xref: /freebsd/sys/dev/usb/controller/ehci_pci.c (revision c697fb7f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
3  *
4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Lennart Augustsson (augustss@carlstedt.se) at
9  * Carlstedt Research & Technology.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 /*
37  * USB Enhanced Host Controller Driver, a.k.a. USB 2.0 controller.
38  *
39  * The EHCI 1.0 spec can be found at
40  * http://developer.intel.com/technology/usb/download/ehci-r10.pdf
41  * and the USB 2.0 spec at
42  * http://www.usb.org/developers/docs/usb_20.zip
43  */
44 
45 /* The low level controller code for EHCI has been split into
46  * PCI probes and EHCI specific code. This was done to facilitate the
47  * sharing of code between *BSD's
48  */
49 
50 #include <sys/stdint.h>
51 #include <sys/stddef.h>
52 #include <sys/param.h>
53 #include <sys/queue.h>
54 #include <sys/types.h>
55 #include <sys/systm.h>
56 #include <sys/kernel.h>
57 #include <sys/bus.h>
58 #include <sys/module.h>
59 #include <sys/lock.h>
60 #include <sys/mutex.h>
61 #include <sys/condvar.h>
62 #include <sys/sysctl.h>
63 #include <sys/sx.h>
64 #include <sys/unistd.h>
65 #include <sys/callout.h>
66 #include <sys/malloc.h>
67 #include <sys/priv.h>
68 
69 #include <dev/usb/usb.h>
70 #include <dev/usb/usbdi.h>
71 
72 #include <dev/usb/usb_core.h>
73 #include <dev/usb/usb_busdma.h>
74 #include <dev/usb/usb_process.h>
75 #include <dev/usb/usb_util.h>
76 
77 #include <dev/usb/usb_controller.h>
78 #include <dev/usb/usb_bus.h>
79 #include <dev/usb/usb_pci.h>
80 #include <dev/usb/controller/ehci.h>
81 #include <dev/usb/controller/ehcireg.h>
82 #include "usb_if.h"
83 
84 #define	PCI_EHCI_VENDORID_ACERLABS	0x10b9
85 #define	PCI_EHCI_VENDORID_AMD		0x1022
86 #define	PCI_EHCI_VENDORID_APPLE		0x106b
87 #define	PCI_EHCI_VENDORID_ATI		0x1002
88 #define	PCI_EHCI_VENDORID_CMDTECH	0x1095
89 #define	PCI_EHCI_VENDORID_HYGON		0x1d94
90 #define	PCI_EHCI_VENDORID_INTEL		0x8086
91 #define	PCI_EHCI_VENDORID_NEC		0x1033
92 #define	PCI_EHCI_VENDORID_OPTI		0x1045
93 #define	PCI_EHCI_VENDORID_PHILIPS	0x1131
94 #define	PCI_EHCI_VENDORID_SIS		0x1039
95 #define	PCI_EHCI_VENDORID_NVIDIA	0x12D2
96 #define	PCI_EHCI_VENDORID_NVIDIA2	0x10DE
97 #define	PCI_EHCI_VENDORID_VIA		0x1106
98 
99 static device_probe_t ehci_pci_probe;
100 static device_attach_t ehci_pci_attach;
101 static device_detach_t ehci_pci_detach;
102 static usb_take_controller_t ehci_pci_take_controller;
103 
104 static const char *
105 ehci_pci_match(device_t self)
106 {
107 	uint32_t device_id = pci_get_devid(self);
108 
109 	switch (device_id) {
110 	case 0x523910b9:
111 		return "ALi M5239 USB 2.0 controller";
112 
113 	case 0x10227463:
114 		return "AMD 8111 USB 2.0 controller";
115 
116 	case 0x20951022:
117 		return ("AMD CS5536 (Geode) USB 2.0 controller");
118 	case 0x78081022:
119 		return ("AMD FCH USB 2.0 controller");
120 
121 	case 0x43451002:
122 		return "ATI SB200 USB 2.0 controller";
123 	case 0x43731002:
124 		return "ATI SB400 USB 2.0 controller";
125 	case 0x43961002:
