xref: /linux/drivers/usb/host/uhci-hcd.c (revision 7b12b9137930eb821b68e1bfa11e9de692208620)
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 #include "pci-quirks.h"
54 
55 /*
56  * Version Information
57  */
58 #define DRIVER_VERSION "v3.0"
59 #define DRIVER_AUTHOR "Linus 'Frodo Rabbit' Torvalds, Johannes Erdfelt, \
60 Randy Dunlap, Georg Acher, Deti Fliegl, Thomas Sailer, Roman Weissgaerber, \
61 Alan Stern"
62 #define DRIVER_DESC "USB Universal Host Controller Interface driver"
63 
64 /*
65  * debug = 0, no debugging messages
66  * debug = 1, dump failed URBs except for stalls
67  * debug = 2, dump all failed URBs (including stalls)
68  *            show all queues in /debug/uhci/[pci_addr]
69  * debug = 3, show all TDs in URBs when dumping
70  */
71 #ifdef DEBUG
72 #define DEBUG_CONFIGURED	1
73 static int debug = 1;
74 module_param(debug, int, S_IRUGO | S_IWUSR);
75 MODULE_PARM_DESC(debug, "Debug level");
76 
77 #else
78 #define DEBUG_CONFIGURED	0
79 #define debug			0
80 #endif
81 
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 TDs */
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  * Finish up a host controller reset and update the recorded state.
106  */
107 static void finish_reset(struct uhci_hcd *uhci)
108 {
109 	int port;
110 
111 	/* HCRESET doesn't affect the Suspend, Reset, and Resume Detect
112 	 * bits in the port status and control registers.
113 	 * We have to clear them by hand.
114 	 */
115 	for (port = 0; port < uhci->rh_numports; ++port)
116 		outw(0, uhci->io_addr + USBPORTSC1 + (port * 2));
117 
118 	uhci->port_c_suspend = uhci->resuming_ports = 0;
119 	uhci->rh_state = UHCI_RH_RESET;
120 	uhci->is_stopped = UHCI_IS_STOPPED;
121 	uhci_to_hcd(uhci)->state = HC_STATE_HALT;
122 	uhci_to_hcd(uhci)->poll_rh = 0;
123 }
124 
125 /*
126  * Last rites for a defunct/nonfunctional controller
127  * or one we don't want to use any more.
128  */
129 static void hc_died(struct uhci_hcd *uhci)
130 {
131 	uhci_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr);
132 	finish_reset(uhci);
133 	uhci->hc_inaccessible = 1;
134 }
135 
136 /*
137  * Initialize a controller that was newly discovered or has just been
138  * resumed.  In either case we can't be sure of its previous state.
139  */
140 static void check_and_reset_hc(struct uhci_hcd *uhci)
141 {
142 	if (uhci_check_and_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr))
143 		finish_reset(uhci);
144 }
145 
146 /*
147  * Store the basic register settings needed by the controller.
148  */
149 static void configure_hc(struct uhci_hcd *uhci)
150 {
151 	/* Set the frame length to the default: 1 ms exactly */
152 	outb(USBSOF_DEFAULT, uhci->io_addr + USBSOF);
153 
154 	/* Store the frame list base address */
155 	outl(uhci->frame_dma_handle, uhci->io_addr + USBFLBASEADD);
156 
157 	/* Set the current frame number */
158 	outw(uhci->frame_number, uhci->io_addr + USBFRNUM);
159 
160 	/* Mark controller as not halted before we enable interrupts */
161 	uhci_to_hcd(uhci)->state = HC_STATE_SUSPENDED;
162 	mb();
163 
164 	/* Enable PIRQ */
165 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
166 			USBLEGSUP_DEFAULT);
167 }
168 
169 
170 static int resume_detect_interrupts_are_broken(struct uhci_hcd *uhci)
171 {
172 	int port;
173 
174 	switch (to_pci_dev(uhci_dev(uhci))->vendor) {
175 	    default:
176 		break;
177 
178 	    case PCI_VENDOR_ID_GENESYS:
179 		/* Genesys Logic's GL880S controllers don't generate
180 		 * resume-detect interrupts.
