xref: /linux/drivers/usb/host/uhci-hcd.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
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 #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/smp_lock.h>
35 #include <linux/errno.h>
36 #include <linux/unistd.h>
37 #include <linux/interrupt.h>
38 #include <linux/spinlock.h>
39 #include <linux/debugfs.h>
40 #include <linux/pm.h>
41 #include <linux/dmapool.h>
42 #include <linux/dma-mapping.h>
43 #include <linux/usb.h>
44 #include <linux/bitops.h>
45 
46 #include <asm/uaccess.h>
47 #include <asm/io.h>
48 #include <asm/irq.h>
49 #include <asm/system.h>
50 
51 #include "../core/hcd.h"
52 #include "uhci-hcd.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 /* If a transfer is still active after this much time, turn off FSBR */
91 #define IDLE_TIMEOUT	msecs_to_jiffies(50)
92 #define FSBR_DELAY	msecs_to_jiffies(50)
93 
94 /* When we timeout an idle transfer for FSBR, we'll switch it over to */
95 /* depth first traversal. We'll do it in groups of this number of TDs */
96 /* to make sure it doesn't hog all of the bandwidth */
97 #define DEPTH_INTERVAL 5
98 
99 #include "uhci-debug.c"
100 #include "uhci-q.c"
101 #include "uhci-hub.c"
102 
103 extern void uhci_reset_hc(struct pci_dev *pdev, unsigned long base);
104 extern int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base);
105 
106 /*
107  * Finish up a host controller reset and update the recorded state.
108  */
109 static void finish_reset(struct uhci_hcd *uhci)
110 {
111 	int port;
112 
113 	/* HCRESET doesn't affect the Suspend, Reset, and Resume Detect
114 	 * bits in the port status and control registers.
115 	 * We have to clear them by hand.
116 	 */
117 	for (port = 0; port < uhci->rh_numports; ++port)
118 		outw(0, uhci->io_addr + USBPORTSC1 + (port * 2));
119 
120 	uhci->port_c_suspend = uhci->suspended_ports =
121 			uhci->resuming_ports = 0;
122 	uhci->rh_state = UHCI_RH_RESET;
123 	uhci->is_stopped = UHCI_IS_STOPPED;
124 	uhci_to_hcd(uhci)->state = HC_STATE_HALT;
125 	uhci_to_hcd(uhci)->poll_rh = 0;
126 }
127 
128 /*
129  * Last rites for a defunct/nonfunctional controller
130  * or one we don't want to use any more.
131  */
132 static void hc_died(struct uhci_hcd *uhci)
133 {
134 	uhci_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr);
135 	finish_reset(uhci);
136 	uhci->hc_inaccessible = 1;
137 }
138 
139 /*
140  * Initialize a controller that was newly discovered or has just been
141  * resumed.  In either case we can't be sure of its previous state.
142  */
143 static void check_and_reset_hc(struct uhci_hcd *uhci)
144 {
145 	if (uhci_check_and_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr))
146 		finish_reset(uhci);
147 }
148 
149 /*
150  * Store the basic register settings needed by the controller.
151  */
152 static void configure_hc(struct uhci_hcd *uhci)
153 {
154 	/* Set the frame length to the default: 1 ms exactly */
155 	outb(USBSOF_DEFAULT, uhci->io_addr + USBSOF);
156 
157 	/* Store the frame list base address */
158 	outl(uhci->frame_dma_handle, uhci->io_addr + USBFLBASEADD);
159 
160 	/* Set the current frame number */
161 	outw(uhci->frame_number, uhci->io_addr + USBFRNUM);
162 
163 	/* Mark controller as not halted before we enable interrupts */
164 	uhci_to_hcd(uhci)->state = HC_STATE_SUSPENDED;
165 	mb();
166 
167 	/* Enable PIRQ */
168 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
169 			USBLEGSUP_DEFAULT);
170 }
171 
172 
173 static int resume_detect_interrupts_are_broken(struct uhci_hcd *uhci)
174 {
175 	int port;
176 
177 	switch (to_pci_dev(uhci_dev(uhci))->vendor) {
178 	    default:
179 		break;
180 
181 	    case PCI_VENDOR_ID_GENESYS:
182 		/* Genesys Logic's GL880S controllers don't generate
183 		 * resume-detect interrupts.
