xref: /openbmc/linux/drivers/usb/host/ohci-hcd.c (revision 87c2ce3b)
1 /*
2  * OHCI HCD (Host Controller Driver) for USB.
3  *
4  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
5  * (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
6  *
7  * [ Initialisation is based on Linus'  ]
8  * [ uhci code and gregs ohci fragments ]
9  * [ (C) Copyright 1999 Linus Torvalds  ]
10  * [ (C) Copyright 1999 Gregory P. Smith]
11  *
12  *
13  * OHCI is the main "non-Intel/VIA" standard for USB 1.1 host controller
14  * interfaces (though some non-x86 Intel chips use it).  It supports
15  * smarter hardware than UHCI.  A download link for the spec available
16  * through the http://www.usb.org website.
17  *
18  * History:
19  *
20  * 2004/03/24 LH7A404 support (Durgesh Pattamatta & Marc Singer)
21  * 2004/02/04 use generic dma_* functions instead of pci_* (dsaxena@plexity.net)
22  * 2003/02/24 show registers in sysfs (Kevin Brosius)
23  *
24  * 2002/09/03 get rid of ed hashtables, rework periodic scheduling and
25  * 	bandwidth accounting; if debugging, show schedules in driverfs
26  * 2002/07/19 fixes to management of ED and schedule state.
27  * 2002/06/09 SA-1111 support (Christopher Hoover)
28  * 2002/06/01 remember frame when HC won't see EDs any more; use that info
29  *	to fix urb unlink races caused by interrupt latency assumptions;
30  *	minor ED field and function naming updates
31  * 2002/01/18 package as a patch for 2.5.3; this should match the
32  *	2.4.17 kernel modulo some bugs being fixed.
33  *
34  * 2001/10/18 merge pmac cleanup (Benjamin Herrenschmidt) and bugfixes
35  *	from post-2.4.5 patches.
36  * 2001/09/20 URB_ZERO_PACKET support; hcca_dma portability, OPTi warning
37  * 2001/09/07 match PCI PM changes, errnos from Linus' tree
38  * 2001/05/05 fork 2.4.5 version into "hcd" framework, cleanup, simplify;
39  *	pbook pci quirks gone (please fix pbook pci sw!) (db)
40  *
41  * 2001/04/08 Identify version on module load (gb)
42  * 2001/03/24 td/ed hashing to remove bus_to_virt (Steve Longerbeam);
43  	pci_map_single (db)
44  * 2001/03/21 td and dev/ed allocation uses new pci_pool API (db)
45  * 2001/03/07 hcca allocation uses pci_alloc_consistent (Steve Longerbeam)
46  *
47  * 2000/09/26 fixed races in removing the private portion of the urb
48  * 2000/09/07 disable bulk and control lists when unlinking the last
49  *	endpoint descriptor in order to avoid unrecoverable errors on
50  *	the Lucent chips. (rwc@sgi)
51  * 2000/08/29 use bandwidth claiming hooks (thanks Randy!), fix some
52  *	urb unlink probs, indentation fixes
53  * 2000/08/11 various oops fixes mostly affecting iso and cleanup from
54  *	device unplugs.
55  * 2000/06/28 use PCI hotplug framework, for better power management
56  *	and for Cardbus support (David Brownell)
57  * 2000/earlier:  fixes for NEC/Lucent chips; suspend/resume handling
58  *	when the controller loses power; handle UE; cleanup; ...
59  *
60  * v5.2 1999/12/07 URB 3rd preview,
61  * v5.1 1999/11/30 URB 2nd preview, cpia, (usb-scsi)
62  * v5.0 1999/11/22 URB Technical preview, Paul Mackerras powerbook susp/resume
63  * 	i386: HUB, Keyboard, Mouse, Printer
64  *
65  * v4.3 1999/10/27 multiple HCs, bulk_request
66  * v4.2 1999/09/05 ISO API alpha, new dev alloc, neg Error-codes
67  * v4.1 1999/08/27 Randy Dunlap's - ISO API first impl.
68  * v4.0 1999/08/18
69  * v3.0 1999/06/25
70  * v2.1 1999/05/09  code clean up
71  * v2.0 1999/05/04
72  * v1.0 1999/04/27 initial release
73  *
74  * This file is licenced under the GPL.