181 		 */
182 		return 1;
183 
184 	    case PCI_VENDOR_ID_INTEL:
185 		/* Some of Intel's USB controllers have a bug that causes
186 		 * resume-detect interrupts if any port has an over-current
187 		 * condition.  To make matters worse, some motherboards
188 		 * hardwire unused USB ports' over-current inputs active!
189 		 * To prevent problems, we will not enable resume-detect
190 		 * interrupts if any ports are OC.
191 		 */
192 		for (port = 0; port < uhci->rh_numports; ++port) {
193 			if (inw(uhci->io_addr + USBPORTSC1 + port * 2) &
194 					USBPORTSC_OC)
195 				return 1;
196 		}
197 		break;
198 	}
199 	return 0;
200 }
201 
202 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state)
203 __releases(uhci->lock)
204 __acquires(uhci->lock)
205 {
206 	int auto_stop;
207 	int int_enable;
208 
209 	auto_stop = (new_state == UHCI_RH_AUTO_STOPPED);
210 	dev_dbg(uhci_dev(uhci), "%s%s\n", __FUNCTION__,
211 			(auto_stop ? " (auto-stop)" : ""));
212 
213 	/* If we get a suspend request when we're already auto-stopped
214 	 * then there's nothing to do.
215 	 */
216 	if (uhci->rh_state == UHCI_RH_AUTO_STOPPED) {
217 		uhci->rh_state = new_state;
218 		return;
219 	}
220 
221 	/* Enable resume-detect interrupts if they work.
222 	 * Then enter Global Suspend mode, still configured.
223 	 */
224 	uhci->working_RD = 1;
225 	int_enable = USBINTR_RESUME;
226 	if (resume_detect_interrupts_are_broken(uhci)) {
227 		uhci->working_RD = int_enable = 0;
228 	}
229 	outw(int_enable, uhci->io_addr + USBINTR);
230 	outw(USBCMD_EGSM | USBCMD_CF, uhci->io_addr + USBCMD);
231 	mb();
232 	udelay(5);
233 
234 	/* If we're auto-stopping then no devices have been attached
235 	 * for a while, so there shouldn't be any active URBs and the
236 	 * controller should stop after a few microseconds.  Otherwise
237 	 * we will give the controller one frame to stop.
238 	 */
239 	if (!auto_stop && !(inw(uhci->io_addr + USBSTS) & USBSTS_HCH)) {
240 		uhci->rh_state = UHCI_RH_SUSPENDING;
241 		spin_unlock_irq(&uhci->lock);
242 		msleep(1);
243 		spin_lock_irq(&uhci->lock);
244 		if (uhci->hc_inaccessible)	/* Died */
245 			return;
246 	}
247 	if (!(inw(uhci->io_addr + USBSTS) & USBSTS_HCH))
248 		dev_warn(uhci_dev(uhci), "Controller not stopped yet!\n");
249 
250 	uhci_get_current_frame_number(uhci);
251 	smp_wmb();
252 
253 	uhci->rh_state = new_state;
254 	uhci->is_stopped = UHCI_IS_STOPPED;
255 	uhci_to_hcd(uhci)->poll_rh = !int_enable;
256 
257 	uhci_scan_schedule(uhci, NULL);
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 	smp_wmb();
265 
266 	/* Mark it configured and running with a 64-byte max packet.
267 	 * All interrupts are enabled, even though RESUME won't do anything.