184 		 */
185 		return 1;
186 
187 	    case PCI_VENDOR_ID_INTEL:
188 		/* Some of Intel's USB controllers have a bug that causes
189 		 * resume-detect interrupts if any port has an over-current
190 		 * condition.  To make matters worse, some motherboards
191 		 * hardwire unused USB ports' over-current inputs active!
192 		 * To prevent problems, we will not enable resume-detect
193 		 * interrupts if any ports are OC.
194 		 */
195 		for (port = 0; port < uhci->rh_numports; ++port) {
196 			if (inw(uhci->io_addr + USBPORTSC1 + port * 2) &
197 					USBPORTSC_OC)
198 				return 1;
199 		}
200 		break;
201 	}
202 	return 0;
203 }
204 
205 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state)
206 __releases(uhci->lock)
207 __acquires(uhci->lock)
208 {
209 	int auto_stop;
210 	int int_enable;
211 
212 	auto_stop = (new_state == UHCI_RH_AUTO_STOPPED);
213 	dev_dbg(uhci_dev(uhci), "%s%s\n", __FUNCTION__,
214 			(auto_stop ? " (auto-stop)" : ""));
215 
216 	/* If we get a suspend request when we're already auto-stopped
217 	 * then there's nothing to do.
218 	 */
219 	if (uhci->rh_state == UHCI_RH_AUTO_STOPPED) {
220 		uhci->rh_state = new_state;
221 		return;
222 	}
223 
224 	/* Enable resume-detect interrupts if they work.
225 	 * Then enter Global Suspend mode, still configured.
226 	 */
227 	uhci->working_RD = 1;
228 	int_enable = USBINTR_RESUME;
229 	if (resume_detect_interrupts_are_broken(uhci)) {
230 		uhci->working_RD = int_enable = 0;
231 	}
232 	outw(int_enable, uhci->io_addr + USBINTR);
233 	outw(USBCMD_EGSM | USBCMD_CF, uhci->io_addr + USBCMD);
234 	mb();
235 	udelay(5);
236 
237 	/* If we're auto-stopping then no devices have been attached
238 	 * for a while, so there shouldn't be any active URBs and the
239 	 * controller should stop after a few microseconds.  Otherwise
240 	 * we will give the controller one frame to stop.
241 	 */
242 	if (!auto_stop && !(inw(uhci->io_addr + USBSTS) & USBSTS_HCH)) {
243 		uhci->rh_state = UHCI_RH_SUSPENDING;
244 		spin_unlock_irq(&uhci->lock);
245 		msleep(1);
246 		spin_lock_irq(&uhci->lock);
247 		if (uhci->hc_inaccessible)	/* Died */
248 			return;
249 	}
250 	if (!(inw(uhci->io_addr + USBSTS) & USBSTS_HCH))
251 		dev_warn(uhci_dev(uhci), "Controller not stopped yet!\n");
252 
253 	uhci_get_current_frame_number(uhci);
254 	smp_wmb();
255 
256 	uhci->rh_state = new_state;
257 	uhci->is_stopped = UHCI_IS_STOPPED;
258 	uhci_to_hcd(uhci)->poll_rh = !int_enable;
259 
260 	uhci_scan_schedule(uhci, NULL);
261 }
262 
263 static void start_rh(struct uhci_hcd *uhci)
264 {
265 	uhci_to_hcd(uhci)->state = HC_STATE_RUNNING;
266 	uhci->is_stopped = 0;
267 	smp_wmb();
268 
269 	/* Mark it configured and running with a 64-byte max packet.
270 	 * All interrupts are enabled, even though RESUME won't do anything.
271 	 */
272 	outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP, uhci->io_addr + USBCMD);
273 	outw(USBINTR_TIMEOUT | USBINTR_RESUME | USBINTR_IOC | USBINTR_SP,
274 			uhci->io_addr + USBINTR);
275 	mb();
276 	uhci->rh_state = UHCI_RH_RUNNING;
277 	uhci_to_hcd(uhci)->poll_rh = 1;
278 }
279 
280 static void wakeup_rh(struct uhci_hcd *uhci)
281 __releases(uhci->lock)
282 __acquires(uhci->lock)
283 {
284 	dev_dbg(uhci_dev(uhci), "%s%s\n", __FUNCTION__,
285 			uhci->rh_state == UHCI_RH_AUTO_STOPPED ?
