xref: /linux/drivers/usb/host/uhci-hcd.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
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 extern void uhci_reset_hc(struct pci_dev *pdev, unsigned long base);
105 extern int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base);
106 
107 /*
108  * Finish up a host controller reset and update the recorded state.
109  */
110 static void finish_reset(struct uhci_hcd *uhci)
111 {
112 	int port;
113 
114 	/* HCRESET doesn't affect the Suspend, Reset, and Resume Detect
115 	 * bits in the port status and control registers.
116 	 * We have to clear them by hand.
117 	 */
118 	for (port = 0; port < uhci->rh_numports; ++port)
119 		outw(0, uhci->io_addr + USBPORTSC1 + (port * 2));
120 
121 	uhci->port_c_suspend = uhci->suspended_ports =
122 			uhci->resuming_ports = 0;
123 	uhci->rh_state = UHCI_RH_RESET;
124 	uhci->is_stopped = UHCI_IS_STOPPED;
125 	uhci_to_hcd(uhci)->state = HC_STATE_HALT;
126 	uhci_to_hcd(uhci)->poll_rh = 0;
127 }
128 
129 /*
130  * Last rites for a defunct/nonfunctional controller
131  * or one we don't want to use any more.
132  */
133 static void hc_died(struct uhci_hcd *uhci)
134 {
135 	uhci_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr);
136 	finish_reset(uhci);
137 	uhci->hc_inaccessible = 1;
138 }
139 
140 /*
141  * Initialize a controller that was newly discovered or has just been
142  * resumed.  In either case we can't be sure of its previous state.
143  */
144 static void check_and_reset_hc(struct uhci_hcd *uhci)
145 {
146 	if (uhci_check_and_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr))
147 		finish_reset(uhci);
148 }
149 
150 /*
151  * Store the basic register settings needed by the controller.
152  */
153 static void configure_hc(struct uhci_hcd *uhci)
154 {
155 	/* Set the frame length to the default: 1 ms exactly */
156 	outb(USBSOF_DEFAULT, uhci->io_addr + USBSOF);
157 
158 	/* Store the frame list base address */
159 	outl(uhci->frame_dma_handle, uhci->io_addr + USBFLBASEADD);
160 
161 	/* Set the current frame number */
162 	outw(uhci->frame_number, uhci->io_addr + USBFRNUM);
163 
164 	/* Mark controller as not halted before we enable interrupts */
165 	uhci_to_hcd(uhci)->state = HC_STATE_SUSPENDED;
166 	mb();
167 
168 	/* Enable PIRQ */
169 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
170 			USBLEGSUP_DEFAULT);
171 }
172 
173 
174 static int resume_detect_interrupts_are_broken(struct uhci_hcd *uhci)
175 {
176 	int port;
177 
178 	switch (to_pci_dev(uhci_dev(uhci))->vendor) {
179 	    default:
180 		break;
181 
182 	    case PCI_VENDOR_ID_GENESYS:
183 		/* Genesys Logic's GL880S controllers don't generate
184 		 * resume-detect interrupts.
185 		 */
186 		return 1;
187 
188 	    case PCI_VENDOR_ID_INTEL:
189 		/* Some of Intel's USB controllers have a bug that causes
190 		 * resume-detect interrupts if any port has an over-current
191 		 * condition.  To make matters worse, some motherboards
192 		 * hardwire unused USB ports' over-current inputs active!
193 		 * To prevent problems, we will not enable resume-detect
194 		 * interrupts if any ports are OC.
195 		 */
196 		for (port = 0; port < uhci->rh_numports; ++port) {
197 			if (inw(uhci->io_addr + USBPORTSC1 + port * 2) &
198 					USBPORTSC_OC)
199 				return 1;
200 		}
201 		break;
202 	}
203 	return 0;
204 }
205 
206 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state)
207 __releases(uhci->lock)
208 __acquires(uhci->lock)
209 {
210 	int auto_stop;
211 	int int_enable;
212 
213 	auto_stop = (new_state == UHCI_RH_AUTO_STOPPED);
214 	dev_dbg(uhci_dev(uhci), "%s%s\n", __FUNCTION__,
215 			(auto_stop ? " (auto-stop)" : ""));
216 
217 	/* If we get a suspend request when we're already auto-stopped
218 	 * then there's nothing to do.