268 	 */
269 	outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP, uhci->io_addr + USBCMD);
270 	outw(USBINTR_TIMEOUT | USBINTR_RESUME | USBINTR_IOC | USBINTR_SP,
271 			uhci->io_addr + USBINTR);
272 	mb();
273 	uhci->rh_state = UHCI_RH_RUNNING;
274 	uhci_to_hcd(uhci)->poll_rh = 1;
275 }
276 
277 static void wakeup_rh(struct uhci_hcd *uhci)
278 __releases(uhci->lock)
279 __acquires(uhci->lock)
280 {
281 	dev_dbg(uhci_dev(uhci), "%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->hc_inaccessible)	/* Died */
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 				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
372  */
373 static void uhci_get_current_frame_number(struct uhci_hcd *uhci)
374 {
375 	if (!uhci->is_stopped)
376 		uhci->frame_number = inw(uhci->io_addr + USBFRNUM);
377 }
378 
379 /*
380  * De-allocate all resources
381  */
382 static void release_uhci(struct uhci_hcd *uhci)
383 {
384 	int i;
385 
386 	if (DEBUG_CONFIGURED) {
387 		spin_lock_irq(&uhci->lock);
388 		uhci->is_initialized = 0;
389 		spin_unlock_irq(&uhci->lock);
390 
391 		debugfs_remove(uhci->dentry);
392 	}
393 
394 	for (i = 0; i < UHCI_NUM_SKELQH; i++)
395 		uhci_free_qh(uhci, uhci->skelqh[i]);
396 
397 	uhci_free_td(uhci, uhci->term_td);
398 
399 	dma_pool_destroy(uhci->qh_pool);
400 
401 	dma_pool_destroy(uhci->td_pool);
402 
403 	kfree(uhci->frame_cpu);
404 
405 	dma_free_coherent(uhci_dev(uhci),
406 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
407 			uhci->frame, uhci->frame_dma_handle);
408 }
409 
410 static int uhci_reset(struct usb_hcd *hcd)
411 {
412 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
413 	unsigned io_size = (unsigned) hcd->rsrc_len;
414 	int port;
415 
416 	uhci->io_addr = (unsigned long) hcd->rsrc_start;
417 
418 	/* The UHCI spec says devices must have 2 ports, and goes on to say
419 	 * they may have more but gives no way to determine how many there
420 	 * are.  However according to the UHCI spec, Bit 7 of the port
421 	 * status and control register is always set to 1.  So we try to
422 	 * use this to our advantage.  Another common failure mode when
423 	 * a nonexistent register is addressed is to return all ones, so
424 	 * we test for that also.
425 	 */
426 	for (port = 0; port < (io_size - USBPORTSC1) / 2; port++) {
427 		unsigned int portstatus;
428 
429 		portstatus = inw(uhci->io_addr + USBPORTSC1 + (port * 2));
430 		if (!(portstatus & 0x0080) || portstatus == 0xffff)
431 			break;
432 	}
433 	if (debug)
434 		dev_info(uhci_dev(uhci), "detected %d ports\n", port);
435 
436 	/* Anything greater than 7 is weird so we'll ignore it. */
437 	if (port > UHCI_RH_MAXCHILD) {
438 		dev_info(uhci_dev(uhci), "port count misdetected? "
439 				"forcing to 2 ports\n");
440 		port = 2;
441 	}
442 	uhci->rh_numports = port;
443 
444 	/* Kick BIOS off this hardware and reset if the controller
445 	 * isn't already safely quiescent.
446 	 */
447 	check_and_reset_hc(uhci);
448 	return 0;
449 }
450 
451 /* Make sure the controller is quiescent and that we're not using it
452  * any more.  This is mainly for the benefit of programs which, like kexec,
453  * expect the hardware to be idle: not doing DMA or generating IRQs.
454  *
455  * This routine may be called in a damaged or failing kernel.  Hence we
456  * do not acquire the spinlock before shutting down the controller.
457  */
458 static void uhci_shutdown(struct pci_dev *pdev)
459 {
460 	struct usb_hcd *hcd = (struct usb_hcd *) pci_get_drvdata(pdev);
461 
462 	hc_died(hcd_to_uhci(hcd));
463 }
464 
465 /*
466  * Allocate a frame list, and then setup the skeleton
467  *
468  * The hardware doesn't really know any difference
469  * in the queues, but the order does matter for the
470  * protocols higher up. The order is:
471  *
472  *  - any isochronous events handled before any
473  *    of the queues. We don't do that here, because
474  *    we'll create the actual TD entries on demand.
475  *  - The first queue is the interrupt queue.
476  *  - The second queue is the control queue, split into low- and full-speed
477  *  - The third queue is bulk queue.
478  *  - The fourth queue is the bandwidth reclamation queue, which loops back
479  *    to the full-speed control queue.
