  65         usb_hcd_giveback_urb(ohci_to_hcd(ohci), urb, status);
  66         spin_lock (&ohci->lock);
  67
  68         /* stop periodic dma if it's not needed */
  69         if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
  70                         && ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0) {
  71                 ohci->hc_control &= ~(OHCI_CTRL_PLE|OHCI_CTRL_IE);
  72                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
  73         }
  74 }
  75
  76
  77 /*-------------------------------------------------------------------------*
  78  * ED handling functions
  79  *-------------------------------------------------------------------------*/
  80
  81 /* search for the right schedule branch to use for a periodic ed.
  82  * does some load balancing; returns the branch, or negative errno.
  83  */
  84 static int balance (struct ohci_hcd *ohci, int interval, int load)
  85 {
  86         int     i, branch = -ENOSPC;
  87
  88         /* iso periods can be huge; iso tds specify frame numbers */
  89         if (interval > NUM_INTS)
  90                 interval = NUM_INTS;
  91
  92         /* search for the least loaded schedule branch of that period
  93          * that has enough bandwidth left unreserved.
  94          */
  95         for (i = 0; i < interval ; i++) {
  96                 if (branch < 0 || ohci->load [branch] > ohci->load [i]) {
  97                         int     j;
  98
  99                         /* usb 1.1 says 90% of one frame */
 100                         for (j = i; j < NUM_INTS; j += interval) {
 101                                 if ((ohci->load [j] + load) > 900)
 102                                         break;
 103                         }
 104                         if (j < NUM_INTS)
 105                                 continue;
 106                         branch = i;
 107                 }
 108         }
 109         return branch;
 110 }
 111
 112 /*-------------------------------------------------------------------------*/
 113
 114 /* both iso and interrupt requests have periods; this routine puts them
 115  * into the schedule tree in the apppropriate place.  most iso devices use
 116  * 1msec periods, but that's not required.
 117  */
 118 static void periodic_link (struct ohci_hcd *ohci, struct ed *ed)
 119 {
 120         unsigned        i;
 121
 122         ohci_vdbg (ohci, "link %sed %p branch %d [%dus.], interval %d\n",
 123                 (ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 124                 ed, ed->branch, ed->load, ed->interval);
 125
 126         for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 127                 struct ed       **prev = &ohci->periodic [i];
 128                 __hc32          *prev_p = &ohci->hcca->int_table [i];
 129                 struct ed       *here = *prev;
 130
 131                 /* sorting each branch by period (slow before fast)
 132                  * lets us share the faster parts of the tree.
 133                  * (plus maybe: put interrupt eds before iso)
 134                  */
 135                 while (here && ed != here) {
 136                         if (ed->interval > here->interval)
 137                                 break;
 138                         prev = &here->ed_next;
 139                         prev_p = &here->hwNextED;
 140                         here = *prev;
 141                 }
 142                 if (ed != here) {
 143                         ed->ed_next = here;
 144                         if (here)
 145                                 ed->hwNextED = *prev_p;
 146                         wmb ();
 147                         *prev = ed;
 148                         *prev_p = cpu_to_hc32(ohci, ed->dma);
 149                         wmb();
 150                 }
 151                 ohci->load [i] += ed->load;
 152         }
 153         ohci_to_hcd(ohci)->self.bandwidth_allocated += ed->load / ed->interval;
 154 }
 155
 156 /* link an ed into one of the HC chains */
 157
 158 static int ed_schedule (struct ohci_hcd *ohci, struct ed *ed)
 159 {
 160         int     branch;
 161
 162         if (ohci_to_hcd(ohci)->state == HC_STATE_QUIESCING)
 163                 return -EAGAIN;
 164
 165         ed->state = ED_OPER;
 166         ed->ed_prev = NULL;
 167         ed->ed_next = NULL;
 168         ed->hwNextED = 0;
 169         if (quirk_zfmicro(ohci)
 170                         && (ed->type == PIPE_INTERRUPT)
 171                         && !(ohci->eds_scheduled++))
 172                 mod_timer(&ohci->unlink_watchdog, round_jiffies(jiffies + HZ));
 173         wmb ();
 174
 175         /* we care about rm_list when setting CLE/BLE in case the HC was at
 176          * work on some TD when CLE/BLE was turned off, and isn't quiesced
 177          * yet.  finish_unlinks() restarts as needed, some upcoming INTR_SF.
 178          *
 179          * control and bulk EDs are doubly linked (ed_next, ed_prev), but
 180          * periodic ones are singly linked (ed_next). that's because the
 181          * periodic schedule encodes a tree like figure 3-5 in the ohci
 182          * spec:  each qh can have several "previous" nodes, and the tree
 183          * doesn't have unused/idle descriptors.
