xref: /linux/drivers/usb/host/uhci-hcd.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 2004-2006 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  */
24 
25 #include <linux/config.h>
26 #include <linux/module.h>
27 #include <linux/pci.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/delay.h>
31 #include <linux/ioport.h>
32 #include <linux/sched.h>
33 #include <linux/slab.h>
34 #include <linux/errno.h>
35 #include <linux/unistd.h>
36 #include <linux/interrupt.h>
37 #include <linux/spinlock.h>
38 #include <linux/debugfs.h>
39 #include <linux/pm.h>
40 #include <linux/dmapool.h>
41 #include <linux/dma-mapping.h>
42 #include <linux/usb.h>
43 #include <linux/bitops.h>
44 
45 #include <asm/uaccess.h>
46 #include <asm/io.h>
47 #include <asm/irq.h>
48 #include <asm/system.h>
49 
50 #include "../core/hcd.h"
51 #include "uhci-hcd.h"
52 #include "pci-quirks.h"
53 
54 /*
55  * Version Information
56  */
57 #define DRIVER_VERSION "v3.0"
58 #define DRIVER_AUTHOR "Linus 'Frodo Rabbit' Torvalds, Johannes Erdfelt, \
59 Randy Dunlap, Georg Acher, Deti Fliegl, Thomas Sailer, Roman Weissgaerber, \
60 Alan Stern"
61 #define DRIVER_DESC "USB Universal Host Controller Interface driver"
62 
63 /*
64  * debug = 0, no debugging messages
65  * debug = 1, dump failed URBs except for stalls
66  * debug = 2, dump all failed URBs (including stalls)
67  *            show all queues in /debug/uhci/[pci_addr]
68  * debug = 3, show all TDs in URBs when dumping
69  */
70 #ifdef DEBUG
71 #define DEBUG_CONFIGURED	1
72 static int debug = 1;
73 module_param(debug, int, S_IRUGO | S_IWUSR);
74 MODULE_PARM_DESC(debug, "Debug level");
75 
76 #else
77 #define DEBUG_CONFIGURED	0
78 #define debug			0
79 #endif
80 
81 static char *errbuf;
82 #define ERRBUF_LEN    (32 * 1024)
83 
84 static kmem_cache_t *uhci_up_cachep;	/* urb_priv */
85 
86 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state);
87 static void wakeup_rh(struct uhci_hcd *uhci);
88 static void uhci_get_current_frame_number(struct uhci_hcd *uhci);
89 
90 #include "uhci-debug.c"
91 #include "uhci-q.c"
92 #include "uhci-hub.c"
93 
94 /*
95  * Finish up a host controller reset and update the recorded state.
96  */
97 static void finish_reset(struct uhci_hcd *uhci)
98 {
99 	int port;
100 
101 	/* HCRESET doesn't affect the Suspend, Reset, and Resume Detect
102 	 * bits in the port status and control registers.
103 	 * We have to clear them by hand.
104 	 */
105 	for (port = 0; port < uhci->rh_numports; ++port)
106 		outw(0, uhci->io_addr + USBPORTSC1 + (port * 2));
107 
108 	uhci->port_c_suspend = uhci->resuming_ports = 0;
109 	uhci->rh_state = UHCI_RH_RESET;
110 	uhci->is_stopped = UHCI_IS_STOPPED;
111 	uhci_to_hcd(uhci)->state = HC_STATE_HALT;
112 	uhci_to_hcd(uhci)->poll_rh = 0;
113 
114 	uhci->dead = 0;		/* Full reset resurrects the controller */
115 }
116 
117 /*
118  * Last rites for a defunct/nonfunctional controller
119  * or one we don't want to use any more.
120  */
121 static void uhci_hc_died(struct uhci_hcd *uhci)
122 {
123 	uhci_get_current_frame_number(uhci);
124 	uhci_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr);
125 	finish_reset(uhci);
126 	uhci->dead = 1;
127 
128 	/* The current frame may already be partway finished */
129 	++uhci->frame_number;
130 }
131 
132 /*
133  * Initialize a controller that was newly discovered or has lost power
134  * or otherwise been reset while it was suspended.  In none of these cases
135  * can we be sure of its previous state.
136  */
137 static void check_and_reset_hc(struct uhci_hcd *uhci)
138 {
139 	if (uhci_check_and_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr))
140 		finish_reset(uhci);
141 }
142 
143 /*
144  * Store the basic register settings needed by the controller.
