xref: /freebsd/sys/dev/mii/mii.c (revision 68d75eff68281c1b445e3010bb975eae07aac225)
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 
51 #include <net/if.h>
52 #include <net/if_var.h>
53 #include <net/if_media.h>
54 
55 #include <dev/mii/mii.h>
56 #include <dev/mii/miivar.h>
57 
58 MODULE_VERSION(miibus, 1);
59 
60 #include "miibus_if.h"
61 
62 static device_attach_t miibus_attach;
63 static bus_child_detached_t miibus_child_detached;
64 static bus_child_location_str_t miibus_child_location_str;
65 static bus_child_pnpinfo_str_t miibus_child_pnpinfo_str;
66 static device_detach_t miibus_detach;
67 static bus_hinted_child_t miibus_hinted_child;
68 static bus_print_child_t miibus_print_child;
69 static device_probe_t miibus_probe;
70 static bus_read_ivar_t miibus_read_ivar;
71 static miibus_readreg_t miibus_readreg;
72 static miibus_statchg_t miibus_statchg;
73 static miibus_writereg_t miibus_writereg;
74 static miibus_linkchg_t miibus_linkchg;
75 static miibus_mediainit_t miibus_mediainit;
76 
77 static unsigned char mii_bitreverse(unsigned char x);
78 
79 static device_method_t miibus_methods[] = {
80 	/* device interface */
81 	DEVMETHOD(device_probe,		miibus_probe),
82 	DEVMETHOD(device_attach,	miibus_attach),
83 	DEVMETHOD(device_detach,	miibus_detach),
84 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
85 
86 	/* bus interface */
87 	DEVMETHOD(bus_print_child,	miibus_print_child),
88 	DEVMETHOD(bus_read_ivar,	miibus_read_ivar),
89 	DEVMETHOD(bus_child_detached,	miibus_child_detached),
90 	DEVMETHOD(bus_child_pnpinfo_str, miibus_child_pnpinfo_str),
91 	DEVMETHOD(bus_child_location_str, miibus_child_location_str),
92 	DEVMETHOD(bus_hinted_child,	miibus_hinted_child),
93 
94 	/* MII interface */
95 	DEVMETHOD(miibus_readreg,	miibus_readreg),
96 	DEVMETHOD(miibus_writereg,	miibus_writereg),
97 	DEVMETHOD(miibus_statchg,	miibus_statchg),
98 	DEVMETHOD(miibus_linkchg,	miibus_linkchg),
99 	DEVMETHOD(miibus_mediainit,	miibus_mediainit),
100 
101 	DEVMETHOD_END
102 };
103 
104 devclass_t miibus_devclass;
105 
106 driver_t miibus_driver = {
107 	"miibus",
108 	miibus_methods,
109 	sizeof(struct mii_data)
110 };
111 
112 struct miibus_ivars {
113 	if_t		ifp;
114 	ifm_change_cb_t	ifmedia_upd;
115 	ifm_stat_cb_t	ifmedia_sts;
116 	u_int		mii_flags;
117 	u_int		mii_offset;
118 };
119 
120 static int
121 miibus_probe(device_t dev)
122 {
123 
124 	device_set_desc(dev, "MII bus");
125 
126 	return (BUS_PROBE_SPECIFIC);
127 }
128 
129 static int
130 miibus_attach(device_t dev)
131 {
132 	struct miibus_ivars	*ivars;
133 	struct mii_attach_args	*ma;
134 	struct mii_data		*mii;
135 	device_t		*children;
136 	int			i, nchildren;
137 
138 	mii = device_get_softc(dev);
139 	if (device_get_children(dev, &children, &nchildren) == 0) {
140 		for (i = 0; i < nchildren; i++) {
141 			ma = device_get_ivars(children[i]);
142 			ma->mii_data = mii;
143 		}
144 		free(children, M_TEMP);
145 	}
146 	if (nchildren == 0) {
147 		device_printf(dev, "cannot get children\n");
148 		return (ENXIO);