75  */
76 
77 #include <linux/config.h>
78 #include <linux/module.h>
79 #include <linux/moduleparam.h>
80 #include <linux/pci.h>
81 #include <linux/kernel.h>
82 #include <linux/delay.h>
83 #include <linux/ioport.h>
84 #include <linux/sched.h>
85 #include <linux/slab.h>
86 #include <linux/smp_lock.h>
87 #include <linux/errno.h>
88 #include <linux/init.h>
89 #include <linux/timer.h>
90 #include <linux/list.h>
91 #include <linux/usb.h>
92 #include <linux/usb_otg.h>
93 #include <linux/dma-mapping.h>
94 #include <linux/dmapool.h>
95 #include <linux/reboot.h>
96 
97 #include <asm/io.h>
98 #include <asm/irq.h>
99 #include <asm/system.h>
100 #include <asm/unaligned.h>
101 #include <asm/byteorder.h>
102 
103 #include "../core/hcd.h"
104 
105 #define DRIVER_VERSION "2005 April 22"
106 #define DRIVER_AUTHOR "Roman Weissgaerber, David Brownell"
107 #define DRIVER_DESC "USB 1.1 'Open' Host Controller (OHCI) Driver"
108 
109 /*-------------------------------------------------------------------------*/
110 
111 #undef OHCI_VERBOSE_DEBUG	/* not always helpful */
112 
113 /* For initializing controller (mask in an HCFS mode too) */
114 #define	OHCI_CONTROL_INIT 	OHCI_CTRL_CBSR
115 #define	OHCI_INTR_INIT \
116 	(OHCI_INTR_MIE | OHCI_INTR_UE | OHCI_INTR_RD | OHCI_INTR_WDH)
117 
118 #ifdef __hppa__
119 /* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
120 #define	IR_DISABLE
121 #endif
122 
123 #ifdef CONFIG_ARCH_OMAP
124 /* OMAP doesn't support IR (no SMM; not needed) */
125 #define	IR_DISABLE
126 #endif
127 
128 /*-------------------------------------------------------------------------*/
129 
130 static const char	hcd_name [] = "ohci_hcd";
131 
132 #include "ohci.h"
133 
134 static void ohci_dump (struct ohci_hcd *ohci, int verbose);
135 static int ohci_init (struct ohci_hcd *ohci);
136 static void ohci_stop (struct usb_hcd *hcd);
137 static int ohci_reboot (struct notifier_block *, unsigned long , void *);
138 
139 #include "ohci-hub.c"
140 #include "ohci-dbg.c"
141 #include "ohci-mem.c"
142 #include "ohci-q.c"
143 
144 
145 /*
146  * On architectures with edge-triggered interrupts we must never return
147  * IRQ_NONE.
148  */
149 #if defined(CONFIG_SA1111)  /* ... or other edge-triggered systems */
150 #define IRQ_NOTMINE	IRQ_HANDLED
151 #else
152 #define IRQ_NOTMINE	IRQ_NONE
153 #endif
154 
155 
156 /* Some boards misreport power switching/overcurrent */
157 static int distrust_firmware = 1;
158 module_param (distrust_firmware, bool, 0);
159 MODULE_PARM_DESC (distrust_firmware,
160 	"true to distrust firmware power/overcurrent setup");
161 
162 /* Some boards leave IR set wrongly, since they fail BIOS/SMM handshakes */
163 static int no_handshake = 0;
164 module_param (no_handshake, bool, 0);
165 MODULE_PARM_DESC (no_handshake, "true (not default) disables BIOS handshake");
166 
167 /*-------------------------------------------------------------------------*/
168 
169 /*
170  * queue up an urb for anything except the root hub
171  */
172 static int ohci_urb_enqueue (
173 	struct usb_hcd	*hcd,
174 	struct usb_host_endpoint *ep,
175 	struct urb	*urb,
176 	gfp_t		mem_flags
177 ) {
178 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
179 	struct ed	*ed;
180 	urb_priv_t	*urb_priv;
181 	unsigned int	pipe = urb->pipe;
182 	int		i, size = 0;
183 	unsigned long	flags;
184 	int		retval = 0;
185 
186 #ifdef OHCI_VERBOSE_DEBUG
187 	urb_print (urb, "SUB", usb_pipein (pipe));
188 #endif
189 
190 	/* every endpoint has a ed, locate and maybe (re)initialize it */
191 	if (! (ed = ed_get (ohci, ep, urb->dev, pipe, urb->interval)))
192 		return -ENOMEM;
193 
194 	/* for the private part of the URB we need the number of TDs (size) */
195 	switch (ed->type) {
196 		case PIPE_CONTROL:
197 			/* td_submit_urb() doesn't yet handle these */
198 			if (urb->transfer_buffer_length > 4096)
199 				return -EMSGSIZE;
200 
201 			/* 1 TD for setup, 1 for ACK, plus ... */
202 			size = 2;
203 			/* FALLTHROUGH */
204 		// case PIPE_INTERRUPT:
205 		// case PIPE_BULK:
206 		default:
