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v3.1
   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#include <linux/slab.h>
  12
  13static void urb_free_priv (struct ohci_hcd *hc, urb_priv_t *urb_priv)
  14{
  15	int		last = urb_priv->length - 1;
  16
  17	if (last >= 0) {
  18		int		i;
  19		struct td	*td;
  20
  21		for (i = 0; i <= last; i++) {
  22			td = urb_priv->td [i];
  23			if (td)
  24				td_free (hc, td);
  25		}
  26	}
  27
  28	list_del (&urb_priv->pending);
  29	kfree (urb_priv);
  30}
  31
  32/*-------------------------------------------------------------------------*/
  33
  34/*
  35 * URB goes back to driver, and isn't reissued.
  36 * It's completely gone from HC data structures.
  37 * PRECONDITION:  ohci lock held, irqs blocked.
  38 */
  39static void
  40finish_urb(struct ohci_hcd *ohci, struct urb *urb, int status)
  41__releases(ohci->lock)
  42__acquires(ohci->lock)
  43{
 
 
 
 
  44	// ASSERT (urb->hcpriv != 0);
  45
 
  46	urb_free_priv (ohci, urb->hcpriv);
 
  47	if (likely(status == -EINPROGRESS))
  48		status = 0;
  49
  50	switch (usb_pipetype (urb->pipe)) {
  51	case PIPE_ISOCHRONOUS:
  52		ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs--;
  53		if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0) {
  54			if (quirk_amdiso(ohci))
  55				usb_amd_quirk_pll_enable();
  56			if (quirk_amdprefetch(ohci))
  57				sb800_prefetch(ohci, 0);
  58		}
  59		break;
  60	case PIPE_INTERRUPT:
  61		ohci_to_hcd(ohci)->self.bandwidth_int_reqs--;
  62		break;
  63	}
  64
  65#ifdef OHCI_VERBOSE_DEBUG
  66	urb_print(urb, "RET", usb_pipeout (urb->pipe), status);
  67#endif
  68
  69	/* urb->complete() can reenter this HCD */
  70	usb_hcd_unlink_urb_from_ep(ohci_to_hcd(ohci), urb);
  71	spin_unlock (&ohci->lock);
  72	usb_hcd_giveback_urb(ohci_to_hcd(ohci), urb, status);
  73	spin_lock (&ohci->lock);
  74
  75	/* stop periodic dma if it's not needed */
  76	if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
  77			&& ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0) {
  78		ohci->hc_control &= ~(OHCI_CTRL_PLE|OHCI_CTRL_IE);
  79		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
  80	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  81}
  82
  83
  84/*-------------------------------------------------------------------------*
  85 * ED handling functions
  86 *-------------------------------------------------------------------------*/
  87
  88/* search for the right schedule branch to use for a periodic ed.
  89 * does some load balancing; returns the branch, or negative errno.
  90 */
  91static int balance (struct ohci_hcd *ohci, int interval, int load)
  92{
  93	int	i, branch = -ENOSPC;
  94
  95	/* iso periods can be huge; iso tds specify frame numbers */
  96	if (interval > NUM_INTS)
  97		interval = NUM_INTS;
  98
  99	/* search for the least loaded schedule branch of that period
 100	 * that has enough bandwidth left unreserved.
 101	 */
 102	for (i = 0; i < interval ; i++) {
 103		if (branch < 0 || ohci->load [branch] > ohci->load [i]) {
 104			int	j;
 105
 106			/* usb 1.1 says 90% of one frame */
 107			for (j = i; j < NUM_INTS; j += interval) {
 108				if ((ohci->load [j] + load) > 900)
 109					break;
 110			}
 111			if (j < NUM_INTS)
 112				continue;
 113			branch = i;
 114		}
 115	}
 116	return branch;
 117}
 118
 119/*-------------------------------------------------------------------------*/
 120
 121/* both iso and interrupt requests have periods; this routine puts them
 122 * into the schedule tree in the apppropriate place.  most iso devices use
 123 * 1msec periods, but that's not required.
 124 */
 125static void periodic_link (struct ohci_hcd *ohci, struct ed *ed)
 126{
 127	unsigned	i;
 128
 129	ohci_vdbg (ohci, "link %sed %p branch %d [%dus.], interval %d\n",
 130		(ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 131		ed, ed->branch, ed->load, ed->interval);
 132
 133	for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 134		struct ed	**prev = &ohci->periodic [i];
 135		__hc32		*prev_p = &ohci->hcca->int_table [i];
 136		struct ed	*here = *prev;
 137
 138		/* sorting each branch by period (slow before fast)
 139		 * lets us share the faster parts of the tree.
 140		 * (plus maybe: put interrupt eds before iso)
 141		 */
 142		while (here && ed != here) {
 143			if (ed->interval > here->interval)
 144				break;
 145			prev = &here->ed_next;
 146			prev_p = &here->hwNextED;
 147			here = *prev;
 148		}
 149		if (ed != here) {
 150			ed->ed_next = here;
 151			if (here)
 152				ed->hwNextED = *prev_p;
 153			wmb ();
 154			*prev = ed;
 155			*prev_p = cpu_to_hc32(ohci, ed->dma);
 156			wmb();
 157		}
 158		ohci->load [i] += ed->load;
 159	}
 160	ohci_to_hcd(ohci)->self.bandwidth_allocated += ed->load / ed->interval;
 161}
 162
 163/* link an ed into one of the HC chains */
 164
 165static int ed_schedule (struct ohci_hcd *ohci, struct ed *ed)
 166{
 167	int	branch;
 168
 169	ed->state = ED_OPER;
 170	ed->ed_prev = NULL;
 171	ed->ed_next = NULL;
 172	ed->hwNextED = 0;
 173	if (quirk_zfmicro(ohci)
 174			&& (ed->type == PIPE_INTERRUPT)
 175			&& !(ohci->eds_scheduled++))
 176		mod_timer(&ohci->unlink_watchdog, round_jiffies(jiffies + HZ));
 177	wmb ();
 178
 179	/* we care about rm_list when setting CLE/BLE in case the HC was at
 180	 * work on some TD when CLE/BLE was turned off, and isn't quiesced
 181	 * yet.  finish_unlinks() restarts as needed, some upcoming INTR_SF.
 182	 *
 183	 * control and bulk EDs are doubly linked (ed_next, ed_prev), but
 184	 * periodic ones are singly linked (ed_next). that's because the
 185	 * periodic schedule encodes a tree like figure 3-5 in the ohci
 186	 * spec:  each qh can have several "previous" nodes, and the tree
 187	 * doesn't have unused/idle descriptors.
 188	 */
 189	switch (ed->type) {
 190	case PIPE_CONTROL:
 191		if (ohci->ed_controltail == NULL) {
 192			WARN_ON (ohci->hc_control & OHCI_CTRL_CLE);
 193			ohci_writel (ohci, ed->dma,
 194					&ohci->regs->ed_controlhead);
 195		} else {
 196			ohci->ed_controltail->ed_next = ed;
 197			ohci->ed_controltail->hwNextED = cpu_to_hc32 (ohci,
 198								ed->dma);
 199		}
 200		ed->ed_prev = ohci->ed_controltail;
 201		if (!ohci->ed_controltail && !ohci->ed_rm_list) {
 202			wmb();
 203			ohci->hc_control |= OHCI_CTRL_CLE;
 204			ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
 205			ohci_writel (ohci, ohci->hc_control,
 206					&ohci->regs->control);
 207		}
 208		ohci->ed_controltail = ed;
 209		break;
 210
 211	case PIPE_BULK:
 212		if (ohci->ed_bulktail == NULL) {
 213			WARN_ON (ohci->hc_control & OHCI_CTRL_BLE);
 214			ohci_writel (ohci, ed->dma, &ohci->regs->ed_bulkhead);
 215		} else {
 216			ohci->ed_bulktail->ed_next = ed;
 217			ohci->ed_bulktail->hwNextED = cpu_to_hc32 (ohci,
 218								ed->dma);
 219		}
 220		ed->ed_prev = ohci->ed_bulktail;
 221		if (!ohci->ed_bulktail && !ohci->ed_rm_list) {
 222			wmb();
 223			ohci->hc_control |= OHCI_CTRL_BLE;
 224			ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
 225			ohci_writel (ohci, ohci->hc_control,
 226					&ohci->regs->control);
 227		}
 228		ohci->ed_bulktail = ed;
 229		break;
 230
 231	// case PIPE_INTERRUPT:
 232	// case PIPE_ISOCHRONOUS:
 233	default:
 234		branch = balance (ohci, ed->interval, ed->load);
 235		if (branch < 0) {
 236			ohci_dbg (ohci,
 237				"ERR %d, interval %d msecs, load %d\n",
 238				branch, ed->interval, ed->load);
 239			// FIXME if there are TDs queued, fail them!
 240			return branch;
 241		}
 242		ed->branch = branch;
 243		periodic_link (ohci, ed);
 244	}
 245
 246	/* the HC may not see the schedule updates yet, but if it does
 247	 * then they'll be properly ordered.
 248	 */
 