145  */
146 static void configure_hc(struct uhci_hcd *uhci)
147 {
148 	/* Set the frame length to the default: 1 ms exactly */
149 	outb(USBSOF_DEFAULT, uhci->io_addr + USBSOF);
150 
151 	/* Store the frame list base address */
152 	outl(uhci->frame_dma_handle, uhci->io_addr + USBFLBASEADD);
153 
154 	/* Set the current frame number */
155 	outw(uhci->frame_number & UHCI_MAX_SOF_NUMBER,
156 			uhci->io_addr + USBFRNUM);
157 
158 	/* Mark controller as not halted before we enable interrupts */
159 	uhci_to_hcd(uhci)->state = HC_STATE_SUSPENDED;
160 	mb();
161 
162 	/* Enable PIRQ */
163 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
164 			USBLEGSUP_DEFAULT);
165 }
166 
167 
168 static int resume_detect_interrupts_are_broken(struct uhci_hcd *uhci)
169 {
170 	int port;
171 
172 	switch (to_pci_dev(uhci_dev(uhci))->vendor) {
173 	    default:
174 		break;
175 
176 	    case PCI_VENDOR_ID_GENESYS:
177 		/* Genesys Logic's GL880S controllers don't generate
178 		 * resume-detect interrupts.
179 		 */
180 		return 1;
181 
182 	    case PCI_VENDOR_ID_INTEL:
183 		/* Some of Intel's USB controllers have a bug that causes
184 		 * resume-detect interrupts if any port has an over-current
185 		 * condition.  To make matters worse, some motherboards
186 		 * hardwire unused USB ports' over-current inputs active!
187 		 * To prevent problems, we will not enable resume-detect
188 		 * interrupts if any ports are OC.
189 		 */
190 		for (port = 0; port < uhci->rh_numports; ++port) {
191 			if (inw(uhci->io_addr + USBPORTSC1 + port * 2) &
192 					USBPORTSC_OC)
193 				return 1;
194 		}
195 		break;
196 	}
197 	return 0;
198 }
199 
200 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state)
201 __releases(uhci->lock)
202 __acquires(uhci->lock)
203 {
204 	int auto_stop;
205 	int int_enable;
206 
207 	auto_stop = (new_state == UHCI_RH_AUTO_STOPPED);
208 	dev_dbg(&uhci_to_hcd(uhci)->self.root_hub->dev,
209 			"%s%s\n", __FUNCTION__,
210 			(auto_stop ? " (auto-stop)" : ""));
211 
212 	/* If we get a suspend request when we're already auto-stopped
213 	 * then there's nothing to do.
214 	 */
215 	if (uhci->rh_state == UHCI_RH_AUTO_STOPPED) {
216 		uhci->rh_state = new_state;
217 		return;
218 	}
219 
220 	/* Enable resume-detect interrupts if they work.
221 	 * Then enter Global Suspend mode, still configured.
222 	 */
223 	uhci->working_RD = 1;
224 	int_enable = USBINTR_RESUME;
225 	if (resume_detect_interrupts_are_broken(uhci)) {
226 		uhci->working_RD = int_enable = 0;
227 	}
228 	outw(int_enable, uhci->io_addr + USBINTR);
229 	outw(USBCMD_EGSM | USBCMD_CF, uhci->io_addr + USBCMD);
230 	mb();
231 	udelay(5);
232 
233 	/* If we're auto-stopping then no devices have been attached
234 	 * for a while, so there shouldn't be any active URBs and the
235 	 * controller should stop after a few microseconds.  Otherwise
236 	 * we will give the controller one frame to stop.
237 	 */
238 	if (!auto_stop && !(inw(uhci->io_addr + USBSTS) & USBSTS_HCH)) {
239 		uhci->rh_state = UHCI_RH_SUSPENDING;
240 		spin_unlock_irq(&uhci->lock);
241 		msleep(1);
242 		spin_lock_irq(&uhci->lock);
243 		if (uhci->dead)
244 			return;
245 	}
246 	if (!(inw(uhci->io_addr + USBSTS) & USBSTS_HCH))
247 		dev_warn(&uhci_to_hcd(uhci)->self.root_hub->dev,
248 			"Controller not stopped yet!\n");
249 
250 	uhci_get_current_frame_number(uhci);
251 
252 	uhci->rh_state = new_state;
253 	uhci->is_stopped = UHCI_IS_STOPPED;
254 	uhci_to_hcd(uhci)->poll_rh = !int_enable;
255 
256 	uhci_scan_schedule(uhci, NULL);
257 	uhci_fsbr_off(uhci);
258 }
259 
260 static void start_rh(struct uhci_hcd *uhci)
261 {
262 	uhci_to_hcd(uhci)->state = HC_STATE_RUNNING;
263 	uhci->is_stopped = 0;
264 
265 	/* Mark it configured and running with a 64-byte max packet.
