xref: /linux/drivers/usb/host/uhci-hcd.c (revision 54a8a2220c936a47840c9a3d74910c5a56fae2ed)
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 2004-2005 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 #ifdef CONFIG_USB_DEBUG
27 #define DEBUG
28 #else
29 #undef DEBUG
30 #endif
31 #include <linux/module.h>
32 #include <linux/pci.h>
33 #include <linux/kernel.h>
34 #include <linux/init.h>
35 #include <linux/delay.h>
36 #include <linux/ioport.h>
37 #include <linux/sched.h>
38 #include <linux/slab.h>
39 #include <linux/smp_lock.h>
40 #include <linux/errno.h>
41 #include <linux/unistd.h>
42 #include <linux/interrupt.h>
43 #include <linux/spinlock.h>
44 #include <linux/debugfs.h>
45 #include <linux/pm.h>
46 #include <linux/dmapool.h>
47 #include <linux/dma-mapping.h>
48 #include <linux/usb.h>
49 #include <linux/bitops.h>
50 
51 #include <asm/uaccess.h>
52 #include <asm/io.h>
53 #include <asm/irq.h>
54 #include <asm/system.h>
55 
56 #include "../core/hcd.h"
57 #include "uhci-hcd.h"
58 
59 /*
60  * Version Information
61  */
62 #define DRIVER_VERSION "v2.3"
63 #define DRIVER_AUTHOR "Linus 'Frodo Rabbit' Torvalds, Johannes Erdfelt, \
64 Randy Dunlap, Georg Acher, Deti Fliegl, Thomas Sailer, Roman Weissgaerber, \
65 Alan Stern"
66 #define DRIVER_DESC "USB Universal Host Controller Interface driver"
67 
68 /*
69  * debug = 0, no debugging messages
70  * debug = 1, dump failed URB's except for stalls
71  * debug = 2, dump all failed URB's (including stalls)
72  *            show all queues in /debug/uhci/[pci_addr]
73  * debug = 3, show all TD's in URB's when dumping
74  */
75 #ifdef DEBUG
76 static int debug = 1;
77 #else
78 static int debug = 0;
79 #endif
80 module_param(debug, int, S_IRUGO | S_IWUSR);
81 MODULE_PARM_DESC(debug, "Debug level");
82 static char *errbuf;
83 #define ERRBUF_LEN    (32 * 1024)
84 
85 static kmem_cache_t *uhci_up_cachep;	/* urb_priv */
86 
87 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state);
88 static void wakeup_rh(struct uhci_hcd *uhci);
89 static void uhci_get_current_frame_number(struct uhci_hcd *uhci);
90 
91 /* If a transfer is still active after this much time, turn off FSBR */
92 #define IDLE_TIMEOUT	msecs_to_jiffies(50)
93 #define FSBR_DELAY	msecs_to_jiffies(50)
94 
95 /* When we timeout an idle transfer for FSBR, we'll switch it over to */
96 /* depth first traversal. We'll do it in groups of this number of TD's */
97 /* to make sure it doesn't hog all of the bandwidth */
98 #define DEPTH_INTERVAL 5
99 
100 #include "uhci-debug.c"
101 #include "uhci-q.c"
102 #include "uhci-hub.c"
103 
104 /*
105  * Make sure the controller is completely inactive, unable to
106  * generate interrupts or do DMA.
107  */
108 static void reset_hc(struct uhci_hcd *uhci)
109 {
110 	int port;
111 
112 	/* Turn off PIRQ enable and SMI enable.  (This also turns off the
113 	 * BIOS's USB Legacy Support.)  Turn off all the R/WC bits too.
114 	 */
115 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
116 			USBLEGSUP_RWC);
117 
118 	/* Reset the HC - this will force us to get a
119 	 * new notification of any already connected
120 	 * ports due to the virtual disconnect that it
121 	 * implies.
122 	 */
123 	outw(USBCMD_HCRESET, uhci->io_addr + USBCMD);
124 	mb();
125 	udelay(5);
126 	if (inw(uhci->io_addr + USBCMD) & USBCMD_HCRESET)
127 		dev_warn(uhci_dev(uhci), "HCRESET not completed yet!\n");
128 
129 	/* Just to be safe, disable interrupt requests and
130 	 * make sure the controller is stopped.
131 	 */
132 	outw(0, uhci->io_addr + USBINTR);
133 	outw(0, uhci->io_addr + USBCMD);
134 
135 	/* HCRESET doesn't affect the Suspend, Reset, and Resume Detect
136 	 * bits in the port status and control registers.
137 	 * We have to clear them by hand.
