xref: /openbmc/linux/drivers/usb/host/uhci-hcd.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Universal Host Controller Interface driver for USB.
3  *
4  * Maintainer: Alan Stern <stern@rowland.harvard.edu>
5  *
6  * (C) Copyright 1999 Linus Torvalds
7  * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
8  * (C) Copyright 1999 Randy Dunlap
9  * (C) Copyright 1999 Georg Acher, acher@in.tum.de
10  * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
11  * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
12  * (C) Copyright 1999 Roman Weissgaerber, weissg@vienna.at
13  * (C) Copyright 2000 Yggdrasil Computing, Inc. (port of new PCI interface
14  *               support from usb-ohci.c by Adam Richter, adam@yggdrasil.com).
15  * (C) Copyright 1999 Gregory P. Smith (from usb-ohci.c)
16  * (C) Copyright 2004 Alan Stern, stern@rowland.harvard.edu
17  *
18  * Intel documents this fairly well, and as far as I know there
19  * are no royalties or anything like that, but even so there are
20  * people who decided that they want to do the same thing in a
21  * completely different way.
22  *
23  * WARNING! The USB documentation is downright evil. Most of it
24  * is just crap, written by a committee. You're better off ignoring
25  * most of it, the important stuff is:
26  *  - the low-level protocol (fairly simple but lots of small details)
27  *  - working around the horridness of the rest
28  */
29 
30 #include <linux/config.h>
31 #ifdef CONFIG_USB_DEBUG
32 #define DEBUG
33 #else
34 #undef DEBUG
35 #endif
36 #include <linux/module.h>
37 #include <linux/pci.h>
38 #include <linux/kernel.h>
39 #include <linux/init.h>
40 #include <linux/delay.h>
41 #include <linux/ioport.h>
42 #include <linux/sched.h>
43 #include <linux/slab.h>
44 #include <linux/smp_lock.h>
45 #include <linux/errno.h>
46 #include <linux/unistd.h>
47 #include <linux/interrupt.h>
48 #include <linux/spinlock.h>
49 #include <linux/debugfs.h>
50 #include <linux/pm.h>
51 #include <linux/dmapool.h>
52 #include <linux/dma-mapping.h>
53 #include <linux/usb.h>
54 #include <linux/bitops.h>
55 
56 #include <asm/uaccess.h>
57 #include <asm/io.h>
58 #include <asm/irq.h>
59 #include <asm/system.h>
60 
61 #include "../core/hcd.h"
62 #include "uhci-hcd.h"
63 
64 /*
65  * Version Information
66  */
67 #define DRIVER_VERSION "v2.2"
68 #define DRIVER_AUTHOR "Linus 'Frodo Rabbit' Torvalds, Johannes Erdfelt, \
69 Randy Dunlap, Georg Acher, Deti Fliegl, Thomas Sailer, Roman Weissgaerber, \
70 Alan Stern"
71 #define DRIVER_DESC "USB Universal Host Controller Interface driver"
72 
73 /*
74  * debug = 0, no debugging messages
75  * debug = 1, dump failed URB's except for stalls
76  * debug = 2, dump all failed URB's (including stalls)
77  *            show all queues in /debug/uhci/[pci_addr]
78  * debug = 3, show all TD's in URB's when dumping
79  */
80 #ifdef DEBUG
81 static int debug = 1;
82 #else
83 static int debug = 0;
84 #endif
85 module_param(debug, int, S_IRUGO | S_IWUSR);
86 MODULE_PARM_DESC(debug, "Debug level");
87 static char *errbuf;
88 #define ERRBUF_LEN    (32 * 1024)
89 
90 static kmem_cache_t *uhci_up_cachep;	/* urb_priv */
91 
92 static void uhci_get_current_frame_number(struct uhci_hcd *uhci);
93 static void hc_state_transitions(struct uhci_hcd *uhci);
94 
95 /* If a transfer is still active after this much time, turn off FSBR */
96 #define IDLE_TIMEOUT	msecs_to_jiffies(50)
97 #define FSBR_DELAY	msecs_to_jiffies(50)
98 