126 		return ("AMD SB7x0/SB8x0/SB9x0 USB 2.0 controller");
127 
128 	case 0x0f348086:
129 		return ("Intel BayTrail USB 2.0 controller");
130 	case 0x1c268086:
131 		return ("Intel Cougar Point USB 2.0 controller");
132 	case 0x1c2d8086:
133 		return ("Intel Cougar Point USB 2.0 controller");
134 	case 0x1d268086:
135 		return ("Intel Patsburg USB 2.0 controller");
136 	case 0x1d2d8086:
137 		return ("Intel Patsburg USB 2.0 controller");
138 	case 0x1e268086:
139 		return ("Intel Panther Point USB 2.0 controller");
140 	case 0x1e2d8086:
141 		return ("Intel Panther Point USB 2.0 controller");
142 	case 0x1f2c8086:
143 		return ("Intel Avoton USB 2.0 controller");
144 	case 0x25ad8086:
145 		return "Intel 6300ESB USB 2.0 controller";
146 	case 0x24cd8086:
147 		return "Intel 82801DB/L/M (ICH4) USB 2.0 controller";
148 	case 0x24dd8086:
149 		return "Intel 82801EB/R (ICH5) USB 2.0 controller";
150 	case 0x265c8086:
151 		return "Intel 82801FB (ICH6) USB 2.0 controller";
152 	case 0x268c8086:
153 		return ("Intel 63XXESB USB 2.0 controller");
154 	case 0x27cc8086:
155 		return "Intel 82801GB/R (ICH7) USB 2.0 controller";
156 	case 0x28368086:
157 		return "Intel 82801H (ICH8) USB 2.0 controller USB2-A";
158 	case 0x283a8086:
159 		return "Intel 82801H (ICH8) USB 2.0 controller USB2-B";
160 	case 0x293a8086:
161 		return "Intel 82801I (ICH9) USB 2.0 controller";
162 	case 0x293c8086:
163 		return "Intel 82801I (ICH9) USB 2.0 controller";
164 	case 0x3a3a8086:
165 		return "Intel 82801JI (ICH10) USB 2.0 controller USB-A";
166 	case 0x3a3c8086:
167 		return "Intel 82801JI (ICH10) USB 2.0 controller USB-B";
168 	case 0x3b348086:
169 		return ("Intel PCH USB 2.0 controller USB-A");
170 	case 0x3b3c8086:
171 		return ("Intel PCH USB 2.0 controller USB-B");
172 	case 0x8c268086:
173 		return ("Intel Lynx Point USB 2.0 controller USB-A");
174 	case 0x8c2d8086:
175 		return ("Intel Lynx Point USB 2.0 controller USB-B");
176 	case 0x8ca68086:
177 		return ("Intel Wildcat Point USB 2.0 controller USB-A");
178 	case 0x8cad8086:
179 		return ("Intel Wildcat Point USB 2.0 controller USB-B");
180 	case 0x8d268086:
181 		return ("Intel Wellsburg USB 2.0 controller");
182 	case 0x8d2d8086:
183 		return ("Intel Wellsburg USB 2.0 controller");
184 	case 0x9c268086:
185 		return ("Intel Lynx Point-LP USB 2.0 controller");
186 	case 0x9ca68086:
187 		return ("Intel Wildcat Point-LP USB 2.0 controller");
188 
189 	case 0x00e01033:
190 		return ("NEC uPD 72010x USB 2.0 controller");
191 
192 	case 0x006810de:
193 		return "NVIDIA nForce2 USB 2.0 controller";
194 	case 0x008810de:
195 		return "NVIDIA nForce2 Ultra 400 USB 2.0 controller";
196 	case 0x00d810de:
197 		return "NVIDIA nForce3 USB 2.0 controller";
198 	case 0x00e810de:
199 		return "NVIDIA nForce3 250 USB 2.0 controller";
200 	case 0x005b10de:
201 		return "NVIDIA nForce CK804 USB 2.0 controller";
202 	case 0x036d10de:
203 		return "NVIDIA nForce MCP55 USB 2.0 controller";
204 	case 0x03f210de:
205 		return "NVIDIA nForce MCP61 USB 2.0 controller";