219 	 */
220 	if (uhci->rh_state == UHCI_RH_AUTO_STOPPED) {
221 		uhci->rh_state = new_state;
222 		return;
223 	}
224 
225 	/* Enable resume-detect interrupts if they work.
226 	 * Then enter Global Suspend mode, still configured.
227 	 */
228 	uhci->working_RD = 1;
229 	int_enable = USBINTR_RESUME;
230 	if (resume_detect_interrupts_are_broken(uhci)) {
231 		uhci->working_RD = int_enable = 0;
232 	}
233 	outw(int_enable, uhci->io_addr + USBINTR);
234 	outw(USBCMD_EGSM | USBCMD_CF, uhci->io_addr + USBCMD);
235 	mb();
236 	udelay(5);
237 
238 	/* If we're auto-stopping then no devices have been attached
239 	 * for a while, so there shouldn't be any active URBs and the
240 	 * controller should stop after a few microseconds.  Otherwise
241 	 * we will give the controller one frame to stop.
242 	 */
243 	if (!auto_stop && !(inw(uhci->io_addr + USBSTS) & USBSTS_HCH)) {
244 		uhci->rh_state = UHCI_RH_SUSPENDING;
245 		spin_unlock_irq(&uhci->lock);
246 		msleep(1);
247 		spin_lock_irq(&uhci->lock);
248 		if (uhci->hc_inaccessible)	/* Died */
249 			return;
250 	}
251 	if (!(inw(uhci->io_addr + USBSTS) & USBSTS_HCH))
252 		dev_warn(uhci_dev(uhci), "Controller not stopped yet!\n");
253 
254 	uhci_get_current_frame_number(uhci);
255 	smp_wmb();
256 
257 	uhci->rh_state = new_state;
258 	uhci->is_stopped = UHCI_IS_STOPPED;
259 	uhci_to_hcd(uhci)->poll_rh = !int_enable;
260 
261 	uhci_scan_schedule(uhci, NULL);
262 }
263 
264 static void start_rh(struct uhci_hcd *uhci)
265 {
266 	uhci_to_hcd(uhci)->state = HC_STATE_RUNNING;
267 	uhci->is_stopped = 0;
268 	smp_wmb();
269 
270 	/* Mark it configured and running with a 64-byte max packet.
271 	 * All interrupts are enabled, even though RESUME won't do anything.
272 	 */
273 	outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP, uhci->io_addr + USBCMD);
274 	outw(USBINTR_TIMEOUT | USBINTR_RESUME | USBINTR_IOC | USBINTR_SP,
275 			uhci->io_addr + USBINTR);
276 	mb();
277 	uhci->rh_state = UHCI_RH_RUNNING;
278 	uhci_to_hcd(uhci)->poll_rh = 1;
279 }
280 
281 static void wakeup_rh(struct uhci_hcd *uhci)
282 __releases(uhci->lock)
283 __acquires(uhci->lock)
284 {
285 	dev_dbg(uhci_dev(uhci), "%s%s\n", __FUNCTION__,
286 			uhci->rh_state == UHCI_RH_AUTO_STOPPED ?
287 				" (auto-start)" : "");
288 
289 	/* If we are auto-stopped then no devices are attached so there's
290 	 * no need for wakeup signals.  Otherwise we send Global Resume
291 	 * for 20 ms.