99 /* When we timeout an idle transfer for FSBR, we'll switch it over to */
100 /* depth first traversal. We'll do it in groups of this number of TD's */
101 /* to make sure it doesn't hog all of the bandwidth */
102 #define DEPTH_INTERVAL 5
103 
104 #include "uhci-hub.c"
105 #include "uhci-debug.c"
106 #include "uhci-q.c"
107 
108 static int init_stall_timer(struct usb_hcd *hcd);
109 
110 static void stall_callback(unsigned long ptr)
111 {
112 	struct usb_hcd *hcd = (struct usb_hcd *)ptr;
113 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
114 	struct urb_priv *up;
115 	unsigned long flags;
116 
117 	spin_lock_irqsave(&uhci->lock, flags);
118 	uhci_scan_schedule(uhci, NULL);
119 
120 	list_for_each_entry(up, &uhci->urb_list, urb_list) {
121 		struct urb *u = up->urb;
122 
123 		spin_lock(&u->lock);
124 
125 		/* Check if the FSBR timed out */
126 		if (up->fsbr && !up->fsbr_timeout && time_after_eq(jiffies, up->fsbrtime + IDLE_TIMEOUT))
127 			uhci_fsbr_timeout(uhci, u);
128 
129 		spin_unlock(&u->lock);
130 	}
131 
132 	/* Really disable FSBR */
133 	if (!uhci->fsbr && uhci->fsbrtimeout && time_after_eq(jiffies, uhci->fsbrtimeout)) {
134 		uhci->fsbrtimeout = 0;
135 		uhci->skel_term_qh->link = UHCI_PTR_TERM;
136 	}
137 
138 	/* Poll for and perform state transitions */
139 	hc_state_transitions(uhci);
140 	if (unlikely(uhci->suspended_ports && uhci->state != UHCI_SUSPENDED))
141 		uhci_check_ports(uhci);
142 
143 	init_stall_timer(hcd);
144 	spin_unlock_irqrestore(&uhci->lock, flags);
145 }
146 
147 static int init_stall_timer(struct usb_hcd *hcd)
148 {
149 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
150 
151 	init_timer(&uhci->stall_timer);
152 	uhci->stall_timer.function = stall_callback;
153 	uhci->stall_timer.data = (unsigned long)hcd;
154 	uhci->stall_timer.expires = jiffies + msecs_to_jiffies(100);
155 	add_timer(&uhci->stall_timer);
156 
157 	return 0;
158 }
159 
160 static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
161 {
162 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
163 	unsigned long io_addr = uhci->io_addr;
164 	unsigned short status;
165 
166 	/*
167 	 * Read the interrupt status, and write it back to clear the
168 	 * interrupt cause.  Contrary to the UHCI specification, the
169 	 * "HC Halted" status bit is persistent: it is RO, not R/WC.
170 	 */
171 	status = inw(io_addr + USBSTS);
172 	if (!(status & ~USBSTS_HCH))	/* shared interrupt, not mine */
173 		return IRQ_NONE;
174 	outw(status, io_addr + USBSTS);		/* Clear it */
175 
176 	if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) {
177 		if (status & USBSTS_HSE)
178 			dev_err(uhci_dev(uhci), "host system error, "
179 					"PCI problems?\n");
180 		if (status & USBSTS_HCPE)
181 			dev_err(uhci_dev(uhci), "host controller process "
182 					"error, something bad happened!\n");
183 		if ((status & USBSTS_HCH) && uhci->state > 0) {
184 			dev_err(uhci_dev(uhci), "host controller halted, "
185 					"very bad!\n");
186 			/* FIXME: Reset the controller, fix the offending TD */
187 		}
188 	}
189 
190 	if (status & USBSTS_RD)
191 		uhci->resume_detect = 1;
192 
193 	spin_lock(&uhci->lock);
194 	uhci_scan_schedule(uhci, regs);
195 	spin_unlock(&uhci->lock);
196 
197 	return IRQ_HANDLED;
198 }
199 
200 static void reset_hc(struct uhci_hcd *uhci)
201 {
202 	unsigned long io_addr = uhci->io_addr;
203 
204 	/* Turn off PIRQ, SMI, and all interrupts.  This also turns off
205 	 * the BIOS's USB Legacy Support.