206 	case 0x0aa610de:
207 		return "NVIDIA nForce MCP79 USB 2.0 controller";
208 	case 0x0aa910de:
209 		return "NVIDIA nForce MCP79 USB 2.0 controller";
210 	case 0x0aaa10de:
211 		return "NVIDIA nForce MCP79 USB 2.0 controller";
212 
213 	case 0x15621131:
214 		return "Philips ISP156x USB 2.0 controller";
215 
216 	case 0x70021039:
217 		return "SiS 968 USB 2.0 controller";
218 
219 	case 0x31041106:
220 		return ("VIA VT6202 USB 2.0 controller");
221 
222 	default:
223 		break;
224 	}
225 
226 	if ((pci_get_class(self) == PCIC_SERIALBUS)
227 	    && (pci_get_subclass(self) == PCIS_SERIALBUS_USB)
228 	    && (pci_get_progif(self) == PCI_INTERFACE_EHCI)) {
229 		return ("EHCI (generic) USB 2.0 controller");
230 	}
231 	return (NULL);			/* dunno */
232 }
233 
234 static int
235 ehci_pci_probe(device_t self)
236 {
237 	const char *desc = ehci_pci_match(self);
238 
239 	if (desc) {
240 		device_set_desc(self, desc);
241 		return (BUS_PROBE_DEFAULT);
242 	} else {
243 		return (ENXIO);
244 	}
245 }
246 
247 static void
248 ehci_pci_ati_quirk(device_t self, uint8_t is_sb700)
249 {
250 	device_t smbdev;
251 	uint32_t val;
252 
253 	if (is_sb700) {
254 		/* Lookup SMBUS PCI device */
255 		smbdev = pci_find_device(PCI_EHCI_VENDORID_ATI, 0x4385);
256 		if (smbdev == NULL)
257 			return;
258 		val = pci_get_revid(smbdev);
259 		if (val != 0x3a && val != 0x3b)
260 			return;
261 	}
262 
263 	/*
264 	 * Note: this bit is described as reserved in SB700
265 	 * Register Reference Guide.
266 	 */
267 	val = pci_read_config(self, 0x53, 1);
268 	if (!(val & 0x8)) {
269 		val |= 0x8;
270 		pci_write_config(self, 0x53, val, 1);
271 		device_printf(self, "AMD SB600/700 quirk applied\n");
272 	}
273 }
274 
275 static void
276 ehci_pci_via_quirk(device_t self)
277 {
278 	uint32_t val;
279 
280 	if ((pci_get_device(self) == 0x3104) &&
281 	    ((pci_get_revid(self) & 0xf0) == 0x60)) {
282 		/* Correct schedule sleep time to 10us */
283 		val = pci_read_config(self, 0x4b, 1);
284 		if (val & 0x20)
285 			return;
286 		val |= 0x20;
287 		pci_write_config(self, 0x4b, val, 1);
288 		device_printf(self, "VIA-quirk applied\n");
289 	}
290 }
291 
292 static int
293 ehci_pci_attach(device_t self)
294 {
295 	ehci_softc_t *sc = device_get_softc(self);
296 	int err;
297 	int rid;
298 
299 	/* initialise some bus fields */
300 	sc->sc_bus.parent = self;
301 	sc->sc_bus.devices = sc->sc_devices;
302 	sc->sc_bus.devices_max = EHCI_MAX_DEVICES;
303 	sc->sc_bus.dma_bits = 32;
304 
305 	/* get all DMA memory */
306 	if (usb_bus_mem_alloc_all(&sc->sc_bus,
307 	    USB_GET_DMA_TAG(self), &ehci_iterate_hw_softc)) {
308 		return (ENOMEM);
309 	}
310 
311 	pci_enable_busmaster(self);
312 
313 	switch (pci_read_config(self, PCI_USBREV, 1) & PCI_USB_REV_MASK) {
314 	case PCI_USB_REV_PRE_1_0:
315 	case PCI_USB_REV_1_0:
316 	case PCI_USB_REV_1_1:
317 		/*
318 		 * NOTE: some EHCI USB controllers have the wrong USB
319 		 * revision number. It appears those controllers are
320 		 * fully compliant so we just ignore this value in
321 		 * some common cases.