207 			/* one TD for every 4096 Bytes (can be upto 8K) */
208 			size += urb->transfer_buffer_length / 4096;
209 			/* ... and for any remaining bytes ... */
210 			if ((urb->transfer_buffer_length % 4096) != 0)
211 				size++;
212 			/* ... and maybe a zero length packet to wrap it up */
213 			if (size == 0)
214 				size++;
215 			else if ((urb->transfer_flags & URB_ZERO_PACKET) != 0
216 				&& (urb->transfer_buffer_length
217 					% usb_maxpacket (urb->dev, pipe,
218 						usb_pipeout (pipe))) == 0)
219 				size++;
220 			break;
221 		case PIPE_ISOCHRONOUS: /* number of packets from URB */
222 			size = urb->number_of_packets;
223 			break;
224 	}
225 
226 	/* allocate the private part of the URB */
227 	urb_priv = kmalloc (sizeof (urb_priv_t) + size * sizeof (struct td *),
228 			mem_flags);
229 	if (!urb_priv)
230 		return -ENOMEM;
231 	memset (urb_priv, 0, sizeof (urb_priv_t) + size * sizeof (struct td *));
232 	INIT_LIST_HEAD (&urb_priv->pending);
233 	urb_priv->length = size;
234 	urb_priv->ed = ed;
235 
236 	/* allocate the TDs (deferring hash chain updates) */
237 	for (i = 0; i < size; i++) {
238 		urb_priv->td [i] = td_alloc (ohci, mem_flags);
239 		if (!urb_priv->td [i]) {
240 			urb_priv->length = i;
241 			urb_free_priv (ohci, urb_priv);
242 			return -ENOMEM;
243 		}
244 	}
245 
246 	spin_lock_irqsave (&ohci->lock, flags);
247 
248 	/* don't submit to a dead HC */
249 	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
250 		retval = -ENODEV;
251 		goto fail;
252 	}
253 	if (!HC_IS_RUNNING(hcd->state)) {
254 		retval = -ENODEV;
255 		goto fail;
256 	}
257 
258 	/* in case of unlink-during-submit */
259 	spin_lock (&urb->lock);
260 	if (urb->status != -EINPROGRESS) {
261 		spin_unlock (&urb->lock);
262 		urb->hcpriv = urb_priv;
263 		finish_urb (ohci, urb, NULL);
264 		retval = 0;
265 		goto fail;
266 	}
267 
268 	/* schedule the ed if needed */
269 	if (ed->state == ED_IDLE) {
270 		retval = ed_schedule (ohci, ed);
271 		if (retval < 0)
272 			goto fail0;
273 		if (ed->type == PIPE_ISOCHRONOUS) {
274 			u16	frame = ohci_frame_no(ohci);
275 
276 			/* delay a few frames before the first TD */
277 			frame += max_t (u16, 8, ed->interval);
278 			frame &= ~(ed->interval - 1);
279 			frame |= ed->branch;
280 			urb->start_frame = frame;
281 
282 			/* yes, only URB_ISO_ASAP is supported, and
283 			 * urb->start_frame is never used as input.
284 			 */
285 		}
286 	} else if (ed->type == PIPE_ISOCHRONOUS)
287 		urb->start_frame = ed->last_iso + ed->interval;
288 
289 	/* fill the TDs and link them to the ed; and
290 	 * enable that part of the schedule, if needed
291 	 * and update count of queued periodic urbs
292 	 */
293 	urb->hcpriv = urb_priv;
294 	td_submit_urb (ohci, urb);
295 
296 fail0:
297 	spin_unlock (&urb->lock);
298 fail:
299 	if (retval)
300 		urb_free_priv (ohci, urb_priv);
301 	spin_unlock_irqrestore (&ohci->lock, flags);
302 	return retval;
303 }
304 
305 /*
306  * decouple the URB from the HC queues (TDs, urb_priv); it's
307  * already marked using urb->status.  reporting is always done
308  * asynchronously, and we might be dealing with an urb that's
309  * partially transferred, or an ED with other urbs being unlinked.
310  */
311 static int ohci_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
312 {
313 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
314 	unsigned long		flags;
315 
316 #ifdef OHCI_VERBOSE_DEBUG
317 	urb_print (urb, "UNLINK", 1);
318 #endif
319 
320 	spin_lock_irqsave (&ohci->lock, flags);
321  	if (HC_IS_RUNNING(hcd->state)) {
322 		urb_priv_t  *urb_priv;
323 
324 		/* Unless an IRQ completed the unlink while it was being
325 		 * handed to us, flag it for unlink and giveback, and force
326 		 * some upcoming INTR_SF to call finish_unlinks()
327 		 */
328 		urb_priv = urb->hcpriv;
329 		if (urb_priv) {
330 			if (urb_priv->ed->state == ED_OPER)
331 				start_ed_unlink (ohci, urb_priv->ed);
332 		}
333 	} else {
334 		/*
335 		 * with HC dead, we won't respect hc queue pointers
336 		 * any more ... just clean up every urb's memory.