286 				" (auto-start)" : "");
287 
288 	/* If we are auto-stopped then no devices are attached so there's
289 	 * no need for wakeup signals.  Otherwise we send Global Resume
290 	 * for 20 ms.
291 	 */
292 	if (uhci->rh_state == UHCI_RH_SUSPENDED) {
293 		uhci->rh_state = UHCI_RH_RESUMING;
294 		outw(USBCMD_FGR | USBCMD_EGSM | USBCMD_CF,
295 				uhci->io_addr + USBCMD);
296 		spin_unlock_irq(&uhci->lock);
297 		msleep(20);
298 		spin_lock_irq(&uhci->lock);
299 		if (uhci->hc_inaccessible)	/* Died */
300 			return;
301 
302 		/* End Global Resume and wait for EOP to be sent */
303 		outw(USBCMD_CF, uhci->io_addr + USBCMD);
304 		mb();
305 		udelay(4);
306 		if (inw(uhci->io_addr + USBCMD) & USBCMD_FGR)
307 			dev_warn(uhci_dev(uhci), "FGR not stopped yet!\n");
308 	}
309 
310 	start_rh(uhci);
311 
312 	/* Restart root hub polling */
313 	mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
314 }
315 
316 static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
317 {
318 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
319 	unsigned short status;
320 	unsigned long flags;
321 
322 	/*
323 	 * Read the interrupt status, and write it back to clear the
324 	 * interrupt cause.  Contrary to the UHCI specification, the
325 	 * "HC Halted" status bit is persistent: it is RO, not R/WC.
326 	 */
327 	status = inw(uhci->io_addr + USBSTS);
328 	if (!(status & ~USBSTS_HCH))	/* shared interrupt, not mine */
329 		return IRQ_NONE;
330 	outw(status, uhci->io_addr + USBSTS);		/* Clear it */
331 
332 	if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) {
333 		if (status & USBSTS_HSE)
334 			dev_err(uhci_dev(uhci), "host system error, "
335 					"PCI problems?\n");
336 		if (status & USBSTS_HCPE)
337 			dev_err(uhci_dev(uhci), "host controller process "
338 					"error, something bad happened!\n");
339 		if (status & USBSTS_HCH) {
340 			spin_lock_irqsave(&uhci->lock, flags);
341 			if (uhci->rh_state >= UHCI_RH_RUNNING) {
342 				dev_err(uhci_dev(uhci),
343 					"host controller halted, "
344 					"very bad!\n");
345 				if (debug > 1 && errbuf) {
346 					/* Print the schedule for debugging */
347 					uhci_sprint_schedule(uhci,
348 							errbuf, ERRBUF_LEN);
349 					lprintk(errbuf);
350 				}
351 				hc_died(uhci);
352 
353 				/* Force a callback in case there are
354 				 * pending unlinks */
355 				mod_timer(&hcd->rh_timer, jiffies);
356 			}
357 			spin_unlock_irqrestore(&uhci->lock, flags);
358 		}
359 	}
360 
361 	if (status & USBSTS_RD)
362 		usb_hcd_poll_rh_status(hcd);
363 	else {
364 		spin_lock_irqsave(&uhci->lock, flags);
365 		uhci_scan_schedule(uhci, regs);
366 		spin_unlock_irqrestore(&uhci->lock, flags);
367 	}
368 
369 	return IRQ_HANDLED;
370 }
371 
372 /*
373  * Store the current frame number in uhci->frame_number if the controller
374  * is runnning
375  */
376 static void uhci_get_current_frame_number(struct uhci_hcd *uhci)
377 {
378 	if (!uhci->is_stopped)
379 		uhci->frame_number = inw(uhci->io_addr + USBFRNUM);
380 }
381 
382 /*
383  * De-allocate all resources
384  */
385 static void release_uhci(struct uhci_hcd *uhci)
386 {
387 	int i;
388 
389 	if (DEBUG_CONFIGURED) {
390 		spin_lock_irq(&uhci->lock);
391 		uhci->is_initialized = 0;
