xref: /freebsd/sys/dev/mii/mii.c (revision 5bb3134a8c21cb87b30e135ef168483f0333dabb)
1 /*	$NetBSD: mii.c,v 1.12 1999/08/03 19:41:49 drochner Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
5  *
6  * Copyright (c) 1998 The NetBSD Foundation, Inc.
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The NetBSD Foundation
10  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
11  * NASA Ames Research Center.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 /*
39  * MII bus layer, glues MII-capable network interface drivers to sharable
40  * PHY drivers.  This exports an interface compatible with BSD/OS 3.0's,
41  * plus some NetBSD extensions.
42  */
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/socket.h>
47 #include <sys/malloc.h>
48 #include <sys/module.h>
49 #include <sys/bus.h>
50 #include <sys/sbuf.h>
51 
52 #include <net/if.h>
53 #include <net/if_var.h>
54 #include <net/if_media.h>
55 
56 #include <dev/mii/mii.h>
57 #include <dev/mii/miivar.h>
58 
59 MODULE_VERSION(miibus, 1);
60 
61 #include "miibus_if.h"
62 
63 static device_attach_t miibus_attach;
64 static bus_child_detached_t miibus_child_detached;
65 static bus_child_location_t miibus_child_location;
66 static bus_child_pnpinfo_t miibus_child_pnpinfo;
67 static device_detach_t miibus_detach;
68 static bus_hinted_child_t miibus_hinted_child;
69 static bus_print_child_t miibus_print_child;
70 static device_probe_t miibus_probe;
71 static bus_read_ivar_t miibus_read_ivar;
72 static miibus_readreg_t miibus_readreg;
73 static miibus_statchg_t miibus_statchg;
74 static miibus_writereg_t miibus_writereg;
75 static miibus_linkchg_t miibus_linkchg;
76 static miibus_mediainit_t miibus_mediainit;
77 
78 static unsigned char mii_bitreverse(unsigned char x);
79 
80 static device_method_t miibus_methods[] = {
81 	/* device interface */
82 	DEVMETHOD(device_probe,		miibus_probe),
83 	DEVMETHOD(device_attach,	miibus_attach),
84 	DEVMETHOD(device_detach,	miibus_detach),
85 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
86 
87 	/* bus interface */
88 	DEVMETHOD(bus_print_child,	miibus_print_child),
89 	DEVMETHOD(bus_read_ivar,	miibus_read_ivar),
90 	DEVMETHOD(bus_child_detached,	miibus_child_detached),
91 	DEVMETHOD(bus_child_pnpinfo,	miibus_child_pnpinfo),
92 	DEVMETHOD(bus_child_location,	miibus_child_location),
93 	DEVMETHOD(bus_hinted_child,	miibus_hinted_child),
94 
95 	/* MII interface */
96 	DEVMETHOD(miibus_readreg,	miibus_readreg),
97 	DEVMETHOD(miibus_writereg,	miibus_writereg),
98 	DEVMETHOD(miibus_statchg,	miibus_statchg),
99 	DEVMETHOD(miibus_linkchg,	miibus_linkchg),
100 	DEVMETHOD(miibus_mediainit,	miibus_mediainit),
101 
102 	DEVMETHOD_END
103 };
104 
105 devclass_t miibus_devclass;
106 
107 driver_t miibus_driver = {
108 	"miibus",
109 	miibus_methods,
110 	sizeof(struct mii_data)
111 };
112 
113 struct miibus_ivars {
114 	if_t		ifp;
115 	ifm_change_cb_t	ifmedia_upd;
116 	ifm_stat_cb_t	ifmedia_sts;
117 	u_int		mii_flags;
118 	u_int		mii_offset;
119 };
120 
121 static int
122 miibus_probe(device_t dev)
123 {
124 
125 	device_set_desc(dev, "MII bus");
126 
127 	return (BUS_PROBE_SPECIFIC);
128 }
129 
130 static int
131 miibus_attach(device_t dev)
132 {
133 	struct miibus_ivars	*ivars;
134 	struct mii_attach_args	*ma;
135 	struct mii_data		*mii;
136 	device_t		*children;
137 	int			i, nchildren;
138 
139 	mii = device_get_softc(dev);