206 	 */
207 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
208 	outw(0, uhci->io_addr + USBINTR);
209 
210 	/* Global reset for 50ms */
211 	uhci->state = UHCI_RESET;
212 	outw(USBCMD_GRESET, io_addr + USBCMD);
213 	msleep(50);
214 	outw(0, io_addr + USBCMD);
215 
216 	/* Another 10ms delay */
217 	msleep(10);
218 	uhci->resume_detect = 0;
219 	uhci->is_stopped = UHCI_IS_STOPPED;
220 }
221 
222 static void suspend_hc(struct uhci_hcd *uhci)
223 {
224 	unsigned long io_addr = uhci->io_addr;
225 
226 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
227 	uhci->state = UHCI_SUSPENDED;
228 	uhci->resume_detect = 0;
229 	outw(USBCMD_EGSM, io_addr + USBCMD);
230 
231 	/* FIXME: Wait for the controller to actually stop */
232 	uhci_get_current_frame_number(uhci);
233 	uhci->is_stopped = UHCI_IS_STOPPED;
234 
235 	uhci_scan_schedule(uhci, NULL);
236 }
237 
238 static void wakeup_hc(struct uhci_hcd *uhci)
239 {
240 	unsigned long io_addr = uhci->io_addr;
241 
242 	switch (uhci->state) {
243 		case UHCI_SUSPENDED:		/* Start the resume */
244 			dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
245 
246 			/* Global resume for >= 20ms */
247 			outw(USBCMD_FGR | USBCMD_EGSM, io_addr + USBCMD);
248 			uhci->state = UHCI_RESUMING_1;
249 			uhci->state_end = jiffies + msecs_to_jiffies(20);
250 			uhci->is_stopped = 0;
251 			break;
252 
253 		case UHCI_RESUMING_1:		/* End global resume */
254 			uhci->state = UHCI_RESUMING_2;
255 			outw(0, io_addr + USBCMD);
256 			/* Falls through */
257 
258 		case UHCI_RESUMING_2:		/* Wait for EOP to be sent */
259 			if (inw(io_addr + USBCMD) & USBCMD_FGR)
260 				break;
261 
262 			/* Run for at least 1 second, and
263 			 * mark it configured with a 64-byte max packet */
264 			uhci->state = UHCI_RUNNING_GRACE;
265 			uhci->state_end = jiffies + HZ;
266 			outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP,
267 					io_addr + USBCMD);
268 			break;
269 
270 		case UHCI_RUNNING_GRACE:	/* Now allowed to suspend */
271 			uhci->state = UHCI_RUNNING;
272 			break;
273 
274 		default:
275 			break;
276 	}
277 }
278 
279 static int ports_active(struct uhci_hcd *uhci)
280 {
281 	unsigned long io_addr = uhci->io_addr;
282 	int connection = 0;
283 	int i;
284 
285 	for (i = 0; i < uhci->rh_numports; i++)
286 		connection |= (inw(io_addr + USBPORTSC1 + i * 2) & USBPORTSC_CCS);
287 
288 	return connection;
289 }
290 
291 static int suspend_allowed(struct uhci_hcd *uhci)
292 {
293 	unsigned long io_addr = uhci->io_addr;
294 	int i;
295 
296 	if (to_pci_dev(uhci_dev(uhci))->vendor != PCI_VENDOR_ID_INTEL)
297 		return 1;
298 
299 	/* Some of Intel's USB controllers have a bug that causes false
300 	 * resume indications if any port has an over current condition.
301 	 * To prevent problems, we will not allow a global suspend if
302 	 * any ports are OC.
303 	 *
304 	 * Some motherboards using Intel's chipsets (but not using all
305 	 * the USB ports) appear to hardwire the over current inputs active
306 	 * to disable the USB ports.
307 	 */
308 
309 	/* check for over current condition on any port */
310 	for (i = 0; i < uhci->rh_numports; i++) {
311 		if (inw(io_addr + USBPORTSC1 + i * 2) & USBPORTSC_OC)
312 			return 0;
313 	}
314 
315 	return 1;
316 }
317 
318 static void hc_state_transitions(struct uhci_hcd *uhci)
319 {
320 	switch (uhci->state) {
321 		case UHCI_RUNNING:
322 
323 			/* global suspend if nothing connected for 1 second */
324 			if (!ports_active(uhci) && suspend_allowed(uhci)) {
325 				uhci->state = UHCI_SUSPENDING_GRACE;
326 				uhci->state_end = jiffies + HZ;
327 			}
328 			break;
329 
330 		case UHCI_SUSPENDING_GRACE:
331 			if (ports_active(uhci))
332 				uhci->state = UHCI_RUNNING;
333 			else if (time_after_eq(jiffies, uhci->state_end))
334 				suspend_hc(uhci);
335 			break;
336 
337 		case UHCI_SUSPENDED:
338 
339 			/* wakeup if requested by a device */
340 			if (uhci->resume_detect)
341 				wakeup_hc(uhci);
342 			break;
343 
344 		case UHCI_RESUMING_1:
345 		case UHCI_RESUMING_2:
346 		case UHCI_RUNNING_GRACE:
347 			if (time_after_eq(jiffies, uhci->state_end))
348 				wakeup_hc(uhci);
349 			break;
350 
351 		default:
352 			break;
353 	}
354 }
355 
356 /*
357  * Store the current frame number in uhci->frame_number if the controller
358  * is runnning
359  */
360 static void uhci_get_current_frame_number(struct uhci_hcd *uhci)
361 {
362 	if (!uhci->is_stopped)
363 		uhci->frame_number = inw(uhci->io_addr + USBFRNUM);
364 }
365 
366 static int start_hc(struct uhci_hcd *uhci)
367 {
368 	unsigned long io_addr = uhci->io_addr;
369 	int timeout = 10;
370 
371 	/*
372 	 * Reset the HC - this will force us to get a
373 	 * new notification of any already connected
374 	 * ports due to the virtual disconnect that it
375 	 * implies.