392 		spin_unlock_irq(&uhci->lock);
393 
394 		debugfs_remove(uhci->dentry);
395 	}
396 
397 	for (i = 0; i < UHCI_NUM_SKELQH; i++)
398 		uhci_free_qh(uhci, uhci->skelqh[i]);
399 
400 	uhci_free_td(uhci, uhci->term_td);
401 
402 	dma_pool_destroy(uhci->qh_pool);
403 
404 	dma_pool_destroy(uhci->td_pool);
405 
406 	kfree(uhci->frame_cpu);
407 
408 	dma_free_coherent(uhci_dev(uhci),
409 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
410 			uhci->frame, uhci->frame_dma_handle);
411 }
412 
413 static int uhci_reset(struct usb_hcd *hcd)
414 {
415 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
416 	unsigned io_size = (unsigned) hcd->rsrc_len;
417 	int port;
418 
419 	uhci->io_addr = (unsigned long) hcd->rsrc_start;
420 
421 	/* The UHCI spec says devices must have 2 ports, and goes on to say
422 	 * they may have more but gives no way to determine how many there
423 	 * are.  However according to the UHCI spec, Bit 7 of the port
424 	 * status and control register is always set to 1.  So we try to
425 	 * use this to our advantage.  Another common failure mode when
426 	 * a nonexistent register is addressed is to return all ones, so
427 	 * we test for that also.
428 	 */
429 	for (port = 0; port < (io_size - USBPORTSC1) / 2; port++) {
430 		unsigned int portstatus;
431 
432 		portstatus = inw(uhci->io_addr + USBPORTSC1 + (port * 2));
433 		if (!(portstatus & 0x0080) || portstatus == 0xffff)
434 			break;
435 	}
436 	if (debug)
437 		dev_info(uhci_dev(uhci), "detected %d ports\n", port);
438 
439 	/* Anything greater than 7 is weird so we'll ignore it. */
440 	if (port > UHCI_RH_MAXCHILD) {
441 		dev_info(uhci_dev(uhci), "port count misdetected? "
442 				"forcing to 2 ports\n");
443 		port = 2;
444 	}
445 	uhci->rh_numports = port;
446 
447 	/* Kick BIOS off this hardware and reset if the controller
448 	 * isn't already safely quiescent.
449 	 */
450 	check_and_reset_hc(uhci);
451 	return 0;
452 }
453 
454 /* Make sure the controller is quiescent and that we're not using it
455  * any more.  This is mainly for the benefit of programs which, like kexec,
456  * expect the hardware to be idle: not doing DMA or generating IRQs.
457  *
458  * This routine may be called in a damaged or failing kernel.  Hence we
459  * do not acquire the spinlock before shutting down the controller.
460  */
461 static void uhci_shutdown(struct pci_dev *pdev)
462 {
463 	struct usb_hcd *hcd = (struct usb_hcd *) pci_get_drvdata(pdev);
464 
465 	hc_died(hcd_to_uhci(hcd));
466 }
467 
468 /*
469  * Allocate a frame list, and then setup the skeleton
470  *
471  * The hardware doesn't really know any difference
472  * in the queues, but the order does matter for the
473  * protocols higher up. The order is:
474  *
475  *  - any isochronous events handled before any
476  *    of the queues. We don't do that here, because
477  *    we'll create the actual TD entries on demand.
478  *  - The first queue is the interrupt queue.
479  *  - The second queue is the control queue, split into low- and full-speed
480  *  - The third queue is bulk queue.
481  *  - The fourth queue is the bandwidth reclamation queue, which loops back
482  *    to the full-speed control queue.