 184          */
 185         switch (ed->type) {
 186         case PIPE_CONTROL:
 187                 if (ohci->ed_controltail == NULL) {
 188                         WARN_ON (ohci->hc_control & OHCI_CTRL_CLE);
 189                         ohci_writel (ohci, ed->dma,
 190                                         &ohci->regs->ed_controlhead);
 191                 } else {
 192                         ohci->ed_controltail->ed_next = ed;
 193                         ohci->ed_controltail->hwNextED = cpu_to_hc32 (ohci,
 194                                                                 ed->dma);
 195                 }
 196                 ed->ed_prev = ohci->ed_controltail;
 197                 if (!ohci->ed_controltail && !ohci->ed_rm_list) {
 198                         wmb();
 199                         ohci->hc_control |= OHCI_CTRL_CLE;
 200                         ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
 201                         ohci_writel (ohci, ohci->hc_control,
 202                                         &ohci->regs->control);
 203                 }
 204                 ohci->ed_controltail = ed;
 205                 break;
 206
 207         case PIPE_BULK:
 208                 if (ohci->ed_bulktail == NULL) {
 209                         WARN_ON (ohci->hc_control & OHCI_CTRL_BLE);
 210                         ohci_writel (ohci, ed->dma, &ohci->regs->ed_bulkhead);
 211                 } else {
 212                         ohci->ed_bulktail->ed_next = ed;
 213                         ohci->ed_bulktail->hwNextED = cpu_to_hc32 (ohci,
 214                                                                 ed->dma);
 215                 }
 216                 ed->ed_prev = ohci->ed_bulktail;
 217                 if (!ohci->ed_bulktail && !ohci->ed_rm_list) {
 218                         wmb();
 219                         ohci->hc_control |= OHCI_CTRL_BLE;
 220                         ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
 221                         ohci_writel (ohci, ohci->hc_control,
 222                                         &ohci->regs->control);
 223                 }
 224                 ohci->ed_bulktail = ed;
 225                 break;
 226
 227         // case PIPE_INTERRUPT:
 228         // case PIPE_ISOCHRONOUS:
 229         default:
 230                 branch = balance (ohci, ed->interval, ed->load);
 231                 if (branch < 0) {
 232                         ohci_dbg (ohci,
 233                                 "ERR %d, interval %d msecs, load %d\n",
 234                                 branch, ed->interval, ed->load);
 235                         // FIXME if there are TDs queued, fail them!
 236                         return branch;
 237                 }
 238                 ed->branch = branch;
 239                 periodic_link (ohci, ed);
 240         }
 241
 242         /* the HC may not see the schedule updates yet, but if it does
 243          * then they'll be properly ordered.
 244          */
 245         return 0;
 246 }
 247
 248 /*-------------------------------------------------------------------------*/
 249
 250 /* scan the periodic table to find and unlink this ED */
 251 static void periodic_unlink (struct ohci_hcd *ohci, struct ed *ed)
 252 {
 253         int     i;
 254
 255         for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 256                 struct ed       *temp;
 257                 struct ed       **prev = &ohci->periodic [i];
 258                 __hc32          *prev_p = &ohci->hcca->int_table [i];
 259
 260                 while (*prev && (temp = *prev) != ed) {
 261                         prev_p = &temp->hwNextED;
 262                         prev = &temp->ed_next;
 263                 }
 264                 if (*prev) {
 265                         *prev_p = ed->hwNextED;
 266                         *prev = ed->ed_next;
 267                 }
 268                 ohci->load [i] -= ed->load;
 269         }
 270         ohci_to_hcd(ohci)->self.bandwidth_allocated -= ed->load / ed->interval;
 271
 272         ohci_vdbg (ohci, "unlink %sed %p branch %d [%dus.], interval %d\n",
 273                 (ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 274                 ed, ed->branch, ed->load, ed->interval);
 275 }
 276
 277 /* unlink an ed from one of the HC chains.
 278  * just the link to the ed is unlinked.
 279  * the link from the ed still points to another operational ed or 0
 280  * so the HC can eventually finish the processing of the unlinked ed
 281  * (assuming it already started that, which needn't be true).
 282  *
 283  * ED_UNLINK is a transient state: the HC may still see this ED, but soon
 284  * it won't.  ED_SKIP means the HC will finish its current transaction,
 285  * but won't start anything new.  The TD queue may still grow; device
 286  * drivers don't know about this HCD-internal state.
 287  *
 288  * When the HC can't see the ED, something changes ED_UNLINK to one of:
 289  *
 290  *  - ED_OPER: when there's any request queued, the ED gets rescheduled
 291  *    immediately.  HC should be working on them.
 292  *
 293  *  - ED_IDLE:  when there's no TD queue. there's no reason for the HC
 294  *    to care about this ED; safe to disable the endpoint.
 295  *
 296  * When finish_unlinks() runs later, after SOF interrupt, it will often
 297  * complete one or more URB unlinks before making that state change.
 298  */
 299 static void ed_deschedule (struct ohci_hcd *ohci, struct ed *ed)
 300 {
 301         ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 302         wmb ();
 303         ed->state = ED_UNLINK;
 304
 305         /* To deschedule something from the control or bulk list, just
 306          * clear CLE/BLE and wait.  There's no safe way to scrub out list
 307          * head/current registers until later, and "later" isn't very
 308          * tightly specified.  Figure 6-5 and Section 6.4.2.2 show how
 309          * the HC is reading the ED queues (while we modify them).
 310          *
 311          * For now, ed_schedule() is "later".  It might be good paranoia
 312          * to scrub those registers in finish_unlinks(), in case of bugs
 313          * that make the HC try to use them.