266 	 * All interrupts are enabled, even though RESUME won't do anything.
267 	 */
268 	outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP, uhci->io_addr + USBCMD);
269 	outw(USBINTR_TIMEOUT | USBINTR_RESUME | USBINTR_IOC | USBINTR_SP,
270 			uhci->io_addr + USBINTR);
271 	mb();
272 	uhci->rh_state = UHCI_RH_RUNNING;
273 	uhci_to_hcd(uhci)->poll_rh = 1;
274 }
275 
276 static void wakeup_rh(struct uhci_hcd *uhci)
277 __releases(uhci->lock)
278 __acquires(uhci->lock)
279 {
280 	dev_dbg(&uhci_to_hcd(uhci)->self.root_hub->dev,
281 			"%s%s\n", __FUNCTION__,
282 			uhci->rh_state == UHCI_RH_AUTO_STOPPED ?
283 				" (auto-start)" : "");
284 
285 	/* If we are auto-stopped then no devices are attached so there's
286 	 * no need for wakeup signals.  Otherwise we send Global Resume
287 	 * for 20 ms.
288 	 */
289 	if (uhci->rh_state == UHCI_RH_SUSPENDED) {
290 		uhci->rh_state = UHCI_RH_RESUMING;
291 		outw(USBCMD_FGR | USBCMD_EGSM | USBCMD_CF,
292 				uhci->io_addr + USBCMD);
293 		spin_unlock_irq(&uhci->lock);
294 		msleep(20);
295 		spin_lock_irq(&uhci->lock);
296 		if (uhci->dead)
297 			return;
298 
299 		/* End Global Resume and wait for EOP to be sent */
300 		outw(USBCMD_CF, uhci->io_addr + USBCMD);
301 		mb();
302 		udelay(4);
303 		if (inw(uhci->io_addr + USBCMD) & USBCMD_FGR)
304 			dev_warn(uhci_dev(uhci), "FGR not stopped yet!\n");
305 	}
306 
307 	start_rh(uhci);
308 
309 	/* Restart root hub polling */
310 	mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
311 }
312 
313 static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
314 {
315 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
316 	unsigned short status;
317 	unsigned long flags;
318 
319 	/*
320 	 * Read the interrupt status, and write it back to clear the
321 	 * interrupt cause.  Contrary to the UHCI specification, the
322 	 * "HC Halted" status bit is persistent: it is RO, not R/WC.
323 	 */
324 	status = inw(uhci->io_addr + USBSTS);
325 	if (!(status & ~USBSTS_HCH))	/* shared interrupt, not mine */
326 		return IRQ_NONE;
327 	outw(status, uhci->io_addr + USBSTS);		/* Clear it */
328 
329 	if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) {
330 		if (status & USBSTS_HSE)
331 			dev_err(uhci_dev(uhci), "host system error, "
332 					"PCI problems?\n");
333 		if (status & USBSTS_HCPE)
334 			dev_err(uhci_dev(uhci), "host controller process "
335 					"error, something bad happened!\n");
336 		if (status & USBSTS_HCH) {
337 			spin_lock_irqsave(&uhci->lock, flags);
338 			if (uhci->rh_state >= UHCI_RH_RUNNING) {
339 				dev_err(uhci_dev(uhci),
340 					"host controller halted, "
341 					"very bad!\n");
342 				if (debug > 1 && errbuf) {
343 					/* Print the schedule for debugging */
344 					uhci_sprint_schedule(uhci,
345 							errbuf, ERRBUF_LEN);
346 					lprintk(errbuf);
347 				}
348 				uhci_hc_died(uhci);
349 
350 				/* Force a callback in case there are
351 				 * pending unlinks */
352 				mod_timer(&hcd->rh_timer, jiffies);
353 			}
354 			spin_unlock_irqrestore(&uhci->lock, flags);
355 		}
356 	}
357 
358 	if (status & USBSTS_RD)
359 		usb_hcd_poll_rh_status(hcd);
360 	else {
361 		spin_lock_irqsave(&uhci->lock, flags);
362 		uhci_scan_schedule(uhci, regs);
363 		spin_unlock_irqrestore(&uhci->lock, flags);
364 	}
365 
366 	return IRQ_HANDLED;
367 }
368 
369 /*
370  * Store the current frame number in uhci->frame_number if the controller
371  * is runnning.  Expand from 11 bits (of which we use only 10) to a
372  * full-sized integer.