292 	 */
293 	if (uhci->rh_state == UHCI_RH_SUSPENDED) {
294 		uhci->rh_state = UHCI_RH_RESUMING;
295 		outw(USBCMD_FGR | USBCMD_EGSM | USBCMD_CF,
296 				uhci->io_addr + USBCMD);
297 		spin_unlock_irq(&uhci->lock);
298 		msleep(20);
299 		spin_lock_irq(&uhci->lock);
300 		if (uhci->hc_inaccessible)	/* Died */
301 			return;
302 
303 		/* End Global Resume and wait for EOP to be sent */
304 		outw(USBCMD_CF, uhci->io_addr + USBCMD);
305 		mb();
306 		udelay(4);
307 		if (inw(uhci->io_addr + USBCMD) & USBCMD_FGR)
308 			dev_warn(uhci_dev(uhci), "FGR not stopped yet!\n");
309 	}
310 
311 	start_rh(uhci);
312 
313 	/* Restart root hub polling */
314 	mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
315 }
316 
317 static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
318 {
319 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
320 	unsigned short status;
321 	unsigned long flags;
322 
323 	/*
324 	 * Read the interrupt status, and write it back to clear the
325 	 * interrupt cause.  Contrary to the UHCI specification, the
326 	 * "HC Halted" status bit is persistent: it is RO, not R/WC.
327 	 */
328 	status = inw(uhci->io_addr + USBSTS);
329 	if (!(status & ~USBSTS_HCH))	/* shared interrupt, not mine */
330 		return IRQ_NONE;
331 	outw(status, uhci->io_addr + USBSTS);		/* Clear it */
332 
333 	if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) {
334 		if (status & USBSTS_HSE)
335 			dev_err(uhci_dev(uhci), "host system error, "
336 					"PCI problems?\n");
337 		if (status & USBSTS_HCPE)
338 			dev_err(uhci_dev(uhci), "host controller process "
339 					"error, something bad happened!\n");
340 		if (status & USBSTS_HCH) {
341 			spin_lock_irqsave(&uhci->lock, flags);
342 			if (uhci->rh_state >= UHCI_RH_RUNNING) {
343 				dev_err(uhci_dev(uhci),
344 					"host controller halted, "
345 					"very bad!\n");
346 				hc_died(uhci);
347 
348 				/* Force a callback in case there are
349 				 * pending unlinks */
350 				mod_timer(&hcd->rh_timer, jiffies);
351 			}
352 			spin_unlock_irqrestore(&uhci->lock, flags);
353 		}
354 	}
355 
356 	if (status & USBSTS_RD)
357 		usb_hcd_poll_rh_status(hcd);
358 	else {
359 		spin_lock_irqsave(&uhci->lock, flags);
360 		uhci_scan_schedule(uhci, regs);
361 		spin_unlock_irqrestore(&uhci->lock, flags);
362 	}
363 
364 	return IRQ_HANDLED;
365 }
366 
367 /*
368  * Store the current frame number in uhci->frame_number if the controller
369  * is runnning
370  */
371 static void uhci_get_current_frame_number(struct uhci_hcd *uhci)
372 {
373 	if (!uhci->is_stopped)
374 		uhci->frame_number = inw(uhci->io_addr + USBFRNUM);
375 }
376 
377 /*
378  * De-allocate all resources
379  */
380 static void release_uhci(struct uhci_hcd *uhci)
381 {
382 	int i;
383 
384 	for (i = 0; i < UHCI_NUM_SKELQH; i++)
385 		uhci_free_qh(uhci, uhci->skelqh[i]);
386 
387 	uhci_free_td(uhci, uhci->term_td);
388 
389 	dma_pool_destroy(uhci->qh_pool);
390 
391 	dma_pool_destroy(uhci->td_pool);
392 
393 	kfree(uhci->frame_cpu);
394 
395 	dma_free_coherent(uhci_dev(uhci),
396 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
397 			uhci->frame, uhci->frame_dma_handle);
398 
399 	debugfs_remove(uhci->dentry);
400 }
401 
402 static int uhci_reset(struct usb_hcd *hcd)
403 {
404 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
405 	unsigned io_size = (unsigned) hcd->rsrc_len;
406 	int port;
407 
408 	uhci->io_addr = (unsigned long) hcd->rsrc_start;
409 
410 	/* The UHCI spec says devices must have 2 ports, and goes on to say
411 	 * they may have more but gives no way to determine how many there
412 	 * are.  However according to the UHCI spec, Bit 7 of the port
413 	 * status and control register is always set to 1.  So we try to
414 	 * use this to our advantage.  Another common failure mode when
415 	 * a nonexistent register is addressed is to return all ones, so
416 	 * we test for that also.