149 	}
150 	ivars = device_get_ivars(dev);
151 	ifmedia_init(&mii->mii_media, IFM_IMASK, ivars->ifmedia_upd,
152 	    ivars->ifmedia_sts);
153 	mii->mii_ifp = ivars->ifp;
154 	if_setcapabilitiesbit(mii->mii_ifp, IFCAP_LINKSTATE, 0);
155 	if_setcapenablebit(mii->mii_ifp, IFCAP_LINKSTATE, 0);
156 	LIST_INIT(&mii->mii_phys);
157 
158 	return (bus_generic_attach(dev));
159 }
160 
161 static int
162 miibus_detach(device_t dev)
163 {
164 	struct mii_data		*mii;
165 	struct miibus_ivars	*ivars;
166 
167 	ivars = device_get_ivars(dev);
168 	bus_generic_detach(dev);
169 	mii = device_get_softc(dev);
170 	ifmedia_removeall(&mii->mii_media);
171 	free(ivars, M_DEVBUF);
172 	mii->mii_ifp = NULL;
173 
174 	return (0);
175 }
176 
177 static void
178 miibus_child_detached(device_t dev, device_t child)
179 {
180 	struct mii_attach_args *args;
181 
182 	args = device_get_ivars(child);
183 	free(args, M_DEVBUF);
184 }
185 
186 static int
187 miibus_print_child(device_t dev, device_t child)
188 {
189 	struct mii_attach_args *ma;
190 	int retval;
191 
192 	ma = device_get_ivars(child);
193 	retval = bus_print_child_header(dev, child);
194 	retval += printf(" PHY %d", ma->mii_phyno);
195 	retval += bus_print_child_footer(dev, child);
196 
197 	return (retval);
198 }
199 
200 static int
201 miibus_read_ivar(device_t dev, device_t child __unused, int which,
202     uintptr_t *result)
203 {
204 	struct miibus_ivars *ivars;
205 
206 	/*
207 	 * NB: this uses the instance variables of the miibus rather than
208 	 * its PHY children.
209 	 */
210 	ivars = device_get_ivars(dev);
211 	switch (which) {
212 	case MIIBUS_IVAR_FLAGS:
213 		*result = ivars->mii_flags;
214 		break;
215 	default:
216 		return (ENOENT);
217 	}
218 	return (0);
219 }
220 
221 static int
222 miibus_child_pnpinfo_str(device_t dev __unused, device_t child, char *buf,
223     size_t buflen)
224 {
225 	struct mii_attach_args *ma;
226 
227 	ma = device_get_ivars(child);
228 	snprintf(buf, buflen, "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_str(device_t dev __unused, device_t child, char *buf,
236     size_t buflen)
237 {
238 	struct mii_attach_args *ma;
239 
240 	ma = device_get_ivars(child);
241 	snprintf(buf, buflen, "phyno=%d", ma->mii_phyno);
242 	return (0);
243 }
244 
245 static void
246 miibus_hinted_child(device_t dev, const char *name, int unit)
247 {
248 	struct miibus_ivars *ivars;
249 	struct mii_attach_args *args, *ma;
250 	device_t *children, phy;
251 	int i, nchildren;
252 	u_int val;
253 
254 	if (resource_int_value(name, unit, "phyno", &val) != 0)
255 		return;
256 	if (device_get_children(dev, &children, &nchildren) != 0)
257 		return;
258 	ma = NULL;
259 	for (i = 0; i < nchildren; i++) {
260 		args = device_get_ivars(children[i]);
261 		if (args->mii_phyno == val) {
262 			ma = args;
263 			break;
264 		}
265 	}
266 	free(children, M_TEMP);
267 
268 	/*
269 	 * Don't add a PHY that was automatically identified by having media
270 	 * in its BMSR twice, only allow to alter its attach arguments.