373  *
374  * Like many other parts of the driver, this code relies on being polled
375  * more than once per second as long as the controller is running.
376  */
377 static void uhci_get_current_frame_number(struct uhci_hcd *uhci)
378 {
379 	if (!uhci->is_stopped) {
380 		unsigned delta;
381 
382 		delta = (inw(uhci->io_addr + USBFRNUM) - uhci->frame_number) &
383 				(UHCI_NUMFRAMES - 1);
384 		uhci->frame_number += delta;
385 	}
386 }
387 
388 /*
389  * De-allocate all resources
390  */
391 static void release_uhci(struct uhci_hcd *uhci)
392 {
393 	int i;
394 
395 	if (DEBUG_CONFIGURED) {
396 		spin_lock_irq(&uhci->lock);
397 		uhci->is_initialized = 0;
398 		spin_unlock_irq(&uhci->lock);
399 
400 		debugfs_remove(uhci->dentry);
401 	}
402 
403 	for (i = 0; i < UHCI_NUM_SKELQH; i++)
404 		uhci_free_qh(uhci, uhci->skelqh[i]);
405 
406 	uhci_free_td(uhci, uhci->term_td);
407 
408 	dma_pool_destroy(uhci->qh_pool);
409 
410 	dma_pool_destroy(uhci->td_pool);
411 
412 	kfree(uhci->frame_cpu);
413 
414 	dma_free_coherent(uhci_dev(uhci),
415 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
416 			uhci->frame, uhci->frame_dma_handle);
417 }
418 
419 static int uhci_init(struct usb_hcd *hcd)
420 {
421 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
422 	unsigned io_size = (unsigned) hcd->rsrc_len;
423 	int port;
424 
425 	uhci->io_addr = (unsigned long) hcd->rsrc_start;
426 
427 	/* The UHCI spec says devices must have 2 ports, and goes on to say
428 	 * they may have more but gives no way to determine how many there
429 	 * are.  However according to the UHCI spec, Bit 7 of the port
430 	 * status and control register is always set to 1.  So we try to
431 	 * use this to our advantage.  Another common failure mode when
432 	 * a nonexistent register is addressed is to return all ones, so
433 	 * we test for that also.
434 	 */
435 	for (port = 0; port < (io_size - USBPORTSC1) / 2; port++) {
436 		unsigned int portstatus;
437 
438 		portstatus = inw(uhci->io_addr + USBPORTSC1 + (port * 2));
439 		if (!(portstatus & 0x0080) || portstatus == 0xffff)
440 			break;
441 	}
442 	if (debug)
443 		dev_info(uhci_dev(uhci), "detected %d ports\n", port);
444 
445 	/* Anything greater than 7 is weird so we'll ignore it. */
446 	if (port > UHCI_RH_MAXCHILD) {
447 		dev_info(uhci_dev(uhci), "port count misdetected? "
448 				"forcing to 2 ports\n");
449 		port = 2;
450 	}
451 	uhci->rh_numports = port;
452 
453 	/* Kick BIOS off this hardware and reset if the controller
454 	 * isn't already safely quiescent.
455 	 */
456 	check_and_reset_hc(uhci);
457 	return 0;
458 }
459 
460 /* Make sure the controller is quiescent and that we're not using it
461  * any more.  This is mainly for the benefit of programs which, like kexec,
462  * expect the hardware to be idle: not doing DMA or generating IRQs.
463  *
464  * This routine may be called in a damaged or failing kernel.  Hence we
465  * do not acquire the spinlock before shutting down the controller.