417 	 */
418 	for (port = 0; port < (io_size - USBPORTSC1) / 2; port++) {
419 		unsigned int portstatus;
420 
421 		portstatus = inw(uhci->io_addr + USBPORTSC1 + (port * 2));
422 		if (!(portstatus & 0x0080) || portstatus == 0xffff)
423 			break;
424 	}
425 	if (debug)
426 		dev_info(uhci_dev(uhci), "detected %d ports\n", port);
427 
428 	/* Anything greater than 7 is weird so we'll ignore it. */
429 	if (port > UHCI_RH_MAXCHILD) {
430 		dev_info(uhci_dev(uhci), "port count misdetected? "
431 				"forcing to 2 ports\n");
432 		port = 2;
433 	}
434 	uhci->rh_numports = port;
435 
436 	/* Kick BIOS off this hardware and reset if the controller
437 	 * isn't already safely quiescent.
438 	 */
439 	check_and_reset_hc(uhci);
440 	return 0;
441 }
442 
443 /* Make sure the controller is quiescent and that we're not using it
444  * any more.  This is mainly for the benefit of programs which, like kexec,
445  * expect the hardware to be idle: not doing DMA or generating IRQs.
446  *
447  * This routine may be called in a damaged or failing kernel.  Hence we
448  * do not acquire the spinlock before shutting down the controller.
449  */
450 static void uhci_shutdown(struct pci_dev *pdev)
451 {
452 	struct usb_hcd *hcd = (struct usb_hcd *) pci_get_drvdata(pdev);
453 
454 	hc_died(hcd_to_uhci(hcd));
455 }
456 
457 /*
458  * Allocate a frame list, and then setup the skeleton
459  *
460  * The hardware doesn't really know any difference
461  * in the queues, but the order does matter for the
462  * protocols higher up. The order is:
463  *
464  *  - any isochronous events handled before any
465  *    of the queues. We don't do that here, because
466  *    we'll create the actual TD entries on demand.
467  *  - The first queue is the interrupt queue.
468  *  - The second queue is the control queue, split into low- and full-speed
469  *  - The third queue is bulk queue.
470  *  - The fourth queue is the bandwidth reclamation queue, which loops back
471  *    to the full-speed control queue.