483  */
484 static int uhci_start(struct usb_hcd *hcd)
485 {
486 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
487 	int retval = -EBUSY;
488 	int i;
489 	struct dentry *dentry;
490 
491 	hcd->uses_new_polling = 1;
492 
493 	uhci->fsbr = 0;
494 	uhci->fsbrtimeout = 0;
495 
496 	spin_lock_init(&uhci->lock);
497 
498 	INIT_LIST_HEAD(&uhci->td_remove_list);
499 	INIT_LIST_HEAD(&uhci->idle_qh_list);
500 
501 	init_waitqueue_head(&uhci->waitqh);
502 
503 	if (DEBUG_CONFIGURED) {
504 		dentry = debugfs_create_file(hcd->self.bus_name,
505 				S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root,
506 				uhci, &uhci_debug_operations);
507 		if (!dentry) {
508 			dev_err(uhci_dev(uhci), "couldn't create uhci "
509 					"debugfs entry\n");
510 			retval = -ENOMEM;
511 			goto err_create_debug_entry;
512 		}
513 		uhci->dentry = dentry;
514 	}
515 
516 	uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
517 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
518 			&uhci->frame_dma_handle, 0);
519 	if (!uhci->frame) {
520 		dev_err(uhci_dev(uhci), "unable to allocate "
521 				"consistent memory for frame list\n");
522 		goto err_alloc_frame;
523 	}
524 	memset(uhci->frame, 0, UHCI_NUMFRAMES * sizeof(*uhci->frame));
525 
526 	uhci->frame_cpu = kcalloc(UHCI_NUMFRAMES, sizeof(*uhci->frame_cpu),
527 			GFP_KERNEL);
528 	if (!uhci->frame_cpu) {
529 		dev_err(uhci_dev(uhci), "unable to allocate "
530 				"memory for frame pointers\n");
531 		goto err_alloc_frame_cpu;
532 	}
533 
534 	uhci->td_pool = dma_pool_create("uhci_td", uhci_dev(uhci),
535 			sizeof(struct uhci_td), 16, 0);
536 	if (!uhci->td_pool) {
537 		dev_err(uhci_dev(uhci), "unable to create td dma_pool\n");
538 		goto err_create_td_pool;
539 	}
540 
541 	uhci->qh_pool = dma_pool_create("uhci_qh", uhci_dev(uhci),
542 			sizeof(struct uhci_qh), 16, 0);
543 	if (!uhci->qh_pool) {
544 		dev_err(uhci_dev(uhci), "unable to create qh dma_pool\n");
545 		goto err_create_qh_pool;
546 	}
547 
548 	uhci->term_td = uhci_alloc_td(uhci);
549 	if (!uhci->term_td) {
550 		dev_err(uhci_dev(uhci), "unable to allocate terminating TD\n");
551 		goto err_alloc_term_td;
552 	}
553 
554 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
555 		uhci->skelqh[i] = uhci_alloc_qh(uhci, NULL, NULL);
556 		if (!uhci->skelqh[i]) {
557 			dev_err(uhci_dev(uhci), "unable to allocate QH\n");
558 			goto err_alloc_skelqh;
559 		}
560 	}
561 
562 	/*
563 	 * 8 Interrupt queues; link all higher int queues to int1,
564 	 * then link int1 to control and control to bulk
565 	 */
566 	uhci->skel_int128_qh->link =
567 			uhci->skel_int64_qh->link =
568 			uhci->skel_int32_qh->link =
569 			uhci->skel_int16_qh->link =
570 			uhci->skel_int8_qh->link =
571 			uhci->skel_int4_qh->link =
572 			uhci->skel_int2_qh->link = UHCI_PTR_QH |
573 			cpu_to_le32(uhci->skel_int1_qh->dma_handle);
574 
575 	uhci->skel_int1_qh->link = UHCI_PTR_QH |
576 			cpu_to_le32(uhci->skel_ls_control_qh->dma_handle);
577 	uhci->skel_ls_control_qh->link = UHCI_PTR_QH |
578 			cpu_to_le32(uhci->skel_fs_control_qh->dma_handle);
579 	uhci->skel_fs_control_qh->link = UHCI_PTR_QH |
580 			cpu_to_le32(uhci->skel_bulk_qh->dma_handle);
581 	uhci->skel_bulk_qh->link = UHCI_PTR_QH |
582 			cpu_to_le32(uhci->skel_term_qh->dma_handle);
583 
584 	/* This dummy TD is to work around a bug in Intel PIIX controllers */
585 	uhci_fill_td(uhci->term_td, 0, uhci_explen(0) |
586 		(0x7f << TD_TOKEN_DEVADDR_SHIFT) | USB_PID_IN, 0);
587 	uhci->term_td->link = cpu_to_le32(uhci->term_td->dma_handle);
588 
589 	uhci->skel_term_qh->link = UHCI_PTR_TERM;
590 	uhci->skel_term_qh->element = cpu_to_le32(uhci->term_td->dma_handle);
591 
592 	/*
593 	 * Fill the frame list: make all entries point to the proper
594 	 * interrupt queue.