480  */
481 static int uhci_start(struct usb_hcd *hcd)
482 {
483 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
484 	int retval = -EBUSY;
485 	int i;
486 	struct dentry *dentry;
487 
488 	hcd->uses_new_polling = 1;
489 
490 	uhci->fsbr = 0;
491 	uhci->fsbrtimeout = 0;
492 
493 	spin_lock_init(&uhci->lock);
494 
495 	INIT_LIST_HEAD(&uhci->td_remove_list);
496 	INIT_LIST_HEAD(&uhci->idle_qh_list);
497 
498 	init_waitqueue_head(&uhci->waitqh);
499 
500 	if (DEBUG_CONFIGURED) {
501 		dentry = debugfs_create_file(hcd->self.bus_name,
502 				S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root,
503 				uhci, &uhci_debug_operations);
504 		if (!dentry) {
505 			dev_err(uhci_dev(uhci), "couldn't create uhci "
506 					"debugfs entry\n");
507 			retval = -ENOMEM;
508 			goto err_create_debug_entry;
509 		}
510 		uhci->dentry = dentry;
511 	}
512 
513 	uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
514 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
515 			&uhci->frame_dma_handle, 0);
516 	if (!uhci->frame) {
517 		dev_err(uhci_dev(uhci), "unable to allocate "
518 				"consistent memory for frame list\n");
519 		goto err_alloc_frame;
520 	}
521 	memset(uhci->frame, 0, UHCI_NUMFRAMES * sizeof(*uhci->frame));
522 
523 	uhci->frame_cpu = kcalloc(UHCI_NUMFRAMES, sizeof(*uhci->frame_cpu),
524 			GFP_KERNEL);
525 	if (!uhci->frame_cpu) {
526 		dev_err(uhci_dev(uhci), "unable to allocate "
527 				"memory for frame pointers\n");
528 		goto err_alloc_frame_cpu;
529 	}
530 
531 	uhci->td_pool = dma_pool_create("uhci_td", uhci_dev(uhci),
532 			sizeof(struct uhci_td), 16, 0);
533 	if (!uhci->td_pool) {
534 		dev_err(uhci_dev(uhci), "unable to create td dma_pool\n");
535 		goto err_create_td_pool;
536 	}
537 
538 	uhci->qh_pool = dma_pool_create("uhci_qh", uhci_dev(uhci),
539 			sizeof(struct uhci_qh), 16, 0);
540 	if (!uhci->qh_pool) {
541 		dev_err(uhci_dev(uhci), "unable to create qh dma_pool\n");
542 		goto err_create_qh_pool;
543 	}
544 
545 	uhci->term_td = uhci_alloc_td(uhci);
546 	if (!uhci->term_td) {
547 		dev_err(uhci_dev(uhci), "unable to allocate terminating TD\n");
548 		goto err_alloc_term_td;
549 	}
550 
551 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
552 		uhci->skelqh[i] = uhci_alloc_qh(uhci, NULL, NULL);
553 		if (!uhci->skelqh[i]) {
554 			dev_err(uhci_dev(uhci), "unable to allocate QH\n");
555 			goto err_alloc_skelqh;
556 		}
557 	}
558 
559 	/*
560 	 * 8 Interrupt queues; link all higher int queues to int1,
561 	 * then link int1 to control and control to bulk
562 	 */
563 	uhci->skel_int128_qh->link =
564 			uhci->skel_int64_qh->link =
565 			uhci->skel_int32_qh->link =
566 			uhci->skel_int16_qh->link =
567 			uhci->skel_int8_qh->link =
568 			uhci->skel_int4_qh->link =
569 			uhci->skel_int2_qh->link = UHCI_PTR_QH |
570 			cpu_to_le32(uhci->skel_int1_qh->dma_handle);
571 
572 	uhci->skel_int1_qh->link = UHCI_PTR_QH |
573 			cpu_to_le32(uhci->skel_ls_control_qh->dma_handle);
574 	uhci->skel_ls_control_qh->link = UHCI_PTR_QH |
575 			cpu_to_le32(uhci->skel_fs_control_qh->dma_handle);
576 	uhci->skel_fs_control_qh->link = UHCI_PTR_QH |
577 			cpu_to_le32(uhci->skel_bulk_qh->dma_handle);
578 	uhci->skel_bulk_qh->link = UHCI_PTR_QH |
579 			cpu_to_le32(uhci->skel_term_qh->dma_handle);
580 
581 	/* This dummy TD is to work around a bug in Intel PIIX controllers */
582 	uhci_fill_td(uhci->term_td, 0, uhci_explen(0) |
583 		(0x7f << TD_TOKEN_DEVADDR_SHIFT) | USB_PID_IN, 0);
584 	uhci->term_td->link = cpu_to_le32(uhci->term_td->dma_handle);
585 
586 	uhci->skel_term_qh->link = UHCI_PTR_TERM;
587 	uhci->skel_term_qh->element = cpu_to_le32(uhci->term_td->dma_handle);
588 
589 	/*
590 	 * Fill the frame list: make all entries point to the proper
591 	 * interrupt queue.