140 	if (device_get_children(dev, &children, &nchildren) == 0) {
141 		for (i = 0; i < nchildren; i++) {
142 			ma = device_get_ivars(children[i]);
143 			ma->mii_data = mii;
144 		}
145 		free(children, M_TEMP);
146 	}
147 	if (nchildren == 0) {
148 		device_printf(dev, "cannot get children\n");
149 		return (ENXIO);
150 	}
151 	ivars = device_get_ivars(dev);
152 	ifmedia_init(&mii->mii_media, IFM_IMASK, ivars->ifmedia_upd,
153 	    ivars->ifmedia_sts);
154 	mii->mii_ifp = ivars->ifp;
155 	if_setcapabilitiesbit(mii->mii_ifp, IFCAP_LINKSTATE, 0);
156 	if_setcapenablebit(mii->mii_ifp, IFCAP_LINKSTATE, 0);
157 	LIST_INIT(&mii->mii_phys);
158 
159 	return (bus_generic_attach(dev));
160 }
161 
162 static int
163 miibus_detach(device_t dev)
164 {
165 	struct mii_data		*mii;
166 	struct miibus_ivars	*ivars;
167 
168 	ivars = device_get_ivars(dev);
169 	bus_generic_detach(dev);
170 	mii = device_get_softc(dev);
171 	ifmedia_removeall(&mii->mii_media);
172 	free(ivars, M_DEVBUF);
173 	mii->mii_ifp = NULL;
174 
175 	return (0);
176 }
177 
178 static void
179 miibus_child_detached(device_t dev, device_t child)
180 {
181 	struct mii_attach_args *args;
182 
183 	args = device_get_ivars(child);
184 	free(args, M_DEVBUF);
185 }
186 
187 static int
188 miibus_print_child(device_t dev, device_t child)
189 {
190 	struct mii_attach_args *ma;
191 	int retval;
192 
193 	ma = device_get_ivars(child);
194 	retval = bus_print_child_header(dev, child);
195 	retval += printf(" PHY %d", ma->mii_phyno);
196 	retval += bus_print_child_footer(dev, child);
197 
198 	return (retval);
199 }
200 
201 static int
202 miibus_read_ivar(device_t dev, device_t child __unused, int which,
203     uintptr_t *result)
204 {
205 	struct miibus_ivars *ivars;
206 
207 	/*
208 	 * NB: this uses the instance variables of the miibus rather than
209 	 * its PHY children.
210 	 */
211 	ivars = device_get_ivars(dev);
212 	switch (which) {
213 	case MIIBUS_IVAR_FLAGS:
214 		*result = ivars->mii_flags;
215 		break;
216 	default:
217 		return (ENOENT);
218 	}
219 	return (0);
220 }
221 
222 static int
223 miibus_child_pnpinfo(device_t dev __unused, device_t child, struct sbuf *sb)
224 {
225 	struct mii_attach_args *ma;
226 
227 	ma = device_get_ivars(child);
228 	sbuf_printf(sb, "oui=0x%x model=0x%x rev=0x%x",
229 	    MII_OUI(ma->mii_id1, ma->mii_id2),
230 	    MII_MODEL(ma->mii_id2), MII_REV(ma->mii_id2));
231 	return (0);
232 }
233 
234 static int
235 miibus_child_location(device_t dev __unused, device_t child, struct sbuf *sb)
236 {
237 	struct mii_attach_args *ma;
238 
239 	ma = device_get_ivars(child);
240 	sbuf_printf(sb, "phyno=%d", ma->mii_phyno);
241 	return (0);
242 }
243 
244 static void
245 miibus_hinted_child(device_t dev, const char *name, int unit)
246 {
247 	struct miibus_ivars *ivars;
248 	struct mii_attach_args *args, *ma;
249 	device_t *children, phy;
250 	int i, nchildren;
251 	u_int val;
252 
253 	if (resource_int_value(name, unit, "phyno", &val) != 0)
254 		return;
255 	if (device_get_children(dev, &children, &nchildren) != 0)
256 		return;
257 	ma = NULL;
258 	for (i = 0; i < nchildren; i++) {
259 		args = device_get_ivars(children[i]);
260 		if (args->mii_phyno == val) {
261 			ma = args;
262 			break;
263 		}
264 	}
265 	free(children, M_TEMP);
266 
267 	/*
268 	 * Don't add a PHY that was automatically identified by having media
269 	 * in its BMSR twice, only allow to alter its attach arguments.
