Merge branch 'topic/docbook-fix' into for-linus
[linux-2.6] / 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                 if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
53                                 && quirk_amdiso(ohci))
54                         quirk_amd_pll(1);
55                 break;
56         case PIPE_INTERRUPT:
57                 ohci_to_hcd(ohci)->self.bandwidth_int_reqs--;
58                 break;
59         }
60
61 #ifdef OHCI_VERBOSE_DEBUG
62         urb_print(urb, "RET", usb_pipeout (urb->pipe), status);
63 #endif
64
65         /* urb->complete() can reenter this HCD */
66         usb_hcd_unlink_urb_from_ep(ohci_to_hcd(ohci), urb);
67         spin_unlock (&ohci->lock);
68         usb_hcd_giveback_urb(ohci_to_hcd(ohci), urb, status);
69         spin_lock (&ohci->lock);
70
71         /* stop periodic dma if it's not needed */
72         if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
73                         && ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0) {
74                 ohci->hc_control &= ~(OHCI_CTRL_PLE|OHCI_CTRL_IE);
75                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
76         }
77 }
78
79
80 /*-------------------------------------------------------------------------*
81  * ED handling functions
82  *-------------------------------------------------------------------------*/
83
84 /* search for the right schedule branch to use for a periodic ed.
85  * does some load balancing; returns the branch, or negative errno.
86  */
87 static int balance (struct ohci_hcd *ohci, int interval, int load)
88 {
89         int     i, branch = -ENOSPC;
90
91         /* iso periods can be huge; iso tds specify frame numbers */
92         if (interval > NUM_INTS)
93                 interval = NUM_INTS;
94
95         /* search for the least loaded schedule branch of that period
96          * that has enough bandwidth left unreserved.
97          */
98         for (i = 0; i < interval ; i++) {
99                 if (branch < 0 || ohci->load [branch] > ohci->load [i]) {
100                         int     j;
101
102                         /* usb 1.1 says 90% of one frame */
103                         for (j = i; j < NUM_INTS; j += interval) {
104                                 if ((ohci->load [j] + load) > 900)
105                                         break;
106                         }
107                         if (j < NUM_INTS)
108                                 continue;
109                         branch = i;
110                 }
111         }
112         return branch;
113 }
114
115 /*-------------------------------------------------------------------------*/
116
117 /* both iso and interrupt requests have periods; this routine puts them
118  * into the schedule tree in the apppropriate place.  most iso devices use
119  * 1msec periods, but that's not required.
120  */
121 static void periodic_link (struct ohci_hcd *ohci, struct ed *ed)
122 {
123         unsigned        i;
124
125         ohci_vdbg (ohci, "link %sed %p branch %d [%dus.], interval %d\n",
126                 (ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
127                 ed, ed->branch, ed->load, ed->interval);
128
129         for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
130                 struct ed       **prev = &ohci->periodic [i];
131                 __hc32          *prev_p = &ohci->hcca->int_table [i];
132                 struct ed       *here = *prev;
133
134                 /* sorting each branch by period (slow before fast)
135                  * lets us share the faster parts of the tree.
136                  * (plus maybe: put interrupt eds before iso)
137                  */
138                 while (here && ed != here) {
139                         if (ed->interval > here->interval)
140                                 break;
141                         prev = &here->ed_next;
142                         prev_p = &here->hwNextED;
143                         here = *prev;
144                 }
145                 if (ed != here) {
146                         ed->ed_next = here;
147                         if (here)
148                                 ed->hwNextED = *prev_p;
149                         wmb ();
150                         *prev = ed;
151                         *prev_p = cpu_to_hc32(ohci, ed->dma);
152                         wmb();
153                 }
154                 ohci->load [i] += ed->load;
155         }
156         ohci_to_hcd(ohci)->self.bandwidth_allocated += ed->load / ed->interval;
157 }
158
159 /* link an ed into one of the HC chains */
160
161 static int ed_schedule (struct ohci_hcd *ohci, struct ed *ed)
162 {
163         int     branch;
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                 if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
684                                 && quirk_amdiso(ohci))
685                         quirk_amd_pll(0);
686                 periodic = ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs++ == 0
687                         && ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0;
688                 break;
689         }
690
691         /* start periodic dma if needed */
692         if (periodic) {
693                 wmb ();
694                 ohci->hc_control |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
695                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
696         }
697
698         // ASSERT (urb_priv->length == cnt);
699 }
700
701 /*-------------------------------------------------------------------------*
702  * Done List handling functions
703  *-------------------------------------------------------------------------*/
704
705 /* calculate transfer length/status and update the urb */
706 static int td_done(struct ohci_hcd *ohci, struct urb *urb, struct td *td)
707 {
708         u32     tdINFO = hc32_to_cpup (ohci, &td->hwINFO);
709         int     cc = 0;
710         int     status = -EINPROGRESS;
711
712         list_del (&td->td_list);
713
714         /* ISO ... drivers see per-TD length/status */
715         if (tdINFO & TD_ISO) {
716                 u16     tdPSW = ohci_hwPSW(ohci, td, 0);
717                 int     dlen = 0;
718
719                 /* NOTE:  assumes FC in tdINFO == 0, and that
720                  * only the first of 0..MAXPSW psws is used.