337 		 */
338 		if (urb->hcpriv)
339 			finish_urb (ohci, urb, NULL);
340 	}
341 	spin_unlock_irqrestore (&ohci->lock, flags);
342 	return 0;
343 }
344 
345 /*-------------------------------------------------------------------------*/
346 
347 /* frees config/altsetting state for endpoints,
348  * including ED memory, dummy TD, and bulk/intr data toggle
349  */
350 
351 static void
352 ohci_endpoint_disable (struct usb_hcd *hcd, struct usb_host_endpoint *ep)
353 {
354 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
355 	unsigned long		flags;
356 	struct ed		*ed = ep->hcpriv;
357 	unsigned		limit = 1000;
358 
359 	/* ASSERT:  any requests/urbs are being unlinked */
360 	/* ASSERT:  nobody can be submitting urbs for this any more */
361 
362 	if (!ed)
363 		return;
364 
365 rescan:
366 	spin_lock_irqsave (&ohci->lock, flags);
367 
368 	if (!HC_IS_RUNNING (hcd->state)) {
369 sanitize:
370 		ed->state = ED_IDLE;
371 		finish_unlinks (ohci, 0, NULL);
372 	}
373 
374 	switch (ed->state) {
375 	case ED_UNLINK:		/* wait for hw to finish? */
376 		/* major IRQ delivery trouble loses INTR_SF too... */
377 		if (limit-- == 0) {
378 			ohci_warn (ohci, "IRQ INTR_SF lossage\n");
379 			goto sanitize;
380 		}
381 		spin_unlock_irqrestore (&ohci->lock, flags);
382 		schedule_timeout_uninterruptible(1);
383 		goto rescan;
384 	case ED_IDLE:		/* fully unlinked */
385 		if (list_empty (&ed->td_list)) {
386 			td_free (ohci, ed->dummy);
387 			ed_free (ohci, ed);
388 			break;
389 		}
390 		/* else FALL THROUGH */
391 	default:
392 		/* caller was supposed to have unlinked any requests;
393 		 * that's not our job.  can't recover; must leak ed.
394 		 */
395 		ohci_err (ohci, "leak ed %p (#%02x) state %d%s\n",
396 			ed, ep->desc.bEndpointAddress, ed->state,
397 			list_empty (&ed->td_list) ? "" : " (has tds)");
398 		td_free (ohci, ed->dummy);
399 		break;
400 	}
401 	ep->hcpriv = NULL;
402 	spin_unlock_irqrestore (&ohci->lock, flags);
403 	return;
404 }
405 
406 static int ohci_get_frame (struct usb_hcd *hcd)
407 {
408 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
409 
410 	return ohci_frame_no(ohci);
411 }
412 
413 static void ohci_usb_reset (struct ohci_hcd *ohci)
414 {
415 	ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
416 	ohci->hc_control &= OHCI_CTRL_RWC;
417 	ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
418 }
419 
420 /* reboot notifier forcibly disables IRQs and DMA, helping kexec and
421  * other cases where the next software may expect clean state from the
422  * "firmware".  this is bus-neutral, unlike shutdown() methods.
423  */
424 static int
425 ohci_reboot (struct notifier_block *block, unsigned long code, void *null)
426 {
427 	struct ohci_hcd *ohci;
428 
429 	ohci = container_of (block, struct ohci_hcd, reboot_notifier);
430 	ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
431 	ohci_usb_reset (ohci);
432 	/* flush the writes */
433 	(void) ohci_readl (ohci, &ohci->regs->control);
434 	return 0;
435 }
436 
437 /*-------------------------------------------------------------------------*
438  * HC functions
439  *-------------------------------------------------------------------------*/
440 
441 /* init memory, and kick BIOS/SMM off */
442 
443 static int ohci_init (struct ohci_hcd *ohci)
444 {
445 	int ret;
446 
447 	disable (ohci);
448 	ohci->regs = ohci_to_hcd(ohci)->regs;
449 	ohci->next_statechange = jiffies;
450 
451 #ifndef IR_DISABLE
452 	/* SMM owns the HC?  not for long! */
453 	if (!no_handshake && ohci_readl (ohci,
454 					&ohci->regs->control) & OHCI_CTRL_IR) {
455 		u32 temp;
456 
457 		ohci_dbg (ohci, "USB HC TakeOver from BIOS/SMM\n");
458 
459 		/* this timeout is arbitrary.  we make it long, so systems
460 		 * depending on usb keyboards may be usable even if the
461 		 * BIOS/SMM code seems pretty broken.