270 	 */
271 	if (ma == NULL) {
272 		ma = malloc(sizeof(struct mii_attach_args), M_DEVBUF,
273 		    M_NOWAIT);
274 		if (ma == NULL)
275 			return;
276 		phy = device_add_child(dev, name, unit);
277 		if (phy == NULL) {
278 			free(ma, M_DEVBUF);
279 			return;
280 		}
281 		ivars = device_get_ivars(dev);
282 		ma->mii_phyno = val;
283 		ma->mii_offset = ivars->mii_offset++;
284 		ma->mii_id1 = 0;
285 		ma->mii_id2 = 0;
286 		ma->mii_capmask = BMSR_DEFCAPMASK;
287 		device_set_ivars(phy, ma);
288 	}
289 
290 	if (resource_int_value(name, unit, "id1", &val) == 0)
291 		ma->mii_id1 = val;
292 	if (resource_int_value(name, unit, "id2", &val) == 0)
293 		ma->mii_id2 = val;
294 	if (resource_int_value(name, unit, "capmask", &val) == 0)
295 		ma->mii_capmask = val;
296 }
297 
298 static int
299 miibus_readreg(device_t dev, int phy, int reg)
300 {
301 	device_t		parent;
302 
303 	parent = device_get_parent(dev);
304 	return (MIIBUS_READREG(parent, phy, reg));
305 }
306 
307 static int
308 miibus_writereg(device_t dev, int phy, int reg, int data)
309 {
310 	device_t		parent;
311 
312 	parent = device_get_parent(dev);
313 	return (MIIBUS_WRITEREG(parent, phy, reg, data));
314 }
315 
316 static void
317 miibus_statchg(device_t dev)
318 {
319 	device_t		parent;
320 	struct mii_data		*mii;
321 
322 	parent = device_get_parent(dev);
323 	MIIBUS_STATCHG(parent);
324 
325 	mii = device_get_softc(dev);
326 	if_setbaudrate(mii->mii_ifp, ifmedia_baudrate(mii->mii_media_active));
327 }
328 
329 static void
330 miibus_linkchg(device_t dev)
331 {
332 	struct mii_data		*mii;
333 	device_t		parent;
334 	int			link_state;
335 
336 	parent = device_get_parent(dev);
337 	MIIBUS_LINKCHG(parent);
338 
339 	mii = device_get_softc(dev);
340 
341 	if (mii->mii_media_status & IFM_AVALID) {
342 		if (mii->mii_media_status & IFM_ACTIVE)
343 			link_state = LINK_STATE_UP;
344 		else
345 			link_state = LINK_STATE_DOWN;
346 	} else
347 		link_state = LINK_STATE_UNKNOWN;
348 	if_link_state_change(mii->mii_ifp, link_state);
349 }
350 
351 static void
352 miibus_mediainit(device_t dev)
353 {
354 	struct mii_data		*mii;
355 	struct ifmedia_entry	*m;
356 	int			media = 0;
357 
358 	/* Poke the parent in case it has any media of its own to add. */
359 	MIIBUS_MEDIAINIT(device_get_parent(dev));
360 
361 	mii = device_get_softc(dev);
362 	LIST_FOREACH(m, &mii->mii_media.ifm_list, ifm_list) {
363 		media = m->ifm_media;
364 		if (media == (IFM_ETHER | IFM_AUTO))
365 			break;
366 	}
367 
368 	ifmedia_set(&mii->mii_media, media);
369 }
370 
371 /*
372  * Helper function used by network interface drivers, attaches the miibus and
373  * the PHYs to the network interface driver parent.
374  */
375 int
376 mii_attach(device_t dev, device_t *miibus, if_t ifp,
377     ifm_change_cb_t ifmedia_upd, ifm_stat_cb_t ifmedia_sts, int capmask,
378     int phyloc, int offloc, int flags)
379 {
380 	struct miibus_ivars *ivars;
381 	struct mii_attach_args *args, ma;
382 	device_t *children, phy;
383 	int bmsr, first, i, nchildren, phymax, phymin, rv;
384 	uint32_t phymask;
385 
386 	if (phyloc != MII_PHY_ANY && offloc != MII_OFFSET_ANY) {
387 		printf("%s: phyloc and offloc specified\n", __func__);
388 		return (EINVAL);
389 	}
390 
391 	if (offloc != MII_OFFSET_ANY && (offloc < 0 || offloc >= MII_NPHY)) {
392 		printf("%s: invalid offloc %d\n", __func__, offloc);
393 		return (EINVAL);
394 	}
395 
396 	if (phyloc == MII_PHY_ANY) {
397 		phymin = 0;
398 		phymax = MII_NPHY - 1;
399 	} else {
400 		if (phyloc < 0 || phyloc >= MII_NPHY) {
401 			printf("%s: invalid phyloc %d\n", __func__, phyloc);
402 			return (EINVAL);
403 		}
404 		phymin = phymax = phyloc;
405 	}
406 
407 	first = 0;
408 	if (*miibus == NULL) {
409 		first = 1;
410 		ivars = malloc(sizeof(*ivars), M_DEVBUF, M_NOWAIT);
411 		if (ivars == NULL)
412 			return (ENOMEM);
413 		ivars->ifp = ifp;
414 		ivars->ifmedia_upd = ifmedia_upd;
415 		ivars->ifmedia_sts = ifmedia_sts;
416 		ivars->mii_flags = flags;
417 		*miibus = device_add_child(dev, "miibus", -1);
418 		if (*miibus == NULL) {
419 			rv = ENXIO;
420 			goto fail;
421 		}
422 		device_set_ivars(*miibus, ivars);
423 	} else {
424 		ivars = device_get_ivars(*miibus);
425 		if (ivars->ifp != ifp || ivars->ifmedia_upd != ifmedia_upd ||
426 		    ivars->ifmedia_sts != ifmedia_sts ||
427 		    ivars->mii_flags != flags) {
428 			printf("%s: non-matching invariant\n", __func__);
429 			return (EINVAL);
430 		}
431 		/*
432 		 * Assignment of the attach arguments mii_data for the first
433 		 * pass is done in miibus_attach(), i.e. once the miibus softc
434 		 * has been allocated.