 
 249	return 0;
 250}
 251
 252/*-------------------------------------------------------------------------*/
 253
 254/* scan the periodic table to find and unlink this ED */
 255static void periodic_unlink (struct ohci_hcd *ohci, struct ed *ed)
 256{
 257	int	i;
 258
 259	for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 260		struct ed	*temp;
 261		struct ed	**prev = &ohci->periodic [i];
 262		__hc32		*prev_p = &ohci->hcca->int_table [i];
 263
 264		while (*prev && (temp = *prev) != ed) {
 265			prev_p = &temp->hwNextED;
 266			prev = &temp->ed_next;
 267		}
 268		if (*prev) {
 269			*prev_p = ed->hwNextED;
 270			*prev = ed->ed_next;
 271		}
 272		ohci->load [i] -= ed->load;
 273	}
 274	ohci_to_hcd(ohci)->self.bandwidth_allocated -= ed->load / ed->interval;
 275
 276	ohci_vdbg (ohci, "unlink %sed %p branch %d [%dus.], interval %d\n",
 277		(ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 278		ed, ed->branch, ed->load, ed->interval);
 279}
 280
 281/* unlink an ed from one of the HC chains.
 282 * just the link to the ed is unlinked.
 283 * the link from the ed still points to another operational ed or 0
 284 * so the HC can eventually finish the processing of the unlinked ed
 285 * (assuming it already started that, which needn't be true).
 286 *
 287 * ED_UNLINK is a transient state: the HC may still see this ED, but soon
 288 * it won't.  ED_SKIP means the HC will finish its current transaction,
 289 * but won't start anything new.  The TD queue may still grow; device
 290 * drivers don't know about this HCD-internal state.
 291 *
 292 * When the HC can't see the ED, something changes ED_UNLINK to one of:
 293 *
 294 *  - ED_OPER: when there's any request queued, the ED gets rescheduled
 295 *    immediately.  HC should be working on them.
 296 *
 297 *  - ED_IDLE:  when there's no TD queue. there's no reason for the HC
 298 *    to care about this ED; safe to disable the endpoint.
 299 *
 300 * When finish_unlinks() runs later, after SOF interrupt, it will often
 301 * complete one or more URB unlinks before making that state change.
 302 */
 303static void ed_deschedule (struct ohci_hcd *ohci, struct ed *ed)
 304{
 305	ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 306	wmb ();
 307	ed->state = ED_UNLINK;
 308
 309	/* To deschedule something from the control or bulk list, just
 310	 * clear CLE/BLE and wait.  There's no safe way to scrub out list
 311	 * head/current registers until later, and "later" isn't very
 312	 * tightly specified.  Figure 6-5 and Section 6.4.2.2 show how
 313	 * the HC is reading the ED queues (while we modify them).
 314	 *
 315	 * For now, ed_schedule() is "later".  It might be good paranoia
 316	 * to scrub those registers in finish_unlinks(), in case of bugs
 317	 * that make the HC try to use them.
 318	 */
 319	switch (ed->type) {
 320	case PIPE_CONTROL:
 321		/* remove ED from the HC's list: */
 322		if (ed->ed_prev == NULL) {
 323			if (!ed->hwNextED) {
 324				ohci->hc_control &= ~OHCI_CTRL_CLE;
 325				ohci_writel (ohci, ohci->hc_control,
 326						&ohci->regs->control);
 327				// a ohci_readl() later syncs CLE with the HC
 328			} else
 329				ohci_writel (ohci,
 330					hc32_to_cpup (ohci, &ed->hwNextED),
 331					&ohci->regs->ed_controlhead);
 332		} else {
 333			ed->ed_prev->ed_next = ed->ed_next;
 334			ed->ed_prev->hwNextED = ed->hwNextED;
 335		}
 336		/* remove ED from the HCD's list: */
 337		if (ohci->ed_controltail == ed) {
 338			ohci->ed_controltail = ed->ed_prev;
 339			if (ohci->ed_controltail)
 340				ohci->ed_controltail->ed_next = NULL;
 341		} else if (ed->ed_next) {
 342			ed->ed_next->ed_prev = ed->ed_prev;
 343		}
 344		break;
 345
 346	case PIPE_BULK:
 347		/* remove ED from the HC's list: */
 348		if (ed->ed_prev == NULL) {
 349			if (!ed->hwNextED) {
 350				ohci->hc_control &= ~OHCI_CTRL_BLE;
 351				ohci_writel (ohci, ohci->hc_control,
 352						&ohci->regs->control);
 353				// a ohci_readl() later syncs BLE with the HC
 354			} else
 355				ohci_writel (ohci,
 356					hc32_to_cpup (ohci, &ed->hwNextED),
 357					&ohci->regs->ed_bulkhead);
 358		} else {
 359			ed->ed_prev->ed_next = ed->ed_next;
 360			ed->ed_prev->hwNextED = ed->hwNextED;
 361		}
 362		/* remove ED from the HCD's list: */
 363		if (ohci->ed_bulktail == ed) {
 364			ohci->ed_bulktail = ed->ed_prev;
 365			if (ohci->ed_bulktail)
 366				ohci->ed_bulktail->ed_next = NULL;
 367		} else if (ed->ed_next) {
 368			ed->ed_next->ed_prev = ed->ed_prev;
 369		}
 370		break;
 371
 372	// case PIPE_INTERRUPT:
 373	// case PIPE_ISOCHRONOUS:
 374	default:
 375		periodic_unlink (ohci, ed);
 376		break;
 377	}
 378}
 379
 380
 381/*-------------------------------------------------------------------------*/
 382
 383/* get and maybe (re)init an endpoint. init _should_ be done only as part
 384 * of enumeration, usb_set_configuration() or usb_set_interface().
 385 */
 386static struct ed *ed_get (
 387	struct ohci_hcd		*ohci,
 388	struct usb_host_endpoint *ep,
 389	struct usb_device	*udev,
 390	unsigned int		pipe,
 391	int			interval
 392) {
 393	struct ed		*ed;
 394	unsigned long		flags;
 395
 396	spin_lock_irqsave (&ohci->lock, flags);
 397
 398	if (!(ed = ep->hcpriv)) {
 
 399		struct td	*td;
 400		int		is_out;
 401		u32		info;
 402
 403		ed = ed_alloc (ohci, GFP_ATOMIC);
 404		if (!ed) {
 405			/* out of memory */
 406			goto done;
 407		}
 408
 409		/* dummy td; end of td list for ed */
 410		td = td_alloc (ohci, GFP_ATOMIC);
 411		if (!td) {
 412			/* out of memory */
 413			ed_free (ohci, ed);
 414			ed = NULL;
 415			goto done;
 416		}
 417		ed->dummy = td;
 418		ed->hwTailP = cpu_to_hc32 (ohci, td->td_dma);
 419		ed->hwHeadP = ed->hwTailP;	/* ED_C, ED_H zeroed */
 420		ed->state = ED_IDLE;
 421
 422		is_out = !(ep->desc.bEndpointAddress & USB_DIR_IN);
 423
 424		/* FIXME usbcore changes dev->devnum before SET_ADDRESS
 425		 * succeeds ... otherwise we wouldn't need "pipe".
 426		 */
 427		info = usb_pipedevice (pipe);
 428		ed->type = usb_pipetype(pipe);
 429
 430		info |= (ep->desc.bEndpointAddress & ~USB_DIR_IN) << 7;
 431		info |= le16_to_cpu(ep->desc.wMaxPacketSize) << 16;
 432		if (udev->speed == USB_SPEED_LOW)
 433			info |= ED_LOWSPEED;
 434		/* only control transfers store pids in tds */
 435		if (ed->type != PIPE_CONTROL) {
 436			info |= is_out ? ED_OUT : ED_IN;
 437			if (ed->type != PIPE_BULK) {
 438				/* periodic transfers... */
 439				if (ed->type == PIPE_ISOCHRONOUS)
 440					info |= ED_ISO;
 441				else if (interval > 32)	/* iso can be bigger */
 442					interval = 32;
 443				ed->interval = interval;
 444				ed->load = usb_calc_bus_time (
 445					udev->speed, !is_out,
 446					ed->type == PIPE_ISOCHRONOUS,
 447					le16_to_cpu(ep->desc.wMaxPacketSize))
 448						/ 1000;
 449			}
 450		}
 451		ed->hwINFO = cpu_to_hc32(ohci, info);
 452
 453		ep->hcpriv = ed;
 454	}
 455
 456done:
 457	spin_unlock_irqrestore (&ohci->lock, flags);
 458	return ed;
 459}
 460
 461/*-------------------------------------------------------------------------*/
 462
 463/* request unlinking of an endpoint from an operational HC.
 464 * put the ep on the rm_list
 465 * real work is done at the next start frame (SF) hardware interrupt
 466 * caller guarantees HCD is running, so hardware access is safe,
 467 * and that ed->state is ED_OPER
 468 */
 469static void start_ed_unlink (struct ohci_hcd *ohci, struct ed *ed)
 470{
 471	ed->hwINFO |= cpu_to_hc32 (ohci, ED_DEQUEUE);
 472	ed_deschedule (ohci, ed);
 473
 474	/* rm_list is just singly linked, for simplicity */
 475	ed->ed_next = ohci->ed_rm_list;
 476	ed->ed_prev = NULL;
 477	ohci->ed_rm_list = ed;
 478
 479	/* enable SOF interrupt */
 480	ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
 481	ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
 482	// flush those writes, and get latest HCCA contents
 483	(void) ohci_readl (ohci, &ohci->regs->control);
 484
 485	/* SF interrupt might get delayed; record the frame counter value that
 486	 * indicates when the HC isn't looking at it, so concurrent unlinks
 487	 * behave.  frame_no wraps every 2^16 msec, and changes right before
 488	 * SF is triggered.
 489	 */
 490	ed->tick = ohci_frame_no(ohci) + 1;
 491
 492}
 493
 494/*-------------------------------------------------------------------------*
 495 * TD handling functions
 496 *-------------------------------------------------------------------------*/
 497
 498/* enqueue next TD for this URB (OHCI spec 5.2.8.2) */
 499
 500static void
 501td_fill (struct ohci_hcd *ohci, u32 info,
 502	dma_addr_t data, int len,
 503	struct urb *urb, int index)
 504{
 505	struct td		*td, *td_pt;
 506	struct urb_priv		*urb_priv = urb->hcpriv;
 507	int			is_iso = info & TD_ISO;
 508	int			hash;
 509
 510	// ASSERT (index < urb_priv->length);
 511
 512	/* aim for only one interrupt per urb.  mostly applies to control
 513	 * and iso; other urbs rarely need more than one TD per urb.
 514	 * this way, only final tds (or ones with an error) cause IRQs.
 515	 * at least immediately; use DI=6 in case any control request is
 516	 * tempted to die part way through.  (and to force the hc to flush
 517	 * its donelist soonish, even on unlink paths.)
 518	 *
 519	 * NOTE: could delay interrupts even for the last TD, and get fewer
 520	 * interrupts ... increasing per-urb latency by sharing interrupts.
 521	 * Drivers that queue bulk urbs may request that behavior.
 522	 */
 523	if (index != (urb_priv->length - 1)
 524			|| (urb->transfer_flags & URB_NO_INTERRUPT))
 525		info |= TD_DI_SET (6);
 526
 527	/* use this td as the next dummy */
 528	td_pt = urb_priv->td [index];
 529
 530	/* fill the old dummy TD */
 531	td = urb_priv->td [index] = urb_priv->ed->dummy;
 532	urb_priv->ed->dummy = td_pt;
 533
 534	td->ed = urb_priv->ed;
 535	td->next_dl_td = NULL;
 536	td->index = index;
 537	td->urb = urb;
 538	td->data_dma = data;
 539	if (!len)
 540		data = 0;
 541
 542	td->hwINFO = cpu_to_hc32 (ohci, info);
 543	if (is_iso) {
 544		td->hwCBP = cpu_to_hc32 (ohci, data & 0xFFFFF000);
 545		*ohci_hwPSWp(ohci, td, 0) = cpu_to_hc16 (ohci,
 546						(data & 0x0FFF) | 0xE000);
 547		td->ed->last_iso = info & 0xffff;
 548	} else {
 549		td->hwCBP = cpu_to_hc32 (ohci, data);
 550	}
 551	if (data)
 552		td->hwBE = cpu_to_hc32 (ohci, data + len - 1);
 553	else
 554		td->hwBE = 0;
 555	td->hwNextTD = cpu_to_hc32 (ohci, td_pt->td_dma);
 556
 557	/* append to queue */
 558	list_add_tail (&td->td_list, &td->ed->td_list);
 559
 560	/* hash it for later reverse mapping */
 561	hash = TD_HASH_FUNC (td->td_dma);
 562	td->td_hash = ohci->td_hash [hash];
 563	ohci->td_hash [hash] = td;
 564
 565	/* HC might read the TD (or cachelines) right away ... */
 566	wmb ();
 567	td->ed->hwTailP = td->hwNextTD;
 568}
 569
 570/*-------------------------------------------------------------------------*/
 571
 572/* Prepare all TDs of a transfer, and queue them onto the ED.
 573 * Caller guarantees HC is active.
 574 * Usually the ED is already on the schedule, so TDs might be
 575 * processed as soon as they're queued.
 576 */
 577static void td_submit_urb (
 578	struct ohci_hcd	*ohci,
 579	struct urb	*urb
 580) {
 581	struct urb_priv	*urb_priv = urb->hcpriv;
 
 582	dma_addr_t	data;
 583	int		data_len = urb->transfer_buffer_length;
 584	int		cnt = 0;
 585	u32		info = 0;
 586	int		is_out = usb_pipeout (urb->pipe);
 587	int		periodic = 0;
 