138 	 */
139 	for (port = 0; port < uhci->rh_numports; ++port)
140 		outw(0, uhci->io_addr + USBPORTSC1 + (port * 2));
141 
142 	uhci->port_c_suspend = uhci->suspended_ports =
143 			uhci->resuming_ports = 0;
144 	uhci->rh_state = UHCI_RH_RESET;
145 	uhci->is_stopped = UHCI_IS_STOPPED;
146 	uhci_to_hcd(uhci)->state = HC_STATE_HALT;
147 	uhci_to_hcd(uhci)->poll_rh = 0;
148 }
149 
150 /*
151  * Last rites for a defunct/nonfunctional controller
152  * or one we don't want to use any more.
153  */
154 static void hc_died(struct uhci_hcd *uhci)
155 {
156 	reset_hc(uhci);
157 	uhci->hc_inaccessible = 1;
158 }
159 
160 /*
161  * Initialize a controller that was newly discovered or has just been
162  * resumed.  In either case we can't be sure of its previous state.
163  */
164 static void check_and_reset_hc(struct uhci_hcd *uhci)
165 {
166 	u16 legsup;
167 	unsigned int cmd, intr;
168 
169 	/*
170 	 * When restarting a suspended controller, we expect all the
171 	 * settings to be the same as we left them:
172 	 *
173 	 *	PIRQ and SMI disabled, no R/W bits set in USBLEGSUP;
174 	 *	Controller is stopped and configured with EGSM set;
175 	 *	No interrupts enabled except possibly Resume Detect.
176 	 *
177 	 * If any of these conditions are violated we do a complete reset.
178 	 */
179 	pci_read_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, &legsup);
180 	if (legsup & ~(USBLEGSUP_RO | USBLEGSUP_RWC)) {
181 		dev_dbg(uhci_dev(uhci), "%s: legsup = 0x%04x\n",
182 				__FUNCTION__, legsup);
183 		goto reset_needed;
184 	}
185 
186 	cmd = inw(uhci->io_addr + USBCMD);
187 	if ((cmd & USBCMD_RS) || !(cmd & USBCMD_CF) || !(cmd & USBCMD_EGSM)) {
188 		dev_dbg(uhci_dev(uhci), "%s: cmd = 0x%04x\n",
189 				__FUNCTION__, cmd);
190 		goto reset_needed;
191 	}
192 
193 	intr = inw(uhci->io_addr + USBINTR);
194 	if (intr & (~USBINTR_RESUME)) {
195 		dev_dbg(uhci_dev(uhci), "%s: intr = 0x%04x\n",
196 				__FUNCTION__, intr);
197 		goto reset_needed;
198 	}
199 	return;
200 
201 reset_needed:
202 	dev_dbg(uhci_dev(uhci), "Performing full reset\n");
203 	reset_hc(uhci);
204 }
205 
206 /*
207  * Store the basic register settings needed by the controller.
208  */
209 static void configure_hc(struct uhci_hcd *uhci)
210 {
211 	/* Set the frame length to the default: 1 ms exactly */
212 	outb(USBSOF_DEFAULT, uhci->io_addr + USBSOF);
213 
214 	/* Store the frame list base address */
215 	outl(uhci->fl->dma_handle, uhci->io_addr + USBFLBASEADD);
216 
217 	/* Set the current frame number */
218 	outw(uhci->frame_number, uhci->io_addr + USBFRNUM);
219 
220 	/* Mark controller as running before we enable interrupts */
221 	uhci_to_hcd(uhci)->state = HC_STATE_RUNNING;
222 	mb();
223 
224 	/* Enable PIRQ */
225 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
226 			USBLEGSUP_DEFAULT);
227 }
228 
229 
230 static int resume_detect_interrupts_are_broken(struct uhci_hcd *uhci)
231 {
232 	int port;
233 
234 	switch (to_pci_dev(uhci_dev(uhci))->vendor) {
235 	    default:
236 		break;
237 
238 	    case PCI_VENDOR_ID_GENESYS:
239 		/* Genesys Logic's GL880S controllers don't generate
240 		 * resume-detect interrupts.
241 		 */
242 		return 1;
243 
244 	    case PCI_VENDOR_ID_INTEL:
245 		/* Some of Intel's USB controllers have a bug that causes
246 		 * resume-detect interrupts if any port has an over-current
247 		 * condition.  To make matters worse, some motherboards
248 		 * hardwire unused USB ports' over-current inputs active!
249 		 * To prevent problems, we will not enable resume-detect
250 		 * interrupts if any ports are OC.