595 	 *
596 	 * The interrupt queues will be interleaved as evenly as possible.
597 	 * There's not much to be done about period-1 interrupts; they have
598 	 * to occur in every frame.  But we can schedule period-2 interrupts
599 	 * in odd-numbered frames, period-4 interrupts in frames congruent
600 	 * to 2 (mod 4), and so on.  This way each frame only has two
601 	 * interrupt QHs, which will help spread out bandwidth utilization.
602 	 */
603 	for (i = 0; i < UHCI_NUMFRAMES; i++) {
604 		int irq;
605 
606 		/*
607 		 * ffs (Find First bit Set) does exactly what we need:
608 		 * 1,3,5,...  => ffs = 0 => use skel_int2_qh = skelqh[8],
609 		 * 2,6,10,... => ffs = 1 => use skel_int4_qh = skelqh[7], etc.
610 		 * ffs >= 7 => not on any high-period queue, so use
611 		 *	skel_int1_qh = skelqh[9].
612 		 * Add UHCI_NUMFRAMES to insure at least one bit is set.
613 		 */
614 		irq = 8 - (int) __ffs(i + UHCI_NUMFRAMES);
615 		if (irq <= 1)
616 			irq = 9;
617 
618 		/* Only place we don't use the frame list routines */
619 		uhci->frame[i] = UHCI_PTR_QH |
620 				cpu_to_le32(uhci->skelqh[irq]->dma_handle);
621 	}
622 
623 	/*
624 	 * Some architectures require a full mb() to enforce completion of
625 	 * the memory writes above before the I/O transfers in configure_hc().
626 	 */
627 	mb();
628 
629 	configure_hc(uhci);
630 	uhci->is_initialized = 1;
631 	start_rh(uhci);
632 	return 0;
633 
634 /*
635  * error exits:
636  */
637 err_alloc_skelqh:
638 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
639 		if (uhci->skelqh[i])
640 			uhci_free_qh(uhci, uhci->skelqh[i]);
641 	}
642 
643 	uhci_free_td(uhci, uhci->term_td);
644 
645 err_alloc_term_td:
646 	dma_pool_destroy(uhci->qh_pool);
647 
648 err_create_qh_pool:
649 	dma_pool_destroy(uhci->td_pool);
650 
651 err_create_td_pool:
652 	kfree(uhci->frame_cpu);
653 
654 err_alloc_frame_cpu:
655 	dma_free_coherent(uhci_dev(uhci),
656 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
657 			uhci->frame, uhci->frame_dma_handle);
658 
659 err_alloc_frame:
660 	debugfs_remove(uhci->dentry);
661 
662 err_create_debug_entry:
663 	return retval;
664 }
665 
666 static void uhci_stop(struct usb_hcd *hcd)
667 {
668 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
669 
670 	spin_lock_irq(&uhci->lock);
671 	if (!uhci->hc_inaccessible)
672 		hc_died(uhci);
673 	uhci_scan_schedule(uhci, NULL);
674 	spin_unlock_irq(&uhci->lock);
675 
676 	release_uhci(uhci);
677 }
678 
679 #ifdef CONFIG_PM
680 static int uhci_rh_suspend(struct usb_hcd *hcd)
681 {
682 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
683 
684 	spin_lock_irq(&uhci->lock);
685 	if (!uhci->hc_inaccessible)		/* Not dead */
686 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
687 	spin_unlock_irq(&uhci->lock);
688 	return 0;
689 }
690 
691 static int uhci_rh_resume(struct usb_hcd *hcd)
692 {
693 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
694 	int rc = 0;
695 
696 	spin_lock_irq(&uhci->lock);
697 	if (uhci->hc_inaccessible) {
698 		if (uhci->rh_state == UHCI_RH_SUSPENDED) {
699 			dev_warn(uhci_dev(uhci), "HC isn't running!\n");
700 			rc = -ENODEV;
701 		}
702 		/* Otherwise the HC is dead */
703 	} else
704 		wakeup_rh(uhci);
705 	spin_unlock_irq(&uhci->lock);
706 	return rc;
707 }
708 
709 static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
710 {
711 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
712 	int rc = 0;
713 
714 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
715 
716 	spin_lock_irq(&uhci->lock);
717 	if (uhci->hc_inaccessible)	/* Dead or already suspended */
718 		goto done;
719 
720 	if (uhci->rh_state > UHCI_RH_SUSPENDED) {
721 		dev_warn(uhci_dev(uhci), "Root hub isn't suspended!\n");
722 		rc = -EBUSY;
723 		goto done;
724 	};
725 
726 	/* All PCI host controllers are required to disable IRQ generation
727 	 * at the source, so we must turn off PIRQ.