 314          */
 315         switch (ed->type) {
 316         case PIPE_CONTROL:
 317                 /* remove ED from the HC's list: */
 318                 if (ed->ed_prev == NULL) {
 319                         if (!ed->hwNextED) {
 320                                 ohci->hc_control &= ~OHCI_CTRL_CLE;
 321                                 ohci_writel (ohci, ohci->hc_control,
 322                                                 &ohci->regs->control);
 323                                 // a ohci_readl() later syncs CLE with the HC
 324                         } else
 325                                 ohci_writel (ohci,
 326                                         hc32_to_cpup (ohci, &ed->hwNextED),
 327                                         &ohci->regs->ed_controlhead);
 328                 } else {
 329                         ed->ed_prev->ed_next = ed->ed_next;
 330                         ed->ed_prev->hwNextED = ed->hwNextED;
 331                 }
 332                 /* remove ED from the HCD's list: */
 333                 if (ohci->ed_controltail == ed) {
 334                         ohci->ed_controltail = ed->ed_prev;
 335                         if (ohci->ed_controltail)
 336                                 ohci->ed_controltail->ed_next = NULL;
 337                 } else if (ed->ed_next) {
 338                         ed->ed_next->ed_prev = ed->ed_prev;
 339                 }
 340                 break;
 341
 342         case PIPE_BULK:
 343                 /* remove ED from the HC's list: */
 344                 if (ed->ed_prev == NULL) {
 345                         if (!ed->hwNextED) {
 346                                 ohci->hc_control &= ~OHCI_CTRL_BLE;
 347                                 ohci_writel (ohci, ohci->hc_control,
 348                                                 &ohci->regs->control);
 349                                 // a ohci_readl() later syncs BLE with the HC
 350                         } else
 351                                 ohci_writel (ohci,
 352                                         hc32_to_cpup (ohci, &ed->hwNextED),
 353                                         &ohci->regs->ed_bulkhead);
 354                 } else {
 355                         ed->ed_prev->ed_next = ed->ed_next;
 356                         ed->ed_prev->hwNextED = ed->hwNextED;
 357                 }
 358                 /* remove ED from the HCD's list: */
 359                 if (ohci->ed_bulktail == ed) {
 360                         ohci->ed_bulktail = ed->ed_prev;
 361                         if (ohci->ed_bulktail)
 362                                 ohci->ed_bulktail->ed_next = NULL;
 363                 } else if (ed->ed_next) {
 364                         ed->ed_next->ed_prev = ed->ed_prev;
 365                 }
 366                 break;
 367
 368         // case PIPE_INTERRUPT:
 369         // case PIPE_ISOCHRONOUS:
 370         default:
 371                 periodic_unlink (ohci, ed);
 372                 break;
 373         }
 374 }
 375
 376
 377 /*-------------------------------------------------------------------------*/
 378
 379 /* get and maybe (re)init an endpoint. init _should_ be done only as part
 380  * of enumeration, usb_set_configuration() or usb_set_interface().
 381  */
 382 static struct ed *ed_get (
 383         struct ohci_hcd         *ohci,
 384         struct usb_host_endpoint *ep,
 385         struct usb_device       *udev,
 386         unsigned int            pipe,
 387         int                     interval
 388 ) {
 389         struct ed               *ed;
 390         unsigned long           flags;
 391
 392         spin_lock_irqsave (&ohci->lock, flags);
 393
 394         if (!(ed = ep->hcpriv)) {
 395                 struct td       *td;
 396                 int             is_out;
 397                 u32             info;
 398
 399                 ed = ed_alloc (ohci, GFP_ATOMIC);
 400                 if (!ed) {
 401                         /* out of memory */
 402                         goto done;
 403                 }
 404
 405                 /* dummy td; end of td list for ed */
 406                 td = td_alloc (ohci, GFP_ATOMIC);
 407                 if (!td) {
 408                         /* out of memory */
 409                         ed_free (ohci, ed);
 410                         ed = NULL;
 411                         goto done;
 412                 }
 413                 ed->dummy = td;
 414                 ed->hwTailP = cpu_to_hc32 (ohci, td->td_dma);
 415                 ed->hwHeadP = ed->hwTailP;      /* ED_C, ED_H zeroed */
 416                 ed->state = ED_IDLE;
 417
 418                 is_out = !(ep->desc.bEndpointAddress & USB_DIR_IN);
 419
 420                 /* FIXME usbcore changes dev->devnum before SET_ADDRESS
 421                  * suceeds ... otherwise we wouldn't need "pipe".
 422                  */
 423                 info = usb_pipedevice (pipe);
 424                 ed->type = usb_pipetype(pipe);
 425
 426                 info |= (ep->desc.bEndpointAddress & ~USB_DIR_IN) << 7;
 427                 info |= le16_to_cpu(ep->desc.wMaxPacketSize) << 16;
 428                 if (udev->speed == USB_SPEED_LOW)
 429                         info |= ED_LOWSPEED;
 430                 /* only control transfers store pids in tds */
 431                 if (ed->type != PIPE_CONTROL) {
 432                         info |= is_out ? ED_OUT : ED_IN;
 433                         if (ed->type != PIPE_BULK) {
 434                                 /* periodic transfers... */
 435                                 if (ed->type == PIPE_ISOCHRONOUS)
 436                                         info |= ED_ISO;
 437                                 else if (interval > 32) /* iso can be bigger */
 438                                         interval = 32;
 439                                 ed->interval = interval;
 440                                 ed->load = usb_calc_bus_time (
 441                                         udev->speed, !is_out,
 442                                         ed->type == PIPE_ISOCHRONOUS,
 443                                         le16_to_cpu(ep->desc.wMaxPacketSize))
 444                                                 / 1000;
 445                         }
 446                 }
 447                 ed->hwINFO = cpu_to_hc32(ohci, info);
 448
 449                 ep->hcpriv = ed;
 450         }
 451
 452 done:
 453         spin_unlock_irqrestore (&ohci->lock, flags);
 454         return ed;
 455 }
 456
 457 /*-------------------------------------------------------------------------*/
 458
 459 /* request unlinking of an endpoint from an operational HC.