251 		 */
252 		for (port = 0; port < uhci->rh_numports; ++port) {
253 			if (inw(uhci->io_addr + USBPORTSC1 + port * 2) &
254 					USBPORTSC_OC)
255 				return 1;
256 		}
257 		break;
258 	}
259 	return 0;
260 }
261 
262 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state)
263 __releases(uhci->lock)
264 __acquires(uhci->lock)
265 {
266 	int auto_stop;
267 	int int_enable;
268 
269 	auto_stop = (new_state == UHCI_RH_AUTO_STOPPED);
270 	dev_dbg(uhci_dev(uhci), "%s%s\n", __FUNCTION__,
271 			(auto_stop ? " (auto-stop)" : ""));
272 
273 	/* If we get a suspend request when we're already auto-stopped
274 	 * then there's nothing to do.
275 	 */
276 	if (uhci->rh_state == UHCI_RH_AUTO_STOPPED) {
277 		uhci->rh_state = new_state;
278 		return;
279 	}
280 
281 	/* Enable resume-detect interrupts if they work.
282 	 * Then enter Global Suspend mode, still configured.
283 	 */
284 	uhci->working_RD = 1;
285 	int_enable = USBINTR_RESUME;
286 	if (resume_detect_interrupts_are_broken(uhci)) {
287 		uhci->working_RD = int_enable = 0;
288 	}
289 	outw(int_enable, uhci->io_addr + USBINTR);
290 	outw(USBCMD_EGSM | USBCMD_CF, uhci->io_addr + USBCMD);
291 	mb();
292 	udelay(5);
293 
294 	/* If we're auto-stopping then no devices have been attached
295 	 * for a while, so there shouldn't be any active URBs and the
296 	 * controller should stop after a few microseconds.  Otherwise
297 	 * we will give the controller one frame to stop.
298 	 */
299 	if (!auto_stop && !(inw(uhci->io_addr + USBSTS) & USBSTS_HCH)) {
300 		uhci->rh_state = UHCI_RH_SUSPENDING;
301 		spin_unlock_irq(&uhci->lock);
302 		msleep(1);
303 		spin_lock_irq(&uhci->lock);
304 		if (uhci->hc_inaccessible)	/* Died */
305 			return;
306 	}
307 	if (!(inw(uhci->io_addr + USBSTS) & USBSTS_HCH))
308 		dev_warn(uhci_dev(uhci), "Controller not stopped yet!\n");
309 
310 	uhci_get_current_frame_number(uhci);
311 	smp_wmb();
312 
313 	uhci->rh_state = new_state;
314 	uhci->is_stopped = UHCI_IS_STOPPED;
315 	uhci_to_hcd(uhci)->poll_rh = !int_enable;
316 
317 	uhci_scan_schedule(uhci, NULL);
318 }
319 
320 static void start_rh(struct uhci_hcd *uhci)
321 {
322 	uhci->is_stopped = 0;
323 	smp_wmb();
324 
325 	/* Mark it configured and running with a 64-byte max packet.
326 	 * All interrupts are enabled, even though RESUME won't do anything.
327 	 */
328 	outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP, uhci->io_addr + USBCMD);
329 	outw(USBINTR_TIMEOUT | USBINTR_RESUME | USBINTR_IOC | USBINTR_SP,
330 			uhci->io_addr + USBINTR);
331 	mb();
332 	uhci->rh_state = UHCI_RH_RUNNING;
333 	uhci_to_hcd(uhci)->poll_rh = 1;
334 }
335 
336 static void wakeup_rh(struct uhci_hcd *uhci)
337 __releases(uhci->lock)
338 __acquires(uhci->lock)
339 {
340 	dev_dbg(uhci_dev(uhci), "%s%s\n", __FUNCTION__,
341 			uhci->rh_state == UHCI_RH_AUTO_STOPPED ?
342 				" (auto-start)" : "");
343 
344 	/* If we are auto-stopped then no devices are attached so there's
345 	 * no need for wakeup signals.  Otherwise we send Global Resume
346 	 * for 20 ms.
347 	 */
348 	if (uhci->rh_state == UHCI_RH_SUSPENDED) {
349 		uhci->rh_state = UHCI_RH_RESUMING;
350 		outw(USBCMD_FGR | USBCMD_EGSM | USBCMD_CF,
351 				uhci->io_addr + USBCMD);
352 		spin_unlock_irq(&uhci->lock);
353 		msleep(20);
354 		spin_lock_irq(&uhci->lock);
355 		if (uhci->hc_inaccessible)	/* Died */
356 			return;
357 
358 		/* End Global Resume and wait for EOP to be sent */
359 		outw(USBCMD_CF, uhci->io_addr + USBCMD);
360 		mb();
361 		udelay(4);
362 		if (inw(uhci->io_addr + USBCMD) & USBCMD_FGR)
363 			dev_warn(uhci_dev(uhci), "FGR not stopped yet!\n");
364 	}
365 
366 	start_rh(uhci);
367 
368 	/* Restart root hub polling */
369 	mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
370 }
371 
372 static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
373 {
374 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
375 	unsigned short status;
376 	unsigned long flags;
377 
378 	/*
379 	 * Read the interrupt status, and write it back to clear the
380 	 * interrupt cause.  Contrary to the UHCI specification, the
381 	 * "HC Halted" status bit is persistent: it is RO, not R/WC.