466  */
467 static void uhci_shutdown(struct pci_dev *pdev)
468 {
469 	struct usb_hcd *hcd = (struct usb_hcd *) pci_get_drvdata(pdev);
470 
471 	uhci_hc_died(hcd_to_uhci(hcd));
472 }
473 
474 /*
475  * Allocate a frame list, and then setup the skeleton
476  *
477  * The hardware doesn't really know any difference
478  * in the queues, but the order does matter for the
479  * protocols higher up. The order is:
480  *
481  *  - any isochronous events handled before any
482  *    of the queues. We don't do that here, because
483  *    we'll create the actual TD entries on demand.
484  *  - The first queue is the interrupt queue.
485  *  - The second queue is the control queue, split into low- and full-speed
486  *  - The third queue is bulk queue.
487  *  - The fourth queue is the bandwidth reclamation queue, which loops back
488  *    to the full-speed control queue.
489  */
490 static int uhci_start(struct usb_hcd *hcd)
491 {
492 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
493 	int retval = -EBUSY;
494 	int i;
495 	struct dentry *dentry;
496 
497 	hcd->uses_new_polling = 1;
498 
499 	spin_lock_init(&uhci->lock);
500 	setup_timer(&uhci->fsbr_timer, uhci_fsbr_timeout,
501 			(unsigned long) uhci);
502 	INIT_LIST_HEAD(&uhci->idle_qh_list);
503 	init_waitqueue_head(&uhci->waitqh);
504 
505 	if (DEBUG_CONFIGURED) {
506 		dentry = debugfs_create_file(hcd->self.bus_name,
507 				S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root,
508 				uhci, &uhci_debug_operations);
509 		if (!dentry) {
510 			dev_err(uhci_dev(uhci), "couldn't create uhci "
511 					"debugfs entry\n");
512 			retval = -ENOMEM;
513 			goto err_create_debug_entry;
514 		}
515 		uhci->dentry = dentry;
516 	}
517 
518 	uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
519 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
520 			&uhci->frame_dma_handle, 0);
521 	if (!uhci->frame) {
522 		dev_err(uhci_dev(uhci), "unable to allocate "
523 				"consistent memory for frame list\n");
524 		goto err_alloc_frame;
525 	}
526 	memset(uhci->frame, 0, UHCI_NUMFRAMES * sizeof(*uhci->frame));
527 
528 	uhci->frame_cpu = kcalloc(UHCI_NUMFRAMES, sizeof(*uhci->frame_cpu),
529 			GFP_KERNEL);
530 	if (!uhci->frame_cpu) {
531 		dev_err(uhci_dev(uhci), "unable to allocate "
532 				"memory for frame pointers\n");
533 		goto err_alloc_frame_cpu;
534 	}
535 
536 	uhci->td_pool = dma_pool_create("uhci_td", uhci_dev(uhci),
537 			sizeof(struct uhci_td), 16, 0);
538 	if (!uhci->td_pool) {
539 		dev_err(uhci_dev(uhci), "unable to create td dma_pool\n");
540 		goto err_create_td_pool;
541 	}
542 
543 	uhci->qh_pool = dma_pool_create("uhci_qh", uhci_dev(uhci),
544 			sizeof(struct uhci_qh), 16, 0);
545 	if (!uhci->qh_pool) {
546 		dev_err(uhci_dev(uhci), "unable to create qh dma_pool\n");
547 		goto err_create_qh_pool;
548 	}
549 
550 	uhci->term_td = uhci_alloc_td(uhci);
551 	if (!uhci->term_td) {
552 		dev_err(uhci_dev(uhci), "unable to allocate terminating TD\n");
553 		goto err_alloc_term_td;
554 	}
555 
556 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
557 		uhci->skelqh[i] = uhci_alloc_qh(uhci, NULL, NULL);
558 		if (!uhci->skelqh[i]) {
559 			dev_err(uhci_dev(uhci), "unable to allocate QH\n");
560 			goto err_alloc_skelqh;
561 		}
562 	}
563 
564 	/*
565 	 * 8 Interrupt queues; link all higher int queues to int1,
566 	 * then link int1 to control and control to bulk
567 	 */
568 	uhci->skel_int128_qh->link =
569 			uhci->skel_int64_qh->link =
570 			uhci->skel_int32_qh->link =
571 			uhci->skel_int16_qh->link =
572 			uhci->skel_int8_qh->link =