 460  * put the ep on the rm_list
 461  * real work is done at the next start frame (SF) hardware interrupt
 462  * caller guarantees HCD is running, so hardware access is safe,
 463  * and that ed->state is ED_OPER
 464  */
 465 static void start_ed_unlink (struct ohci_hcd *ohci, struct ed *ed)
 466 {
 467         ed->hwINFO |= cpu_to_hc32 (ohci, ED_DEQUEUE);
 468         ed_deschedule (ohci, ed);
 469
 470         /* rm_list is just singly linked, for simplicity */
 471         ed->ed_next = ohci->ed_rm_list;
 472         ed->ed_prev = NULL;
 473         ohci->ed_rm_list = ed;
 474
 475         /* enable SOF interrupt */
 476         ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
 477         ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
 478         // flush those writes, and get latest HCCA contents
 479         (void) ohci_readl (ohci, &ohci->regs->control);
 480
 481         /* SF interrupt might get delayed; record the frame counter value that
 482          * indicates when the HC isn't looking at it, so concurrent unlinks
 483          * behave.  frame_no wraps every 2^16 msec, and changes right before
 484          * SF is triggered.
 485          */
 486         ed->tick = ohci_frame_no(ohci) + 1;
 487
 488 }
 489
 490 /*-------------------------------------------------------------------------*
 491  * TD handling functions
 492  *-------------------------------------------------------------------------*/
 493
 494 /* enqueue next TD for this URB (OHCI spec 5.2.8.2) */
 495
 496 static void
 497 td_fill (struct ohci_hcd *ohci, u32 info,
 498         dma_addr_t data, int len,
 499         struct urb *urb, int index)
 500 {
 501         struct td               *td, *td_pt;
 502         struct urb_priv         *urb_priv = urb->hcpriv;
 503         int                     is_iso = info & TD_ISO;
 504         int                     hash;
 505
 506         // ASSERT (index < urb_priv->length);
 507
 508         /* aim for only one interrupt per urb.  mostly applies to control
 509          * and iso; other urbs rarely need more than one TD per urb.
 510          * this way, only final tds (or ones with an error) cause IRQs.
 511          * at least immediately; use DI=6 in case any control request is
 512          * tempted to die part way through.  (and to force the hc to flush
 513          * its donelist soonish, even on unlink paths.)
 514          *
 515          * NOTE: could delay interrupts even for the last TD, and get fewer
 516          * interrupts ... increasing per-urb latency by sharing interrupts.
 517          * Drivers that queue bulk urbs may request that behavior.
 518          */
 519         if (index != (urb_priv->length - 1)
 520                         || (urb->transfer_flags & URB_NO_INTERRUPT))
 521                 info |= TD_DI_SET (6);
 522
 523         /* use this td as the next dummy */
 524         td_pt = urb_priv->td [index];
 525
 526         /* fill the old dummy TD */
 527         td = urb_priv->td [index] = urb_priv->ed->dummy;
 528         urb_priv->ed->dummy = td_pt;
 529
 530         td->ed = urb_priv->ed;
 531         td->next_dl_td = NULL;
 532         td->index = index;
 533         td->urb = urb;
 534         td->data_dma = data;
 535         if (!len)
 536                 data = 0;
 537
 538         td->hwINFO = cpu_to_hc32 (ohci, info);
 539         if (is_iso) {
 540                 td->hwCBP = cpu_to_hc32 (ohci, data & 0xFFFFF000);
 541                 *ohci_hwPSWp(ohci, td, 0) = cpu_to_hc16 (ohci,
 542                                                 (data & 0x0FFF) | 0xE000);
 543                 td->ed->last_iso = info & 0xffff;
 544         } else {
 545                 td->hwCBP = cpu_to_hc32 (ohci, data);
 546         }
 547         if (data)
 548                 td->hwBE = cpu_to_hc32 (ohci, data + len - 1);
 549         else
 550                 td->hwBE = 0;
 551         td->hwNextTD = cpu_to_hc32 (ohci, td_pt->td_dma);
 552
 553         /* append to queue */
 554         list_add_tail (&td->td_list, &td->ed->td_list);
 555
 556         /* hash it for later reverse mapping */
 557         hash = TD_HASH_FUNC (td->td_dma);
 558         td->td_hash = ohci->td_hash [hash];
 559         ohci->td_hash [hash] = td;
 560
 561         /* HC might read the TD (or cachelines) right away ... */
 562         wmb ();
 563         td->ed->hwTailP = td->hwNextTD;
 564 }
 565
 566 /*-------------------------------------------------------------------------*/
 567
 568 /* Prepare all TDs of a transfer, and queue them onto the ED.
 569  * Caller guarantees HC is active.
 570  * Usually the ED is already on the schedule, so TDs might be
 571  * processed as soon as they're queued.
 572  */
 573 static void td_submit_urb (
 574         struct ohci_hcd *ohci,
 575         struct urb      *urb
 576 ) {
 577         struct urb_priv *urb_priv = urb->hcpriv;
 578         dma_addr_t      data;
 579         int             data_len = urb->transfer_buffer_length;
 580         int             cnt = 0;
 581         u32             info = 0;
 582         int             is_out = usb_pipeout (urb->pipe);
 583         int             periodic = 0;
 584
 585         /* OHCI handles the bulk/interrupt data toggles itself.  We just
 586          * use the device toggle bits for resetting, and rely on the fact
 587          * that resetting toggle is meaningless if the endpoint is active.