382 	 */
383 	status = inw(uhci->io_addr + USBSTS);
384 	if (!(status & ~USBSTS_HCH))	/* shared interrupt, not mine */
385 		return IRQ_NONE;
386 	outw(status, uhci->io_addr + USBSTS);		/* Clear it */
387 
388 	if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) {
389 		if (status & USBSTS_HSE)
390 			dev_err(uhci_dev(uhci), "host system error, "
391 					"PCI problems?\n");
392 		if (status & USBSTS_HCPE)
393 			dev_err(uhci_dev(uhci), "host controller process "
394 					"error, something bad happened!\n");
395 		if (status & USBSTS_HCH) {
396 			spin_lock_irqsave(&uhci->lock, flags);
397 			if (uhci->rh_state >= UHCI_RH_RUNNING) {
398 				dev_err(uhci_dev(uhci),
399 					"host controller halted, "
400 					"very bad!\n");
401 				hc_died(uhci);
402 
403 				/* Force a callback in case there are
404 				 * pending unlinks */
405 				mod_timer(&hcd->rh_timer, jiffies);
406 			}
407 			spin_unlock_irqrestore(&uhci->lock, flags);
408 		}
409 	}
410 
411 	if (status & USBSTS_RD)
412 		usb_hcd_poll_rh_status(hcd);
413 	else {
414 		spin_lock_irqsave(&uhci->lock, flags);
415 		uhci_scan_schedule(uhci, regs);
416 		spin_unlock_irqrestore(&uhci->lock, flags);
417 	}
418 
419 	return IRQ_HANDLED;
420 }
421 
422 /*
423  * Store the current frame number in uhci->frame_number if the controller
424  * is runnning
425  */
426 static void uhci_get_current_frame_number(struct uhci_hcd *uhci)
427 {
428 	if (!uhci->is_stopped)
429 		uhci->frame_number = inw(uhci->io_addr + USBFRNUM);
430 }
431 
432 /*
433  * De-allocate all resources
434  */
435 static void release_uhci(struct uhci_hcd *uhci)
436 {
437 	int i;
438 
439 	for (i = 0; i < UHCI_NUM_SKELQH; i++)
440 		if (uhci->skelqh[i]) {
441 			uhci_free_qh(uhci, uhci->skelqh[i]);
442 			uhci->skelqh[i] = NULL;
443 		}
444 
445 	if (uhci->term_td) {
446 		uhci_free_td(uhci, uhci->term_td);
447 		uhci->term_td = NULL;
448 	}
449 
450 	if (uhci->qh_pool) {
451 		dma_pool_destroy(uhci->qh_pool);
452 		uhci->qh_pool = NULL;
453 	}
454 
455 	if (uhci->td_pool) {
456 		dma_pool_destroy(uhci->td_pool);
457 		uhci->td_pool = NULL;
458 	}
459 
460 	if (uhci->fl) {
461 		dma_free_coherent(uhci_dev(uhci), sizeof(*uhci->fl),
462 				uhci->fl, uhci->fl->dma_handle);
463 		uhci->fl = NULL;
464 	}
465 
466 	if (uhci->dentry) {
467 		debugfs_remove(uhci->dentry);
468 		uhci->dentry = NULL;
469 	}
470 }
471 
472 static int uhci_reset(struct usb_hcd *hcd)
473 {
474 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
475 	unsigned io_size = (unsigned) hcd->rsrc_len;
476 	int port;
477 
478 	uhci->io_addr = (unsigned long) hcd->rsrc_start;
479 
480 	/* The UHCI spec says devices must have 2 ports, and goes on to say
481 	 * they may have more but gives no way to determine how many there
482 	 * are.  However according to the UHCI spec, Bit 7 of the port
483 	 * status and control register is always set to 1.  So we try to
484 	 * use this to our advantage.  Another common failure mode when
485 	 * a nonexistent register is addressed is to return all ones, so
486 	 * we test for that also.