472  */
473 static int uhci_start(struct usb_hcd *hcd)
474 {
475 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
476 	int retval = -EBUSY;
477 	int i;
478 	struct dentry *dentry;
479 
480 	hcd->uses_new_polling = 1;
481 	if (pci_find_capability(to_pci_dev(uhci_dev(uhci)), PCI_CAP_ID_PM))
482 		hcd->can_wakeup = 1;		/* Assume it supports PME# */
483 
484 	dentry = debugfs_create_file(hcd->self.bus_name,
485 			S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root, uhci,
486 			&uhci_debug_operations);
487 	if (!dentry) {
488 		dev_err(uhci_dev(uhci),
489 				"couldn't create uhci debugfs entry\n");
490 		retval = -ENOMEM;
491 		goto err_create_debug_entry;
492 	}
493 	uhci->dentry = dentry;
494 
495 	uhci->fsbr = 0;
496 	uhci->fsbrtimeout = 0;
497 
498 	spin_lock_init(&uhci->lock);
499 	INIT_LIST_HEAD(&uhci->qh_remove_list);
500 
501 	INIT_LIST_HEAD(&uhci->td_remove_list);
502 
503 	INIT_LIST_HEAD(&uhci->urb_remove_list);
504 
505 	INIT_LIST_HEAD(&uhci->urb_list);
506 
507 	INIT_LIST_HEAD(&uhci->complete_list);
508 
509 	init_waitqueue_head(&uhci->waitqh);
510 
511 	uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
512 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
513 			&uhci->frame_dma_handle, 0);
514 	if (!uhci->frame) {
515 		dev_err(uhci_dev(uhci), "unable to allocate "
516 				"consistent memory for frame list\n");
517 		goto err_alloc_frame;
518 	}
519 	memset(uhci->frame, 0, UHCI_NUMFRAMES * sizeof(*uhci->frame));
520 
521 	uhci->frame_cpu = kcalloc(UHCI_NUMFRAMES, sizeof(*uhci->frame_cpu),
522 			GFP_KERNEL);
523 	if (!uhci->frame_cpu) {
524 		dev_err(uhci_dev(uhci), "unable to allocate "
525 				"memory for frame pointers\n");
526 		goto err_alloc_frame_cpu;
527 	}
528 
529 	uhci->td_pool = dma_pool_create("uhci_td", uhci_dev(uhci),
530 			sizeof(struct uhci_td), 16, 0);
531 	if (!uhci->td_pool) {
532 		dev_err(uhci_dev(uhci), "unable to create td dma_pool\n");
533 		goto err_create_td_pool;
534 	}
535 
536 	uhci->qh_pool = dma_pool_create("uhci_qh", uhci_dev(uhci),
537 			sizeof(struct uhci_qh), 16, 0);
538 	if (!uhci->qh_pool) {
539 		dev_err(uhci_dev(uhci), "unable to create qh dma_pool\n");
540 		goto err_create_qh_pool;
541 	}
542 
543 	uhci->term_td = uhci_alloc_td(uhci);
544 	if (!uhci->term_td) {
545 		dev_err(uhci_dev(uhci), "unable to allocate terminating TD\n");
546 		goto err_alloc_term_td;
547 	}
548 
549 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
550 		uhci->skelqh[i] = uhci_alloc_qh(uhci);
551 		if (!uhci->skelqh[i]) {
552 			dev_err(uhci_dev(uhci), "unable to allocate QH\n");
553 			goto err_alloc_skelqh;
554 		}
555 	}
556 
557 	/*
558 	 * 8 Interrupt queues; link all higher int queues to int1,
559 	 * then link int1 to control and control to bulk
560 	 */
561 	uhci->skel_int128_qh->link =
562 			uhci->skel_int64_qh->link =
563 			uhci->skel_int32_qh->link =
564 			uhci->skel_int16_qh->link =
565 			uhci->skel_int8_qh->link =
566 			uhci->skel_int4_qh->link =
567 			uhci->skel_int2_qh->link =
568 			cpu_to_le32(uhci->skel_int1_qh->dma_handle) | UHCI_PTR_QH;
569 	uhci->skel_int1_qh->link = cpu_to_le32(uhci->skel_ls_control_qh->dma_handle) | UHCI_PTR_QH;
570 
571 	uhci->skel_ls_control_qh->link = cpu_to_le32(uhci->skel_fs_control_qh->dma_handle) | UHCI_PTR_QH;
572 	uhci->skel_fs_control_qh->link = cpu_to_le32(uhci->skel_bulk_qh->dma_handle) | UHCI_PTR_QH;
573 	uhci->skel_bulk_qh->link = cpu_to_le32(uhci->skel_term_qh->dma_handle) | UHCI_PTR_QH;
574 
575 	/* This dummy TD is to work around a bug in Intel PIIX controllers */
576 	uhci_fill_td(uhci->term_td, 0, (UHCI_NULL_DATA_SIZE << 21) |
577 		(0x7f << TD_TOKEN_DEVADDR_SHIFT) | USB_PID_IN, 0);
578 	uhci->term_td->link = cpu_to_le32(uhci->term_td->dma_handle);
579 
580 	uhci->skel_term_qh->link = UHCI_PTR_TERM;
581 	uhci->skel_term_qh->element = cpu_to_le32(uhci->term_td->dma_handle);
582 
583 	/*
584 	 * Fill the frame list: make all entries point to the proper
585 	 * interrupt queue.