 588          */
 589         if (!usb_gettoggle (urb->dev, usb_pipeendpoint (urb->pipe), is_out)) {
 590                 usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe),
 591                         is_out, 1);
 592                 urb_priv->ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_C);
 593         }
 594
 595         urb_priv->td_cnt = 0;
 596         list_add (&urb_priv->pending, &ohci->pending);
 597
 598         if (data_len)
 599                 data = urb->transfer_dma;
 600         else
 601                 data = 0;
 602
 603         /* NOTE:  TD_CC is set so we can tell which TDs the HC processed by
 604          * using TD_CC_GET, as well as by seeing them on the done list.
 605          * (CC = NotAccessed ... 0x0F, or 0x0E in PSWs for ISO.)
 606          */
 607         switch (urb_priv->ed->type) {
 608
 609         /* Bulk and interrupt are identical except for where in the schedule
 610          * their EDs live.
 611          */
 612         case PIPE_INTERRUPT:
 613                 /* ... and periodic urbs have extra accounting */
 614                 periodic = ohci_to_hcd(ohci)->self.bandwidth_int_reqs++ == 0
 615                         && ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0;
 616                 /* FALLTHROUGH */
 617         case PIPE_BULK:
 618                 info = is_out
 619                         ? TD_T_TOGGLE | TD_CC | TD_DP_OUT
 620                         : TD_T_TOGGLE | TD_CC | TD_DP_IN;
 621                 /* TDs _could_ transfer up to 8K each */
 622                 while (data_len > 4096) {
 623                         td_fill (ohci, info, data, 4096, urb, cnt);
 624                         data += 4096;
 625                         data_len -= 4096;
 626                         cnt++;
 627                 }
 628                 /* maybe avoid ED halt on final TD short read */
 629                 if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
 630                         info |= TD_R;
 631                 td_fill (ohci, info, data, data_len, urb, cnt);
 632                 cnt++;
 633                 if ((urb->transfer_flags & URB_ZERO_PACKET)
 634                                 && cnt < urb_priv->length) {
 635                         td_fill (ohci, info, 0, 0, urb, cnt);
 636                         cnt++;
 637                 }
 638                 /* maybe kickstart bulk list */
 639                 if (urb_priv->ed->type == PIPE_BULK) {
 640                         wmb ();
 641                         ohci_writel (ohci, OHCI_BLF, &ohci->regs->cmdstatus);
 642                 }
 643                 break;
 644
 645         /* control manages DATA0/DATA1 toggle per-request; SETUP resets it,
 646          * any DATA phase works normally, and the STATUS ack is special.
 647          */
 648         case PIPE_CONTROL:
 649                 info = TD_CC | TD_DP_SETUP | TD_T_DATA0;
 650                 td_fill (ohci, info, urb->setup_dma, 8, urb, cnt++);
 651                 if (data_len > 0) {
 652                         info = TD_CC | TD_R | TD_T_DATA1;
 653                         info |= is_out ? TD_DP_OUT : TD_DP_IN;
 654                         /* NOTE:  mishandles transfers >8K, some >4K */
 655                         td_fill (ohci, info, data, data_len, urb, cnt++);
 656                 }
 657                 info = (is_out || data_len == 0)
 658                         ? TD_CC | TD_DP_IN | TD_T_DATA1
 659                         : TD_CC | TD_DP_OUT | TD_T_DATA1;
 660                 td_fill (ohci, info, data, 0, urb, cnt++);
 661                 /* maybe kickstart control list */
 662                 wmb ();
 663                 ohci_writel (ohci, OHCI_CLF, &ohci->regs->cmdstatus);
 664                 break;
 665
 666         /* ISO has no retransmit, so no toggle; and it uses special TDs.
 667          * Each TD could handle multiple consecutive frames (interval 1);
 668          * we could often reduce the number of TDs here.
 669          */
 670         case PIPE_ISOCHRONOUS:
 671                 for (cnt = 0; cnt < urb->number_of_packets; cnt++) {
 672                         int     frame = urb->start_frame;
 673
 674                         // FIXME scheduling should handle frame counter
 675                         // roll-around ... exotic case (and OHCI has
 676                         // a 2^16 iso range, vs other HCs max of 2^10)
 677                         frame += cnt * urb->interval;
 678                         frame &= 0xffff;
 679                         td_fill (ohci, TD_CC | TD_ISO | frame,
 680                                 data + urb->iso_frame_desc [cnt].offset,
 681                                 urb->iso_frame_desc [cnt].length, urb, cnt);
 682                 }
 683                 periodic = ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs++ == 0
 684                         && ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0;
 685                 break;
 686         }
 687
 688         /* start periodic dma if needed */
 689         if (periodic) {
 690                 wmb ();
 691                 ohci->hc_control |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
 692                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 693         }
 694
 695         // ASSERT (urb_priv->length == cnt);
 696 }
 697
 698 /*-------------------------------------------------------------------------*
 699  * Done List handling functions
 700  *-------------------------------------------------------------------------*/
 701
 702 /* calculate transfer length/status and update the urb */
 703 static int td_done(struct ohci_hcd *ohci, struct urb *urb, struct td *td)
 704 {
 705         u32     tdINFO = hc32_to_cpup (ohci, &td->hwINFO);
 706         int     cc = 0;
 707         int     status = -EINPROGRESS;
 708
 709         list_del (&td->td_list);
 710
 711         /* ISO ... drivers see per-TD length/status */
 712         if (tdINFO & TD_ISO) {
 713                 u16     tdPSW = ohci_hwPSW(ohci, td, 0);
 714                 int     dlen = 0;
 715
 716                 /* NOTE:  assumes FC in tdINFO == 0, and that
 717                  * only the first of 0..MAXPSW psws is used.