462 		 */
463 		temp = 500;	/* arbitrary: five seconds */
464 
465 		ohci_writel (ohci, OHCI_INTR_OC, &ohci->regs->intrenable);
466 		ohci_writel (ohci, OHCI_OCR, &ohci->regs->cmdstatus);
467 		while (ohci_readl (ohci, &ohci->regs->control) & OHCI_CTRL_IR) {
468 			msleep (10);
469 			if (--temp == 0) {
470 				ohci_err (ohci, "USB HC takeover failed!"
471 					"  (BIOS/SMM bug)\n");
472 				return -EBUSY;
473 			}
474 		}
475 		ohci_usb_reset (ohci);
476 	}
477 #endif
478 
479 	/* Disable HC interrupts */
480 	ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
481 	// flush the writes
482 	(void) ohci_readl (ohci, &ohci->regs->control);
483 
484 	/* Read the number of ports unless overridden */
485 	if (ohci->num_ports == 0)
486 		ohci->num_ports = roothub_a(ohci) & RH_A_NDP;
487 
488 	if (ohci->hcca)
489 		return 0;
490 
491 	ohci->hcca = dma_alloc_coherent (ohci_to_hcd(ohci)->self.controller,
492 			sizeof *ohci->hcca, &ohci->hcca_dma, 0);
493 	if (!ohci->hcca)
494 		return -ENOMEM;
495 
496 	if ((ret = ohci_mem_init (ohci)) < 0)
497 		ohci_stop (ohci_to_hcd(ohci));
498 
499 	return ret;
500 
501 }
502 
503 /*-------------------------------------------------------------------------*/
504 
505 /* Start an OHCI controller, set the BUS operational
506  * resets USB and controller
507  * enable interrupts
508  */
509 static int ohci_run (struct ohci_hcd *ohci)
510 {
511   	u32			mask, temp;
512 	int			first = ohci->fminterval == 0;
513 
514 	disable (ohci);
515 
516 	/* boot firmware should have set this up (5.1.1.3.1) */
517 	if (first) {
518 
519 		temp = ohci_readl (ohci, &ohci->regs->fminterval);
520 		ohci->fminterval = temp & 0x3fff;
521 		if (ohci->fminterval != FI)
522 			ohci_dbg (ohci, "fminterval delta %d\n",
523 				ohci->fminterval - FI);
524 		ohci->fminterval |= FSMP (ohci->fminterval) << 16;
525 		/* also: power/overcurrent flags in roothub.a */
526 	}
527 
528   	/* Reset USB nearly "by the book".  RemoteWakeupConnected
529 	 * saved if boot firmware (BIOS/SMM/...) told us it's connected
530 	 * (for OHCI integrated on mainboard, it normally is)
531 	 */
532 	ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
533 	ohci_dbg (ohci, "resetting from state '%s', control = 0x%x\n",
534 			hcfs2string (ohci->hc_control & OHCI_CTRL_HCFS),
535 			ohci->hc_control);
536 
537 	if (ohci->hc_control & OHCI_CTRL_RWC
538 			&& !(ohci->flags & OHCI_QUIRK_AMD756))
539 		ohci_to_hcd(ohci)->can_wakeup = 1;
540 
541 	switch (ohci->hc_control & OHCI_CTRL_HCFS) {
542 	case OHCI_USB_OPER:
543 		temp = 0;
544 		break;
545 	case OHCI_USB_SUSPEND:
546 	case OHCI_USB_RESUME:
547 		ohci->hc_control &= OHCI_CTRL_RWC;
548 		ohci->hc_control |= OHCI_USB_RESUME;
549 		temp = 10 /* msec wait */;
550 		break;
551 	// case OHCI_USB_RESET:
552 	default:
553 		ohci->hc_control &= OHCI_CTRL_RWC;
554 		ohci->hc_control |= OHCI_USB_RESET;
555 		temp = 50 /* msec wait */;
556 		break;
557 	}
558 	ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
559 	// flush the writes
560 	(void) ohci_readl (ohci, &ohci->regs->control);
561 	msleep(temp);
562 	temp = roothub_a (ohci);
563 	if (!(temp & RH_A_NPS)) {
564 		/* power down each port */
565 		for (temp = 0; temp < ohci->num_ports; temp++)
566 			ohci_writel (ohci, RH_PS_LSDA,
567 				&ohci->regs->roothub.portstatus [temp]);
568 	}
569 	// flush those writes
570 	(void) ohci_readl (ohci, &ohci->regs->control);
571 	memset (ohci->hcca, 0, sizeof (struct ohci_hcca));
572 
573 	/* 2msec timelimit here means no irqs/preempt */
574 	spin_lock_irq (&ohci->lock);
575 
576 retry:
577 	/* HC Reset requires max 10 us delay */
578 	ohci_writel (ohci, OHCI_HCR,  &ohci->regs->cmdstatus);
579 	temp = 30;	/* ... allow extra time */
580 	while ((ohci_readl (ohci, &ohci->regs->cmdstatus) & OHCI_HCR) != 0) {
581 		if (--temp == 0) {
582 			spin_unlock_irq (&ohci->lock);
583 			ohci_err (ohci, "USB HC reset timed out!\n");
584 			return -1;
585 		}
586 		udelay (1);
587 	}
588 
589 	/* now we're in the SUSPEND state ... must go OPERATIONAL
590 	 * within 2msec else HC enters RESUME
591 	 *
592 	 * ... but some hardware won't init fmInterval "by the book"
593 	 * (SiS, OPTi ...), so reset again instead.  SiS doesn't need
594 	 * this if we write fmInterval after we're OPERATIONAL.