322 		 */
323 		device_printf(self, "pre-2.0 USB revision (ignored)\n");
324 		/* fallthrough */
325 	case PCI_USB_REV_2_0:
326 		break;
327 	default:
328 		/* Quirk for Parallels Desktop 4.0 */
329 		device_printf(self, "USB revision is unknown. Assuming v2.0.\n");
330 		break;
331 	}
332 
333 	rid = PCI_CBMEM;
334 	sc->sc_io_res = bus_alloc_resource_any(self, SYS_RES_MEMORY, &rid,
335 	    RF_ACTIVE);
336 	if (!sc->sc_io_res) {
337 		device_printf(self, "Could not map memory\n");
338 		goto error;
339 	}
340 	sc->sc_io_tag = rman_get_bustag(sc->sc_io_res);
341 	sc->sc_io_hdl = rman_get_bushandle(sc->sc_io_res);
342 	sc->sc_io_size = rman_get_size(sc->sc_io_res);
343 
344 	rid = 0;
345 	sc->sc_irq_res = bus_alloc_resource_any(self, SYS_RES_IRQ, &rid,
346 	    RF_SHAREABLE | RF_ACTIVE);
347 	if (sc->sc_irq_res == NULL) {
348 		device_printf(self, "Could not allocate irq\n");
349 		goto error;
350 	}
351 	sc->sc_bus.bdev = device_add_child(self, "usbus", -1);
352 	if (!sc->sc_bus.bdev) {
353 		device_printf(self, "Could not add USB device\n");
354 		goto error;
355 	}
356 	device_set_ivars(sc->sc_bus.bdev, &sc->sc_bus);
357 
358 	/*
359 	 * ehci_pci_match will never return NULL if ehci_pci_probe
360 	 * succeeded
361 	 */
362 	device_set_desc(sc->sc_bus.bdev, ehci_pci_match(self));
363 	switch (pci_get_vendor(self)) {
364 	case PCI_EHCI_VENDORID_ACERLABS:
365 		sprintf(sc->sc_vendor, "AcerLabs");
366 		break;
367 	case PCI_EHCI_VENDORID_AMD:
368 		sprintf(sc->sc_vendor, "AMD");
369 		break;
370 	case PCI_EHCI_VENDORID_APPLE:
371 		sprintf(sc->sc_vendor, "Apple");
372 		break;
373 	case PCI_EHCI_VENDORID_ATI:
374 		sprintf(sc->sc_vendor, "ATI");
375 		break;
376 	case PCI_EHCI_VENDORID_CMDTECH:
377 		sprintf(sc->sc_vendor, "CMDTECH");
378 		break;
379 	case PCI_EHCI_VENDORID_HYGON:
380 		sprintf(sc->sc_vendor, "Hygon");
381 		break;
382 	case PCI_EHCI_VENDORID_INTEL:
383 		sprintf(sc->sc_vendor, "Intel");
384 		break;
385 	case PCI_EHCI_VENDORID_NEC:
386 		sprintf(sc->sc_vendor, "NEC");
387 		break;
388 	case PCI_EHCI_VENDORID_OPTI:
389 		sprintf(sc->sc_vendor, "OPTi");
390 		break;
391 	case PCI_EHCI_VENDORID_PHILIPS:
392 		sprintf(sc->sc_vendor, "Philips");
393 		break;
394 	case PCI_EHCI_VENDORID_SIS:
395 		sprintf(sc->sc_vendor, "SiS");
396 		break;
397 	case PCI_EHCI_VENDORID_NVIDIA:
398 	case PCI_EHCI_VENDORID_NVIDIA2:
399 		sprintf(sc->sc_vendor, "nVidia");
400 		break;
401 	case PCI_EHCI_VENDORID_VIA:
402 		sprintf(sc->sc_vendor, "VIA");
403 		break;
404 	default:
405 		if (bootverbose)
406 			device_printf(self, "(New EHCI DeviceId=0x%08x)\n",