 718                  */
 719
 720                 cc = (tdPSW >> 12) & 0xF;
 721                 if (tdINFO & TD_CC)     /* hc didn't touch? */
 722                         return status;
 723
 724                 if (usb_pipeout (urb->pipe))
 725                         dlen = urb->iso_frame_desc [td->index].length;
 726                 else {
 727                         /* short reads are always OK for ISO */
 728                         if (cc == TD_DATAUNDERRUN)
 729                                 cc = TD_CC_NOERROR;
 730                         dlen = tdPSW & 0x3ff;
 731                 }
 732                 urb->actual_length += dlen;
 733                 urb->iso_frame_desc [td->index].actual_length = dlen;
 734                 urb->iso_frame_desc [td->index].status = cc_to_error [cc];
 735
 736                 if (cc != TD_CC_NOERROR)
 737                         ohci_vdbg (ohci,
 738                                 "urb %p iso td %p (%d) len %d cc %d\n",
 739                                 urb, td, 1 + td->index, dlen, cc);
 740
 741         /* BULK, INT, CONTROL ... drivers see aggregate length/status,
 742          * except that "setup" bytes aren't counted and "short" transfers
 743          * might not be reported as errors.
 744          */
 745         } else {
 746                 int     type = usb_pipetype (urb->pipe);
 747                 u32     tdBE = hc32_to_cpup (ohci, &td->hwBE);
 748
 749                 cc = TD_CC_GET (tdINFO);
 750
 751                 /* update packet status if needed (short is normally ok) */
 752                 if (cc == TD_DATAUNDERRUN
 753                                 && !(urb->transfer_flags & URB_SHORT_NOT_OK))
 754                         cc = TD_CC_NOERROR;
 755                 if (cc != TD_CC_NOERROR && cc < 0x0E)
 756                         status = cc_to_error[cc];
 757
 758                 /* count all non-empty packets except control SETUP packet */
 759                 if ((type != PIPE_CONTROL || td->index != 0) && tdBE != 0) {
 760                         if (td->hwCBP == 0)
 761                                 urb->actual_length += tdBE - td->data_dma + 1;
 762                         else
 763                                 urb->actual_length +=
 764                                           hc32_to_cpup (ohci, &td->hwCBP)
 765                                         - td->data_dma;
 766                 }
 767
 768                 if (cc != TD_CC_NOERROR && cc < 0x0E)
 769                         ohci_vdbg (ohci,
 770                                 "urb %p td %p (%d) cc %d, len=%d/%d\n",
 771                                 urb, td, 1 + td->index, cc,
 772                                 urb->actual_length,
 773                                 urb->transfer_buffer_length);
 774         }
 775         return status;
 776 }
 777
 778 /*-------------------------------------------------------------------------*/
 779
 780 static void ed_halted(struct ohci_hcd *ohci, struct td *td, int cc)
 781 {
 782         struct urb              *urb = td->urb;
 783         urb_priv_t              *urb_priv = urb->hcpriv;
 784         struct ed               *ed = td->ed;
 785         struct list_head        *tmp = td->td_list.next;
 786         __hc32                  toggle = ed->hwHeadP & cpu_to_hc32 (ohci, ED_C);
 787
 788         /* clear ed halt; this is the td that caused it, but keep it inactive
 789          * until its urb->complete() has a chance to clean up.
 790          */
 791         ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 792         wmb ();
 793         ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_H);
 794
 795         /* Get rid of all later tds from this urb.  We don't have
 796          * to be careful: no errors and nothing was transferred.
 797          * Also patch the ed so it looks as if those tds completed normally.
 798          */
 799         while (tmp != &ed->td_list) {
 800                 struct td       *next;
 801
 802                 next = list_entry (tmp, struct td, td_list);
 803                 tmp = next->td_list.next;
 804
 805                 if (next->urb != urb)
 806                         break;
 807
 808                 /* NOTE: if multi-td control DATA segments get supported,
 809                  * this urb had one of them, this td wasn't the last td
 810                  * in that segment (TD_R clear), this ed halted because
 811                  * of a short read, _and_ URB_SHORT_NOT_OK is clear ...
 812                  * then we need to leave the control STATUS packet queued
 813                  * and clear ED_SKIP.
 814                  */
 815
 816                 list_del(&next->td_list);
 817                 urb_priv->td_cnt++;
 818                 ed->hwHeadP = next->hwNextTD | toggle;
 819         }
 820
 821         /* help for troubleshooting:  report anything that
 822          * looks odd ... that doesn't include protocol stalls
 823          * (or maybe some other things)
 824          */
 825         switch (cc) {
 826         case TD_DATAUNDERRUN:
 827                 if ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0)
 828                         break;
 829                 /* fallthrough */
 830         case TD_CC_STALL:
 831                 if (usb_pipecontrol (urb->pipe))
 832                         break;
 833                 /* fallthrough */
 834         default:
 835                 ohci_dbg (ohci,
 836                         "urb %p path %s ep%d%s %08x cc %d --> status %d\n",
 837                         urb, urb->dev->devpath,
 838                         usb_pipeendpoint (urb->pipe),
 839                         usb_pipein (urb->pipe) ? "in" : "out",
 840                         hc32_to_cpu (ohci, td->hwINFO),
 841                         cc, cc_to_error [cc]);
 842         }
 843 }
 844
 845 /* replies to the request have to be on a FIFO basis so
 846  * we unreverse the hc-reversed done-list
 847  */
 848 static struct td *dl_reverse_done_list (struct ohci_hcd *ohci)
 849 {
 850         u32             td_dma;
 851         struct td       *td_rev = NULL;
 852         struct td       *td = NULL;
 853
 854         td_dma = hc32_to_cpup (ohci, &ohci->hcca->done_head);
 855         ohci->hcca->done_head = 0;
 856         wmb();
 857
 858         /* get TD from hc's singly linked list, and
 859          * prepend to ours.  ed->td_list changes later.