376 	 */
377 	outw(USBCMD_HCRESET, io_addr + USBCMD);
378 	while (inw(io_addr + USBCMD) & USBCMD_HCRESET) {
379 		if (--timeout < 0) {
380 			dev_err(uhci_dev(uhci), "USBCMD_HCRESET timed out!\n");
381 			return -ETIMEDOUT;
382 		}
383 		msleep(1);
384 	}
385 
386 	/* Mark controller as running before we enable interrupts */
387 	uhci_to_hcd(uhci)->state = HC_STATE_RUNNING;
388 
389 	/* Turn on PIRQ and all interrupts */
390 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
391 			USBLEGSUP_DEFAULT);
392 	outw(USBINTR_TIMEOUT | USBINTR_RESUME | USBINTR_IOC | USBINTR_SP,
393 		io_addr + USBINTR);
394 
395 	/* Start at frame 0 */
396 	outw(0, io_addr + USBFRNUM);
397 	outl(uhci->fl->dma_handle, io_addr + USBFLBASEADD);
398 
399 	/* Run and mark it configured with a 64-byte max packet */
400 	uhci->state = UHCI_RUNNING_GRACE;
401 	uhci->state_end = jiffies + HZ;
402 	outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP, io_addr + USBCMD);
403 	uhci->is_stopped = 0;
404 
405 	return 0;
406 }
407 
408 /*
409  * De-allocate all resources
410  */
411 static void release_uhci(struct uhci_hcd *uhci)
412 {
413 	int i;
414 
415 	for (i = 0; i < UHCI_NUM_SKELQH; i++)
416 		if (uhci->skelqh[i]) {
417 			uhci_free_qh(uhci, uhci->skelqh[i]);
418 			uhci->skelqh[i] = NULL;
419 		}
420 
421 	if (uhci->term_td) {
422 		uhci_free_td(uhci, uhci->term_td);
423 		uhci->term_td = NULL;
424 	}
425 
426 	if (uhci->qh_pool) {
427 		dma_pool_destroy(uhci->qh_pool);
428 		uhci->qh_pool = NULL;
429 	}
430 
431 	if (uhci->td_pool) {
432 		dma_pool_destroy(uhci->td_pool);
433 		uhci->td_pool = NULL;
434 	}
435 
436 	if (uhci->fl) {
437 		dma_free_coherent(uhci_dev(uhci), sizeof(*uhci->fl),
438 				uhci->fl, uhci->fl->dma_handle);
439 		uhci->fl = NULL;
440 	}
441 
442 	if (uhci->dentry) {
443 		debugfs_remove(uhci->dentry);
444 		uhci->dentry = NULL;
445 	}
446 }
447 
448 static int uhci_reset(struct usb_hcd *hcd)
449 {
450 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
451 
452 	uhci->io_addr = (unsigned long) hcd->rsrc_start;
453 
454 	/* Kick BIOS off this hardware and reset, so we won't get
455 	 * interrupts from any previous setup.
456 	 */
457 	reset_hc(uhci);
458 	return 0;
459 }
460 
461 /*
462  * Allocate a frame list, and then setup the skeleton
463  *
464  * The hardware doesn't really know any difference
465  * in the queues, but the order does matter for the
466  * protocols higher up. The order is:
467  *
468  *  - any isochronous events handled before any
469  *    of the queues. We don't do that here, because
470  *    we'll create the actual TD entries on demand.