407 			    pci_get_devid(self));
408 		sprintf(sc->sc_vendor, "(0x%04x)", pci_get_vendor(self));
409 	}
410 
411 #if (__FreeBSD_version >= 700031)
412 	err = bus_setup_intr(self, sc->sc_irq_res, INTR_TYPE_BIO | INTR_MPSAFE,
413 	    NULL, (driver_intr_t *)ehci_interrupt, sc, &sc->sc_intr_hdl);
414 #else
415 	err = bus_setup_intr(self, sc->sc_irq_res, INTR_TYPE_BIO | INTR_MPSAFE,
416 	    (driver_intr_t *)ehci_interrupt, sc, &sc->sc_intr_hdl);
417 #endif
418 	if (err) {
419 		device_printf(self, "Could not setup irq, %d\n", err);
420 		sc->sc_intr_hdl = NULL;
421 		goto error;
422 	}
423 	ehci_pci_take_controller(self);
424 
425 	/* Undocumented quirks taken from Linux */
426 
427 	switch (pci_get_vendor(self)) {
428 	case PCI_EHCI_VENDORID_ATI:
429 		/* SB600 and SB700 EHCI quirk */
430 		switch (pci_get_device(self)) {
431 		case 0x4386:
432 			ehci_pci_ati_quirk(self, 0);
433 			break;
434 		case 0x4396:
435 			ehci_pci_ati_quirk(self, 1);
436 			break;
437 		default:
438 			break;
439 		}
440 		break;
441 
442 	case PCI_EHCI_VENDORID_VIA:
443 		ehci_pci_via_quirk(self);
444 		break;
445 
446 	default:
447 		break;
448 	}
449 
450 	/* Dropped interrupts workaround */
451 	switch (pci_get_vendor(self)) {
452 	case PCI_EHCI_VENDORID_ATI:
453 	case PCI_EHCI_VENDORID_VIA:
454 		sc->sc_flags |= EHCI_SCFLG_LOSTINTRBUG;
455 		if (bootverbose)
456 			device_printf(self,
457 			    "Dropped interrupts workaround enabled\n");
458 		break;
459 	default:
460 		break;
461 	}
462 
463 	/* Doorbell feature workaround */
464 	switch (pci_get_vendor(self)) {
465 	case PCI_EHCI_VENDORID_NVIDIA:
466 	case PCI_EHCI_VENDORID_NVIDIA2:
467 		sc->sc_flags |= EHCI_SCFLG_IAADBUG;
468 		if (bootverbose)
469 			device_printf(self,
470 			    "Doorbell workaround enabled\n");
471 		break;
472 	default:
473 		break;
474 	}
475 
476 	err = ehci_init(sc);
477 	if (!err) {
478 		err = device_probe_and_attach(sc->sc_bus.bdev);
479 	}
480 	if (err) {
481 		device_printf(self, "USB init failed err=%d\n", err);
482 		goto error;
483 	}
484 	return (0);
485 
486 error:
487 	ehci_pci_detach(self);
488 	return (ENXIO);
489 }
490 
491 static int
492 ehci_pci_detach(device_t self)
493 {
494 	ehci_softc_t *sc = device_get_softc(self);
495 
496 	/* during module unload there are lots of children leftover */
497 	device_delete_children(self);
498 
499 	pci_disable_busmaster(self);
500 
501 	if (sc->sc_irq_res && sc->sc_intr_hdl) {
502 		/*
503 		 * only call ehci_detach() after ehci_init()
504 		 */
505 		ehci_detach(sc);
506 
507 		int err = bus_teardown_intr(self, sc->sc_irq_res, sc->sc_intr_hdl);