721                  */
722
723                 cc = (tdPSW >> 12) & 0xF;
724                 if (tdINFO & TD_CC)     /* hc didn't touch? */
725                         return status;
726
727                 if (usb_pipeout (urb->pipe))
728                         dlen = urb->iso_frame_desc [td->index].length;
729                 else {
730                         /* short reads are always OK for ISO */
731                         if (cc == TD_DATAUNDERRUN)
732                                 cc = TD_CC_NOERROR;
733                         dlen = tdPSW & 0x3ff;
734                 }
735                 urb->actual_length += dlen;
736                 urb->iso_frame_desc [td->index].actual_length = dlen;
737                 urb->iso_frame_desc [td->index].status = cc_to_error [cc];
738
739                 if (cc != TD_CC_NOERROR)
740                         ohci_vdbg (ohci,
741                                 "urb %p iso td %p (%d) len %d cc %d\n",
742                                 urb, td, 1 + td->index, dlen, cc);
743
744         /* BULK, INT, CONTROL ... drivers see aggregate length/status,
745          * except that "setup" bytes aren't counted and "short" transfers
746          * might not be reported as errors.
747          */
748         } else {
749                 int     type = usb_pipetype (urb->pipe);
750                 u32     tdBE = hc32_to_cpup (ohci, &td->hwBE);
751
752                 cc = TD_CC_GET (tdINFO);
753
754                 /* update packet status if needed (short is normally ok) */
755                 if (cc == TD_DATAUNDERRUN
756                                 && !(urb->transfer_flags & URB_SHORT_NOT_OK))
757                         cc = TD_CC_NOERROR;
758                 if (cc != TD_CC_NOERROR && cc < 0x0E)
759                         status = cc_to_error[cc];
760
761                 /* count all non-empty packets except control SETUP packet */
762                 if ((type != PIPE_CONTROL || td->index != 0) && tdBE != 0) {
763                         if (td->hwCBP == 0)
764                                 urb->actual_length += tdBE - td->data_dma + 1;
765                         else
766                                 urb->actual_length +=
767                                           hc32_to_cpup (ohci, &td->hwCBP)
768                                         - td->data_dma;
769                 }
770
771                 if (cc != TD_CC_NOERROR && cc < 0x0E)
772                         ohci_vdbg (ohci,
773                                 "urb %p td %p (%d) cc %d, len=%d/%d\n",
774                                 urb, td, 1 + td->index, cc,
775                                 urb->actual_length,
776                                 urb->transfer_buffer_length);
777         }
778         return status;
779 }
780
781 /*-------------------------------------------------------------------------*/
782
783 static void ed_halted(struct ohci_hcd *ohci, struct td *td, int cc)
784 {
785         struct urb              *urb = td->urb;
786         urb_priv_t              *urb_priv = urb->hcpriv;
787         struct ed               *ed = td->ed;
788         struct list_head        *tmp = td->td_list.next;
789         __hc32                  toggle = ed->hwHeadP & cpu_to_hc32 (ohci, ED_C);
790
791         /* clear ed halt; this is the td that caused it, but keep it inactive
792          * until its urb->complete() has a chance to clean up.
793          */
794         ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
795         wmb ();
796         ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_H);
797
798         /* Get rid of all later tds from this urb.  We don't have
799          * to be careful: no errors and nothing was transferred.