 860          */
 861         while (td_dma) {
 862                 int             cc;
 863
 864                 td = dma_to_td (ohci, td_dma);
 865                 if (!td) {
 866                         ohci_err (ohci, "bad entry %8x\n", td_dma);
 867                         break;
 868                 }
 869
 870                 td->hwINFO |= cpu_to_hc32 (ohci, TD_DONE);
 871                 cc = TD_CC_GET (hc32_to_cpup (ohci, &td->hwINFO));
 872
 873                 /* Non-iso endpoints can halt on error; un-halt,
 874                  * and dequeue any other TDs from this urb.
 875                  * No other TD could have caused the halt.
 876                  */
 877                 if (cc != TD_CC_NOERROR
 878                                 && (td->ed->hwHeadP & cpu_to_hc32 (ohci, ED_H)))
 879                         ed_halted(ohci, td, cc);
 880
 881                 td->next_dl_td = td_rev;
 882                 td_rev = td;
 883                 td_dma = hc32_to_cpup (ohci, &td->hwNextTD);
 884         }
 885         return td_rev;
 886 }
 887
 888 /*-------------------------------------------------------------------------*/
 889
 890 /* there are some urbs/eds to unlink; called in_irq(), with HCD locked */
 891 static void
 892 finish_unlinks (struct ohci_hcd *ohci, u16 tick)
 893 {
 894         struct ed       *ed, **last;
 895
 896 rescan_all:
 897         for (last = &ohci->ed_rm_list, ed = *last; ed != NULL; ed = *last) {
 898                 struct list_head        *entry, *tmp;
 899                 int                     completed, modified;
 900                 __hc32                  *prev;
 901
 902                 /* only take off EDs that the HC isn't using, accounting for
 903                  * frame counter wraps and EDs with partially retired TDs
 904                  */
 905                 if (likely (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))) {
 906                         if (tick_before (tick, ed->tick)) {
 907 skip_ed:
 908                                 last = &ed->ed_next;
 909                                 continue;
 910                         }
 911
 912                         if (!list_empty (&ed->td_list)) {
 913                                 struct td       *td;
 914                                 u32             head;
 915
 916                                 td = list_entry (ed->td_list.next, struct td,
 917                                                         td_list);
 918                                 head = hc32_to_cpu (ohci, ed->hwHeadP) &
 919                                                                 TD_MASK;
 920
 921                                 /* INTR_WDH may need to clean up first */
 922                                 if (td->td_dma != head) {
 923                                         if (ed == ohci->ed_to_check)
 924                                                 ohci->ed_to_check = NULL;
 925                                         else
 926                                                 goto skip_ed;
 927                                 }
 928                         }
 929                 }
 930
 931                 /* reentrancy:  if we drop the schedule lock, someone might
 932                  * have modified this list.  normally it's just prepending
 933                  * entries (which we'd ignore), but paranoia won't hurt.
 934                  */
 935                 *last = ed->ed_next;
 936                 ed->ed_next = NULL;
 937                 modified = 0;
 938
 939                 /* unlink urbs as requested, but rescan the list after
 940                  * we call a completion since it might have unlinked
 941                  * another (earlier) urb
 942                  *
 943                  * When we get here, the HC doesn't see this ed.  But it
 944                  * must not be rescheduled until all completed URBs have
 945                  * been given back to the driver.