592 	 *
593 	 * The interrupt queues will be interleaved as evenly as possible.
594 	 * There's not much to be done about period-1 interrupts; they have
595 	 * to occur in every frame.  But we can schedule period-2 interrupts
596 	 * in odd-numbered frames, period-4 interrupts in frames congruent
597 	 * to 2 (mod 4), and so on.  This way each frame only has two
598 	 * interrupt QHs, which will help spread out bandwidth utilization.
599 	 */
600 	for (i = 0; i < UHCI_NUMFRAMES; i++) {
601 		int irq;
602 
603 		/*
604 		 * ffs (Find First bit Set) does exactly what we need:
605 		 * 1,3,5,...  => ffs = 0 => use skel_int2_qh = skelqh[8],
606 		 * 2,6,10,... => ffs = 1 => use skel_int4_qh = skelqh[7], etc.
607 		 * ffs >= 7 => not on any high-period queue, so use
608 		 *	skel_int1_qh = skelqh[9].
609 		 * Add UHCI_NUMFRAMES to insure at least one bit is set.
610 		 */
611 		irq = 8 - (int) __ffs(i + UHCI_NUMFRAMES);
612 		if (irq <= 1)
613 			irq = 9;
614 
615 		/* Only place we don't use the frame list routines */
616 		uhci->frame[i] = UHCI_PTR_QH |
617 				cpu_to_le32(uhci->skelqh[irq]->dma_handle);
618 	}
619 
620 	/*
621 	 * Some architectures require a full mb() to enforce completion of
622 	 * the memory writes above before the I/O transfers in configure_hc().
623 	 */
624 	mb();
625 
626 	configure_hc(uhci);
627 	uhci->is_initialized = 1;
628 	start_rh(uhci);
629 	return 0;
630 
631 /*
632  * error exits:
633  */
634 err_alloc_skelqh:
635 	for (i = 0; i < UHCI_NUM_SKELQH; i++) {
636 		if (uhci->skelqh[i])
637 			uhci_free_qh(uhci, uhci->skelqh[i]);
638 	}
639 
640 	uhci_free_td(uhci, uhci->term_td);
641 
642 err_alloc_term_td:
643 	dma_pool_destroy(uhci->qh_pool);
644 
645 err_create_qh_pool:
646 	dma_pool_destroy(uhci->td_pool);
647 
648 err_create_td_pool:
649 	kfree(uhci->frame_cpu);
650 
651 err_alloc_frame_cpu:
652 	dma_free_coherent(uhci_dev(uhci),
653 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
654 			uhci->frame, uhci->frame_dma_handle);
655 
656 err_alloc_frame:
657 	debugfs_remove(uhci->dentry);
658 
659 err_create_debug_entry:
660 	return retval;
661 }
662 
663 static void uhci_stop(struct usb_hcd *hcd)
664 {
665 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
666 
667 	spin_lock_irq(&uhci->lock);
668 	if (!uhci->hc_inaccessible)
669 		hc_died(uhci);
670 	uhci_scan_schedule(uhci, NULL);
671 	spin_unlock_irq(&uhci->lock);
672 
673 	release_uhci(uhci);
674 }
675 
676 #ifdef CONFIG_PM
677 static int uhci_rh_suspend(struct usb_hcd *hcd)
678 {
679 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
680 
681 	spin_lock_irq(&uhci->lock);
682 	if (!uhci->hc_inaccessible)		/* Not dead */
683 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
684 	spin_unlock_irq(&uhci->lock);
685 	return 0;
686 }
687 
688 static int uhci_rh_resume(struct usb_hcd *hcd)
689 {
690 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
691 	int rc = 0;
692 
693 	spin_lock_irq(&uhci->lock);
694 	if (uhci->hc_inaccessible) {
695 		if (uhci->rh_state == UHCI_RH_SUSPENDED) {
696 			dev_warn(uhci_dev(uhci), "HC isn't running!\n");
697 			rc = -ENODEV;
698 		}
699 		/* Otherwise the HC is dead */
700 	} else
701 		wakeup_rh(uhci);
702 	spin_unlock_irq(&uhci->lock);
703 	return rc;
704 }
705 
706 static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
707 {
708 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
709 	int rc = 0;
710 
711 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
712 
713 	spin_lock_irq(&uhci->lock);
714 	if (uhci->hc_inaccessible)	/* Dead or already suspended */
715 		goto done;
716 
717 	if (uhci->rh_state > UHCI_RH_SUSPENDED) {
718 		dev_warn(uhci_dev(uhci), "Root hub isn't suspended!\n");
719 		rc = -EBUSY;
720 		goto done;
721 	};
722 
723 	/* All PCI host controllers are required to disable IRQ generation
724 	 * at the source, so we must turn off PIRQ.