595 	 * Unclear about ALi, ServerWorks, and others ... this could
596 	 * easily be a longstanding bug in chip init on Linux.
597 	 */
598 	if (ohci->flags & OHCI_QUIRK_INITRESET) {
599 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
600 		// flush those writes
601 		(void) ohci_readl (ohci, &ohci->regs->control);
602 	}
603 
604 	/* Tell the controller where the control and bulk lists are
605 	 * The lists are empty now. */
606 	ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
607 	ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
608 
609 	/* a reset clears this */
610 	ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
611 
612 	periodic_reinit (ohci);
613 
614 	/* some OHCI implementations are finicky about how they init.
615 	 * bogus values here mean not even enumeration could work.
616 	 */
617 	if ((ohci_readl (ohci, &ohci->regs->fminterval) & 0x3fff0000) == 0
618 			|| !ohci_readl (ohci, &ohci->regs->periodicstart)) {
619 		if (!(ohci->flags & OHCI_QUIRK_INITRESET)) {
620 			ohci->flags |= OHCI_QUIRK_INITRESET;
621 			ohci_dbg (ohci, "enabling initreset quirk\n");
622 			goto retry;
623 		}
624 		spin_unlock_irq (&ohci->lock);
625 		ohci_err (ohci, "init err (%08x %04x)\n",
626 			ohci_readl (ohci, &ohci->regs->fminterval),
627 			ohci_readl (ohci, &ohci->regs->periodicstart));
628 		return -EOVERFLOW;
629 	}
630 
631  	/* start controller operations */
632 	ohci->hc_control &= OHCI_CTRL_RWC;
633  	ohci->hc_control |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
634  	ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
635 	ohci_to_hcd(ohci)->state = HC_STATE_RUNNING;
636 
637 	/* wake on ConnectStatusChange, matching external hubs */
638 	ohci_writel (ohci, RH_HS_DRWE, &ohci->regs->roothub.status);
639 
640 	/* Choose the interrupts we care about now, others later on demand */
641 	mask = OHCI_INTR_INIT;
642 	ohci_writel (ohci, mask, &ohci->regs->intrstatus);
643 	ohci_writel (ohci, mask, &ohci->regs->intrenable);
644 
645 	/* handle root hub init quirks ... */
646 	temp = roothub_a (ohci);
647 	temp &= ~(RH_A_PSM | RH_A_OCPM);
648 	if (ohci->flags & OHCI_QUIRK_SUPERIO) {
649 		/* NSC 87560 and maybe others */
650 		temp |= RH_A_NOCP;
651 		temp &= ~(RH_A_POTPGT | RH_A_NPS);
652 		ohci_writel (ohci, temp, &ohci->regs->roothub.a);
653 	} else if ((ohci->flags & OHCI_QUIRK_AMD756) || distrust_firmware) {
654 		/* hub power always on; required for AMD-756 and some
655 		 * Mac platforms.  ganged overcurrent reporting, if any.
656 		 */
657 		temp |= RH_A_NPS;
658 		ohci_writel (ohci, temp, &ohci->regs->roothub.a);
659 	}
660 	ohci_writel (ohci, RH_HS_LPSC, &ohci->regs->roothub.status);
661 	ohci_writel (ohci, (temp & RH_A_NPS) ? 0 : RH_B_PPCM,
662 						&ohci->regs->roothub.b);
663 	// flush those writes
664 	(void) ohci_readl (ohci, &ohci->regs->control);
665 
666 	spin_unlock_irq (&ohci->lock);
667 
668 	// POTPGT delay is bits 24-31, in 2 ms units.