471  *  - The first queue is the interrupt queue.
472  *  - The second queue is the control queue, split into low- and full-speed
473  *  - The third queue is bulk queue.
474  *  - The fourth queue is the bandwidth reclamation queue, which loops back
475  *    to the full-speed control queue.
476  */
477 static int uhci_start(struct usb_hcd *hcd)
478 {
479 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
480 	int retval = -EBUSY;
481 	int i, port;
482 	unsigned io_size;
483 	dma_addr_t dma_handle;
484 	struct usb_device *udev;
485 	struct dentry *dentry;
486 
487 	io_size = (unsigned) hcd->rsrc_len;
488 
489 	dentry = debugfs_create_file(hcd->self.bus_name, S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root, uhci, &uhci_debug_operations);
490 	if (!dentry) {
491 		dev_err(uhci_dev(uhci), "couldn't create uhci debugfs entry\n");
492 		retval = -ENOMEM;
493 		goto err_create_debug_entry;
494 	}
495 	uhci->dentry = dentry;
496 
497 	uhci->fsbr = 0;
498 	uhci->fsbrtimeout = 0;
499 
500 	spin_lock_init(&uhci->lock);
501 	INIT_LIST_HEAD(&uhci->qh_remove_list);
502 
503 	INIT_LIST_HEAD(&uhci->td_remove_list);
504 
505 	INIT_LIST_HEAD(&uhci->urb_remove_list);
506 
507 	INIT_LIST_HEAD(&uhci->urb_list);
508 
509 	INIT_LIST_HEAD(&uhci->complete_list);
510 
511 	init_waitqueue_head(&uhci->waitqh);
512 
513 	uhci->fl = dma_alloc_coherent(uhci_dev(uhci), sizeof(*uhci->fl),
514 			&dma_handle, 0);
515 	if (!uhci->fl) {
516 		dev_err(uhci_dev(uhci), "unable to allocate "
517 				"consistent memory for frame list\n");
518 		goto err_alloc_fl;
519 	}
520 
521 	memset((void *)uhci->fl, 0, sizeof(*uhci->fl));
522 
523 	uhci->fl->dma_handle = dma_handle;
524 
525 	uhci->td_pool = dma_pool_create("uhci_td", uhci_dev(uhci),
526 			sizeof(struct uhci_td), 16, 0);
527 	if (!uhci->td_pool) {
528 		dev_err(uhci_dev(uhci), "unable to create td dma_pool\n");
529 		goto err_create_td_pool;
530 	}
531 
532 	uhci->qh_pool = dma_pool_create("uhci_qh", uhci_dev(uhci),
533 			sizeof(struct uhci_qh), 16, 0);
534 	if (!uhci->qh_pool) {
535 		dev_err(uhci_dev(uhci), "unable to create qh dma_pool\n");
536 		goto err_create_qh_pool;
537 	}
538 
539 	/* Initialize the root hub */
540 
541 	/* UHCI specs says devices must have 2 ports, but goes on to say */
542 	/*  they may have more but give no way to determine how many they */
543 	/*  have. However, according to the UHCI spec, Bit 7 is always set */
544 	/*  to 1. So we try to use this to our advantage */
545 	for (port = 0; port < (io_size - 0x10) / 2; port++) {
546 		unsigned int portstatus;
547 
548 		portstatus = inw(uhci->io_addr + 0x10 + (port * 2));
549 		if (!(portstatus & 0x0080))
550 			break;
551 	}
552 	if (debug)
553 		dev_info(uhci_dev(uhci), "detected %d ports\n", port);
554 
555 	/* This is experimental so anything less than 2 or greater than 8 is */
556 	/*  something weird and we'll ignore it */
557 	if (port < 2 || port > UHCI_RH_MAXCHILD) {
558 		dev_info(uhci_dev(uhci), "port count misdetected? "
559 				"forcing to 2 ports\n");
560 		port = 2;
561 	}
562 
563 	uhci->rh_numports = port;
564 
565 	udev = usb_alloc_dev(NULL, &hcd->self, 0);
566 	if (!udev) {