586 	 *
587 	 * The interrupt queues will be interleaved as evenly as possible.
588 	 * There's not much to be done about period-1 interrupts; they have
589 	 * to occur in every frame.  But we can schedule period-2 interrupts
590 	 * in odd-numbered frames, period-4 interrupts in frames congruent
591 	 * to 2 (mod 4), and so on.  This way each frame only has two
592 	 * interrupt QHs, which will help spread out bandwidth utilization.
593 	 */
594 	for (i = 0; i < UHCI_NUMFRAMES; i++) {
595 		int irq;
596 
597 		/*
598 		 * ffs (Find First bit Set) does exactly what we need:
599 		 * 1,3,5,...  => ffs = 0 => use skel_int2_qh = skelqh[6],
600 		 * 2,6,10,... => ffs = 1 => use skel_int4_qh = skelqh[5], etc.
601 		 * ffs > 6 => not on any high-period queue, so use
602 		 *	skel_int1_qh = skelqh[7].
603 		 * Add UHCI_NUMFRAMES to insure at least one bit is set.
604 		 */
605 		irq = 6 - (int) __ffs(i + UHCI_NUMFRAMES);
606 		if (irq < 0)
607 			irq = 7;
608 
609 		/* Only place we don't use the frame list routines */
610 		uhci->frame[i] = UHCI_PTR_QH |
611 				cpu_to_le32(uhci->skelqh[irq]->dma_handle);
612 	}
613 
614 	/*
615 	 * Some architectures require a full mb() to enforce completion of
616 	 * the memory writes above before the I/O transfers in configure_hc().
617 	 */
618 	mb();
619 
620 	configure_hc(uhci);
621 	start_rh(uhci);
622 	return 0;
623 
624 /*
625  * error exits:
626  */
627 err_alloc_skelqh:
628 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
629 		if (uhci->skelqh[i])
630 			uhci_free_qh(uhci, uhci->skelqh[i]);
631 	}
632 
633 	uhci_free_td(uhci, uhci->term_td);
634 
635 err_alloc_term_td:
636 	dma_pool_destroy(uhci->qh_pool);
637 
638 err_create_qh_pool:
639 	dma_pool_destroy(uhci->td_pool);
640 
641 err_create_td_pool:
642 	kfree(uhci->frame_cpu);
643 
644 err_alloc_frame_cpu:
645 	dma_free_coherent(uhci_dev(uhci),
646 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
647 			uhci->frame, uhci->frame_dma_handle);
648 
649 err_alloc_frame:
650 	debugfs_remove(uhci->dentry);
651 
652 err_create_debug_entry:
653 	return retval;
654 }
655 
656 static void uhci_stop(struct usb_hcd *hcd)
657 {
658 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
659 
660 	spin_lock_irq(&uhci->lock);
661 	if (!uhci->hc_inaccessible)
662 		hc_died(uhci);
663 	uhci_scan_schedule(uhci, NULL);
664 	spin_unlock_irq(&uhci->lock);
665 
666 	release_uhci(uhci);
667 }
668 
669 #ifdef CONFIG_PM
670 static int uhci_rh_suspend(struct usb_hcd *hcd)
671 {
672 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
673 
674 	spin_lock_irq(&uhci->lock);
675 	if (!uhci->hc_inaccessible)		/* Not dead */
676 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
677 	spin_unlock_irq(&uhci->lock);
678 	return 0;
679 }
680 
681 static int uhci_rh_resume(struct usb_hcd *hcd)
682 {
683 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
684 	int rc = 0;
685 
686 	spin_lock_irq(&uhci->lock);
687 	if (uhci->hc_inaccessible) {
688 		if (uhci->rh_state == UHCI_RH_SUSPENDED) {
689 			dev_warn(uhci_dev(uhci), "HC isn't running!\n");