669 	mdelay ((temp >> 23) & 0x1fe);
670 	ohci_to_hcd(ohci)->state = HC_STATE_RUNNING;
671 
672 	ohci_dump (ohci, 1);
673 
674 	if (ohci_to_hcd(ohci)->self.root_hub == NULL) {
675 		register_reboot_notifier (&ohci->reboot_notifier);
676 		create_debug_files (ohci);
677 	}
678 
679 	return 0;
680 }
681 
682 /*-------------------------------------------------------------------------*/
683 
684 /* an interrupt happens */
685 
686 static irqreturn_t ohci_irq (struct usb_hcd *hcd, struct pt_regs *ptregs)
687 {
688 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
689 	struct ohci_regs __iomem *regs = ohci->regs;
690  	int			ints;
691 
692 	/* we can eliminate a (slow) ohci_readl()
693 	   if _only_ WDH caused this irq */
694 	if ((ohci->hcca->done_head != 0)
695 			&& ! (hc32_to_cpup (ohci, &ohci->hcca->done_head)
696 				& 0x01)) {
697 		ints =  OHCI_INTR_WDH;
698 
699 	/* cardbus/... hardware gone before remove() */
700 	} else if ((ints = ohci_readl (ohci, &regs->intrstatus)) == ~(u32)0) {
701 		disable (ohci);
702 		ohci_dbg (ohci, "device removed!\n");
703 		return IRQ_HANDLED;
704 
705 	/* interrupt for some other device? */
706 	} else if ((ints &= ohci_readl (ohci, &regs->intrenable)) == 0) {
707 		return IRQ_NOTMINE;
708 	}
709 
710 	if (ints & OHCI_INTR_UE) {
711 		disable (ohci);
712 		ohci_err (ohci, "OHCI Unrecoverable Error, disabled\n");
713 		// e.g. due to PCI Master/Target Abort
714 
715 		ohci_dump (ohci, 1);
716 		ohci_usb_reset (ohci);
717 	}
718 
719 	if (ints & OHCI_INTR_RD) {
720 		ohci_vdbg (ohci, "resume detect\n");
721 		ohci_writel (ohci, OHCI_INTR_RD, &regs->intrstatus);
722 		if (hcd->state != HC_STATE_QUIESCING)
723 			usb_hcd_resume_root_hub(hcd);
724 	}
725 
726 	if (ints & OHCI_INTR_WDH) {
727 		if (HC_IS_RUNNING(hcd->state))
728 			ohci_writel (ohci, OHCI_INTR_WDH, &regs->intrdisable);
729 		spin_lock (&ohci->lock);
730 		dl_done_list (ohci, ptregs);
731 		spin_unlock (&ohci->lock);
732 		if (HC_IS_RUNNING(hcd->state))
733 			ohci_writel (ohci, OHCI_INTR_WDH, &regs->intrenable);
734 	}
735 
736 	/* could track INTR_SO to reduce available PCI/... bandwidth */
737 
738 	/* handle any pending URB/ED unlinks, leaving INTR_SF enabled
739 	 * when there's still unlinking to be done (next frame).
740 	 */
741 	spin_lock (&ohci->lock);
742 	if (ohci->ed_rm_list)
743 		finish_unlinks (ohci, ohci_frame_no(ohci), ptregs);
744 	if ((ints & OHCI_INTR_SF) != 0 && !ohci->ed_rm_list
745 			&& HC_IS_RUNNING(hcd->state))
746 		ohci_writel (ohci, OHCI_INTR_SF, &regs->intrdisable);
747 	spin_unlock (&ohci->lock);
748 
749 	if (HC_IS_RUNNING(hcd->state)) {
750 		ohci_writel (ohci, ints, &regs->intrstatus);
751 		ohci_writel (ohci, OHCI_INTR_MIE, &regs->intrenable);
752 		// flush those writes
753 		(void) ohci_readl (ohci, &ohci->regs->control);
754 	}
755 
756 	return IRQ_HANDLED;
757 }
758 
759 /*-------------------------------------------------------------------------*/
760 
761 static void ohci_stop (struct usb_hcd *hcd)
762 {
763 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
764 
765 	ohci_dbg (ohci, "stop %s controller (state 0x%02x)\n",
766 		hcfs2string (ohci->hc_control & OHCI_CTRL_HCFS),
767 		hcd->state);
768 	ohci_dump (ohci, 1);
769 
770 	flush_scheduled_work();
771 
772 	ohci_usb_reset (ohci);
773 	ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
774 
775 	remove_debug_files (ohci);
776 	unregister_reboot_notifier (&ohci->reboot_notifier);
777 	ohci_mem_cleanup (ohci);
778 	if (ohci->hcca) {
779 		dma_free_coherent (hcd->self.controller,
780 				sizeof *ohci->hcca,
781 				ohci->hcca, ohci->hcca_dma);
782 		ohci->hcca = NULL;
783 		ohci->hcca_dma = 0;
784 	}
785 }
786 
787 /*-------------------------------------------------------------------------*/
788 
789 /* must not be called from interrupt context */
790 
791 #ifdef	CONFIG_PM
792 
793 static int ohci_restart (struct ohci_hcd *ohci)
794 {
795 	int temp;
796 	int i;
797 	struct urb_priv *priv;
798 
799 	/* mark any devices gone, so they do nothing till khubd disconnects.