567 		dev_err(uhci_dev(uhci), "unable to allocate root hub\n");
568 		goto err_alloc_root_hub;
569 	}
570 
571 	uhci->term_td = uhci_alloc_td(uhci, udev);
572 	if (!uhci->term_td) {
573 		dev_err(uhci_dev(uhci), "unable to allocate terminating TD\n");
574 		goto err_alloc_term_td;
575 	}
576 
577 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
578 		uhci->skelqh[i] = uhci_alloc_qh(uhci, udev);
579 		if (!uhci->skelqh[i]) {
580 			dev_err(uhci_dev(uhci), "unable to allocate QH\n");
581 			goto err_alloc_skelqh;
582 		}
583 	}
584 
585 	/*
586 	 * 8 Interrupt queues; link all higher int queues to int1,
587 	 * then link int1 to control and control to bulk
588 	 */
589 	uhci->skel_int128_qh->link =
590 			uhci->skel_int64_qh->link =
591 			uhci->skel_int32_qh->link =
592 			uhci->skel_int16_qh->link =
593 			uhci->skel_int8_qh->link =
594 			uhci->skel_int4_qh->link =
595 			uhci->skel_int2_qh->link =
596 			cpu_to_le32(uhci->skel_int1_qh->dma_handle) | UHCI_PTR_QH;
597 	uhci->skel_int1_qh->link = cpu_to_le32(uhci->skel_ls_control_qh->dma_handle) | UHCI_PTR_QH;
598 
599 	uhci->skel_ls_control_qh->link = cpu_to_le32(uhci->skel_fs_control_qh->dma_handle) | UHCI_PTR_QH;
600 	uhci->skel_fs_control_qh->link = cpu_to_le32(uhci->skel_bulk_qh->dma_handle) | UHCI_PTR_QH;
601 	uhci->skel_bulk_qh->link = cpu_to_le32(uhci->skel_term_qh->dma_handle) | UHCI_PTR_QH;
602 
603 	/* This dummy TD is to work around a bug in Intel PIIX controllers */
604 	uhci_fill_td(uhci->term_td, 0, (UHCI_NULL_DATA_SIZE << 21) |
605 		(0x7f << TD_TOKEN_DEVADDR_SHIFT) | USB_PID_IN, 0);
606 	uhci->term_td->link = cpu_to_le32(uhci->term_td->dma_handle);
607 
608 	uhci->skel_term_qh->link = UHCI_PTR_TERM;
609 	uhci->skel_term_qh->element = cpu_to_le32(uhci->term_td->dma_handle);
610 
611 	/*
612 	 * Fill the frame list: make all entries point to the proper
613 	 * interrupt queue.
614 	 *
615 	 * The interrupt queues will be interleaved as evenly as possible.
616 	 * There's not much to be done about period-1 interrupts; they have
617 	 * to occur in every frame.  But we can schedule period-2 interrupts
618 	 * in odd-numbered frames, period-4 interrupts in frames congruent
619 	 * to 2 (mod 4), and so on.  This way each frame only has two
620 	 * interrupt QHs, which will help spread out bandwidth utilization.
621 	 */
622 	for (i = 0; i < UHCI_NUMFRAMES; i++) {
623 		int irq;
624 
625 		/*
626 		 * ffs (Find First bit Set) does exactly what we need:
627 		 * 1,3,5,...  => ffs = 0 => use skel_int2_qh = skelqh[6],
628 		 * 2,6,10,... => ffs = 1 => use skel_int4_qh = skelqh[5], etc.
629 		 * ffs > 6 => not on any high-period queue, so use
630 		 *	skel_int1_qh = skelqh[7].
631 		 * Add UHCI_NUMFRAMES to insure at least one bit is set.
632 		 */
633 		irq = 6 - (int) __ffs(i + UHCI_NUMFRAMES);
634 		if (irq < 0)
635 			irq = 7;
636 
637 		/* Only place we don't use the frame list routines */
638 		uhci->fl->frame[i] = UHCI_PTR_QH |
639 				cpu_to_le32(uhci->skelqh[irq]->dma_handle);
640 	}
641 
642 	/*
643 	 * Some architectures require a full mb() to enforce completion of
644 	 * the memory writes above before the I/O transfers in start_hc().