487 	 */
488 	for (port = 0; port < (io_size - USBPORTSC1) / 2; port++) {
489 		unsigned int portstatus;
490 
491 		portstatus = inw(uhci->io_addr + USBPORTSC1 + (port * 2));
492 		if (!(portstatus & 0x0080) || portstatus == 0xffff)
493 			break;
494 	}
495 	if (debug)
496 		dev_info(uhci_dev(uhci), "detected %d ports\n", port);
497 
498 	/* Anything greater than 7 is weird so we'll ignore it. */
499 	if (port > UHCI_RH_MAXCHILD) {
500 		dev_info(uhci_dev(uhci), "port count misdetected? "
501 				"forcing to 2 ports\n");
502 		port = 2;
503 	}
504 	uhci->rh_numports = port;
505 
506 	/* Kick BIOS off this hardware and reset if the controller
507 	 * isn't already safely quiescent.
508 	 */
509 	check_and_reset_hc(uhci);
510 	return 0;
511 }
512 
513 /* Make sure the controller is quiescent and that we're not using it
514  * any more.  This is mainly for the benefit of programs which, like kexec,
515  * expect the hardware to be idle: not doing DMA or generating IRQs.
516  *
517  * This routine may be called in a damaged or failing kernel.  Hence we
518  * do not acquire the spinlock before shutting down the controller.
519  */
520 static void uhci_shutdown(struct pci_dev *pdev)
521 {
522 	struct usb_hcd *hcd = (struct usb_hcd *) pci_get_drvdata(pdev);
523 
524 	hc_died(hcd_to_uhci(hcd));
525 }
526 
527 /*
528  * Allocate a frame list, and then setup the skeleton
529  *
530  * The hardware doesn't really know any difference
531  * in the queues, but the order does matter for the
532  * protocols higher up. The order is:
533  *
534  *  - any isochronous events handled before any
535  *    of the queues. We don't do that here, because
536  *    we'll create the actual TD entries on demand.
537  *  - The first queue is the interrupt queue.
538  *  - The second queue is the control queue, split into low- and full-speed
539  *  - The third queue is bulk queue.
540  *  - The fourth queue is the bandwidth reclamation queue, which loops back
541  *    to the full-speed control queue.
542  */
543 static int uhci_start(struct usb_hcd *hcd)
544 {
545 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
546 	int retval = -EBUSY;
547 	int i;
548 	dma_addr_t dma_handle;
549 	struct dentry *dentry;
550 
551 	hcd->uses_new_polling = 1;
552 	if (pci_find_capability(to_pci_dev(uhci_dev(uhci)), PCI_CAP_ID_PM))
553 		hcd->can_wakeup = 1;		/* Assume it supports PME# */
554 
555 	dentry = debugfs_create_file(hcd->self.bus_name,
556 			S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root, uhci,
557 			&uhci_debug_operations);
558 	if (!dentry) {
559 		dev_err(uhci_dev(uhci),
560 				"couldn't create uhci debugfs entry\n");
561 		retval = -ENOMEM;
562 		goto err_create_debug_entry;
563 	}
564 	uhci->dentry = dentry;
565 
566 	uhci->fsbr = 0;
567 	uhci->fsbrtimeout = 0;
568 
569 	spin_lock_init(&uhci->lock);
570 	INIT_LIST_HEAD(&uhci->qh_remove_list);
571 
572 	INIT_LIST_HEAD(&uhci->td_remove_list);
573 
574 	INIT_LIST_HEAD(&uhci->urb_remove_list);
575 
576 	INIT_LIST_HEAD(&uhci->urb_list);
577 
578 	INIT_LIST_HEAD(&uhci->complete_list);
579 
580 	init_waitqueue_head(&uhci->waitqh);
581 
582 	uhci->fl = dma_alloc_coherent(uhci_dev(uhci), sizeof(*uhci->fl),
583 			&dma_handle, 0);
584 	if (!uhci->fl) {
585 		dev_err(uhci_dev(uhci), "unable to allocate "
586 				"consistent memory for frame list\n");
587 		goto err_alloc_fl;
588 	}
589 
590 	memset((void *)uhci->fl, 0, sizeof(*uhci->fl));
591 
592 	uhci->fl->dma_handle = dma_handle;
593 