800          * Also patch the ed so it looks as if those tds completed normally.
801          */
802         while (tmp != &ed->td_list) {
803                 struct td       *next;
804
805                 next = list_entry (tmp, struct td, td_list);
806                 tmp = next->td_list.next;
807
808                 if (next->urb != urb)
809                         break;
810
811                 /* NOTE: if multi-td control DATA segments get supported,
812                  * this urb had one of them, this td wasn't the last td
813                  * in that segment (TD_R clear), this ed halted because
814                  * of a short read, _and_ URB_SHORT_NOT_OK is clear ...
815                  * then we need to leave the control STATUS packet queued
816                  * and clear ED_SKIP.
817                  */
818
819                 list_del(&next->td_list);
820                 urb_priv->td_cnt++;
821                 ed->hwHeadP = next->hwNextTD | toggle;
822         }
823
824         /* help for troubleshooting:  report anything that
825          * looks odd ... that doesn't include protocol stalls
826          * (or maybe some other things)
827          */
828         switch (cc) {
829         case TD_DATAUNDERRUN:
830                 if ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0)
831                         break;
832                 /* fallthrough */
833         case TD_CC_STALL:
834                 if (usb_pipecontrol (urb->pipe))
835                         break;
836                 /* fallthrough */
837         default:
838                 ohci_dbg (ohci,
839                         "urb %p path %s ep%d%s %08x cc %d --> status %d\n",
840                         urb, urb->dev->devpath,
841                         usb_pipeendpoint (urb->pipe),
842                         usb_pipein (urb->pipe) ? "in" : "out",
843                         hc32_to_cpu (ohci, td->hwINFO),
844                         cc, cc_to_error [cc]);
845         }
846 }
847
848 /* replies to the request have to be on a FIFO basis so
849  * we unreverse the hc-reversed done-list
850  */
851 static struct td *dl_reverse_done_list (struct ohci_hcd *ohci)
852 {
853         u32             td_dma;
854         struct td       *td_rev = NULL;
855         struct td       *td = NULL;
856
857         td_dma = hc32_to_cpup (ohci, &ohci->hcca->done_head);
858         ohci->hcca->done_head = 0;
859         wmb();
860
861         /* get TD from hc's singly linked list, and
862          * prepend to ours.  ed->td_list changes later.
863          */
864         while (td_dma) {
865                 int             cc;
866
867                 td = dma_to_td (ohci, td_dma);
868                 if (!td) {
869                         ohci_err (ohci, "bad entry %8x\n", td_dma);
870                         break;
871                 }
872
873                 td->hwINFO |= cpu_to_hc32 (ohci, TD_DONE);
874                 cc = TD_CC_GET (hc32_to_cpup (ohci, &td->hwINFO));
875
876                 /* Non-iso endpoints can halt on error; un-halt,
877                  * and dequeue any other TDs from this urb.
878                  * No other TD could have caused the halt.
879                  */
880                 if (cc != TD_CC_NOERROR
881                                 && (td->ed->hwHeadP & cpu_to_hc32 (ohci, ED_H)))
882                         ed_halted(ohci, td, cc);
883
884                 td->next_dl_td = td_rev;
885                 td_rev = td;
886                 td_dma = hc32_to_cpup (ohci, &td->hwNextTD);
887         }
888         return td_rev;
889 }
890
891 /*-------------------------------------------------------------------------*/
892
893 /* there are some urbs/eds to unlink; called in_irq(), with HCD locked */
894 static void
895 finish_unlinks (struct ohci_hcd *ohci, u16 tick)
896 {
897         struct ed       *ed, **last;
898
899 rescan_all:
900         for (last = &ohci->ed_rm_list, ed = *last; ed != NULL; ed = *last) {
901                 struct list_head        *entry, *tmp;
902                 int                     completed, modified;
903                 __hc32                  *prev;
904
905                 /* only take off EDs that the HC isn't using, accounting for
906                  * frame counter wraps and EDs with partially retired TDs
907                  */
908                 if (likely (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))) {
909                         if (tick_before (tick, ed->tick)) {
910 skip_ed:
911                                 last = &ed->ed_next;
912                                 continue;
913                         }
914
915                         if (!list_empty (&ed->td_list)) {
916                                 struct td       *td;
917                                 u32             head;
918
919                                 td = list_entry (ed->td_list.next, struct td,
920                                                         td_list);
921                                 head = hc32_to_cpu (ohci, ed->hwHeadP) &
922                                                                 TD_MASK;
923
924                                 /* INTR_WDH may need to clean up first */
925                                 if (td->td_dma != head) {
926                                         if (ed == ohci->ed_to_check)
927                                                 ohci->ed_to_check = NULL;
928                                         else
929                                                 goto skip_ed;
930                                 }
931                         }
932                 }
933
934                 /* reentrancy:  if we drop the schedule lock, someone might
935                  * have modified this list.  normally it's just prepending
936                  * entries (which we'd ignore), but paranoia won't hurt.