 
 588
 589	/* OHCI handles the bulk/interrupt data toggles itself.  We just
 590	 * use the device toggle bits for resetting, and rely on the fact
 591	 * that resetting toggle is meaningless if the endpoint is active.
 592	 */
 593	if (!usb_gettoggle (urb->dev, usb_pipeendpoint (urb->pipe), is_out)) {
 594		usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe),
 595			is_out, 1);
 596		urb_priv->ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_C);
 597	}
 598
 599	urb_priv->td_cnt = 0;
 600	list_add (&urb_priv->pending, &ohci->pending);
 601
 602	if (data_len)
 603		data = urb->transfer_dma;
 604	else
 605		data = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 606
 607	/* NOTE:  TD_CC is set so we can tell which TDs the HC processed by
 608	 * using TD_CC_GET, as well as by seeing them on the done list.
 609	 * (CC = NotAccessed ... 0x0F, or 0x0E in PSWs for ISO.)
 610	 */
 611	switch (urb_priv->ed->type) {
 612
 613	/* Bulk and interrupt are identical except for where in the schedule
 614	 * their EDs live.
 615	 */
 616	case PIPE_INTERRUPT:
 617		/* ... and periodic urbs have extra accounting */
 618		periodic = ohci_to_hcd(ohci)->self.bandwidth_int_reqs++ == 0
 619			&& ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0;
 620		/* FALLTHROUGH */
 621	case PIPE_BULK:
 622		info = is_out
 623			? TD_T_TOGGLE | TD_CC | TD_DP_OUT
 624			: TD_T_TOGGLE | TD_CC | TD_DP_IN;
 625		/* TDs _could_ transfer up to 8K each */
 626		while (data_len > 4096) {
 627			td_fill (ohci, info, data, 4096, urb, cnt);
 628			data += 4096;
 629			data_len -= 4096;
 
 
 
 
 
 
 
 
 630			cnt++;
 
 
 
 
 
 
 
 
 
 631		}
 632		/* maybe avoid ED halt on final TD short read */
 633		if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
 634			info |= TD_R;
 635		td_fill (ohci, info, data, data_len, urb, cnt);
 636		cnt++;
 637		if ((urb->transfer_flags & URB_ZERO_PACKET)
 638				&& cnt < urb_priv->length) {
 639			td_fill (ohci, info, 0, 0, urb, cnt);
 640			cnt++;
 641		}
 642		/* maybe kickstart bulk list */
 643		if (urb_priv->ed->type == PIPE_BULK) {
 644			wmb ();
 645			ohci_writel (ohci, OHCI_BLF, &ohci->regs->cmdstatus);
 646		}
 647		break;
 648
 649	/* control manages DATA0/DATA1 toggle per-request; SETUP resets it,
 650	 * any DATA phase works normally, and the STATUS ack is special.
 651	 */
 652	case PIPE_CONTROL:
 653		info = TD_CC | TD_DP_SETUP | TD_T_DATA0;
 654		td_fill (ohci, info, urb->setup_dma, 8, urb, cnt++);
 655		if (data_len > 0) {
 656			info = TD_CC | TD_R | TD_T_DATA1;
 657			info |= is_out ? TD_DP_OUT : TD_DP_IN;
 658			/* NOTE:  mishandles transfers >8K, some >4K */
 659			td_fill (ohci, info, data, data_len, urb, cnt++);
 660		}
 661		info = (is_out || data_len == 0)
 662			? TD_CC | TD_DP_IN | TD_T_DATA1
 663			: TD_CC | TD_DP_OUT | TD_T_DATA1;
 664		td_fill (ohci, info, data, 0, urb, cnt++);
 665		/* maybe kickstart control list */
 666		wmb ();
 667		ohci_writel (ohci, OHCI_CLF, &ohci->regs->cmdstatus);
 668		break;
 669
 670	/* ISO has no retransmit, so no toggle; and it uses special TDs.
 671	 * Each TD could handle multiple consecutive frames (interval 1);
 672	 * we could often reduce the number of TDs here.
 673	 */
 674	case PIPE_ISOCHRONOUS:
 675		for (cnt = 0; cnt < urb->number_of_packets; cnt++) {
 
 676			int	frame = urb->start_frame;
 677
 678			// FIXME scheduling should handle frame counter
 679			// roll-around ... exotic case (and OHCI has
 680			// a 2^16 iso range, vs other HCs max of 2^10)
 681			frame += cnt * urb->interval;
 682			frame &= 0xffff;
 683			td_fill (ohci, TD_CC | TD_ISO | frame,
 684				data + urb->iso_frame_desc [cnt].offset,
 685				urb->iso_frame_desc [cnt].length, urb, cnt);
 686		}
 687		if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0) {
 688			if (quirk_amdiso(ohci))
 689				usb_amd_quirk_pll_disable();
 690			if (quirk_amdprefetch(ohci))
 691				sb800_prefetch(ohci, 1);
 692		}
 693		periodic = ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs++ == 0
 694			&& ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0;
 695		break;
 696	}
 697
 698	/* start periodic dma if needed */
 699	if (periodic) {
 700		wmb ();
 701		ohci->hc_control |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
 702		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 703	}
 704
 705	// ASSERT (urb_priv->length == cnt);
 706}
 707
 708/*-------------------------------------------------------------------------*
 709 * Done List handling functions
 710 *-------------------------------------------------------------------------*/
 711
 712/* calculate transfer length/status and update the urb */
 713static int td_done(struct ohci_hcd *ohci, struct urb *urb, struct td *td)
 714{
 715	u32	tdINFO = hc32_to_cpup (ohci, &td->hwINFO);
 716	int	cc = 0;
 717	int	status = -EINPROGRESS;
 718
 719	list_del (&td->td_list);
 720
 721	/* ISO ... drivers see per-TD length/status */
 722	if (tdINFO & TD_ISO) {
 723		u16	tdPSW = ohci_hwPSW(ohci, td, 0);
 724		int	dlen = 0;
 725
 726		/* NOTE:  assumes FC in tdINFO == 0, and that
 727		 * only the first of 0..MAXPSW psws is used.
 728		 */
 729
 730		cc = (tdPSW >> 12) & 0xF;
 731		if (tdINFO & TD_CC)	/* hc didn't touch? */
 732			return status;
 733
 734		if (usb_pipeout (urb->pipe))
 735			dlen = urb->iso_frame_desc [td->index].length;
 736		else {
 737			/* short reads are always OK for ISO */
 738			if (cc == TD_DATAUNDERRUN)
 739				cc = TD_CC_NOERROR;
 740			dlen = tdPSW & 0x3ff;
 741		}
 742		urb->actual_length += dlen;
 743		urb->iso_frame_desc [td->index].actual_length = dlen;
 744		urb->iso_frame_desc [td->index].status = cc_to_error [cc];
 745
 746		if (cc != TD_CC_NOERROR)
 747			ohci_vdbg (ohci,
 748				"urb %p iso td %p (%d) len %d cc %d\n",
 749				urb, td, 1 + td->index, dlen, cc);
 750
 751	/* BULK, INT, CONTROL ... drivers see aggregate length/status,
 752	 * except that "setup" bytes aren't counted and "short" transfers
 753	 * might not be reported as errors.
 754	 */
 755	} else {
 756		int	type = usb_pipetype (urb->pipe);
 757		u32	tdBE = hc32_to_cpup (ohci, &td->hwBE);
 758
 759		cc = TD_CC_GET (tdINFO);
 760
 761		/* update packet status if needed (short is normally ok) */
 762		if (cc == TD_DATAUNDERRUN
 763				&& !(urb->transfer_flags & URB_SHORT_NOT_OK))
 764			cc = TD_CC_NOERROR;
 765		if (cc != TD_CC_NOERROR && cc < 0x0E)
 766			status = cc_to_error[cc];
 767
 768		/* count all non-empty packets except control SETUP packet */
 769		if ((type != PIPE_CONTROL || td->index != 0) && tdBE != 0) {
 770			if (td->hwCBP == 0)
 771				urb->actual_length += tdBE - td->data_dma + 1;
 772			else
 773				urb->actual_length +=
 774					  hc32_to_cpup (ohci, &td->hwCBP)
 775					- td->data_dma;
 776		}
 777
 778		if (cc != TD_CC_NOERROR && cc < 0x0E)
 779			ohci_vdbg (ohci,
 780				"urb %p td %p (%d) cc %d, len=%d/%d\n",
 781				urb, td, 1 + td->index, cc,
 782				urb->actual_length,
 783				urb->transfer_buffer_length);
 784	}
 785	return status;
 786}
 787
 788/*-------------------------------------------------------------------------*/
 789
 790static void ed_halted(struct ohci_hcd *ohci, struct td *td, int cc)
 791{
 792	struct urb		*urb = td->urb;
 793	urb_priv_t		*urb_priv = urb->hcpriv;
 794	struct ed		*ed = td->ed;
 795	struct list_head	*tmp = td->td_list.next;
 796	__hc32			toggle = ed->hwHeadP & cpu_to_hc32 (ohci, ED_C);
 797
 798	/* clear ed halt; this is the td that caused it, but keep it inactive
 799	 * until its urb->complete() has a chance to clean up.
 800	 */
 801	ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 802	wmb ();
 803	ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_H);
 804
 805	/* Get rid of all later tds from this urb.  We don't have
 806	 * to be careful: no errors and nothing was transferred.
 807	 * Also patch the ed so it looks as if those tds completed normally.
 808	 */
 809	while (tmp != &ed->td_list) {
 810		struct td	*next;
 811
 812		next = list_entry (tmp, struct td, td_list);
 813		tmp = next->td_list.next;
 814
 815		if (next->urb != urb)
 816			break;
 817
 818		/* NOTE: if multi-td control DATA segments get supported,
 819		 * this urb had one of them, this td wasn't the last td
 820		 * in that segment (TD_R clear), this ed halted because
 821		 * of a short read, _and_ URB_SHORT_NOT_OK is clear ...
 822		 * then we need to leave the control STATUS packet queued
 823		 * and clear ED_SKIP.
 824		 */
 825
 826		list_del(&next->td_list);
 827		urb_priv->td_cnt++;
 828		ed->hwHeadP = next->hwNextTD | toggle;
 829	}
 830
 831	/* help for troubleshooting:  report anything that
 832	 * looks odd ... that doesn't include protocol stalls
 833	 * (or maybe some other things)
 834	 */
 835	switch (cc) {
 836	case TD_DATAUNDERRUN:
 837		if ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0)
 838			break;
 839		/* fallthrough */
 840	case TD_CC_STALL:
 841		if (usb_pipecontrol (urb->pipe))
 842			break;
 843		/* fallthrough */
 844	default:
 845		ohci_dbg (ohci,
 846			"urb %p path %s ep%d%s %08x cc %d --> status %d\n",
 847			urb, urb->dev->devpath,
 848			usb_pipeendpoint (urb->pipe),
 849			usb_pipein (urb->pipe) ? "in" : "out",
 850			hc32_to_cpu (ohci, td->hwINFO),
 851			cc, cc_to_error [cc]);
 852	}
 853}
 854
 855/* replies to the request have to be on a FIFO basis so
 856 * we unreverse the hc-reversed done-list
 857 */
 858static struct td *dl_reverse_done_list (struct ohci_hcd *ohci)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 859{
 860	u32		td_dma;
 861	struct td	*td_rev = NULL;
 862	struct td	*td = NULL;
 863
 864	td_dma = hc32_to_cpup (ohci, &ohci->hcca->done_head);
 865	ohci->hcca->done_head = 0;
 866	wmb();
 867
 868	/* get TD from hc's singly linked list, and
 869	 * prepend to ours.  ed->td_list changes later.
 870	 */
 871	while (td_dma) {
 872		int		cc;
 873
 874		td = dma_to_td (ohci, td_dma);
 875		if (!td) {
 876			ohci_err (ohci, "bad entry %8x\n", td_dma);
 877			break;
 878		}
 879
 880		td->hwINFO |= cpu_to_hc32 (ohci, TD_DONE);
 881		cc = TD_CC_GET (hc32_to_cpup (ohci, &td->hwINFO));
 882
 883		/* Non-iso endpoints can halt on error; un-halt,
 884		 * and dequeue any other TDs from this urb.
 885		 * No other TD could have caused the halt.
 886		 */
 887		if (cc != TD_CC_NOERROR
 888				&& (td->ed->hwHeadP & cpu_to_hc32 (ohci, ED_H)))
 889			ed_halted(ohci, td, cc);
 890
 891		td->next_dl_td = td_rev;
 892		td_rev = td;
 893		td_dma = hc32_to_cpup (ohci, &td->hwNextTD);
 