435 		 */
436 		ma.mii_data = device_get_softc(*miibus);
437 	}
438 
439 	ma.mii_capmask = capmask;
440 
441 	if (resource_int_value(device_get_name(*miibus),
442 	    device_get_unit(*miibus), "phymask", &phymask) != 0)
443 		phymask = 0xffffffff;
444 
445 	if (device_get_children(*miibus, &children, &nchildren) != 0) {
446 		children = NULL;
447 		nchildren = 0;
448 	}
449 	ivars->mii_offset = 0;
450 	for (ma.mii_phyno = phymin; ma.mii_phyno <= phymax; ma.mii_phyno++) {
451 		/*
452 		 * Make sure we haven't already configured a PHY at this
453 		 * address.  This allows mii_attach() to be called
454 		 * multiple times.
455 		 */
456 		for (i = 0; i < nchildren; i++) {
457 			args = device_get_ivars(children[i]);
458 			if (args->mii_phyno == ma.mii_phyno) {
459 				/*
460 				 * Yes, there is already something
461 				 * configured at this address.
462 				 */
463 				goto skip;
464 			}
465 		}
466 
467 		/*
468 		 * Check to see if there is a PHY at this address.  Note,
469 		 * many braindead PHYs report 0/0 in their ID registers,
470 		 * so we test for media in the BMSR.
471 		 */
472 		bmsr = MIIBUS_READREG(dev, ma.mii_phyno, MII_BMSR);
473 		if (bmsr == 0 || bmsr == 0xffff ||
474 		    (bmsr & (BMSR_EXTSTAT | BMSR_MEDIAMASK)) == 0) {
475 			/* Assume no PHY at this address. */
476 			continue;
477 		}
478 
479 		/*
480 		 * There is a PHY at this address.  If we were given an
481 		 * `offset' locator, skip this PHY if it doesn't match.
482 		 */
483 		if (offloc != MII_OFFSET_ANY && offloc != ivars->mii_offset)
484 			goto skip;
485 
486 		/*
487 		 * Skip this PHY if it's not included in the phymask hint.
488 		 */
489 		if ((phymask & (1 << ma.mii_phyno)) == 0)
490 			goto skip;
491 
492 		/*
493 		 * Extract the IDs.  Braindead PHYs will be handled by
494 		 * the `ukphy' driver, as we have no ID information to
495 		 * match on.
496 		 */
497 		ma.mii_id1 = MIIBUS_READREG(dev, ma.mii_phyno, MII_PHYIDR1);
498 		ma.mii_id2 = MIIBUS_READREG(dev, ma.mii_phyno, MII_PHYIDR2);
499 
500 		ma.mii_offset = ivars->mii_offset;
501 		args = malloc(sizeof(struct mii_attach_args), M_DEVBUF,
502 		    M_NOWAIT);
503 		if (args == NULL)
504 			goto skip;
505 		bcopy((char *)&ma, (char *)args, sizeof(ma));
506 		phy = device_add_child(*miibus, NULL, -1);
507 		if (phy == NULL) {
508 			free(args, M_DEVBUF);
509 			goto skip;
510 		}
511 		device_set_ivars(phy, args);
512  skip:
513 		ivars->mii_offset++;
514 	}
515 	free(children, M_TEMP);
516 
517 	if (first != 0) {
518 		rv = device_set_driver(*miibus, &miibus_driver);
519 		if (rv != 0)
520 			goto fail;
521 		bus_enumerate_hinted_children(*miibus);
522 		rv = device_get_children(*miibus, &children, &nchildren);
523 		if (rv != 0)
524 			goto fail;
525 		free(children, M_TEMP);
526 		if (nchildren == 0) {
527 			rv = ENXIO;
528 			goto fail;
529 		}
530 		rv = bus_generic_attach(dev);
531 		if (rv != 0)
532 			goto fail;
533 
534 		/* Attaching of the PHY drivers is done in miibus_attach(). */
535 		return (0);
536 	}
537 	rv = bus_generic_attach(*miibus);
538 	if (rv != 0)
539 		goto fail;
540 
541 	return (0);
542 
543  fail:
544 	if (*miibus != NULL)
545 		device_delete_child(dev, *miibus);
546 	free(ivars, M_DEVBUF);
547 	if (first != 0)
548 		*miibus = NULL;
549 	return (rv);
550 }
551 
552 /*
553  * Media changed; notify all PHYs.