271 	 */
272 	if (ma == NULL) {
273 		ma = malloc(sizeof(struct mii_attach_args), M_DEVBUF,
274 		    M_NOWAIT);
275 		if (ma == NULL)
276 			return;
277 		phy = device_add_child(dev, name, unit);
278 		if (phy == NULL) {
279 			free(ma, M_DEVBUF);
280 			return;
281 		}
282 		ivars = device_get_ivars(dev);
283 		ma->mii_phyno = val;
284 		ma->mii_offset = ivars->mii_offset++;
285 		ma->mii_id1 = 0;
286 		ma->mii_id2 = 0;
287 		ma->mii_capmask = BMSR_DEFCAPMASK;
288 		device_set_ivars(phy, ma);
289 	}
290 
291 	if (resource_int_value(name, unit, "id1", &val) == 0)
292 		ma->mii_id1 = val;
293 	if (resource_int_value(name, unit, "id2", &val) == 0)
294 		ma->mii_id2 = val;
295 	if (resource_int_value(name, unit, "capmask", &val) == 0)
296 		ma->mii_capmask = val;
297 }
298 
299 static int
300 miibus_readreg(device_t dev, int phy, int reg)
301 {
302 	device_t		parent;
303 
304 	parent = device_get_parent(dev);
305 	return (MIIBUS_READREG(parent, phy, reg));
306 }
307 
308 static int
309 miibus_writereg(device_t dev, int phy, int reg, int data)
310 {
311 	device_t		parent;
312 
313 	parent = device_get_parent(dev);
314 	return (MIIBUS_WRITEREG(parent, phy, reg, data));
315 }
316 
317 static void
318 miibus_statchg(device_t dev)
319 {
320 	device_t		parent;
321 	struct mii_data		*mii;
322 
323 	parent = device_get_parent(dev);
324 	MIIBUS_STATCHG(parent);
325 
326 	mii = device_get_softc(dev);
327 	if_setbaudrate(mii->mii_ifp, ifmedia_baudrate(mii->mii_media_active));
328 }
329 
330 static void
331 miibus_linkchg(device_t dev)
332 {
333 	struct mii_data		*mii;
334 	device_t		parent;
335 	int			link_state;
336 
337 	parent = device_get_parent(dev);
338 	MIIBUS_LINKCHG(parent);
339 
340 	mii = device_get_softc(dev);
341 
342 	if (mii->mii_media_status & IFM_AVALID) {
343 		if (mii->mii_media_status & IFM_ACTIVE)
344 			link_state = LINK_STATE_UP;
345 		else
346 			link_state = LINK_STATE_DOWN;
347 	} else
348 		link_state = LINK_STATE_UNKNOWN;
349 	if_link_state_change(mii->mii_ifp, link_state);
350 }
351 
352 static void
353 miibus_mediainit(device_t dev)
354 {
355 	struct mii_data		*mii;
356 	struct ifmedia_entry	*m;
357 	int			media = 0;
358 
359 	/* Poke the parent in case it has any media of its own to add. */
360 	MIIBUS_MEDIAINIT(device_get_parent(dev));
361 
362 	mii = device_get_softc(dev);
363 	LIST_FOREACH(m, &mii->mii_media.ifm_list, ifm_list) {
364 		media = m->ifm_media;
365 		if (media == (IFM_ETHER | IFM_AUTO))
366 			break;
367 	}
368 
369 	ifmedia_set(&mii->mii_media, media);
370 }
371 
372 /*
373  * Helper function used by network interface drivers, attaches the miibus and
374  * the PHYs to the network interface driver parent.
375  */
376 int
377 mii_attach(device_t dev, device_t *miibus, if_t ifp,
378     ifm_change_cb_t ifmedia_upd, ifm_stat_cb_t ifmedia_sts, int capmask,
379     int phyloc, int offloc, int flags)
380 {
381 	struct miibus_ivars *ivars;
382 	struct mii_attach_args *args, ma;
383 	device_t *children, phy;
384 	int bmsr, first, i, nchildren, phymax, phymin, rv;
385 	uint32_t phymask;
386 
387 	if (phyloc != MII_PHY_ANY && offloc != MII_OFFSET_ANY) {
388 		printf("%s: phyloc and offloc specified\n", __func__);
389 		return (EINVAL);
390 	}
391 
392 	if (offloc != MII_OFFSET_ANY && (offloc < 0 || offloc >= MII_NPHY)) {
393 		printf("%s: invalid offloc %d\n", __func__, offloc);
394 		return (EINVAL);
395 	}
396 
397 	if (phyloc == MII_PHY_ANY) {
398 		phymin = 0;
399 		phymax = MII_NPHY - 1;
400 	} else {
401 		if (phyloc < 0 || phyloc >= MII_NPHY) {
402 			printf("%s: invalid phyloc %d\n", __func__, phyloc);
403 			return (EINVAL);
404 		}
405 		phymin = phymax = phyloc;
406 	}
407 
408 	first = 0;
409 	if (*miibus == NULL) {
410 		first = 1;
411 		ivars = malloc(sizeof(*ivars), M_DEVBUF, M_NOWAIT);
412 		if (ivars == NULL)
413 			return (ENOMEM);
414 		ivars->ifp = ifp;
415 		ivars->ifmedia_upd = ifmedia_upd;
416 		ivars->ifmedia_sts = ifmedia_sts;
417 		ivars->mii_flags = flags;
418 		*miibus = device_add_child(dev, "miibus", -1);
419 		if (*miibus == NULL) {
420 			rv = ENXIO;
421 			goto fail;
422 		}
423 		device_set_ivars(*miibus, ivars);
424 	} else {
425 		ivars = device_get_ivars(*miibus);
426 		if (ivars->ifp != ifp || ivars->ifmedia_upd != ifmedia_upd ||
427 		    ivars->ifmedia_sts != ifmedia_sts ||
428 		    ivars->mii_flags != flags) {
429 			printf("%s: non-matching invariant\n", __func__);
430 			return (EINVAL);
431 		}
432 		/*
433 		 * Assignment of the attach arguments mii_data for the first
434 		 * pass is done in miibus_attach(), i.e. once the miibus softc
435 		 * has been allocated.