 894	}
 895	return td_rev;
 896}
 897
 898/*-------------------------------------------------------------------------*/
 899
 900/* there are some urbs/eds to unlink; called in_irq(), with HCD locked */
 901static void
 902finish_unlinks (struct ohci_hcd *ohci, u16 tick)
 903{
 
 904	struct ed	*ed, **last;
 905
 906rescan_all:
 907	for (last = &ohci->ed_rm_list, ed = *last; ed != NULL; ed = *last) {
 908		struct list_head	*entry, *tmp;
 909		int			completed, modified;
 910		__hc32			*prev;
 911
 912		/* only take off EDs that the HC isn't using, accounting for
 913		 * frame counter wraps and EDs with partially retired TDs
 914		 */
 915		if (likely (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))) {
 916			if (tick_before (tick, ed->tick)) {
 917skip_ed:
 918				last = &ed->ed_next;
 919				continue;
 920			}
 
 
 
 921
 922			if (!list_empty (&ed->td_list)) {
 923				struct td	*td;
 924				u32		head;
 925
 926				td = list_entry (ed->td_list.next, struct td,
 927							td_list);
 928				head = hc32_to_cpu (ohci, ed->hwHeadP) &
 929								TD_MASK;
 930
 931				/* INTR_WDH may need to clean up first */
 932				if (td->td_dma != head) {
 933					if (ed == ohci->ed_to_check)
 934						ohci->ed_to_check = NULL;
 935					else
 936						goto skip_ed;
 937				}
 938			}
 939		}
 940
 
 
 
 
 
 
 941		/* reentrancy:  if we drop the schedule lock, someone might
 942		 * have modified this list.  normally it's just prepending
 943		 * entries (which we'd ignore), but paranoia won't hurt.
 944		 */
 945		*last = ed->ed_next;
 946		ed->ed_next = NULL;
 947		modified = 0;
 948
 949		/* unlink urbs as requested, but rescan the list after
 950		 * we call a completion since it might have unlinked
 951		 * another (earlier) urb
 952		 *
 953		 * When we get here, the HC doesn't see this ed.  But it
 954		 * must not be rescheduled until all completed URBs have
 955		 * been given back to the driver.
 956		 */
 957rescan_this:
 958		completed = 0;
 959		prev = &ed->hwHeadP;
 960		list_for_each_safe (entry, tmp, &ed->td_list) {
 961			struct td	*td;
 962			struct urb	*urb;
 963			urb_priv_t	*urb_priv;
 964			__hc32		savebits;
 965			u32		tdINFO;
 966
 967			td = list_entry (entry, struct td, td_list);
 968			urb = td->urb;
 969			urb_priv = td->urb->hcpriv;
 970
 971			if (!urb->unlinked) {
 972				prev = &td->hwNextTD;
 973				continue;
 974			}
 975
 976			/* patch pointer hc uses */
 977			savebits = *prev & ~cpu_to_hc32 (ohci, TD_MASK);
 978			*prev = td->hwNextTD | savebits;
 979
 980			/* If this was unlinked, the TD may not have been
 981			 * retired ... so manually save the data toggle.
 982			 * The controller ignores the value we save for
 983			 * control and ISO endpoints.
 984			 */
 985			tdINFO = hc32_to_cpup(ohci, &td->hwINFO);
 986			if ((tdINFO & TD_T) == TD_T_DATA0)
 987				ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_C);
 988			else if ((tdINFO & TD_T) == TD_T_DATA1)
 989				ed->hwHeadP |= cpu_to_hc32(ohci, ED_C);
 990
 991			/* HC may have partly processed this TD */
 992			td_done (ohci, urb, td);
 993			urb_priv->td_cnt++;
 994
 995			/* if URB is done, clean up */
 996			if (urb_priv->td_cnt == urb_priv->length) {
 997				modified = completed = 1;
 998				finish_urb(ohci, urb, 0);
 999			}
1000		}
1001		if (completed && !list_empty (&ed->td_list))
1002			goto rescan_this;
1003
1004		/* ED's now officially unlinked, hc doesn't see */
1005		ed->state = ED_IDLE;
1006		if (quirk_zfmicro(ohci) && ed->type == PIPE_INTERRUPT)
1007			ohci->eds_scheduled--;
1008		ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_H);
1009		ed->hwNextED = 0;
1010		wmb ();
1011		ed->hwINFO &= ~cpu_to_hc32 (ohci, ED_SKIP | ED_DEQUEUE);
1012
1013		/* but if there's work queued, reschedule */
1014		if (!list_empty (&ed->td_list)) {
1015			if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))
1016				ed_schedule (ohci, ed);
 
 
 
1017		}
1018
1019		if (modified)
1020			goto rescan_all;
1021	}
1022
1023	/* maybe reenable control and bulk lists */
1024	if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state)
1025			&& ohci_to_hcd(ohci)->state != HC_STATE_QUIESCING
1026			&& !ohci->ed_rm_list) {
1027		u32	command = 0, control = 0;
1028
1029		if (ohci->ed_controltail) {
1030			command |= OHCI_CLF;
1031			if (quirk_zfmicro(ohci))
1032				mdelay(1);
1033			if (!(ohci->hc_control & OHCI_CTRL_CLE)) {
1034				control |= OHCI_CTRL_CLE;
1035				ohci_writel (ohci, 0,
1036					&ohci->regs->ed_controlcurrent);
1037			}
1038		}
1039		if (ohci->ed_bulktail) {
1040			command |= OHCI_BLF;
1041			if (quirk_zfmicro(ohci))
1042				mdelay(1);
1043			if (!(ohci->hc_control & OHCI_CTRL_BLE)) {
1044				control |= OHCI_CTRL_BLE;
1045				ohci_writel (ohci, 0,
1046					&ohci->regs->ed_bulkcurrent);
1047			}
1048		}
1049
1050		/* CLE/BLE to enable, CLF/BLF to (maybe) kickstart */
1051		if (control) {
1052			ohci->hc_control |= control;
1053			if (quirk_zfmicro(ohci))
1054				mdelay(1);
1055			ohci_writel (ohci, ohci->hc_control,
1056					&ohci->regs->control);
1057		}
1058		if (command) {
1059			if (quirk_zfmicro(ohci))
1060				mdelay(1);
1061			ohci_writel (ohci, command, &ohci->regs->cmdstatus);
1062		}
1063	}
1064}
1065
1066
1067
1068/*-------------------------------------------------------------------------*/
1069
1070/*
1071 * Used to take back a TD from the host controller. This would normally be
1072 * called from within dl_done_list, however it may be called directly if the
1073 * HC no longer sees the TD and it has not appeared on the donelist (after
1074 * two frames).  This bug has been observed on ZF Micro systems.
1075 */
1076static void takeback_td(struct ohci_hcd *ohci, struct td *td)
1077{
1078	struct urb	*urb = td->urb;
1079	urb_priv_t	*urb_priv = urb->hcpriv;
1080	struct ed	*ed = td->ed;
1081	int		status;
1082
1083	/* update URB's length and status from TD */
1084	status = td_done(ohci, urb, td);
1085	urb_priv->td_cnt++;
1086
1087	/* If all this urb's TDs are done, call complete() */
1088	if (urb_priv->td_cnt == urb_priv->length)
1089		finish_urb(ohci, urb, status);
1090
1091	/* clean schedule:  unlink EDs that are no longer busy */
1092	if (list_empty(&ed->td_list)) {
1093		if (ed->state == ED_OPER)
1094			start_ed_unlink(ohci, ed);
1095
1096	/* ... reenabling halted EDs only after fault cleanup */
1097	} else if ((ed->hwINFO & cpu_to_hc32(ohci, ED_SKIP | ED_DEQUEUE))
1098			== cpu_to_hc32(ohci, ED_SKIP)) {
1099		td = list_entry(ed->td_list.next, struct td, td_list);
1100		if (!(td->hwINFO & cpu_to_hc32(ohci, TD_DONE))) {
1101			ed->hwINFO &= ~cpu_to_hc32(ohci, ED_SKIP);
1102			/* ... hc may need waking-up */
1103			switch (ed->type) {
1104			case PIPE_CONTROL:
1105				ohci_writel(ohci, OHCI_CLF,
1106						&ohci->regs->cmdstatus);
1107				break;
1108			case PIPE_BULK:
1109				ohci_writel(ohci, OHCI_BLF,
1110						&ohci->regs->cmdstatus);
1111				break;
1112			}
1113		}
1114	}
1115}
1116
1117/*
1118 * Process normal completions (error or success) and clean the schedules.
1119 *
1120 * This is the main path for handing urbs back to drivers.  The only other
1121 * normal path is finish_unlinks(), which unlinks URBs using ed_rm_list,
1122 * instead of scanning the (re-reversed) donelist as this does.  There's
1123 * an abnormal path too, handling a quirk in some Compaq silicon:  URBs
1124 * with TDs that appear to be orphaned are directly reclaimed.
1125 */
1126static void
1127dl_done_list (struct ohci_hcd *ohci)
1128{
1129	struct td	*td = dl_reverse_done_list (ohci);
 
 
 
 
 
 
 
1130
1131	while (td) {
1132		struct td	*td_next = td->next_dl_td;
1133		takeback_td(ohci, td);
1134		td = td_next;
1135	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1136}
v4.10.11
   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#include <linux/slab.h>
  12
  13static void urb_free_priv (struct ohci_hcd *hc, urb_priv_t *urb_priv)
  14{
  15	int		last = urb_priv->length - 1;
  16
  17	if (last >= 0) {
  18		int		i;
  19		struct td	*td;
  20
  21		for (i = 0; i <= last; i++) {
  22			td = urb_priv->td [i];
  23			if (td)
  24				td_free (hc, td);
  25		}
  26	}
  27
  28	list_del (&urb_priv->pending);
  29	kfree (urb_priv);
  30}
  31
  32/*-------------------------------------------------------------------------*/
  33
  34/*
  35 * URB goes back to driver, and isn't reissued.
  36 * It's completely gone from HC data structures.
  37 * PRECONDITION:  ohci lock held, irqs blocked.
  38 */
  39static void
  40finish_urb(struct ohci_hcd *ohci, struct urb *urb, int status)
  41__releases(ohci->lock)
  42__acquires(ohci->lock)
  43{
  44	struct device *dev = ohci_to_hcd(ohci)->self.controller;
  45	struct usb_host_endpoint *ep = urb->ep;
  46	struct urb_priv *urb_priv;
  47
  48	// ASSERT (urb->hcpriv != 0);
  49
  50 restart:
  51	urb_free_priv (ohci, urb->hcpriv);
  52	urb->hcpriv = NULL;
  53	if (likely(status == -EINPROGRESS))
  54		status = 0;
  55
  56	switch (usb_pipetype (urb->pipe)) {
  57	case PIPE_ISOCHRONOUS:
  58		ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs--;
  59		if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0) {
  60			if (quirk_amdiso(ohci))
  61				usb_amd_quirk_pll_enable();
  62			if (quirk_amdprefetch(ohci))
  63				sb800_prefetch(dev, 0);
  64		}
  65		break;
  66	case PIPE_INTERRUPT:
  67		ohci_to_hcd(ohci)->self.bandwidth_int_reqs--;
  68		break;
  69	}
  70
 