594 	uhci->td_pool = dma_pool_create("uhci_td", uhci_dev(uhci),
595 			sizeof(struct uhci_td), 16, 0);
596 	if (!uhci->td_pool) {
597 		dev_err(uhci_dev(uhci), "unable to create td dma_pool\n");
598 		goto err_create_td_pool;
599 	}
600 
601 	uhci->qh_pool = dma_pool_create("uhci_qh", uhci_dev(uhci),
602 			sizeof(struct uhci_qh), 16, 0);
603 	if (!uhci->qh_pool) {
604 		dev_err(uhci_dev(uhci), "unable to create qh dma_pool\n");
605 		goto err_create_qh_pool;
606 	}
607 
608 	uhci->term_td = uhci_alloc_td(uhci);
609 	if (!uhci->term_td) {
610 		dev_err(uhci_dev(uhci), "unable to allocate terminating TD\n");
611 		goto err_alloc_term_td;
612 	}
613 
614 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
615 		uhci->skelqh[i] = uhci_alloc_qh(uhci);
616 		if (!uhci->skelqh[i]) {
617 			dev_err(uhci_dev(uhci), "unable to allocate QH\n");
618 			goto err_alloc_skelqh;
619 		}
620 	}
621 
622 	/*
623 	 * 8 Interrupt queues; link all higher int queues to int1,
624 	 * then link int1 to control and control to bulk
625 	 */
626 	uhci->skel_int128_qh->link =
627 			uhci->skel_int64_qh->link =
628 			uhci->skel_int32_qh->link =
629 			uhci->skel_int16_qh->link =
630 			uhci->skel_int8_qh->link =
631 			uhci->skel_int4_qh->link =
632 			uhci->skel_int2_qh->link =
633 			cpu_to_le32(uhci->skel_int1_qh->dma_handle) | UHCI_PTR_QH;
634 	uhci->skel_int1_qh->link = cpu_to_le32(uhci->skel_ls_control_qh->dma_handle) | UHCI_PTR_QH;
635 
636 	uhci->skel_ls_control_qh->link = cpu_to_le32(uhci->skel_fs_control_qh->dma_handle) | UHCI_PTR_QH;
637 	uhci->skel_fs_control_qh->link = cpu_to_le32(uhci->skel_bulk_qh->dma_handle) | UHCI_PTR_QH;
638 	uhci->skel_bulk_qh->link = cpu_to_le32(uhci->skel_term_qh->dma_handle) | UHCI_PTR_QH;
639 
640 	/* This dummy TD is to work around a bug in Intel PIIX controllers */
641 	uhci_fill_td(uhci->term_td, 0, (UHCI_NULL_DATA_SIZE << 21) |
642 		(0x7f << TD_TOKEN_DEVADDR_SHIFT) | USB_PID_IN, 0);
643 	uhci->term_td->link = cpu_to_le32(uhci->term_td->dma_handle);
644 
645 	uhci->skel_term_qh->link = UHCI_PTR_TERM;
646 	uhci->skel_term_qh->element = cpu_to_le32(uhci->term_td->dma_handle);
647 
648 	/*
649 	 * Fill the frame list: make all entries point to the proper
650 	 * interrupt queue.
651 	 *
652 	 * The interrupt queues will be interleaved as evenly as possible.
653 	 * There's not much to be done about period-1 interrupts; they have
654 	 * to occur in every frame.  But we can schedule period-2 interrupts
655 	 * in odd-numbered frames, period-4 interrupts in frames congruent
656 	 * to 2 (mod 4), and so on.  This way each frame only has two
657 	 * interrupt QHs, which will help spread out bandwidth utilization.
658 	 */
659 	for (i = 0; i < UHCI_NUMFRAMES; i++) {
660 		int irq;
661 
662 		/*
663 		 * ffs (Find First bit Set) does exactly what we need:
664 		 * 1,3,5,...  => ffs = 0 => use skel_int2_qh = skelqh[6],
665 		 * 2,6,10,... => ffs = 1 => use skel_int4_qh = skelqh[5], etc.
666 		 * ffs > 6 => not on any high-period queue, so use
667 		 *	skel_int1_qh = skelqh[7].
668 		 * Add UHCI_NUMFRAMES to insure at least one bit is set.
669 		 */
670 		irq = 6 - (int) __ffs(i + UHCI_NUMFRAMES);
671 		if (irq < 0)
672 			irq = 7;
673 
674 		/* Only place we don't use the frame list routines */
675 		uhci->fl->frame[i] = UHCI_PTR_QH |
676 				cpu_to_le32(uhci->skelqh[irq]->dma_handle);
677 	}
678 
679 	/*
680 	 * Some architectures require a full mb() to enforce completion of
681 	 * the memory writes above before the I/O transfers in configure_hc().