645 	 */
646 	mb();
647 	if ((retval = start_hc(uhci)) != 0)
648 		goto err_alloc_skelqh;
649 
650 	init_stall_timer(hcd);
651 
652 	udev->speed = USB_SPEED_FULL;
653 
654 	if (usb_hcd_register_root_hub(udev, hcd) != 0) {
655 		dev_err(uhci_dev(uhci), "unable to start root hub\n");
656 		retval = -ENOMEM;
657 		goto err_start_root_hub;
658 	}
659 
660 	return 0;
661 
662 /*
663  * error exits:
664  */
665 err_start_root_hub:
666 	reset_hc(uhci);
667 
668 	del_timer_sync(&uhci->stall_timer);
669 
670 err_alloc_skelqh:
671 	for (i = 0; i < UHCI_NUM_SKELQH; i++)
672 		if (uhci->skelqh[i]) {
673 			uhci_free_qh(uhci, uhci->skelqh[i]);
674 			uhci->skelqh[i] = NULL;
675 		}
676 
677 	uhci_free_td(uhci, uhci->term_td);
678 	uhci->term_td = NULL;
679 
680 err_alloc_term_td:
681 	usb_put_dev(udev);
682 
683 err_alloc_root_hub:
684 	dma_pool_destroy(uhci->qh_pool);
685 	uhci->qh_pool = NULL;
686 
687 err_create_qh_pool:
688 	dma_pool_destroy(uhci->td_pool);
689 	uhci->td_pool = NULL;
690 
691 err_create_td_pool:
692 	dma_free_coherent(uhci_dev(uhci), sizeof(*uhci->fl),
693 			uhci->fl, uhci->fl->dma_handle);
694 	uhci->fl = NULL;
695 
696 err_alloc_fl:
697 	debugfs_remove(uhci->dentry);
698 	uhci->dentry = NULL;
699 
700 err_create_debug_entry:
701 	return retval;
702 }
703 
704 static void uhci_stop(struct usb_hcd *hcd)
705 {
706 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
707 
708 	del_timer_sync(&uhci->stall_timer);
709 	reset_hc(uhci);
710 
711 	spin_lock_irq(&uhci->lock);
712 	uhci_scan_schedule(uhci, NULL);
713 	spin_unlock_irq(&uhci->lock);
714 
715 	release_uhci(uhci);
716 }
717 
718 #ifdef CONFIG_PM
719 static int uhci_suspend(struct usb_hcd *hcd, u32 state)
720 {
721 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
722 
723 	spin_lock_irq(&uhci->lock);
724 
725 	/* Don't try to suspend broken motherboards, reset instead */
726 	if (suspend_allowed(uhci))
727 		suspend_hc(uhci);
728 	else {
729 		spin_unlock_irq(&uhci->lock);
730 		reset_hc(uhci);
731 		spin_lock_irq(&uhci->lock);
732 		uhci_scan_schedule(uhci, NULL);
733 	}
734 
735 	spin_unlock_irq(&uhci->lock);
736 	return 0;
737 }
738 
739 static int uhci_resume(struct usb_hcd *hcd)
740 {
741 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
742 	int rc;
743 
744 	pci_set_master(to_pci_dev(uhci_dev(uhci)));
745 
746 	spin_lock_irq(&uhci->lock);
747 
748 	if (uhci->state == UHCI_SUSPENDED) {
749 
750 		/*
751 		 * Some systems don't maintain the UHCI register values
752 		 * during a PM suspend/resume cycle, so reinitialize
753 		 * the Frame Number, Framelist Base Address, Interrupt
754 		 * Enable, and Legacy Support registers.
755 		 */
756 		pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
757 				0);
758 		outw(uhci->frame_number, uhci->io_addr + USBFRNUM);
759 		outl(uhci->fl->dma_handle, uhci->io_addr + USBFLBASEADD);
760 		outw(USBINTR_TIMEOUT | USBINTR_RESUME | USBINTR_IOC |
761 				USBINTR_SP, uhci->io_addr + USBINTR);
762 		uhci->resume_detect = 1;
763 		pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
764 				USBLEGSUP_DEFAULT);
765 	} else {
766 		spin_unlock_irq(&uhci->lock);
767 		reset_hc(uhci);
768 		if ((rc = start_hc(uhci)) != 0)
769 			return rc;
770 		spin_lock_irq(&uhci->lock);
771 	}
772 	hcd->state = HC_STATE_RUNNING;
773 
774 	spin_unlock_irq(&uhci->lock);
775 	return 0;
776 }
777 #endif
778 
779 /* Wait until all the URBs for a particular device/endpoint are gone */
780 static void uhci_hcd_endpoint_disable(struct usb_hcd *hcd,
781 		struct usb_host_endpoint *ep)