690 			rc = -ENODEV;
691 		}
692 		/* Otherwise the HC is dead */
693 	} else
694 		wakeup_rh(uhci);
695 	spin_unlock_irq(&uhci->lock);
696 	return rc;
697 }
698 
699 static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
700 {
701 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
702 	int rc = 0;
703 
704 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
705 
706 	spin_lock_irq(&uhci->lock);
707 	if (uhci->hc_inaccessible)	/* Dead or already suspended */
708 		goto done;
709 
710 	if (uhci->rh_state > UHCI_RH_SUSPENDED) {
711 		dev_warn(uhci_dev(uhci), "Root hub isn't suspended!\n");
712 		rc = -EBUSY;
713 		goto done;
714 	};
715 
716 	/* All PCI host controllers are required to disable IRQ generation
717 	 * at the source, so we must turn off PIRQ.
718 	 */
719 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
720 	mb();
721 	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
722 	uhci->hc_inaccessible = 1;
723 	hcd->poll_rh = 0;
724 
725 	/* FIXME: Enable non-PME# remote wakeup? */
726 
727 done:
728 	spin_unlock_irq(&uhci->lock);
729 	return rc;
730 }
731 
732 static int uhci_resume(struct usb_hcd *hcd)
733 {
734 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
735 
736 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
737 
738 	/* We aren't in D3 state anymore, we do that even if dead as I
739 	 * really don't want to keep a stale HCD_FLAG_HW_ACCESSIBLE=0
740 	 */
741 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
742 	mb();
743 
744 	if (uhci->rh_state == UHCI_RH_RESET)	/* Dead */
745 		return 0;
746 	spin_lock_irq(&uhci->lock);
747 
748 	/* FIXME: Disable non-PME# remote wakeup? */
749 
750 	uhci->hc_inaccessible = 0;
751 
752 	/* The BIOS may have changed the controller settings during a
753 	 * system wakeup.  Check it and reconfigure to avoid problems.
754 	 */
755 	check_and_reset_hc(uhci);
756 	configure_hc(uhci);
757 
758 	if (uhci->rh_state == UHCI_RH_RESET)
759 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
760 
761 	spin_unlock_irq(&uhci->lock);
762 
763 	if (!uhci->working_RD) {
764 		/* Suspended root hub needs to be polled */
765 		hcd->poll_rh = 1;
766 		usb_hcd_poll_rh_status(hcd);
767 	}
768 	return 0;
769 }
770 #endif
771 
772 /* Wait until all the URBs for a particular device/endpoint are gone */
773 static void uhci_hcd_endpoint_disable(struct usb_hcd *hcd,
774 		struct usb_host_endpoint *ep)
775 {
776 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
777 
778 	wait_event_interruptible(uhci->waitqh, list_empty(&ep->urb_list));
779 }
780 
781 static int uhci_hcd_get_frame_number(struct usb_hcd *hcd)
782 {
783 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
784 	unsigned long flags;
785 	int is_stopped;
786 	int frame_number;
787 
788 	/* Minimize latency by avoiding the spinlock */
789 	local_irq_save(flags);
790 	is_stopped = uhci->is_stopped;
791 	smp_rmb();
792 	frame_number = (is_stopped ? uhci->frame_number :
793 			inw(uhci->io_addr + USBFRNUM));
794 	local_irq_restore(flags);