728 	 */
729 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
730 	mb();
731 	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
732 	uhci->hc_inaccessible = 1;
733 	hcd->poll_rh = 0;
734 
735 	/* FIXME: Enable non-PME# remote wakeup? */
736 
737 done:
738 	spin_unlock_irq(&uhci->lock);
739 	return rc;
740 }
741 
742 static int uhci_resume(struct usb_hcd *hcd)
743 {
744 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
745 
746 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
747 
748 	/* Since we aren't in D3 any more, it's safe to set this flag
749 	 * even if the controller was dead.  It might not even be dead
750 	 * any more, if the firmware or quirks code has reset it.
751 	 */
752 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
753 	mb();
754 
755 	if (uhci->rh_state == UHCI_RH_RESET)	/* Dead */
756 		return 0;
757 	spin_lock_irq(&uhci->lock);
758 
759 	/* FIXME: Disable non-PME# remote wakeup? */
760 
761 	uhci->hc_inaccessible = 0;
762 
763 	/* The BIOS may have changed the controller settings during a
764 	 * system wakeup.  Check it and reconfigure to avoid problems.
765 	 */
766 	check_and_reset_hc(uhci);
767 	configure_hc(uhci);
768 
769 	if (uhci->rh_state == UHCI_RH_RESET) {
770 
771 		/* The controller had to be reset */
772 		usb_root_hub_lost_power(hcd->self.root_hub);
773 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
774 	}
775 
776 	spin_unlock_irq(&uhci->lock);
777 
778 	if (!uhci->working_RD) {
779 		/* Suspended root hub needs to be polled */
780 		hcd->poll_rh = 1;
781 		usb_hcd_poll_rh_status(hcd);
782 	}
783 	return 0;
784 }
785 #endif
786 
787 /* Wait until a particular device/endpoint's QH is idle, and free it */
788 static void uhci_hcd_endpoint_disable(struct usb_hcd *hcd,
789 		struct usb_host_endpoint *hep)
790 {
791 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
792 	struct uhci_qh *qh;
793 
794 	spin_lock_irq(&uhci->lock);
795 	qh = (struct uhci_qh *) hep->hcpriv;
796 	if (qh == NULL)
797 		goto done;
798 
799 	while (qh->state != QH_STATE_IDLE) {
800 		++uhci->num_waiting;
801 		spin_unlock_irq(&uhci->lock);
802 		wait_event_interruptible(uhci->waitqh,
803 				qh->state == QH_STATE_IDLE);
804 		spin_lock_irq(&uhci->lock);
805 		--uhci->num_waiting;
806 	}
807 
808 	uhci_free_qh(uhci, qh);
809 done:
810 	spin_unlock_irq(&uhci->lock);
811 }
812 
813 static int uhci_hcd_get_frame_number(struct usb_hcd *hcd)
814 {
815 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
816 	unsigned long flags;
817 	int is_stopped;
818 	int frame_number;
819 
820 	/* Minimize latency by avoiding the spinlock */
821 	local_irq_save(flags);
822 	is_stopped = uhci->is_stopped;
823 	smp_rmb();
824 	frame_number = (is_stopped ? uhci->frame_number :
825 			inw(uhci->io_addr + USBFRNUM));
826 	local_irq_restore(flags);
827 	return frame_number;
828 }
829 
830 static const char hcd_name[] = "uhci_hcd";
831 
832 static const struct hc_driver uhci_driver = {