573 			uhci->skel_int4_qh->link =
574 			uhci->skel_int2_qh->link = UHCI_PTR_QH |
575 			cpu_to_le32(uhci->skel_int1_qh->dma_handle);
576 
577 	uhci->skel_int1_qh->link = UHCI_PTR_QH |
578 			cpu_to_le32(uhci->skel_ls_control_qh->dma_handle);
579 	uhci->skel_ls_control_qh->link = UHCI_PTR_QH |
580 			cpu_to_le32(uhci->skel_fs_control_qh->dma_handle);
581 	uhci->skel_fs_control_qh->link = UHCI_PTR_QH |
582 			cpu_to_le32(uhci->skel_bulk_qh->dma_handle);
583 	uhci->skel_bulk_qh->link = UHCI_PTR_QH |
584 			cpu_to_le32(uhci->skel_term_qh->dma_handle);
585 
586 	/* This dummy TD is to work around a bug in Intel PIIX controllers */
587 	uhci_fill_td(uhci->term_td, 0, uhci_explen(0) |
588 		(0x7f << TD_TOKEN_DEVADDR_SHIFT) | USB_PID_IN, 0);
589 	uhci->term_td->link = cpu_to_le32(uhci->term_td->dma_handle);
590 
591 	uhci->skel_term_qh->link = UHCI_PTR_TERM;
592 	uhci->skel_term_qh->element = cpu_to_le32(uhci->term_td->dma_handle);
593 
594 	/*
595 	 * Fill the frame list: make all entries point to the proper
596 	 * interrupt queue.
597 	 *
598 	 * The interrupt queues will be interleaved as evenly as possible.
599 	 * There's not much to be done about period-1 interrupts; they have
600 	 * to occur in every frame.  But we can schedule period-2 interrupts
601 	 * in odd-numbered frames, period-4 interrupts in frames congruent
602 	 * to 2 (mod 4), and so on.  This way each frame only has two
603 	 * interrupt QHs, which will help spread out bandwidth utilization.
604 	 */
605 	for (i = 0; i < UHCI_NUMFRAMES; i++) {
606 		int irq;
607 
608 		/*
609 		 * ffs (Find First bit Set) does exactly what we need:
610 		 * 1,3,5,...  => ffs = 0 => use skel_int2_qh = skelqh[8],
611 		 * 2,6,10,... => ffs = 1 => use skel_int4_qh = skelqh[7], etc.
612 		 * ffs >= 7 => not on any high-period queue, so use
613 		 *	skel_int1_qh = skelqh[9].
614 		 * Add UHCI_NUMFRAMES to insure at least one bit is set.
615 		 */
616 		irq = 8 - (int) __ffs(i + UHCI_NUMFRAMES);
617 		if (irq <= 1)
618 			irq = 9;
619 
620 		/* Only place we don't use the frame list routines */
621 		uhci->frame[i] = UHCI_PTR_QH |
622 				cpu_to_le32(uhci->skelqh[irq]->dma_handle);
623 	}
624 
625 	/*
626 	 * Some architectures require a full mb() to enforce completion of
627 	 * the memory writes above before the I/O transfers in configure_hc().
628 	 */
629 	mb();
630 
631 	configure_hc(uhci);
632 	uhci->is_initialized = 1;
633 	start_rh(uhci);
634 	return 0;
635 
636 /*
637  * error exits:
638  */
639 err_alloc_skelqh:
640 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
641 		if (uhci->skelqh[i])
642 			uhci_free_qh(uhci, uhci->skelqh[i]);
643 	}
644 
645 	uhci_free_td(uhci, uhci->term_td);
646 
647 err_alloc_term_td:
648 	dma_pool_destroy(uhci->qh_pool);
649 
650 err_create_qh_pool:
651 	dma_pool_destroy(uhci->td_pool);
652 
653 err_create_td_pool:
654 	kfree(uhci->frame_cpu);
655 
656 err_alloc_frame_cpu:
657 	dma_free_coherent(uhci_dev(uhci),
658 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
659 			uhci->frame, uhci->frame_dma_handle);
660 
661 err_alloc_frame:
662 	debugfs_remove(uhci->dentry);
663 
664 err_create_debug_entry:
665 	return retval;
666 }
667 
668 static void uhci_stop(struct usb_hcd *hcd)
669 {
670 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
671 
672 	spin_lock_irq(&uhci->lock);
673 	if (test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) && !uhci->dead)
674 		uhci_hc_died(uhci);
675 	uhci_scan_schedule(uhci, NULL);
676 	spin_unlock_irq(&uhci->lock);
677 
678 	del_timer_sync(&uhci->fsbr_timer);
679 	release_uhci(uhci);
680 }
681 