682 	 */
683 	mb();
684 
685 	configure_hc(uhci);
686 	start_rh(uhci);
687 	return 0;
688 
689 /*
690  * error exits:
691  */
692 err_alloc_skelqh:
693 	for (i = 0; i < UHCI_NUM_SKELQH; i++)
694 		if (uhci->skelqh[i]) {
695 			uhci_free_qh(uhci, uhci->skelqh[i]);
696 			uhci->skelqh[i] = NULL;
697 		}
698 
699 	uhci_free_td(uhci, uhci->term_td);
700 	uhci->term_td = NULL;
701 
702 err_alloc_term_td:
703 	dma_pool_destroy(uhci->qh_pool);
704 	uhci->qh_pool = NULL;
705 
706 err_create_qh_pool:
707 	dma_pool_destroy(uhci->td_pool);
708 	uhci->td_pool = NULL;
709 
710 err_create_td_pool:
711 	dma_free_coherent(uhci_dev(uhci), sizeof(*uhci->fl),
712 			uhci->fl, uhci->fl->dma_handle);
713 	uhci->fl = NULL;
714 
715 err_alloc_fl:
716 	debugfs_remove(uhci->dentry);
717 	uhci->dentry = NULL;
718 
719 err_create_debug_entry:
720 	return retval;
721 }
722 
723 static void uhci_stop(struct usb_hcd *hcd)
724 {
725 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
726 
727 	spin_lock_irq(&uhci->lock);
728 	if (!uhci->hc_inaccessible)
729 		reset_hc(uhci);
730 	uhci_scan_schedule(uhci, NULL);
731 	spin_unlock_irq(&uhci->lock);
732 
733 	release_uhci(uhci);
734 }
735 
736 #ifdef CONFIG_PM
737 static int uhci_rh_suspend(struct usb_hcd *hcd)
738 {
739 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
740 
741 	spin_lock_irq(&uhci->lock);
742 	if (!uhci->hc_inaccessible)		/* Not dead */
743 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
744 	spin_unlock_irq(&uhci->lock);
745 	return 0;
746 }
747 
748 static int uhci_rh_resume(struct usb_hcd *hcd)
749 {
750 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
751 	int rc = 0;
752 
753 	spin_lock_irq(&uhci->lock);
754 	if (uhci->hc_inaccessible) {
755 		if (uhci->rh_state == UHCI_RH_SUSPENDED) {
756 			dev_warn(uhci_dev(uhci), "HC isn't running!\n");
757 			rc = -ENODEV;
758 		}
759 		/* Otherwise the HC is dead */
760 	} else
761 		wakeup_rh(uhci);
762 	spin_unlock_irq(&uhci->lock);
763 	return rc;
764 }
765 
766 static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
767 {
768 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
769 	int rc = 0;
770 
771 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
772 
773 	spin_lock_irq(&uhci->lock);
774 	if (uhci->hc_inaccessible)	/* Dead or already suspended */
775 		goto done;
776 
777 #ifndef CONFIG_USB_SUSPEND
778 	/* Otherwise this would never happen */
779 	suspend_rh(uhci, UHCI_RH_SUSPENDED);
780 #endif
781 
782 	if (uhci->rh_state > UHCI_RH_SUSPENDED) {
783 		dev_warn(uhci_dev(uhci), "Root hub isn't suspended!\n");
784 		hcd->state = HC_STATE_RUNNING;
785 		rc = -EBUSY;
786 		goto done;
787 	};
788 
789 	/* All PCI host controllers are required to disable IRQ generation
790 	 * at the source, so we must turn off PIRQ.
791 	 */
792 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
793 	uhci->hc_inaccessible = 1;
794 	hcd->poll_rh = 0;
795 
796 	/* FIXME: Enable non-PME# remote wakeup? */
797 
798 done:
799 	spin_unlock_irq(&uhci->lock);
800 	return rc;
801 }
802 
803 static int uhci_resume(struct usb_hcd *hcd)
804 {
805 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
806 
807 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
808 
809 	if (uhci->rh_state == UHCI_RH_RESET)	/* Dead */
810 		return 0;
811 	spin_lock_irq(&uhci->lock);
812 
813 	/* FIXME: Disable non-PME# remote wakeup? */
814 
815 	uhci->hc_inaccessible = 0;
816 
817 	/* The BIOS may have changed the controller settings during a
818 	 * system wakeup.  Check it and reconfigure to avoid problems.