 946                  */
 947 rescan_this:
 948                 completed = 0;
 949                 prev = &ed->hwHeadP;
 950                 list_for_each_safe (entry, tmp, &ed->td_list) {
 951                         struct td       *td;
 952                         struct urb      *urb;
 953                         urb_priv_t      *urb_priv;
 954                         __hc32          savebits;
 955
 956                         td = list_entry (entry, struct td, td_list);
 957                         urb = td->urb;
 958                         urb_priv = td->urb->hcpriv;
 959
 960                         if (!urb->unlinked) {
 961                                 prev = &td->hwNextTD;
 962                                 continue;
 963                         }
 964
 965                         /* patch pointer hc uses */
 966                         savebits = *prev & ~cpu_to_hc32 (ohci, TD_MASK);
 967                         *prev = td->hwNextTD | savebits;
 968
 969                         /* HC may have partly processed this TD */
 970                         td_done (ohci, urb, td);
 971                         urb_priv->td_cnt++;
 972
 973                         /* if URB is done, clean up */
 974                         if (urb_priv->td_cnt == urb_priv->length) {
 975                                 modified = completed = 1;
 976                                 finish_urb(ohci, urb, 0);
 977                         }
 978                 }
 979                 if (completed && !list_empty (&ed->td_list))
 980                         goto rescan_this;
 981
 982                 /* ED's now officially unlinked, hc doesn't see */
 983                 ed->state = ED_IDLE;
 984                 if (quirk_zfmicro(ohci) && ed->type == PIPE_INTERRUPT)
 985                         ohci->eds_scheduled--;
 986                 ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_H);
 987                 ed->hwNextED = 0;
 988                 wmb ();
 989                 ed->hwINFO &= ~cpu_to_hc32 (ohci, ED_SKIP | ED_DEQUEUE);
 990
 991                 /* but if there's work queued, reschedule */
 992                 if (!list_empty (&ed->td_list)) {
 993                         if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))
 994                                 ed_schedule (ohci, ed);
 995                 }
 996
 997                 if (modified)
 998                         goto rescan_all;
 999         }
1000
1001         /* maybe reenable control and bulk lists */
1002         if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state)
1003                         && ohci_to_hcd(ohci)->state != HC_STATE_QUIESCING
1004                         && !ohci->ed_rm_list) {
1005                 u32     command = 0, control = 0;
1006
1007                 if (ohci->ed_controltail) {
1008                         command |= OHCI_CLF;
1009                         if (quirk_zfmicro(ohci))
1010                                 mdelay(1);
1011                         if (!(ohci->hc_control & OHCI_CTRL_CLE)) {
1012                                 control |= OHCI_CTRL_CLE;
1013                                 ohci_writel (ohci, 0,
1014                                         &ohci->regs->ed_controlcurrent);
1015                         }
1016                 }
1017                 if (ohci->ed_bulktail) {
1018                         command |= OHCI_BLF;
1019                         if (quirk_zfmicro(ohci))
1020                                 mdelay(1);
1021                         if (!(ohci->hc_control & OHCI_CTRL_BLE)) {
1022                                 control |= OHCI_CTRL_BLE;
1023                                 ohci_writel (ohci, 0,
1024                                         &ohci->regs->ed_bulkcurrent);
1025                         }
1026                 }
1027
1028                 /* CLE/BLE to enable, CLF/BLF to (maybe) kickstart */
1029                 if (control) {
1030                         ohci->hc_control |= control;
1031                         if (quirk_zfmicro(ohci))
1032                                 mdelay(1);
1033                         ohci_writel (ohci, ohci->hc_control,
1034                                         &ohci->regs->control);
1035                 }
1036                 if (command) {
1037                         if (quirk_zfmicro(ohci))
1038                                 mdelay(1);
1039                         ohci_writel (ohci, command, &ohci->regs->cmdstatus);
1040                 }
1041         }
1042 }
1043
1044
1045
1046 /*-------------------------------------------------------------------------*/
1047
1048 /*
1049  * Used to take back a TD from the host controller. This would normally be
1050  * called from within dl_done_list, however it may be called directly if the
1051  * HC no longer sees the TD and it has not appeared on the donelist (after
1052  * two frames).  This bug has been observed on ZF Micro systems.
1053  */
1054 static void takeback_td(struct ohci_hcd *ohci, struct td *td)
1055 {
1056         struct urb      *urb = td->urb;
1057         urb_priv_t      *urb_priv = urb->hcpriv;
1058         struct ed       *ed = td->ed;
1059         int             status;
1060
1061         /* update URB's length and status from TD */
1062         status = td_done(ohci, urb, td);
1063         urb_priv->td_cnt++;
1064
1065         /* If all this urb's TDs are done, call complete() */
1066         if (urb_priv->td_cnt == urb_priv->length)
1067                 finish_urb(ohci, urb, status);
1068
1069         /* clean schedule:  unlink EDs that are no longer busy */
1070         if (list_empty(&ed->td_list)) {
1071                 if (ed->state == ED_OPER)
1072                         start_ed_unlink(ohci, ed);
1073
1074         /* ... reenabling halted EDs only after fault cleanup */
1075         } else if ((ed->hwINFO & cpu_to_hc32(ohci, ED_SKIP | ED_DEQUEUE))
1076                         == cpu_to_hc32(ohci, ED_SKIP)) {
1077                 td = list_entry(ed->td_list.next, struct td, td_list);
1078                 if (!(td->hwINFO & cpu_to_hc32(ohci, TD_DONE))) {
1079                         ed->hwINFO &= ~cpu_to_hc32(ohci, ED_SKIP);
1080                         /* ... hc may need waking-up */
1081                         switch (ed->type) {
1082                         case PIPE_CONTROL:
1083                                 ohci_writel(ohci, OHCI_CLF,
1084                                                 &ohci->regs->cmdstatus);
1085                                 break;
1086                         case PIPE_BULK:
1087                                 ohci_writel(ohci, OHCI_BLF,
1088                                                 &ohci->regs->cmdstatus);
1089                                 break;
1090                         }
1091                 }
1092         }
1093 }
1094
1095 /*
1096  * Process normal completions (error or success) and clean the schedules.
1097  *
1098  * This is the main path for handing urbs back to drivers.  The only other
1099  * normal path is finish_unlinks(), which unlinks URBs using ed_rm_list,
1100  * instead of scanning the (re-reversed) donelist as this does.  There's
1101  * an abnormal path too, handling a quirk in some Compaq silicon:  URBs
1102  * with TDs that appear to be orphaned are directly reclaimed.
1103  */
1104 static void
1105 dl_done_list (struct ohci_hcd *ohci)
1106 {
1107         struct td       *td = dl_reverse_done_list (ohci);
1108
1109         while (td) {
1110                 struct td       *td_next = td->next_dl_td;
1111                 takeback_td(ohci, td);
1112                 td = td_next;
1113         }
1114 }