725 	 */
726 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
727 	mb();
728 	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
729 	uhci->hc_inaccessible = 1;
730 	hcd->poll_rh = 0;
731 
732 	/* FIXME: Enable non-PME# remote wakeup? */
733 
734 done:
735 	spin_unlock_irq(&uhci->lock);
736 	return rc;
737 }
738 
739 static int uhci_resume(struct usb_hcd *hcd)
740 {
741 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
742 
743 	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
744 
745 	/* Since we aren't in D3 any more, it's safe to set this flag
746 	 * even if the controller was dead.  It might not even be dead
747 	 * any more, if the firmware or quirks code has reset it.
748 	 */
749 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
750 	mb();
751 
752 	if (uhci->rh_state == UHCI_RH_RESET)	/* Dead */
753 		return 0;
754 	spin_lock_irq(&uhci->lock);
755 
756 	/* FIXME: Disable non-PME# remote wakeup? */
757 
758 	uhci->hc_inaccessible = 0;
759 
760 	/* The BIOS may have changed the controller settings during a
761 	 * system wakeup.  Check it and reconfigure to avoid problems.
762 	 */
763 	check_and_reset_hc(uhci);
764 	configure_hc(uhci);
765 
766 	if (uhci->rh_state == UHCI_RH_RESET) {
767 
768 		/* The controller had to be reset */
769 		usb_root_hub_lost_power(hcd->self.root_hub);
770 		suspend_rh(uhci, UHCI_RH_SUSPENDED);
771 	}
772 
773 	spin_unlock_irq(&uhci->lock);
774 
775 	if (!uhci->working_RD) {
776 		/* Suspended root hub needs to be polled */
777 		hcd->poll_rh = 1;
778 		usb_hcd_poll_rh_status(hcd);
779 	}
780 	return 0;
781 }
782 #endif
783 
784 /* Wait until a particular device/endpoint's QH is idle, and free it */
785 static void uhci_hcd_endpoint_disable(struct usb_hcd *hcd,
786 		struct usb_host_endpoint *hep)
787 {
788 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
789 	struct uhci_qh *qh;
790 
791 	spin_lock_irq(&uhci->lock);
792 	qh = (struct uhci_qh *) hep->hcpriv;
793 	if (qh == NULL)
794 		goto done;
795 
796 	while (qh->state != QH_STATE_IDLE) {
797 		++uhci->num_waiting;
798 		spin_unlock_irq(&uhci->lock);
799 		wait_event_interruptible(uhci->waitqh,
800 				qh->state == QH_STATE_IDLE);
801 		spin_lock_irq(&uhci->lock);
802 		--uhci->num_waiting;
803 	}
804 
805 	uhci_free_qh(uhci, qh);
806 done:
807 	spin_unlock_irq(&uhci->lock);
808 }
809 
810 static int uhci_hcd_get_frame_number(struct usb_hcd *hcd)
811 {
812 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
813 	unsigned long flags;
814 	int is_stopped;
815 	int frame_number;
816 
817 	/* Minimize latency by avoiding the spinlock */
818 	local_irq_save(flags);
819 	is_stopped = uhci->is_stopped;
820 	smp_rmb();
821 	frame_number = (is_stopped ? uhci->frame_number :
822 			inw(uhci->io_addr + USBFRNUM));
823 	local_irq_restore(flags);
824 	return frame_number;
825 }
826 
827 static const char hcd_name[] = "uhci_hcd";
828 
829 static const struct hc_driver uhci_driver = {