819 	 */
820 	check_and_reset_hc(uhci);
821 	configure_hc(uhci);
822 
823 #ifndef CONFIG_USB_SUSPEND
824 	/* Otherwise this would never happen */
825 	wakeup_rh(uhci);
826 #endif
827 	if (uhci->rh_state == UHCI_RH_RESET)
828 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
829 
830 	spin_unlock_irq(&uhci->lock);
831 
832 	if (!uhci->working_RD) {
833 		/* Suspended root hub needs to be polled */
834 		hcd->poll_rh = 1;
835 		usb_hcd_poll_rh_status(hcd);
836 	}
837 	return 0;
838 }
839 #endif
840 
841 /* Wait until all the URBs for a particular device/endpoint are gone */
842 static void uhci_hcd_endpoint_disable(struct usb_hcd *hcd,
843 		struct usb_host_endpoint *ep)
844 {
845 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
846 
847 	wait_event_interruptible(uhci->waitqh, list_empty(&ep->urb_list));
848 }
849 
850 static int uhci_hcd_get_frame_number(struct usb_hcd *hcd)
851 {
852 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
853 	unsigned long flags;
854 	int is_stopped;
855 	int frame_number;
856 
857 	/* Minimize latency by avoiding the spinlock */
858 	local_irq_save(flags);
859 	is_stopped = uhci->is_stopped;
860 	smp_rmb();
861 	frame_number = (is_stopped ? uhci->frame_number :
862 			inw(uhci->io_addr + USBFRNUM));
863 	local_irq_restore(flags);
864 	return frame_number;
865 }
866 
867 static const char hcd_name[] = "uhci_hcd";
868 
869 static const struct hc_driver uhci_driver = {
870 	.description =		hcd_name,
871 	.product_desc =		"UHCI Host Controller",
872 	.hcd_priv_size =	sizeof(struct uhci_hcd),
873 
874 	/* Generic hardware linkage */
875 	.irq =			uhci_irq,
876 	.flags =		HCD_USB11,
877 
878 	/* Basic lifecycle operations */
879 	.reset =		uhci_reset,
880 	.start =		uhci_start,
881 #ifdef CONFIG_PM
882 	.suspend =		uhci_suspend,
883 	.resume =		uhci_resume,
884 	.hub_suspend =		uhci_rh_suspend,
885 	.hub_resume =		uhci_rh_resume,
886 #endif
887 	.stop =			uhci_stop,
888 
889 	.urb_enqueue =		uhci_urb_enqueue,
890 	.urb_dequeue =		uhci_urb_dequeue,
891 
892 	.endpoint_disable =	uhci_hcd_endpoint_disable,
893 	.get_frame_number =	uhci_hcd_get_frame_number,
894 
895 	.hub_status_data =	uhci_hub_status_data,
896 	.hub_control =		uhci_hub_control,
897 };
898 
899 static const struct pci_device_id uhci_pci_ids[] = { {
900 	/* handle any USB UHCI controller */
901 	PCI_DEVICE_CLASS(((PCI_CLASS_SERIAL_USB << 8) | 0x00), ~0),
902 	.driver_data =	(unsigned long) &uhci_driver,
903 	}, { /* end: all zeroes */ }
904 };
905 
906 MODULE_DEVICE_TABLE(pci, uhci_pci_ids);
907 
908 static struct pci_driver uhci_pci_driver = {
909 	.name =		(char *)hcd_name,
910 	.id_table =	uhci_pci_ids,
911 
912 	.probe =	usb_hcd_pci_probe,
913 	.remove =	usb_hcd_pci_remove,
914 	.shutdown =	uhci_shutdown,
915 
916 #ifdef	CONFIG_PM
917 	.suspend =	usb_hcd_pci_suspend,
918 	.resume =	usb_hcd_pci_resume,
919 #endif	/* PM */
920 };
921 
922 static int __init uhci_hcd_init(void)
923 {
924 	int retval = -ENOMEM;
925 
926 	printk(KERN_INFO DRIVER_DESC " " DRIVER_VERSION "\n");
927 
928 	if (usb_disabled())
929 		return -ENODEV;
930 
931 	if (debug) {
932 		errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
933 		if (!errbuf)
934 			goto errbuf_failed;
935 	}
936 
937 	uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
938 	if (!uhci_debugfs_root)
939 		goto debug_failed;
940 
941 	uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
942 		sizeof(struct urb_priv), 0, 0, NULL, NULL);
943 	if (!uhci_up_cachep)
944 		goto up_failed;
945 
946 	retval = pci_register_driver(&uhci_pci_driver);
947 	if (retval)
948 		goto init_failed;
949 
950 	return 0;
951 
952 init_failed:
953 	if (kmem_cache_destroy(uhci_up_cachep))
954 		warn("not all urb_priv's were freed!");
955 
956 up_failed:
957 	debugfs_remove(uhci_debugfs_root);
958 
959 debug_failed:
960 	kfree(errbuf);
961 
962 errbuf_failed:
963 
964 	return retval;
965 }
966 
967 static void __exit uhci_hcd_cleanup(void)
968 {
969 	pci_unregister_driver(&uhci_pci_driver);
970 
971 	if (kmem_cache_destroy(uhci_up_cachep))
972 		warn("not all urb_priv's were freed!");
973 
974 	debugfs_remove(uhci_debugfs_root);
975 	kfree(errbuf);
976 }
977 
978 module_init(uhci_hcd_init);
979 module_exit(uhci_hcd_cleanup);
980 
981 MODULE_AUTHOR(DRIVER_AUTHOR);
982 MODULE_DESCRIPTION(DRIVER_DESC);
983 MODULE_LICENSE("GPL");
984