833 	.description =		hcd_name,
834 	.product_desc =		"UHCI Host Controller",
835 	.hcd_priv_size =	sizeof(struct uhci_hcd),
836 
837 	/* Generic hardware linkage */
838 	.irq =			uhci_irq,
839 	.flags =		HCD_USB11,
840 
841 	/* Basic lifecycle operations */
842 	.reset =		uhci_reset,
843 	.start =		uhci_start,
844 #ifdef CONFIG_PM
845 	.suspend =		uhci_suspend,
846 	.resume =		uhci_resume,
847 	.bus_suspend =		uhci_rh_suspend,
848 	.bus_resume =		uhci_rh_resume,
849 #endif
850 	.stop =			uhci_stop,
851 
852 	.urb_enqueue =		uhci_urb_enqueue,
853 	.urb_dequeue =		uhci_urb_dequeue,
854 
855 	.endpoint_disable =	uhci_hcd_endpoint_disable,
856 	.get_frame_number =	uhci_hcd_get_frame_number,
857 
858 	.hub_status_data =	uhci_hub_status_data,
859 	.hub_control =		uhci_hub_control,
860 };
861 
862 static const struct pci_device_id uhci_pci_ids[] = { {
863 	/* handle any USB UHCI controller */
864 	PCI_DEVICE_CLASS(((PCI_CLASS_SERIAL_USB << 8) | 0x00), ~0),
865 	.driver_data =	(unsigned long) &uhci_driver,
866 	}, { /* end: all zeroes */ }
867 };
868 
869 MODULE_DEVICE_TABLE(pci, uhci_pci_ids);
870 
871 static struct pci_driver uhci_pci_driver = {
872 	.name =		(char *)hcd_name,
873 	.id_table =	uhci_pci_ids,
874 
875 	.probe =	usb_hcd_pci_probe,
876 	.remove =	usb_hcd_pci_remove,
877 	.shutdown =	uhci_shutdown,
878 
879 #ifdef	CONFIG_PM
880 	.suspend =	usb_hcd_pci_suspend,
881 	.resume =	usb_hcd_pci_resume,
882 #endif	/* PM */
883 };
884 
885 static int __init uhci_hcd_init(void)
886 {
887 	int retval = -ENOMEM;
888 
889 	printk(KERN_INFO DRIVER_DESC " " DRIVER_VERSION "\n");
890 
891 	if (usb_disabled())
892 		return -ENODEV;
893 
894 	if (DEBUG_CONFIGURED) {
895 		errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
896 		if (!errbuf)
897 			goto errbuf_failed;
898 		uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
899 		if (!uhci_debugfs_root)
900 			goto debug_failed;
901 	}
902 
903 	uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
904 		sizeof(struct urb_priv), 0, 0, NULL, NULL);
905 	if (!uhci_up_cachep)
906 		goto up_failed;
907 
908 	retval = pci_register_driver(&uhci_pci_driver);
909 	if (retval)
910 		goto init_failed;
911 
912 	return 0;
913 
914 init_failed:
915 	if (kmem_cache_destroy(uhci_up_cachep))
916 		warn("not all urb_privs were freed!");
917 
918 up_failed:
919 	debugfs_remove(uhci_debugfs_root);
920 
921 debug_failed:
922 	kfree(errbuf);
923 
924 errbuf_failed:
925 
926 	return retval;
927 }
928 
929 static void __exit uhci_hcd_cleanup(void)
930 {
931 	pci_unregister_driver(&uhci_pci_driver);
932 
933 	if (kmem_cache_destroy(uhci_up_cachep))
934 		warn("not all urb_privs were freed!");
935 
936 	debugfs_remove(uhci_debugfs_root);
937 	kfree(errbuf);
938 }
939 
940 module_init(uhci_hcd_init);
941 module_exit(uhci_hcd_cleanup);
942 
943 MODULE_AUTHOR(DRIVER_AUTHOR);
944 MODULE_DESCRIPTION(DRIVER_DESC);
945 MODULE_LICENSE("GPL");
946