554  */
555 int
556 mii_mediachg(struct mii_data *mii)
557 {
558 	struct mii_softc *child;
559 	struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
560 	int rv;
561 
562 	mii->mii_media_status = 0;
563 	mii->mii_media_active = IFM_NONE;
564 
565 	LIST_FOREACH(child, &mii->mii_phys, mii_list) {
566 		/*
567 		 * If the media indicates a different PHY instance,
568 		 * isolate this one.
569 		 */
570 		if (IFM_INST(ife->ifm_media) != child->mii_inst) {
571 			if ((child->mii_flags & MIIF_NOISOLATE) != 0) {
572 				device_printf(child->mii_dev, "%s: "
573 				    "can't handle non-zero PHY instance %d\n",
574 				    __func__, child->mii_inst);
575 				continue;
576 			}
577 			PHY_WRITE(child, MII_BMCR, PHY_READ(child, MII_BMCR) |
578 			    BMCR_ISO);
579 			continue;
580 		}
581 		rv = PHY_SERVICE(child, mii, MII_MEDIACHG);
582 		if (rv)
583 			return (rv);
584 	}
585 	return (0);
586 }
587 
588 /*
589  * Call the PHY tick routines, used during autonegotiation.
590  */
591 void
592 mii_tick(struct mii_data *mii)
593 {
594 	struct mii_softc *child;
595 	struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
596 
597 	LIST_FOREACH(child, &mii->mii_phys, mii_list) {
598 		/*
599 		 * If this PHY instance isn't currently selected, just skip
600 		 * it.
601 		 */
602 		if (IFM_INST(ife->ifm_media) != child->mii_inst)
603 			continue;
604 		(void)PHY_SERVICE(child, mii, MII_TICK);
605 	}
606 }
607 
608 /*
609  * Get media status from PHYs.
610  */
611 void
612 mii_pollstat(struct mii_data *mii)
613 {
614 	struct mii_softc *child;
615 	struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
616 
617 	mii->mii_media_status = 0;
618 	mii->mii_media_active = IFM_NONE;
619 
620 	LIST_FOREACH(child, &mii->mii_phys, mii_list) {
621 		/*
622 		 * If we're not polling this PHY instance, just skip it.
623 		 */
624 		if (IFM_INST(ife->ifm_media) != child->mii_inst)
625 			continue;
626 		(void)PHY_SERVICE(child, mii, MII_POLLSTAT);
627 	}
628 }
629 
630 static unsigned char
631 mii_bitreverse(unsigned char x)
632 {
633 	static unsigned const char nibbletab[16] = {
634 		0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15
635 	};
636 
637 	return ((nibbletab[x & 15] << 4) | nibbletab[x >> 4]);
638 }
639 
640 u_int
641 mii_oui(u_int id1, u_int id2)
642 {
643 	u_int h;
644 
645 	h = (id1 << 6) | (id2 >> 10);
646 
647 	return ((mii_bitreverse(h >> 16) << 16) |
648 	    (mii_bitreverse((h >> 8) & 0xff) << 8) |
649 	    mii_bitreverse(h & 0xff));
650 }
651 
652 int
653 mii_phy_mac_match(struct mii_softc *mii, const char *name)
654 {
655 
656 	return (strcmp(device_get_name(device_get_parent(mii->mii_dev)),
657 	    name) == 0);
658 }
659 
660 int
661 mii_dev_mac_match(device_t parent, const char *name)
662 {
663 
664 	return (strcmp(device_get_name(device_get_parent(
665 	    device_get_parent(parent))), name) == 0);
666 }
667 
668 void *
669 mii_phy_mac_softc(struct mii_softc *mii)
670 {
671 
672 	return (device_get_softc(device_get_parent(mii->mii_dev)));
673 }
674 
675 void *
676 mii_dev_mac_softc(device_t parent)
677 {
678 
679 	return (device_get_softc(device_get_parent(device_get_parent(parent))));
680 }
681