508 
509 		if (err)
510 			/* XXX or should we panic? */
511 			device_printf(self, "Could not tear down irq, %d\n",
512 			    err);
513 		sc->sc_intr_hdl = NULL;
514 	}
515 	if (sc->sc_irq_res) {
516 		bus_release_resource(self, SYS_RES_IRQ, 0, sc->sc_irq_res);
517 		sc->sc_irq_res = NULL;
518 	}
519 	if (sc->sc_io_res) {
520 		bus_release_resource(self, SYS_RES_MEMORY, PCI_CBMEM,
521 		    sc->sc_io_res);
522 		sc->sc_io_res = NULL;
523 	}
524 	usb_bus_mem_free_all(&sc->sc_bus, &ehci_iterate_hw_softc);
525 
526 	return (0);
527 }
528 
529 static int
530 ehci_pci_take_controller(device_t self)
531 {
532 	ehci_softc_t *sc = device_get_softc(self);
533 	uint32_t cparams;
534 	uint32_t eec;
535 	uint16_t to;
536 	uint8_t eecp;
537 	uint8_t bios_sem;
538 
539 	cparams = EREAD4(sc, EHCI_HCCPARAMS);
540 
541 	/* Synchronise with the BIOS if it owns the controller. */
542 	for (eecp = EHCI_HCC_EECP(cparams); eecp != 0;
543 	    eecp = EHCI_EECP_NEXT(eec)) {
544 		eec = pci_read_config(self, eecp, 4);
545 		if (EHCI_EECP_ID(eec) != EHCI_EC_LEGSUP) {
546 			continue;
547 		}
548 		bios_sem = pci_read_config(self, eecp +
549 		    EHCI_LEGSUP_BIOS_SEM, 1);
550 		if (bios_sem == 0) {
551 			continue;
552 		}
553 		device_printf(sc->sc_bus.bdev, "waiting for BIOS "
554 		    "to give up control\n");
555 		pci_write_config(self, eecp +
556 		    EHCI_LEGSUP_OS_SEM, 1, 1);
557 		to = 500;
558 		while (1) {
559 			bios_sem = pci_read_config(self, eecp +
560 			    EHCI_LEGSUP_BIOS_SEM, 1);
561 			if (bios_sem == 0)
562 				break;
563 
564 			if (--to == 0) {
565 				device_printf(sc->sc_bus.bdev,
566 				    "timed out waiting for BIOS\n");
567 				break;
568 			}
569 			usb_pause_mtx(NULL, hz / 100);	/* wait 10ms */
570 		}
571 	}
572 	return (0);
573 }
574 
575 static device_method_t ehci_pci_methods[] = {
576 	/* Device interface */
577 	DEVMETHOD(device_probe, ehci_pci_probe),
578 	DEVMETHOD(device_attach, ehci_pci_attach),
579 	DEVMETHOD(device_detach, ehci_pci_detach),
580 	DEVMETHOD(device_suspend, bus_generic_suspend),
581 	DEVMETHOD(device_resume, bus_generic_resume),
582 	DEVMETHOD(device_shutdown, bus_generic_shutdown),
583 	DEVMETHOD(usb_take_controller, ehci_pci_take_controller),
584 
585 	DEVMETHOD_END
586 };
587 
588 static driver_t ehci_driver = {
589 	.name = "ehci",
590 	.methods = ehci_pci_methods,
591 	.size = sizeof(struct ehci_softc),
592 };
593 
594 static devclass_t ehci_devclass;
595 
596 DRIVER_MODULE(ehci, pci, ehci_driver, ehci_devclass, 0, 0);
597 MODULE_DEPEND(ehci, usb, 1, 1, 1);
598