937                  */
938                 *last = ed->ed_next;
939                 ed->ed_next = NULL;
940                 modified = 0;
941
942                 /* unlink urbs as requested, but rescan the list after
943                  * we call a completion since it might have unlinked
944                  * another (earlier) urb
945                  *
946                  * When we get here, the HC doesn't see this ed.  But it
947                  * must not be rescheduled until all completed URBs have
948                  * been given back to the driver.
949                  */
950 rescan_this:
951                 completed = 0;
952                 prev = &ed->hwHeadP;
953                 list_for_each_safe (entry, tmp, &ed->td_list) {
954                         struct td       *td;
955                         struct urb      *urb;
956                         urb_priv_t      *urb_priv;
957                         __hc32          savebits;
958                         u32             tdINFO;
959
960                         td = list_entry (entry, struct td, td_list);
961                         urb = td->urb;
962                         urb_priv = td->urb->hcpriv;
963
964                         if (!urb->unlinked) {
965                                 prev = &td->hwNextTD;
966                                 continue;
967                         }
968
969                         /* patch pointer hc uses */
970                         savebits = *prev & ~cpu_to_hc32 (ohci, TD_MASK);
971                         *prev = td->hwNextTD | savebits;
972
973                         /* If this was unlinked, the TD may not have been
974                          * retired ... so manually save the data toggle.
975                          * The controller ignores the value we save for
976                          * control and ISO endpoints.
977                          */
978                         tdINFO = hc32_to_cpup(ohci, &td->hwINFO);
979                         if ((tdINFO & TD_T) == TD_T_DATA0)
980                                 ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_C);
981                         else if ((tdINFO & TD_T) == TD_T_DATA1)
982                                 ed->hwHeadP |= cpu_to_hc32(ohci, ED_C);
983
984                         /* HC may have partly processed this TD */
985                         td_done (ohci, urb, td);
986                         urb_priv->td_cnt++;
987
988                         /* if URB is done, clean up */
989                         if (urb_priv->td_cnt == urb_priv->length) {
990                                 modified = completed = 1;
991                                 finish_urb(ohci, urb, 0);
992                         }
993                 }
994                 if (completed && !list_empty (&ed->td_list))
995                         goto rescan_this;
996
997                 /* ED's now officially unlinked, hc doesn't see */
998                 ed->state = ED_IDLE;
999                 if (quirk_zfmicro(ohci) && ed->type == PIPE_INTERRUPT)
1000                         ohci->eds_scheduled--;
1001                 ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_H);
1002                 ed->hwNextED = 0;
1003                 wmb ();
1004                 ed->hwINFO &= ~cpu_to_hc32 (ohci, ED_SKIP | ED_DEQUEUE);
1005
1006                 /* but if there's work queued, reschedule */
1007                 if (!list_empty (&ed->td_list)) {
1008                         if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))
1009                                 ed_schedule (ohci, ed);
1010                 }
1011
1012                 if (modified)
1013                         goto rescan_all;
1014         }
1015
1016         /* maybe reenable control and bulk lists */
1017         if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state)
1018                         && ohci_to_hcd(ohci)->state != HC_STATE_QUIESCING
1019                         && !ohci->ed_rm_list) {
1020                 u32     command = 0, control = 0;
1021
1022                 if (ohci->ed_controltail) {
1023                         command |= OHCI_CLF;
1024                         if (quirk_zfmicro(ohci))
1025                                 mdelay(1);
1026                         if (!(ohci->hc_control & OHCI_CTRL_CLE)) {
1027                                 control |= OHCI_CTRL_CLE;
1028                                 ohci_writel (ohci, 0,