 
 
 
  71	/* urb->complete() can reenter this HCD */
  72	usb_hcd_unlink_urb_from_ep(ohci_to_hcd(ohci), urb);
  73	spin_unlock (&ohci->lock);
  74	usb_hcd_giveback_urb(ohci_to_hcd(ohci), urb, status);
  75	spin_lock (&ohci->lock);
  76
  77	/* stop periodic dma if it's not needed */
  78	if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
  79			&& ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0) {
  80		ohci->hc_control &= ~(OHCI_CTRL_PLE|OHCI_CTRL_IE);
  81		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
  82	}
  83
  84	/*
  85	 * An isochronous URB that is sumitted too late won't have any TDs
  86	 * (marked by the fact that the td_cnt value is larger than the
  87	 * actual number of TDs).  If the next URB on this endpoint is like
  88	 * that, give it back now.
  89	 */
  90	if (!list_empty(&ep->urb_list)) {
  91		urb = list_first_entry(&ep->urb_list, struct urb, urb_list);
  92		urb_priv = urb->hcpriv;
  93		if (urb_priv->td_cnt > urb_priv->length) {
  94			status = 0;
  95			goto restart;
  96		}
  97	}
  98}
  99
 100
 101/*-------------------------------------------------------------------------*
 102 * ED handling functions
 103 *-------------------------------------------------------------------------*/
 104
 105/* search for the right schedule branch to use for a periodic ed.
 106 * does some load balancing; returns the branch, or negative errno.
 107 */
 108static int balance (struct ohci_hcd *ohci, int interval, int load)
 109{
 110	int	i, branch = -ENOSPC;
 111
 112	/* iso periods can be huge; iso tds specify frame numbers */
 113	if (interval > NUM_INTS)
 114		interval = NUM_INTS;
 115
 116	/* search for the least loaded schedule branch of that period
 117	 * that has enough bandwidth left unreserved.
 118	 */
 119	for (i = 0; i < interval ; i++) {
 120		if (branch < 0 || ohci->load [branch] > ohci->load [i]) {
 121			int	j;
 122
 123			/* usb 1.1 says 90% of one frame */
 124			for (j = i; j < NUM_INTS; j += interval) {
 125				if ((ohci->load [j] + load) > 900)
 126					break;
 127			}
 128			if (j < NUM_INTS)
 129				continue;
 130			branch = i;
 131		}
 132	}
 133	return branch;
 134}
 135
 136/*-------------------------------------------------------------------------*/
 137
 138/* both iso and interrupt requests have periods; this routine puts them
 139 * into the schedule tree in the apppropriate place.  most iso devices use
 140 * 1msec periods, but that's not required.
 141 */
 142static void periodic_link (struct ohci_hcd *ohci, struct ed *ed)
 143{
 144	unsigned	i;
 145
 146	ohci_dbg(ohci, "link %sed %p branch %d [%dus.], interval %d\n",
 147		(ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 148		ed, ed->branch, ed->load, ed->interval);
 149
 150	for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 151		struct ed	**prev = &ohci->periodic [i];
 152		__hc32		*prev_p = &ohci->hcca->int_table [i];
 153		struct ed	*here = *prev;
 154
 155		/* sorting each branch by period (slow before fast)
 156		 * lets us share the faster parts of the tree.
 157		 * (plus maybe: put interrupt eds before iso)
 158		 */
 159		while (here && ed != here) {
 160			if (ed->interval > here->interval)
 161				break;
 162			prev = &here->ed_next;
 163			prev_p = &here->hwNextED;
 164			here = *prev;
 165		}
 166		if (ed != here) {
 167			ed->ed_next = here;
 168			if (here)
 169				ed->hwNextED = *prev_p;
 170			wmb ();
 171			*prev = ed;
 172			*prev_p = cpu_to_hc32(ohci, ed->dma);
 173			wmb();
 174		}
 175		ohci->load [i] += ed->load;
 176	}
 177	ohci_to_hcd(ohci)->self.bandwidth_allocated += ed->load / ed->interval;
 178}
 179
 180/* link an ed into one of the HC chains */
 181
 182static int ed_schedule (struct ohci_hcd *ohci, struct ed *ed)
 183{
 184	int	branch;
 185
 
 186	ed->ed_prev = NULL;
 187	ed->ed_next = NULL;
 188	ed->hwNextED = 0;
 
 
 
 
 189	wmb ();
 190
 191	/* we care about rm_list when setting CLE/BLE in case the HC was at
 192	 * work on some TD when CLE/BLE was turned off, and isn't quiesced
 193	 * yet.  finish_unlinks() restarts as needed, some upcoming INTR_SF.
 194	 *
 195	 * control and bulk EDs are doubly linked (ed_next, ed_prev), but
 196	 * periodic ones are singly linked (ed_next). that's because the
 197	 * periodic schedule encodes a tree like figure 3-5 in the ohci
 198	 * spec:  each qh can have several "previous" nodes, and the tree
 199	 * doesn't have unused/idle descriptors.
 200	 */
 201	switch (ed->type) {
 202	case PIPE_CONTROL:
 203		if (ohci->ed_controltail == NULL) {
 204			WARN_ON (ohci->hc_control & OHCI_CTRL_CLE);
 205			ohci_writel (ohci, ed->dma,
 206					&ohci->regs->ed_controlhead);
 207		} else {
 208			ohci->ed_controltail->ed_next = ed;
 209			ohci->ed_controltail->hwNextED = cpu_to_hc32 (ohci,
 210								ed->dma);
 211		}
 212		ed->ed_prev = ohci->ed_controltail;
 213		if (!ohci->ed_controltail && !ohci->ed_rm_list) {
 214			wmb();
 215			ohci->hc_control |= OHCI_CTRL_CLE;
 216			ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
 217			ohci_writel (ohci, ohci->hc_control,
 218					&ohci->regs->control);
 219		}
 220		ohci->ed_controltail = ed;
 221		break;
 222
 223	case PIPE_BULK:
 224		if (ohci->ed_bulktail == NULL) {
 225			WARN_ON (ohci->hc_control & OHCI_CTRL_BLE);
 226			ohci_writel (ohci, ed->dma, &ohci->regs->ed_bulkhead);
 227		} else {
 228			ohci->ed_bulktail->ed_next = ed;
 229			ohci->ed_bulktail->hwNextED = cpu_to_hc32 (ohci,
 230								ed->dma);
 231		}
 232		ed->ed_prev = ohci->ed_bulktail;
 233		if (!ohci->ed_bulktail && !ohci->ed_rm_list) {
 234			wmb();
 235			ohci->hc_control |= OHCI_CTRL_BLE;
 236			ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
 237			ohci_writel (ohci, ohci->hc_control,
 238					&ohci->regs->control);
 239		}
 240		ohci->ed_bulktail = ed;
 241		break;
 242
 243	// case PIPE_INTERRUPT:
 244	// case PIPE_ISOCHRONOUS:
 245	default:
 246		branch = balance (ohci, ed->interval, ed->load);
 247		if (branch < 0) {
 248			ohci_dbg (ohci,
 249				"ERR %d, interval %d msecs, load %d\n",
 250				branch, ed->interval, ed->load);
 251			// FIXME if there are TDs queued, fail them!
 252			return branch;
 253		}
 254		ed->branch = branch;
 255		periodic_link (ohci, ed);
 256	}
 257
 258	/* the HC may not see the schedule updates yet, but if it does
 259	 * then they'll be properly ordered.
 260	 */
 261
 262	ed->state = ED_OPER;
 263	return 0;
 264}
 265
 266/*-------------------------------------------------------------------------*/
 267
 268/* scan the periodic table to find and unlink this ED */
 269static void periodic_unlink (struct ohci_hcd *ohci, struct ed *ed)
 270{
 271	int	i;
 272
 273	for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 274		struct ed	*temp;
 275		struct ed	**prev = &ohci->periodic [i];
 276		__hc32		*prev_p = &ohci->hcca->int_table [i];
 277
 278		while (*prev && (temp = *prev) != ed) {
 279			prev_p = &temp->hwNextED;
 280			prev = &temp->ed_next;
 281		}
 282		if (*prev) {
 283			*prev_p = ed->hwNextED;
 284			*prev = ed->ed_next;
 285		}
 286		ohci->load [i] -= ed->load;
 287	}
 288	ohci_to_hcd(ohci)->self.bandwidth_allocated -= ed->load / ed->interval;
 289
 290	ohci_dbg(ohci, "unlink %sed %p branch %d [%dus.], interval %d\n",
 291		(ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 292		ed, ed->branch, ed->load, ed->interval);
 293}
 294
 295/* unlink an ed from one of the HC chains.
 296 * just the link to the ed is unlinked.
 297 * the link from the ed still points to another operational ed or 0
 298 * so the HC can eventually finish the processing of the unlinked ed
 299 * (assuming it already started that, which needn't be true).
 300 *
 301 * ED_UNLINK is a transient state: the HC may still see this ED, but soon
 302 * it won't.  ED_SKIP means the HC will finish its current transaction,
 303 * but won't start anything new.  The TD queue may still grow; device
 304 * drivers don't know about this HCD-internal state.
 305 *
 306 * When the HC can't see the ED, something changes ED_UNLINK to one of:
 307 *
 308 *  - ED_OPER: when there's any request queued, the ED gets rescheduled
 309 *    immediately.  HC should be working on them.
 310 *
 311 *  - ED_IDLE: when there's no TD queue or the HC isn't running.
 