436 		 */
437 		ma.mii_data = device_get_softc(*miibus);
438 	}
439 
440 	ma.mii_capmask = capmask;
441 
442 	if (resource_int_value(device_get_name(*miibus),
443 	    device_get_unit(*miibus), "phymask", &phymask) != 0)
444 		phymask = 0xffffffff;
445 
446 	if (device_get_children(*miibus, &children, &nchildren) != 0) {
447 		children = NULL;
448 		nchildren = 0;
449 	}
450 	ivars->mii_offset = 0;
451 	for (ma.mii_phyno = phymin; ma.mii_phyno <= phymax; ma.mii_phyno++) {
452 		/*
453 		 * Make sure we haven't already configured a PHY at this
454 		 * address.  This allows mii_attach() to be called
455 		 * multiple times.
456 		 */
457 		for (i = 0; i < nchildren; i++) {
458 			args = device_get_ivars(children[i]);
459 			if (args->mii_phyno == ma.mii_phyno) {
460 				/*
461 				 * Yes, there is already something
462 				 * configured at this address.
463 				 */
464 				goto skip;
465 			}
466 		}
467 
468 		/*
469 		 * Check to see if there is a PHY at this address.  Note,
470 		 * many braindead PHYs report 0/0 in their ID registers,
471 		 * so we test for media in the BMSR.
472 		 */
473 		bmsr = MIIBUS_READREG(dev, ma.mii_phyno, MII_BMSR);
474 		if (bmsr == 0 || bmsr == 0xffff ||
475 		    (bmsr & (BMSR_EXTSTAT | BMSR_MEDIAMASK)) == 0) {
476 			/* Assume no PHY at this address. */
477 			continue;
478 		}
479 
480 		/*
481 		 * There is a PHY at this address.  If we were given an
482 		 * `offset' locator, skip this PHY if it doesn't match.
483 		 */
484 		if (offloc != MII_OFFSET_ANY && offloc != ivars->mii_offset)
485 			goto skip;
486 
487 		/*
488 		 * Skip this PHY if it's not included in the phymask hint.
489 		 */
490 		if ((phymask & (1 << ma.mii_phyno)) == 0)
491 			goto skip;
492 
493 		/*
494 		 * Extract the IDs.  Braindead PHYs will be handled by
495 		 * the `ukphy' driver, as we have no ID information to
496 		 * match on.