1029                                         &ohci->regs->ed_controlcurrent);
1030                         }
1031                 }
1032                 if (ohci->ed_bulktail) {
1033                         command |= OHCI_BLF;
1034                         if (quirk_zfmicro(ohci))
1035                                 mdelay(1);
1036                         if (!(ohci->hc_control & OHCI_CTRL_BLE)) {
1037                                 control |= OHCI_CTRL_BLE;
1038                                 ohci_writel (ohci, 0,
1039                                         &ohci->regs->ed_bulkcurrent);
1040                         }
1041                 }
1042
1043                 /* CLE/BLE to enable, CLF/BLF to (maybe) kickstart */
1044                 if (control) {
1045                         ohci->hc_control |= control;
1046                         if (quirk_zfmicro(ohci))
1047                                 mdelay(1);
1048                         ohci_writel (ohci, ohci->hc_control,
1049                                         &ohci->regs->control);
1050                 }
1051                 if (command) {
1052                         if (quirk_zfmicro(ohci))
1053                                 mdelay(1);
1054                         ohci_writel (ohci, command, &ohci->regs->cmdstatus);
1055                 }
1056         }
1057 }
1058
1059
1060
1061 /*-------------------------------------------------------------------------*/
1062
1063 /*
1064  * Used to take back a TD from the host controller. This would normally be
1065  * called from within dl_done_list, however it may be called directly if the
1066  * HC no longer sees the TD and it has not appeared on the donelist (after
1067  * two frames).  This bug has been observed on ZF Micro systems.
1068  */
1069 static void takeback_td(struct ohci_hcd *ohci, struct td *td)
1070 {
1071         struct urb      *urb = td->urb;
1072         urb_priv_t      *urb_priv = urb->hcpriv;
1073         struct ed       *ed = td->ed;
1074         int             status;
1075
1076         /* update URB's length and status from TD */
1077         status = td_done(ohci, urb, td);
1078         urb_priv->td_cnt++;
1079
1080         /* If all this urb's TDs are done, call complete() */
1081         if (urb_priv->td_cnt == urb_priv->length)
1082                 finish_urb(ohci, urb, status);
1083
1084         /* clean schedule:  unlink EDs that are no longer busy */
1085         if (list_empty(&ed->td_list)) {
1086                 if (ed->state == ED_OPER)
1087                         start_ed_unlink(ohci, ed);
1088
1089         /* ... reenabling halted EDs only after fault cleanup */
1090         } else if ((ed->hwINFO & cpu_to_hc32(ohci, ED_SKIP | ED_DEQUEUE))
1091                         == cpu_to_hc32(ohci, ED_SKIP)) {
1092                 td = list_entry(ed->td_list.next, struct td, td_list);
1093                 if (!(td->hwINFO & cpu_to_hc32(ohci, TD_DONE))) {
1094                         ed->hwINFO &= ~cpu_to_hc32(ohci, ED_SKIP);
1095                         /* ... hc may need waking-up */
1096                         switch (ed->type) {
1097                         case PIPE_CONTROL:
1098                                 ohci_writel(ohci, OHCI_CLF,
1099                                                 &ohci->regs->cmdstatus);
1100                                 break;
1101                         case PIPE_BULK:
1102                                 ohci_writel(ohci, OHCI_BLF,
1103                                                 &ohci->regs->cmdstatus);
1104                                 break;
1105                         }
1106                 }
1107         }
1108 }
1109
1110 /*
1111  * Process normal completions (error or success) and clean the schedules.
1112  *
1113  * This is the main path for handing urbs back to drivers.  The only other
1114  * normal path is finish_unlinks(), which unlinks URBs using ed_rm_list,
1115  * instead of scanning the (re-reversed) donelist as this does.  There's
1116  * an abnormal path too, handling a quirk in some Compaq silicon:  URBs
1117  * with TDs that appear to be orphaned are directly reclaimed.
1118  */
1119 static void
1120 dl_done_list (struct ohci_hcd *ohci)
1121 {
1122         struct td       *td = dl_reverse_done_list (ohci);
1123
1124         while (td) {
1125                 struct td       *td_next = td->next_dl_td;
1126                 takeback_td(ohci, td);
1127                 td = td_next;
1128         }
1129 }