 312 *
 313 * When finish_unlinks() runs later, after SOF interrupt, it will often
 314 * complete one or more URB unlinks before making that state change.
 315 */
 316static void ed_deschedule (struct ohci_hcd *ohci, struct ed *ed)
 317{
 318	ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 319	wmb ();
 320	ed->state = ED_UNLINK;
 321
 322	/* To deschedule something from the control or bulk list, just
 323	 * clear CLE/BLE and wait.  There's no safe way to scrub out list
 324	 * head/current registers until later, and "later" isn't very
 325	 * tightly specified.  Figure 6-5 and Section 6.4.2.2 show how
 326	 * the HC is reading the ED queues (while we modify them).
 327	 *
 328	 * For now, ed_schedule() is "later".  It might be good paranoia
 329	 * to scrub those registers in finish_unlinks(), in case of bugs
 330	 * that make the HC try to use them.
 331	 */
 332	switch (ed->type) {
 333	case PIPE_CONTROL:
 334		/* remove ED from the HC's list: */
 335		if (ed->ed_prev == NULL) {
 336			if (!ed->hwNextED) {
 337				ohci->hc_control &= ~OHCI_CTRL_CLE;
 338				ohci_writel (ohci, ohci->hc_control,
 339						&ohci->regs->control);
 340				// a ohci_readl() later syncs CLE with the HC
 341			} else
 342				ohci_writel (ohci,
 343					hc32_to_cpup (ohci, &ed->hwNextED),
 344					&ohci->regs->ed_controlhead);
 345		} else {
 346			ed->ed_prev->ed_next = ed->ed_next;
 347			ed->ed_prev->hwNextED = ed->hwNextED;
 348		}
 349		/* remove ED from the HCD's list: */
 350		if (ohci->ed_controltail == ed) {
 351			ohci->ed_controltail = ed->ed_prev;
 352			if (ohci->ed_controltail)
 353				ohci->ed_controltail->ed_next = NULL;
 354		} else if (ed->ed_next) {
 355			ed->ed_next->ed_prev = ed->ed_prev;
 356		}
 357		break;
 358
 359	case PIPE_BULK:
 360		/* remove ED from the HC's list: */
 361		if (ed->ed_prev == NULL) {
 362			if (!ed->hwNextED) {
 363				ohci->hc_control &= ~OHCI_CTRL_BLE;
 364				ohci_writel (ohci, ohci->hc_control,
 365						&ohci->regs->control);
 366				// a ohci_readl() later syncs BLE with the HC
 367			} else
 368				ohci_writel (ohci,
 369					hc32_to_cpup (ohci, &ed->hwNextED),
 370					&ohci->regs->ed_bulkhead);
 371		} else {
 372			ed->ed_prev->ed_next = ed->ed_next;
 373			ed->ed_prev->hwNextED = ed->hwNextED;
 374		}
 375		/* remove ED from the HCD's list: */
 376		if (ohci->ed_bulktail == ed) {
 377			ohci->ed_bulktail = ed->ed_prev;
 378			if (ohci->ed_bulktail)
 379				ohci->ed_bulktail->ed_next = NULL;
 380		} else if (ed->ed_next) {
 381			ed->ed_next->ed_prev = ed->ed_prev;
 382		}
 383		break;
 384
 385	// case PIPE_INTERRUPT:
 386	// case PIPE_ISOCHRONOUS:
 387	default:
 388		periodic_unlink (ohci, ed);
 389		break;
 390	}
 391}
 392
 393
 394/*-------------------------------------------------------------------------*/
 395
 396/* get and maybe (re)init an endpoint. init _should_ be done only as part
 397 * of enumeration, usb_set_configuration() or usb_set_interface().
 398 */
 399static struct ed *ed_get (
 400	struct ohci_hcd		*ohci,
 401	struct usb_host_endpoint *ep,
 402	struct usb_device	*udev,
 403	unsigned int		pipe,
 404	int			interval
 405) {
 406	struct ed		*ed;
 407	unsigned long		flags;
 408
 409	spin_lock_irqsave (&ohci->lock, flags);
 410
 411	ed = ep->hcpriv;
 412	if (!ed) {
 413		struct td	*td;
 414		int		is_out;
 415		u32		info;
 416
 417		ed = ed_alloc (ohci, GFP_ATOMIC);
 418		if (!ed) {
 419			/* out of memory */
 420			goto done;
 421		}
 422
 423		/* dummy td; end of td list for ed */
 424		td = td_alloc (ohci, GFP_ATOMIC);
 425		if (!td) {
 426			/* out of memory */
 427			ed_free (ohci, ed);
 428			ed = NULL;
 429			goto done;
 430		}
 431		ed->dummy = td;
 432		ed->hwTailP = cpu_to_hc32 (ohci, td->td_dma);
 433		ed->hwHeadP = ed->hwTailP;	/* ED_C, ED_H zeroed */
 434		ed->state = ED_IDLE;
 435
 436		is_out = !(ep->desc.bEndpointAddress & USB_DIR_IN);
 437
 438		/* FIXME usbcore changes dev->devnum before SET_ADDRESS
 439		 * succeeds ... otherwise we wouldn't need "pipe".
 440		 */
 441		info = usb_pipedevice (pipe);
 442		ed->type = usb_pipetype(pipe);
 443
 444		info |= (ep->desc.bEndpointAddress & ~USB_DIR_IN) << 7;
 445		info |= usb_endpoint_maxp(&ep->desc) << 16;
 446		if (udev->speed == USB_SPEED_LOW)
 447			info |= ED_LOWSPEED;
 448		/* only control transfers store pids in tds */
 449		if (ed->type != PIPE_CONTROL) {
 450			info |= is_out ? ED_OUT : ED_IN;
 451			if (ed->type != PIPE_BULK) {
 452				/* periodic transfers... */
 453				if (ed->type == PIPE_ISOCHRONOUS)
 454					info |= ED_ISO;
 455				else if (interval > 32)	/* iso can be bigger */
 456					interval = 32;
 457				ed->interval = interval;
 458				ed->load = usb_calc_bus_time (
 459					udev->speed, !is_out,
 460					ed->type == PIPE_ISOCHRONOUS,
 461					usb_endpoint_maxp(&ep->desc))
 462						/ 1000;
 463			}
 464		}
 465		ed->hwINFO = cpu_to_hc32(ohci, info);
 466
 467		ep->hcpriv = ed;
 468	}
 469
 470done:
 471	spin_unlock_irqrestore (&ohci->lock, flags);
 472	return ed;
 473}
 474
 475/*-------------------------------------------------------------------------*/
 476
 477/* request unlinking of an endpoint from an operational HC.
 478 * put the ep on the rm_list
 479 * real work is done at the next start frame (SF) hardware interrupt
 480 * caller guarantees HCD is running, so hardware access is safe,
 481 * and that ed->state is ED_OPER
 482 */
 483static void start_ed_unlink (struct ohci_hcd *ohci, struct ed *ed)
 484{
 485	ed->hwINFO |= cpu_to_hc32 (ohci, ED_DEQUEUE);
 486	ed_deschedule (ohci, ed);
 487
 488	/* rm_list is just singly linked, for simplicity */
 489	ed->ed_next = ohci->ed_rm_list;
 490	ed->ed_prev = NULL;
 491	ohci->ed_rm_list = ed;
 492
 493	/* enable SOF interrupt */
 494	ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
 495	ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
 496	// flush those writes, and get latest HCCA contents
 497	(void) ohci_readl (ohci, &ohci->regs->control);
 498
 499	/* SF interrupt might get delayed; record the frame counter value that
 500	 * indicates when the HC isn't looking at it, so concurrent unlinks
 501	 * behave.  frame_no wraps every 2^16 msec, and changes right before
 502	 * SF is triggered.
 503	 */
 504	ed->tick = ohci_frame_no(ohci) + 1;
 505
 506}
 507
 508/*-------------------------------------------------------------------------*
 509 * TD handling functions
 510 *-------------------------------------------------------------------------*/
 511
 512/* enqueue next TD for this URB (OHCI spec 5.2.8.2) */
 513
 514static void
 515td_fill (struct ohci_hcd *ohci, u32 info,
 516	dma_addr_t data, int len,
 517	struct urb *urb, int index)
 518{
 519	struct td		*td, *td_pt;
 520	struct urb_priv		*urb_priv = urb->hcpriv;
 521	int			is_iso = info & TD_ISO;
 522	int			hash;
 523
 524	// ASSERT (index < urb_priv->length);
 525
 526	/* aim for only one interrupt per urb.  mostly applies to control
 527	 * and iso; other urbs rarely need more than one TD per urb.
 528	 * this way, only final tds (or ones with an error) cause IRQs.
 529	 * at least immediately; use DI=6 in case any control request is
 530	 * tempted to die part way through.  (and to force the hc to flush
 531	 * its donelist soonish, even on unlink paths.)
 532	 *
 533	 * NOTE: could delay interrupts even for the last TD, and get fewer
 534	 * interrupts ... increasing per-urb latency by sharing interrupts.
 535	 * Drivers that queue bulk urbs may request that behavior.
 536	 */
 537	if (index != (urb_priv->length - 1)
 538			|| (urb->transfer_flags & URB_NO_INTERRUPT))
 539		info |= TD_DI_SET (6);
 540
 541	/* use this td as the next dummy */
 542	td_pt = urb_priv->td [index];
 543
 544	/* fill the old dummy TD */
 545	td = urb_priv->td [index] = urb_priv->ed->dummy;
 546	urb_priv->ed->dummy = td_pt;
 547
 548	td->ed = urb_priv->ed;
 549	td->next_dl_td = NULL;
 550	td->index = index;
 551	td->urb = urb;
 552	td->data_dma = data;
 553	if (!len)
 554		data = 0;
 555
 556	td->hwINFO = cpu_to_hc32 (ohci, info);
 557	if (is_iso) {
 558		td->hwCBP = cpu_to_hc32 (ohci, data & 0xFFFFF000);
 559		*ohci_hwPSWp(ohci, td, 0) = cpu_to_hc16 (ohci,
 560						(data & 0x0FFF) | 0xE000);
 
 561	} else {
 562		td->hwCBP = cpu_to_hc32 (ohci, data);
 563	}
 564	if (data)
 565		td->hwBE = cpu_to_hc32 (ohci, data + len - 1);
 566	else
 567		td->hwBE = 0;
 568	td->hwNextTD = cpu_to_hc32 (ohci, td_pt->td_dma);
 569
 570	/* append to queue */
 571	list_add_tail (&td->td_list, &td->ed->td_list);
 572
 573	/* hash it for later reverse mapping */
 574	hash = TD_HASH_FUNC (td->td_dma);
 575	td->td_hash = ohci->td_hash [hash];
 576	ohci->td_hash [hash] = td;
 577
 578	/* HC might read the TD (or cachelines) right away ... */
 579	wmb ();
 580	td->ed->hwTailP = td->hwNextTD;
 581}
 582
 583/*-------------------------------------------------------------------------*/
 584
 585/* Prepare all TDs of a transfer, and queue them onto the ED.
 586 * Caller guarantees HC is active.
 587 * Usually the ED is already on the schedule, so TDs might be
 588 * processed as soon as they're queued.
 589 */
 590static void td_submit_urb (
 591	struct ohci_hcd	*ohci,
 592	struct urb	*urb
 593) {
 594	struct urb_priv	*urb_priv = urb->hcpriv;
 595	struct device *dev = ohci_to_hcd(ohci)->self.controller;
 596	dma_addr_t	data;
 597	int		data_len = urb->transfer_buffer_length;
 598	int		cnt = 0;
 599	u32		info = 0;
 600	int		is_out = usb_pipeout (urb->pipe);
 601	int		periodic = 0;
 602	int		i, this_sg_len, n;
 603	struct scatterlist	*sg;
 604
 605	/* OHCI handles the bulk/interrupt data toggles itself.  We just
 606	 * use the device toggle bits for resetting, and rely on the fact
 607	 * that resetting toggle is meaningless if the endpoint is active.
 608	 */
 609	if (!usb_gettoggle (urb->dev, usb_pipeendpoint (urb->pipe), is_out)) {
 610		usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe),
 611			is_out, 1);
 612		urb_priv->ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_C);
 613	}
 614
 