795 	return frame_number;
796 }
797 
798 static const char hcd_name[] = "uhci_hcd";
799 
800 static const struct hc_driver uhci_driver = {
801 	.description =		hcd_name,
802 	.product_desc =		"UHCI Host Controller",
803 	.hcd_priv_size =	sizeof(struct uhci_hcd),
804 
805 	/* Generic hardware linkage */
806 	.irq =			uhci_irq,
807 	.flags =		HCD_USB11,
808 
809 	/* Basic lifecycle operations */
810 	.reset =		uhci_reset,
811 	.start =		uhci_start,
812 #ifdef CONFIG_PM
813 	.suspend =		uhci_suspend,
814 	.resume =		uhci_resume,
815 	.bus_suspend =		uhci_rh_suspend,
816 	.bus_resume =		uhci_rh_resume,
817 #endif
818 	.stop =			uhci_stop,
819 
820 	.urb_enqueue =		uhci_urb_enqueue,
821 	.urb_dequeue =		uhci_urb_dequeue,
822 
823 	.endpoint_disable =	uhci_hcd_endpoint_disable,
824 	.get_frame_number =	uhci_hcd_get_frame_number,
825 
826 	.hub_status_data =	uhci_hub_status_data,
827 	.hub_control =		uhci_hub_control,
828 };
829 
830 static const struct pci_device_id uhci_pci_ids[] = { {
831 	/* handle any USB UHCI controller */
832 	PCI_DEVICE_CLASS(((PCI_CLASS_SERIAL_USB << 8) | 0x00), ~0),
833 	.driver_data =	(unsigned long) &uhci_driver,
834 	}, { /* end: all zeroes */ }
835 };
836 
837 MODULE_DEVICE_TABLE(pci, uhci_pci_ids);
838 
839 static struct pci_driver uhci_pci_driver = {
840 	.name =		(char *)hcd_name,
841 	.id_table =	uhci_pci_ids,
842 
843 	.probe =	usb_hcd_pci_probe,
844 	.remove =	usb_hcd_pci_remove,
845 	.shutdown =	uhci_shutdown,
846 
847 #ifdef	CONFIG_PM
848 	.suspend =	usb_hcd_pci_suspend,
849 	.resume =	usb_hcd_pci_resume,
850 #endif	/* PM */
851 };
852 
853 static int __init uhci_hcd_init(void)
854 {
855 	int retval = -ENOMEM;
856 
857 	printk(KERN_INFO DRIVER_DESC " " DRIVER_VERSION "\n");
858 
859 	if (usb_disabled())
860 		return -ENODEV;
861 
862 	if (debug) {
863 		errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
864 		if (!errbuf)
865 			goto errbuf_failed;
866 	}
867 
868 	uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
869 	if (!uhci_debugfs_root)
870 		goto debug_failed;
871 
872 	uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
873 		sizeof(struct urb_priv), 0, 0, NULL, NULL);
874 	if (!uhci_up_cachep)
875 		goto up_failed;
876 
877 	retval = pci_register_driver(&uhci_pci_driver);
878 	if (retval)
879 		goto init_failed;
880 
881 	return 0;
882 
883 init_failed:
884 	if (kmem_cache_destroy(uhci_up_cachep))
885 		warn("not all urb_priv's were freed!");
886 
887 up_failed:
888 	debugfs_remove(uhci_debugfs_root);
889 
890 debug_failed:
891 	kfree(errbuf);
892 
893 errbuf_failed:
894 
895 	return retval;
896 }
897 
898 static void __exit uhci_hcd_cleanup(void)
899 {
900 	pci_unregister_driver(&uhci_pci_driver);
901 
902 	if (kmem_cache_destroy(uhci_up_cachep))
903 		warn("not all urb_priv's were freed!");
904 
905 	debugfs_remove(uhci_debugfs_root);
906 	kfree(errbuf);
907 }
908 
909 module_init(uhci_hcd_init);
910 module_exit(uhci_hcd_cleanup);
911 
912 MODULE_AUTHOR(DRIVER_AUTHOR);
913 MODULE_DESCRIPTION(DRIVER_DESC);
914 MODULE_LICENSE("GPL");
915