830 	.description =		hcd_name,
831 	.product_desc =		"UHCI Host Controller",
832 	.hcd_priv_size =	sizeof(struct uhci_hcd),
833 
834 	/* Generic hardware linkage */
835 	.irq =			uhci_irq,
836 	.flags =		HCD_USB11,
837 
838 	/* Basic lifecycle operations */
839 	.reset =		uhci_reset,
840 	.start =		uhci_start,
841 #ifdef CONFIG_PM
842 	.suspend =		uhci_suspend,
843 	.resume =		uhci_resume,
844 	.bus_suspend =		uhci_rh_suspend,
845 	.bus_resume =		uhci_rh_resume,
846 #endif
847 	.stop =			uhci_stop,
848 
849 	.urb_enqueue =		uhci_urb_enqueue,
850 	.urb_dequeue =		uhci_urb_dequeue,
851 
852 	.endpoint_disable =	uhci_hcd_endpoint_disable,
853 	.get_frame_number =	uhci_hcd_get_frame_number,
854 
855 	.hub_status_data =	uhci_hub_status_data,
856 	.hub_control =		uhci_hub_control,
857 };
858 
859 static const struct pci_device_id uhci_pci_ids[] = { {
860 	/* handle any USB UHCI controller */
861 	PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_UHCI, ~0),
862 	.driver_data =	(unsigned long) &uhci_driver,
863 	}, { /* end: all zeroes */ }
864 };
865 
866 MODULE_DEVICE_TABLE(pci, uhci_pci_ids);
867 
868 static struct pci_driver uhci_pci_driver = {
869 	.name =		(char *)hcd_name,
870 	.id_table =	uhci_pci_ids,
871 
872 	.probe =	usb_hcd_pci_probe,
873 	.remove =	usb_hcd_pci_remove,
874 	.shutdown =	uhci_shutdown,
875 
876 #ifdef	CONFIG_PM
877 	.suspend =	usb_hcd_pci_suspend,
878 	.resume =	usb_hcd_pci_resume,
879 #endif	/* PM */
880 };
881 
882 static int __init uhci_hcd_init(void)
883 {
884 	int retval = -ENOMEM;
885 
886 	printk(KERN_INFO DRIVER_DESC " " DRIVER_VERSION "\n");
887 
888 	if (usb_disabled())
889 		return -ENODEV;
890 
891 	if (DEBUG_CONFIGURED) {
892 		errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
893 		if (!errbuf)
894 			goto errbuf_failed;
895 		uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
896 		if (!uhci_debugfs_root)
897 			goto debug_failed;
898 	}
899 
900 	uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
901 		sizeof(struct urb_priv), 0, 0, NULL, NULL);
902 	if (!uhci_up_cachep)
903 		goto up_failed;
904 
905 	retval = pci_register_driver(&uhci_pci_driver);
906 	if (retval)
907 		goto init_failed;
908 
909 	return 0;
910 
911 init_failed:
912 	if (kmem_cache_destroy(uhci_up_cachep))
913 		warn("not all urb_privs were freed!");
914 
915 up_failed:
916 	debugfs_remove(uhci_debugfs_root);
917 
918 debug_failed:
919 	kfree(errbuf);
920 
921 errbuf_failed:
922 
923 	return retval;
924 }
925 
926 static void __exit uhci_hcd_cleanup(void)
927 {
928 	pci_unregister_driver(&uhci_pci_driver);
929 
930 	if (kmem_cache_destroy(uhci_up_cachep))
931 		warn("not all urb_privs were freed!");
932 
933 	debugfs_remove(uhci_debugfs_root);
934 	kfree(errbuf);
935 }
936 
937 module_init(uhci_hcd_init);
938 module_exit(uhci_hcd_cleanup);
939 
940 MODULE_AUTHOR(DRIVER_AUTHOR);
941 MODULE_DESCRIPTION(DRIVER_DESC);
942 MODULE_LICENSE("GPL");
943