 615	list_add (&urb_priv->pending, &ohci->pending);
 616
 617	i = urb->num_mapped_sgs;
 618	if (data_len > 0 && i > 0) {
 619		sg = urb->sg;
 620		data = sg_dma_address(sg);
 621
 622		/*
 623		 * urb->transfer_buffer_length may be smaller than the
 624		 * size of the scatterlist (or vice versa)
 625		 */
 626		this_sg_len = min_t(int, sg_dma_len(sg), data_len);
 627	} else {
 628		sg = NULL;
 629		if (data_len)
 630			data = urb->transfer_dma;
 631		else
 632			data = 0;
 633		this_sg_len = data_len;
 634	}
 635
 636	/* NOTE:  TD_CC is set so we can tell which TDs the HC processed by
 637	 * using TD_CC_GET, as well as by seeing them on the done list.
 638	 * (CC = NotAccessed ... 0x0F, or 0x0E in PSWs for ISO.)
 639	 */
 640	switch (urb_priv->ed->type) {
 641
 642	/* Bulk and interrupt are identical except for where in the schedule
 643	 * their EDs live.
 644	 */
 645	case PIPE_INTERRUPT:
 646		/* ... and periodic urbs have extra accounting */
 647		periodic = ohci_to_hcd(ohci)->self.bandwidth_int_reqs++ == 0
 648			&& ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0;
 649		/* FALLTHROUGH */
 650	case PIPE_BULK:
 651		info = is_out
 652			? TD_T_TOGGLE | TD_CC | TD_DP_OUT
 653			: TD_T_TOGGLE | TD_CC | TD_DP_IN;
 654		/* TDs _could_ transfer up to 8K each */
 655		for (;;) {
 656			n = min(this_sg_len, 4096);
 657
 658			/* maybe avoid ED halt on final TD short read */
 659			if (n >= data_len || (i == 1 && n >= this_sg_len)) {
 660				if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
 661					info |= TD_R;
 662			}
 663			td_fill(ohci, info, data, n, urb, cnt);
 664			this_sg_len -= n;
 665			data_len -= n;
 666			data += n;
 667			cnt++;
 668
 669			if (this_sg_len <= 0) {
 670				if (--i <= 0 || data_len <= 0)
 671					break;
 672				sg = sg_next(sg);
 673				data = sg_dma_address(sg);
 674				this_sg_len = min_t(int, sg_dma_len(sg),
 675						data_len);
 676			}
 677		}
 
 
 
 
 
 678		if ((urb->transfer_flags & URB_ZERO_PACKET)
 679				&& cnt < urb_priv->length) {
 680			td_fill (ohci, info, 0, 0, urb, cnt);
 681			cnt++;
 682		}
 683		/* maybe kickstart bulk list */
 684		if (urb_priv->ed->type == PIPE_BULK) {
 685			wmb ();
 686			ohci_writel (ohci, OHCI_BLF, &ohci->regs->cmdstatus);
 687		}
 688		break;
 689
 690	/* control manages DATA0/DATA1 toggle per-request; SETUP resets it,
 691	 * any DATA phase works normally, and the STATUS ack is special.
 692	 */
 693	case PIPE_CONTROL:
 694		info = TD_CC | TD_DP_SETUP | TD_T_DATA0;
 695		td_fill (ohci, info, urb->setup_dma, 8, urb, cnt++);
 696		if (data_len > 0) {
 697			info = TD_CC | TD_R | TD_T_DATA1;
 698			info |= is_out ? TD_DP_OUT : TD_DP_IN;
 699			/* NOTE:  mishandles transfers >8K, some >4K */
 700			td_fill (ohci, info, data, data_len, urb, cnt++);
 701		}
 702		info = (is_out || data_len == 0)
 703			? TD_CC | TD_DP_IN | TD_T_DATA1
 704			: TD_CC | TD_DP_OUT | TD_T_DATA1;
 705		td_fill (ohci, info, data, 0, urb, cnt++);
 706		/* maybe kickstart control list */
 707		wmb ();
 708		ohci_writel (ohci, OHCI_CLF, &ohci->regs->cmdstatus);
 709		break;
 710
 711	/* ISO has no retransmit, so no toggle; and it uses special TDs.
 712	 * Each TD could handle multiple consecutive frames (interval 1);
 713	 * we could often reduce the number of TDs here.
 714	 */
 715	case PIPE_ISOCHRONOUS:
 716		for (cnt = urb_priv->td_cnt; cnt < urb->number_of_packets;
 717				cnt++) {
 718			int	frame = urb->start_frame;
 719
 720			// FIXME scheduling should handle frame counter
 721			// roll-around ... exotic case (and OHCI has
 722			// a 2^16 iso range, vs other HCs max of 2^10)
 723			frame += cnt * urb->interval;
 724			frame &= 0xffff;
 725			td_fill (ohci, TD_CC | TD_ISO | frame,
 726				data + urb->iso_frame_desc [cnt].offset,
 727				urb->iso_frame_desc [cnt].length, urb, cnt);
 728		}
 729		if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0) {
 730			if (quirk_amdiso(ohci))
 731				usb_amd_quirk_pll_disable();
 732			if (quirk_amdprefetch(ohci))
 733				sb800_prefetch(dev, 1);
 734		}
 735		periodic = ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs++ == 0
 736			&& ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0;
 737		break;
 738	}
 739
 740	/* start periodic dma if needed */
 741	if (periodic) {
 742		wmb ();
 743		ohci->hc_control |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
 744		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 745	}
 746
 747	// ASSERT (urb_priv->length == cnt);
 748}
 749
 750/*-------------------------------------------------------------------------*
 751 * Done List handling functions
 752 *-------------------------------------------------------------------------*/
 753
 754/* calculate transfer length/status and update the urb */
 755static int td_done(struct ohci_hcd *ohci, struct urb *urb, struct td *td)
 756{
 757	u32	tdINFO = hc32_to_cpup (ohci, &td->hwINFO);
 758	int	cc = 0;
 759	int	status = -EINPROGRESS;
 760
 761	list_del (&td->td_list);
 762
 763	/* ISO ... drivers see per-TD length/status */
 764	if (tdINFO & TD_ISO) {
 765		u16	tdPSW = ohci_hwPSW(ohci, td, 0);
 766		int	dlen = 0;
 767
 768		/* NOTE:  assumes FC in tdINFO == 0, and that
 769		 * only the first of 0..MAXPSW psws is used.
 770		 */
 771
 772		cc = (tdPSW >> 12) & 0xF;
 773		if (tdINFO & TD_CC)	/* hc didn't touch? */
 774			return status;
 775
 776		if (usb_pipeout (urb->pipe))
 777			dlen = urb->iso_frame_desc [td->index].length;
 778		else {
 779			/* short reads are always OK for ISO */
 780			if (cc == TD_DATAUNDERRUN)
 781				cc = TD_CC_NOERROR;
 782			dlen = tdPSW & 0x3ff;
 783		}
 784		urb->actual_length += dlen;
 785		urb->iso_frame_desc [td->index].actual_length = dlen;
 786		urb->iso_frame_desc [td->index].status = cc_to_error [cc];
 787
 788		if (cc != TD_CC_NOERROR)
 789			ohci_dbg(ohci,
 790				"urb %p iso td %p (%d) len %d cc %d\n",
 791				urb, td, 1 + td->index, dlen, cc);
 792
 793	/* BULK, INT, CONTROL ... drivers see aggregate length/status,
 794	 * except that "setup" bytes aren't counted and "short" transfers
 795	 * might not be reported as errors.
 796	 */
 797	} else {
 798		int	type = usb_pipetype (urb->pipe);
 799		u32	tdBE = hc32_to_cpup (ohci, &td->hwBE);
 800
 801		cc = TD_CC_GET (tdINFO);
 802
 803		/* update packet status if needed (short is normally ok) */
 804		if (cc == TD_DATAUNDERRUN
 805				&& !(urb->transfer_flags & URB_SHORT_NOT_OK))
 806			cc = TD_CC_NOERROR;
 807		if (cc != TD_CC_NOERROR && cc < 0x0E)
 808			status = cc_to_error[cc];
 809
 810		/* count all non-empty packets except control SETUP packet */
 811		if ((type != PIPE_CONTROL || td->index != 0) && tdBE != 0) {
 812			if (td->hwCBP == 0)
 813				urb->actual_length += tdBE - td->data_dma + 1;
 814			else
 815				urb->actual_length +=
 816					  hc32_to_cpup (ohci, &td->hwCBP)
 817					- td->data_dma;
 818		}
 819
 820		if (cc != TD_CC_NOERROR && cc < 0x0E)
 821			ohci_dbg(ohci,
 822				"urb %p td %p (%d) cc %d, len=%d/%d\n",
 823				urb, td, 1 + td->index, cc,
 824				urb->actual_length,
 825				urb->transfer_buffer_length);
 826	}
 827	return status;
 828}
 829
 830/*-------------------------------------------------------------------------*/
 831
 832static void ed_halted(struct ohci_hcd *ohci, struct td *td, int cc)
 833{
 834	struct urb		*urb = td->urb;
 835	urb_priv_t		*urb_priv = urb->hcpriv;
 836	struct ed		*ed = td->ed;
 837	struct list_head	*tmp = td->td_list.next;
 838	__hc32			toggle = ed->hwHeadP & cpu_to_hc32 (ohci, ED_C);
 839
 840	/* clear ed halt; this is the td that caused it, but keep it inactive
 841	 * until its urb->complete() has a chance to clean up.
 842	 */
 843	ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 844	wmb ();
 845	ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_H);
 846
 847	/* Get rid of all later tds from this urb.  We don't have
 848	 * to be careful: no errors and nothing was transferred.
 849	 * Also patch the ed so it looks as if those tds completed normally.
 850	 */
 851	while (tmp != &ed->td_list) {
 852		struct td	*next;
 853
 854		next = list_entry (tmp, struct td, td_list);
 855		tmp = next->td_list.next;
 856
 857		if (next->urb != urb)
 858			break;
 859
 860		/* NOTE: if multi-td control DATA segments get supported,
 861		 * this urb had one of them, this td wasn't the last td
 862		 * in that segment (TD_R clear), this ed halted because
 863		 * of a short read, _and_ URB_SHORT_NOT_OK is clear ...
 864		 * then we need to leave the control STATUS packet queued
 865		 * and clear ED_SKIP.
 866		 */
 867
 868		list_del(&next->td_list);
 869		urb_priv->td_cnt++;
 870		ed->hwHeadP = next->hwNextTD | toggle;
 871	}
 872
 873	/* help for troubleshooting:  report anything that
 874	 * looks odd ... that doesn't include protocol stalls
 875	 * (or maybe some other things)
 876	 */
 877	switch (cc) {
 878	case TD_DATAUNDERRUN:
 879		if ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0)
 880			break;
 881		/* fallthrough */
 882	case TD_CC_STALL:
 883		if (usb_pipecontrol (urb->pipe))
 884			break;
 885		/* fallthrough */
 886	default:
 887		ohci_dbg (ohci,
 888			"urb %p path %s ep%d%s %08x cc %d --> status %d\n",
 889			urb, urb->dev->devpath,
 890			usb_pipeendpoint (urb->pipe),
 891			usb_pipein (urb->pipe) ? "in" : "out",
 892			hc32_to_cpu (ohci, td->hwINFO),
 893			cc, cc_to_error [cc]);
 894	}
 895}
 896
 897/* Add a TD to the done list */
 898static void add_to_done_list(struct ohci_hcd *ohci, struct td *td)
 899{
 900	struct td	*td2, *td_prev;
 901	struct ed	*ed;
 902
 903	if (td->next_dl_td)
 904		return;		/* Already on the list */
 905
 906	/* Add all the TDs going back until we reach one that's on the list */
 907	ed = td->ed;
 908	td2 = td_prev = td;
 909	list_for_each_entry_continue_reverse(td2, &ed->td_list, td_list) {
 910		if (td2->next_dl_td)
 911			break;
 912		td2->next_dl_td = td_prev;
 913		td_prev = td2;
 914	}
 915
 916	if (ohci->dl_end)
 917		ohci->dl_end->next_dl_td = td_prev;
 918	else
 919		ohci->dl_start = td_prev;
 920
 921	/*
 922	 * Make td->next_dl_td point to td itself, to mark the fact
 923	 * that td is on the done list.
 924	 */
 925	ohci->dl_end = td->next_dl_td = td;
 926
 927	/* Did we just add the latest pending TD? */
 928	td2 = ed->pending_td;
 929	if (td2 && td2->next_dl_td)
 930		ed->pending_td = NULL;
 931}
 932
 933/* Get the entries on the hardware done queue and put them on our list */
 934static void update_done_list(struct ohci_hcd *ohci)
 935{
 936	u32		td_dma;
 