782 {
783 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
784 
785 	wait_event_interruptible(uhci->waitqh, list_empty(&ep->urb_list));
786 }
787 
788 static int uhci_hcd_get_frame_number(struct usb_hcd *hcd)
789 {
790 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
791 	int frame_number;
792 	unsigned long flags;
793 
794 	/* Minimize latency by avoiding the spinlock */
795 	local_irq_save(flags);
796 	rmb();
797 	frame_number = (uhci->is_stopped ? uhci->frame_number :
798 			inw(uhci->io_addr + USBFRNUM));
799 	local_irq_restore(flags);
800 	return frame_number;
801 }
802 
803 static const char hcd_name[] = "uhci_hcd";
804 
805 static const struct hc_driver uhci_driver = {
806 	.description =		hcd_name,
807 	.product_desc =		"UHCI Host Controller",
808 	.hcd_priv_size =	sizeof(struct uhci_hcd),
809 
810 	/* Generic hardware linkage */
811 	.irq =			uhci_irq,
812 	.flags =		HCD_USB11,
813 
814 	/* Basic lifecycle operations */
815 	.reset =		uhci_reset,
816 	.start =		uhci_start,
817 #ifdef CONFIG_PM
818 	.suspend =		uhci_suspend,
819 	.resume =		uhci_resume,
820 #endif
821 	.stop =			uhci_stop,
822 
823 	.urb_enqueue =		uhci_urb_enqueue,
824 	.urb_dequeue =		uhci_urb_dequeue,
825 
826 	.endpoint_disable =	uhci_hcd_endpoint_disable,
827 	.get_frame_number =	uhci_hcd_get_frame_number,
828 
829 	.hub_status_data =	uhci_hub_status_data,
830 	.hub_control =		uhci_hub_control,
831 };
832 
833 static const struct pci_device_id uhci_pci_ids[] = { {
834 	/* handle any USB UHCI controller */
835 	PCI_DEVICE_CLASS(((PCI_CLASS_SERIAL_USB << 8) | 0x00), ~0),
836 	.driver_data =	(unsigned long) &uhci_driver,
837 	}, { /* end: all zeroes */ }
838 };
839 
840 MODULE_DEVICE_TABLE(pci, uhci_pci_ids);
841 
842 static struct pci_driver uhci_pci_driver = {
843 	.name =		(char *)hcd_name,
844 	.id_table =	uhci_pci_ids,
845 
846 	.probe =	usb_hcd_pci_probe,
847 	.remove =	usb_hcd_pci_remove,
848 
849 #ifdef	CONFIG_PM
850 	.suspend =	usb_hcd_pci_suspend,
851 	.resume =	usb_hcd_pci_resume,
852 #endif	/* PM */
853 };
854 
855 static int __init uhci_hcd_init(void)
856 {
857 	int retval = -ENOMEM;
858 
859 	printk(KERN_INFO DRIVER_DESC " " DRIVER_VERSION "\n");
860 
861 	if (usb_disabled())
862 		return -ENODEV;
863 
864 	if (debug) {
865 		errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
866 		if (!errbuf)
867 			goto errbuf_failed;
868 	}
869 
870 	uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
871 	if (!uhci_debugfs_root)
872 		goto debug_failed;
873 
874 	uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
875 		sizeof(struct urb_priv), 0, 0, NULL, NULL);
876 	if (!uhci_up_cachep)
877 		goto up_failed;
878 
879 	retval = pci_register_driver(&uhci_pci_driver);
880 	if (retval)
881 		goto init_failed;
882 
883 	return 0;
884 
885 init_failed:
886 	if (kmem_cache_destroy(uhci_up_cachep))
887 		warn("not all urb_priv's were freed!");
888 
889 up_failed:
890 	debugfs_remove(uhci_debugfs_root);
891 
892 debug_failed:
893 	if (errbuf)
894 		kfree(errbuf);
895 
896 errbuf_failed:
897 
898 	return retval;
899 }
900 
901 static void __exit uhci_hcd_cleanup(void)
902 {
903 	pci_unregister_driver(&uhci_pci_driver);
904 
905 	if (kmem_cache_destroy(uhci_up_cachep))
906 		warn("not all urb_priv's were freed!");
907 
908 	debugfs_remove(uhci_debugfs_root);
909 
910 	if (errbuf)
911 		kfree(errbuf);
912 }
913 
914 module_init(uhci_hcd_init);
915 module_exit(uhci_hcd_cleanup);
916 
917 MODULE_AUTHOR(DRIVER_AUTHOR);
918 MODULE_DESCRIPTION(DRIVER_DESC);
919 MODULE_LICENSE("GPL");
920