800 	 * recycle any "live" eds/tds (and urbs) right away.
801 	 * later, khubd disconnect processing will recycle the other state,
802 	 * (either as disconnect/reconnect, or maybe someday as a reset).
803 	 */
804 	spin_lock_irq(&ohci->lock);
805 	disable (ohci);
806 	usb_root_hub_lost_power(ohci_to_hcd(ohci)->self.root_hub);
807 	if (!list_empty (&ohci->pending))
808 		ohci_dbg(ohci, "abort schedule...\n");
809 	list_for_each_entry (priv, &ohci->pending, pending) {
810 		struct urb	*urb = priv->td[0]->urb;
811 		struct ed	*ed = priv->ed;
812 
813 		switch (ed->state) {
814 		case ED_OPER:
815 			ed->state = ED_UNLINK;
816 			ed->hwINFO |= cpu_to_hc32(ohci, ED_DEQUEUE);
817 			ed_deschedule (ohci, ed);
818 
819 			ed->ed_next = ohci->ed_rm_list;
820 			ed->ed_prev = NULL;
821 			ohci->ed_rm_list = ed;
822 			/* FALLTHROUGH */
823 		case ED_UNLINK:
824 			break;
825 		default:
826 			ohci_dbg(ohci, "bogus ed %p state %d\n",
827 					ed, ed->state);
828 		}
829 
830 		spin_lock (&urb->lock);
831 		urb->status = -ESHUTDOWN;
832 		spin_unlock (&urb->lock);
833 	}
834 	finish_unlinks (ohci, 0, NULL);
835 	spin_unlock_irq(&ohci->lock);
836 
837 	/* paranoia, in case that didn't work: */
838 
839 	/* empty the interrupt branches */
840 	for (i = 0; i < NUM_INTS; i++) ohci->load [i] = 0;
841 	for (i = 0; i < NUM_INTS; i++) ohci->hcca->int_table [i] = 0;
842 
843 	/* no EDs to remove */
844 	ohci->ed_rm_list = NULL;
845 
846 	/* empty control and bulk lists */
847 	ohci->ed_controltail = NULL;
848 	ohci->ed_bulktail    = NULL;
849 
850 	if ((temp = ohci_run (ohci)) < 0) {
851 		ohci_err (ohci, "can't restart, %d\n", temp);
852 		return temp;
853 	} else {
854 		/* here we "know" root ports should always stay powered,
855 		 * and that if we try to turn them back on the root hub
856 		 * will respond to CSC processing.
857 		 */
858 		i = ohci->num_ports;
859 		while (i--)
860 			ohci_writel (ohci, RH_PS_PSS,
861 				&ohci->regs->roothub.portstatus [temp]);
862 		ohci_dbg (ohci, "restart complete\n");
863 	}
864 	return 0;
865 }
866 #endif
867 
868 /*-------------------------------------------------------------------------*/
869 
870 #define DRIVER_INFO DRIVER_VERSION " " DRIVER_DESC
871 
872 MODULE_AUTHOR (DRIVER_AUTHOR);
873 MODULE_DESCRIPTION (DRIVER_INFO);
874 MODULE_LICENSE ("GPL");
875 
876 #ifdef CONFIG_PCI
877 #include "ohci-pci.c"
878 #endif
879 
880 #ifdef CONFIG_SA1111
881 #include "ohci-sa1111.c"
882 #endif
883 
884 #ifdef CONFIG_ARCH_S3C2410
885 #include "ohci-s3c2410.c"
886 #endif
887 
888 #ifdef CONFIG_ARCH_OMAP
889 #include "ohci-omap.c"
890 #endif
891 
892 #ifdef CONFIG_ARCH_LH7A404
893 #include "ohci-lh7a404.c"
894 #endif
895 
896 #ifdef CONFIG_PXA27x
897 #include "ohci-pxa27x.c"
898 #endif
899 
900 #ifdef CONFIG_SOC_AU1X00
901 #include "ohci-au1xxx.c"
902 #endif
903 
904 #ifdef CONFIG_USB_OHCI_HCD_PPC_SOC
905 #include "ohci-ppc-soc.c"
906 #endif
907 
908 #if !(defined(CONFIG_PCI) \
909       || defined(CONFIG_SA1111) \
910       || defined(CONFIG_ARCH_S3C2410) \
911       || defined(CONFIG_ARCH_OMAP) \
912       || defined (CONFIG_ARCH_LH7A404) \
913       || defined (CONFIG_PXA27x) \
914       || defined (CONFIG_SOC_AU1X00) \
915       || defined (CONFIG_USB_OHCI_HCD_PPC_SOC) \
916 	)
917 #error "missing bus glue for ohci-hcd"
918 #endif
919