 937	struct td	*td = NULL;
 938
 939	td_dma = hc32_to_cpup (ohci, &ohci->hcca->done_head);
 940	ohci->hcca->done_head = 0;
 941	wmb();
 942
 943	/* get TD from hc's singly linked list, and
 944	 * add to ours.  ed->td_list changes later.
 945	 */
 946	while (td_dma) {
 947		int		cc;
 948
 949		td = dma_to_td (ohci, td_dma);
 950		if (!td) {
 951			ohci_err (ohci, "bad entry %8x\n", td_dma);
 952			break;
 953		}
 954
 955		td->hwINFO |= cpu_to_hc32 (ohci, TD_DONE);
 956		cc = TD_CC_GET (hc32_to_cpup (ohci, &td->hwINFO));
 957
 958		/* Non-iso endpoints can halt on error; un-halt,
 959		 * and dequeue any other TDs from this urb.
 960		 * No other TD could have caused the halt.
 961		 */
 962		if (cc != TD_CC_NOERROR
 963				&& (td->ed->hwHeadP & cpu_to_hc32 (ohci, ED_H)))
 964			ed_halted(ohci, td, cc);
 965
 
 
 966		td_dma = hc32_to_cpup (ohci, &td->hwNextTD);
 967		add_to_done_list(ohci, td);
 968	}
 
 969}
 970
 971/*-------------------------------------------------------------------------*/
 972
 973/* there are some urbs/eds to unlink; called in_irq(), with HCD locked */
 974static void finish_unlinks(struct ohci_hcd *ohci)
 
 975{
 976	unsigned	tick = ohci_frame_no(ohci);
 977	struct ed	*ed, **last;
 978
 979rescan_all:
 980	for (last = &ohci->ed_rm_list, ed = *last; ed != NULL; ed = *last) {
 981		struct list_head	*entry, *tmp;
 982		int			completed, modified;
 983		__hc32			*prev;
 984
 985		/* only take off EDs that the HC isn't using, accounting for
 986		 * frame counter wraps and EDs with partially retired TDs
 987		 */
 988		if (likely(ohci->rh_state == OHCI_RH_RUNNING) &&
 989				tick_before(tick, ed->tick)) {
 990skip_ed:
 991			last = &ed->ed_next;
 992			continue;
 993		}
 994		if (!list_empty(&ed->td_list)) {
 995			struct td	*td;
 996			u32		head;
 997
 998			td = list_first_entry(&ed->td_list, struct td, td_list);
 999
1000			/* INTR_WDH may need to clean up first */
1001			head = hc32_to_cpu(ohci, ed->hwHeadP) & TD_MASK;
1002			if (td->td_dma != head &&
1003					ohci->rh_state == OHCI_RH_RUNNING)
1004				goto skip_ed;
1005
1006			/* Don't mess up anything already on the done list */
1007			if (td->next_dl_td)
1008				goto skip_ed;
 
 
 
 
 
 
1009		}
1010
1011		/* ED's now officially unlinked, hc doesn't see */
1012		ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_H);
1013		ed->hwNextED = 0;
1014		wmb();
1015		ed->hwINFO &= ~cpu_to_hc32(ohci, ED_SKIP | ED_DEQUEUE);
1016
1017		/* reentrancy:  if we drop the schedule lock, someone might
1018		 * have modified this list.  normally it's just prepending
1019		 * entries (which we'd ignore), but paranoia won't hurt.
1020		 */
 
 
1021		modified = 0;
1022
1023		/* unlink urbs as requested, but rescan the list after
1024		 * we call a completion since it might have unlinked
1025		 * another (earlier) urb
1026		 *
1027		 * When we get here, the HC doesn't see this ed.  But it
1028		 * must not be rescheduled until all completed URBs have
1029		 * been given back to the driver.
1030		 */
1031rescan_this:
1032		completed = 0;
1033		prev = &ed->hwHeadP;
1034		list_for_each_safe (entry, tmp, &ed->td_list) {
1035			struct td	*td;
1036			struct urb	*urb;
1037			urb_priv_t	*urb_priv;
1038			__hc32		savebits;
1039			u32		tdINFO;
1040
1041			td = list_entry (entry, struct td, td_list);
1042			urb = td->urb;
1043			urb_priv = td->urb->hcpriv;
1044
1045			if (!urb->unlinked) {
1046				prev = &td->hwNextTD;
1047				continue;
1048			}
1049
1050			/* patch pointer hc uses */
1051			savebits = *prev & ~cpu_to_hc32 (ohci, TD_MASK);
1052			*prev = td->hwNextTD | savebits;
1053
1054			/* If this was unlinked, the TD may not have been
1055			 * retired ... so manually save the data toggle.
1056			 * The controller ignores the value we save for
1057			 * control and ISO endpoints.
1058			 */
1059			tdINFO = hc32_to_cpup(ohci, &td->hwINFO);
1060			if ((tdINFO & TD_T) == TD_T_DATA0)
1061				ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_C);
1062			else if ((tdINFO & TD_T) == TD_T_DATA1)
1063				ed->hwHeadP |= cpu_to_hc32(ohci, ED_C);
1064
1065			/* HC may have partly processed this TD */
1066			td_done (ohci, urb, td);
1067			urb_priv->td_cnt++;
1068
1069			/* if URB is done, clean up */
1070			if (urb_priv->td_cnt >= urb_priv->length) {
1071				modified = completed = 1;
1072				finish_urb(ohci, urb, 0);
1073			}
1074		}
1075		if (completed && !list_empty (&ed->td_list))
1076			goto rescan_this;
1077
1078		/*
1079		 * If no TDs are queued, take ED off the ed_rm_list.
1080		 * Otherwise, if the HC is running, reschedule.
1081		 * If not, leave it on the list for further dequeues.
1082		 */
1083		if (list_empty(&ed->td_list)) {
1084			*last = ed->ed_next;
1085			ed->ed_next = NULL;
1086			ed->state = ED_IDLE;
1087			list_del(&ed->in_use_list);
1088		} else if (ohci->rh_state == OHCI_RH_RUNNING) {
1089			*last = ed->ed_next;
1090			ed->ed_next = NULL;
1091			ed_schedule(ohci, ed);
1092		} else {
1093			last = &ed->ed_next;
1094		}
1095
1096		if (modified)
1097			goto rescan_all;
1098	}
1099
1100	/* maybe reenable control and bulk lists */
1101	if (ohci->rh_state == OHCI_RH_RUNNING && !ohci->ed_rm_list) {
 
 
1102		u32	command = 0, control = 0;
1103
1104		if (ohci->ed_controltail) {
1105			command |= OHCI_CLF;
1106			if (quirk_zfmicro(ohci))
1107				mdelay(1);
1108			if (!(ohci->hc_control & OHCI_CTRL_CLE)) {
1109				control |= OHCI_CTRL_CLE;
1110				ohci_writel (ohci, 0,
1111					&ohci->regs->ed_controlcurrent);
1112			}
1113		}
1114		if (ohci->ed_bulktail) {
1115			command |= OHCI_BLF;
1116			if (quirk_zfmicro(ohci))
1117				mdelay(1);
1118			if (!(ohci->hc_control & OHCI_CTRL_BLE)) {
1119				control |= OHCI_CTRL_BLE;
1120				ohci_writel (ohci, 0,
1121					&ohci->regs->ed_bulkcurrent);
1122			}
1123		}
1124
1125		/* CLE/BLE to enable, CLF/BLF to (maybe) kickstart */
1126		if (control) {
1127			ohci->hc_control |= control;
1128			if (quirk_zfmicro(ohci))
1129				mdelay(1);
1130			ohci_writel (ohci, ohci->hc_control,
1131					&ohci->regs->control);
1132		}
1133		if (command) {
1134			if (quirk_zfmicro(ohci))
1135				mdelay(1);
1136			ohci_writel (ohci, command, &ohci->regs->cmdstatus);
1137		}
1138	}
1139}
1140
1141
1142
1143/*-------------------------------------------------------------------------*/
1144
1145/* Take back a TD from the host controller */
 
 
 
 
 
1146static void takeback_td(struct ohci_hcd *ohci, struct td *td)
1147{
1148	struct urb	*urb = td->urb;
1149	urb_priv_t	*urb_priv = urb->hcpriv;
1150	struct ed	*ed = td->ed;
1151	int		status;
1152
1153	/* update URB's length and status from TD */
1154	status = td_done(ohci, urb, td);
1155	urb_priv->td_cnt++;
1156
1157	/* If all this urb's TDs are done, call complete() */
1158	if (urb_priv->td_cnt >= urb_priv->length)
1159		finish_urb(ohci, urb, status);
1160
1161	/* clean schedule:  unlink EDs that are no longer busy */
1162	if (list_empty(&ed->td_list)) {
1163		if (ed->state == ED_OPER)
1164			start_ed_unlink(ohci, ed);
1165
1166	/* ... reenabling halted EDs only after fault cleanup */
1167	} else if ((ed->hwINFO & cpu_to_hc32(ohci, ED_SKIP | ED_DEQUEUE))
1168			== cpu_to_hc32(ohci, ED_SKIP)) {
1169		td = list_entry(ed->td_list.next, struct td, td_list);
1170		if (!(td->hwINFO & cpu_to_hc32(ohci, TD_DONE))) {
1171			ed->hwINFO &= ~cpu_to_hc32(ohci, ED_SKIP);
1172			/* ... hc may need waking-up */
1173			switch (ed->type) {
1174			case PIPE_CONTROL:
1175				ohci_writel(ohci, OHCI_CLF,
1176						&ohci->regs->cmdstatus);
1177				break;
1178			case PIPE_BULK:
1179				ohci_writel(ohci, OHCI_BLF,
1180						&ohci->regs->cmdstatus);
1181				break;
1182			}
1183		}
1184	}
1185}
1186
1187/*
1188 * Process normal completions (error or success) and clean the schedules.
1189 *
1190 * This is the main path for handing urbs back to drivers.  The only other
1191 * normal path is finish_unlinks(), which unlinks URBs using ed_rm_list,
1192 * instead of scanning the (re-reversed) donelist as this does.
 
 
1193 */
1194static void process_done_list(struct ohci_hcd *ohci)
 
1195{
1196	struct td	*td;
1197
1198	while (ohci->dl_start) {
1199		td = ohci->dl_start;
1200		if (td == ohci->dl_end)
1201			ohci->dl_start = ohci->dl_end = NULL;
1202		else
1203			ohci->dl_start = td->next_dl_td;
1204
 
 
1205		takeback_td(ohci, td);
 
1206	}
1207}
1208
1209/*
1210 * TD takeback and URB giveback must be single-threaded.
1211 * This routine takes care of it all.
1212 */
1213static void ohci_work(struct ohci_hcd *ohci)
1214{
1215	if (ohci->working) {
1216		ohci->restart_work = 1;
1217		return;
1218	}
1219	ohci->working = 1;
1220
1221 restart:
1222	process_done_list(ohci);
1223	if (ohci->ed_rm_list)
1224		finish_unlinks(ohci);
1225
1226	if (ohci->restart_work) {
1227		ohci->restart_work = 0;
1228		goto restart;
1229	}
1230	ohci->working = 0;
1231}