682 #ifdef CONFIG_PM
683 static int uhci_rh_suspend(struct usb_hcd *hcd)
684 {
685 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
686 	int rc = 0;
687 
688 	spin_lock_irq(&uhci->lock);
689 	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
690 		rc = -ESHUTDOWN;
691 	else if (!uhci->dead)
692 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
693 	spin_unlock_irq(&uhci->lock);
694 	return rc;
695 }
696 
697 static int uhci_rh_resume(struct usb_hcd *hcd)
698 {
699 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
700 	int rc = 0;
701 
702 	spin_lock_irq(&uhci->lock);
703 	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
704 		dev_warn(&hcd->self.root_hub->dev, "HC isn't running!\n");
705 		rc = -ESHUTDOWN;
706 	} else if (!uhci->dead)
707 		wakeup_rh(uhci);
708 	spin_unlock_irq(&uhci->lock);
709 	return rc;
710 }
711 
712 static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
713 {
714 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
715 	int rc = 0;
716 
717 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
718 
719 	spin_lock_irq(&uhci->lock);
720 	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
721 		goto done_okay;		/* Already suspended or dead */
722 
723 	if (uhci->rh_state > UHCI_RH_SUSPENDED) {
724 		dev_warn(uhci_dev(uhci), "Root hub isn't suspended!\n");
725 		rc = -EBUSY;
726 		goto done;
727 	};
728 
729 	/* All PCI host controllers are required to disable IRQ generation
730 	 * at the source, so we must turn off PIRQ.
731 	 */
732 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
733 	mb();
734 	hcd->poll_rh = 0;
735 
736 	/* FIXME: Enable non-PME# remote wakeup? */
737 
738 done_okay:
739 	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
740 done:
741 	spin_unlock_irq(&uhci->lock);
742 	return rc;
743 }
744 
745 static int uhci_resume(struct usb_hcd *hcd)
746 {
747 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
748 
749 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
750 
751 	/* Since we aren't in D3 any more, it's safe to set this flag
752 	 * even if the controller was dead.
753 	 */
754 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
755 	mb();
756 
757 	spin_lock_irq(&uhci->lock);
758 
759 	/* FIXME: Disable non-PME# remote wakeup? */
760 
761 	/* The firmware or a boot kernel may have changed the controller
762 	 * settings during a system wakeup.  Check it and reconfigure
763 	 * to avoid problems.
764 	 */
765 	check_and_reset_hc(uhci);
766 
767 	/* If the controller was dead before, it's back alive now */
768 	configure_hc(uhci);
769 
770 	if (uhci->rh_state == UHCI_RH_RESET) {
771 
772 		/* The controller had to be reset */
773 		usb_root_hub_lost_power(hcd->self.root_hub);
774 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
775 	}
776 
777 	spin_unlock_irq(&uhci->lock);
778 
779 	if (!uhci->working_RD) {
780 		/* Suspended root hub needs to be polled */
781 		hcd->poll_rh = 1;
782 		usb_hcd_poll_rh_status(hcd);
783 	}
784 	return 0;
785 }
786 #endif
787 
788 /* Wait until a particular device/endpoint's QH is idle, and free it */
789 static void uhci_hcd_endpoint_disable(struct usb_hcd *hcd,
790 		struct usb_host_endpoint *hep)
791 {
792 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
793 	struct uhci_qh *qh;
794 
795 	spin_lock_irq(&uhci->lock);
796 	qh = (struct uhci_qh *) hep->hcpriv;
797 	if (qh == NULL)
798 		goto done;
799 
800 	while (qh->state != QH_STATE_IDLE) {
801 		++uhci->num_waiting;
802 		spin_unlock_irq(&uhci->lock);
803 		wait_event_interruptible(uhci->waitqh,
804 				qh->state == QH_STATE_IDLE);
805 		spin_lock_irq(&uhci->lock);
806 		--uhci->num_waiting;
807 	}
808 
809 	uhci_free_qh(uhci, qh);
810 done:
811 	spin_unlock_irq(&uhci->lock);
812 }
813 
814 static int uhci_hcd_get_frame_number(struct usb_hcd *hcd)
815 {
816 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
817 	unsigned frame_number;
818 	unsigned delta;
819 
820 	/* Minimize latency by avoiding the spinlock */
821 	frame_number = uhci->frame_number;
822 	barrier();
823 	delta = (inw(uhci->io_addr + USBFRNUM) - frame_number) &
824 			(UHCI_NUMFRAMES - 1);
825 	return frame_number + delta;
826 }
827 
828 static const char hcd_name[] = "uhci_hcd";
829 
830 static const struct hc_driver uhci_driver = {
831 	.description =		hcd_name,
832 	.product_desc =		"UHCI Host Controller",
833 	.hcd_priv_size =	sizeof(struct uhci_hcd),
834 
835 	/* Generic hardware linkage */
836 	.irq =			uhci_irq,
837 	.flags =		HCD_USB11,
838 
839 	/* Basic lifecycle operations */
840 	.reset =		uhci_init,
841 	.start =		uhci_start,
842 #ifdef CONFIG_PM
843 	.suspend =		uhci_suspend,
844 	.resume =		uhci_resume,
845 	.bus_suspend =		uhci_rh_suspend,
846 	.bus_resume =		uhci_rh_resume,
847 #endif
848 	.stop =			uhci_stop,
849 
850 	.urb_enqueue =		uhci_urb_enqueue,
851 	.urb_dequeue =		uhci_urb_dequeue,
852 
853 	.endpoint_disable =	uhci_hcd_endpoint_disable,
854 	.get_frame_number =	uhci_hcd_get_frame_number,
855 
856 	.hub_status_data =	uhci_hub_status_data,
857 	.hub_control =		uhci_hub_control,
858 };
859 
860 static const struct pci_device_id uhci_pci_ids[] = { {
861 	/* handle any USB UHCI controller */
862 	PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_UHCI, ~0),
863 	.driver_data =	(unsigned long) &uhci_driver,
864 	}, { /* end: all zeroes */ }
865 };
866 
867 MODULE_DEVICE_TABLE(pci, uhci_pci_ids);
868 
869 static struct pci_driver uhci_pci_driver = {
870 	.name =		(char *)hcd_name,
871 	.id_table =	uhci_pci_ids,
872 
873 	.probe =	usb_hcd_pci_probe,
874 	.remove =	usb_hcd_pci_remove,
875 	.shutdown =	uhci_shutdown,
876 
877 #ifdef	CONFIG_PM
878 	.suspend =	usb_hcd_pci_suspend,
879 	.resume =	usb_hcd_pci_resume,
880 #endif	/* PM */
881 };
882 
883 static int __init uhci_hcd_init(void)
884 {
885 	int retval = -ENOMEM;
886 
887 	printk(KERN_INFO DRIVER_DESC " " DRIVER_VERSION "\n");
888 
889 	if (usb_disabled())
890 		return -ENODEV;
891 
892 	if (DEBUG_CONFIGURED) {
893 		errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
894 		if (!errbuf)
895 			goto errbuf_failed;
896 		uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
897 		if (!uhci_debugfs_root)
898 			goto debug_failed;
899 	}
900 
901 	uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
902 		sizeof(struct urb_priv), 0, 0, NULL, NULL);
903 	if (!uhci_up_cachep)
904 		goto up_failed;
905 
906 	retval = pci_register_driver(&uhci_pci_driver);
907 	if (retval)
908 		goto init_failed;
909 
910 	return 0;
911 
912 init_failed:
913 	if (kmem_cache_destroy(uhci_up_cachep))
914 		warn("not all urb_privs were freed!");
915 
916 up_failed:
917 	debugfs_remove(uhci_debugfs_root);
918 
919 debug_failed:
920 	kfree(errbuf);
921 
922 errbuf_failed:
923 
924 	return retval;
925 }
926 
927 static void __exit uhci_hcd_cleanup(void)
928 {
929 	pci_unregister_driver(&uhci_pci_driver);
930 
931 	if (kmem_cache_destroy(uhci_up_cachep))
932 		warn("not all urb_privs were freed!");
933 
934 	debugfs_remove(uhci_debugfs_root);
935 	kfree(errbuf);
936 }
937 
938 module_init(uhci_hcd_init);
939 module_exit(uhci_hcd_cleanup);
940 
941 MODULE_AUTHOR(DRIVER_AUTHOR);
942 MODULE_DESCRIPTION(DRIVER_DESC);
943 MODULE_LICENSE("GPL");
944