497 		 */
498 		ma.mii_id1 = MIIBUS_READREG(dev, ma.mii_phyno, MII_PHYIDR1);
499 		ma.mii_id2 = MIIBUS_READREG(dev, ma.mii_phyno, MII_PHYIDR2);
500 
501 		ma.mii_offset = ivars->mii_offset;
502 		args = malloc(sizeof(struct mii_attach_args), M_DEVBUF,
503 		    M_NOWAIT);
504 		if (args == NULL)
505 			goto skip;
506 		bcopy((char *)&ma, (char *)args, sizeof(ma));
507 		phy = device_add_child(*miibus, NULL, -1);
508 		if (phy == NULL) {
509 			free(args, M_DEVBUF);
510 			goto skip;
511 		}
512 		device_set_ivars(phy, args);
513  skip:
514 		ivars->mii_offset++;
515 	}
516 	free(children, M_TEMP);
517 
518 	if (first != 0) {
519 		rv = device_set_driver(*miibus, &miibus_driver);
520 		if (rv != 0)
521 			goto fail;
522 		bus_enumerate_hinted_children(*miibus);
523 		rv = device_get_children(*miibus, &children, &nchildren);
524 		if (rv != 0)
525 			goto fail;
526 		free(children, M_TEMP);
527 		if (nchildren == 0) {
528 			rv = ENXIO;
529 			goto fail;
530 		}
531 		rv = bus_generic_attach(dev);
532 		if (rv != 0)
533 			goto fail;
534 
535 		/* Attaching of the PHY drivers is done in miibus_attach(). */
536 		return (0);
537 	}
538 	rv = bus_generic_attach(*miibus);
539 	if (rv != 0)
540 		goto fail;
541 
542 	return (0);
543 
544  fail:
545 	if (*miibus != NULL)
546 		device_delete_child(dev, *miibus);
547 	free(ivars, M_DEVBUF);
548 	if (first != 0)
549 		*miibus = NULL;
550 	return (rv);
551 }
552 
553 /*
554  * Media changed; notify all PHYs.
555  */
556 int
557 mii_mediachg(struct mii_data *mii)
558 {
559 	struct mii_softc *child;
560 	struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
561 	int rv;
562 
563 	mii->mii_media_status = 0;
564 	mii->mii_media_active = IFM_NONE;
565 
566 	LIST_FOREACH(child, &mii->mii_phys, mii_list) {
567 		/*
568 		 * If the media indicates a different PHY instance,
569 		 * isolate this one.
570 		 */
571 		if (IFM_INST(ife->ifm_media) != child->mii_inst) {
572 			if ((child->mii_flags & MIIF_NOISOLATE) != 0) {
573 				device_printf(child->mii_dev, "%s: "
574 				    "can't handle non-zero PHY instance %d\n",
575 				    __func__, child->mii_inst);
576 				continue;
577 			}
578 			PHY_WRITE(child, MII_BMCR, PHY_READ(child, MII_BMCR) |
579 			    BMCR_ISO);
580 			continue;
581 		}
582 		rv = PHY_SERVICE(child, mii, MII_MEDIACHG);
583 		if (rv)
584 			return (rv);
585 	}
586 	return (0);
587 }
588 
589 /*
590  * Call the PHY tick routines, used during autonegotiation.
591  */
592 void
593 mii_tick(struct mii_data *mii)
594 {
595 	struct mii_softc *child;
596 	struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
597 
598 	LIST_FOREACH(child, &mii->mii_phys, mii_list) {
599 		/*
600 		 * If this PHY instance isn't currently selected, just skip
601 		 * it.
602 		 */
603 		if (IFM_INST(ife->ifm_media) != child->mii_inst)
604 			continue;
605 		(void)PHY_SERVICE(child, mii, MII_TICK);
606 	}
607 }
608 
609 /*
610  * Get media status from PHYs.
611  */
612 void
613 mii_pollstat(struct mii_data *mii)
614 {
615 	struct mii_softc *child;
616 	struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
617 
618 	mii->mii_media_status = 0;
619 	mii->mii_media_active = IFM_NONE;
620 
621 	LIST_FOREACH(child, &mii->mii_phys, mii_list) {
622 		/*
623 		 * If we're not polling this PHY instance, just skip it.
624 		 */
625 		if (IFM_INST(ife->ifm_media) != child->mii_inst)
626 			continue;
627 		(void)PHY_SERVICE(child, mii, MII_POLLSTAT);
628 	}
629 }
630 
631 static unsigned char
632 mii_bitreverse(unsigned char x)
633 {
634 	static unsigned const char nibbletab[16] = {
635 		0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15
636 	};
637 
638 	return ((nibbletab[x & 15] << 4) | nibbletab[x >> 4]);
639 }
640 
641 u_int
642 mii_oui(u_int id1, u_int id2)
643 {
644 	u_int h;
645 
646 	h = (id1 << 6) | (id2 >> 10);
647 
648 	return ((mii_bitreverse(h >> 16) << 16) |
649 	    (mii_bitreverse((h >> 8) & 0xff) << 8) |
650 	    mii_bitreverse(h & 0xff));
651 }
652 
653 int
654 mii_phy_mac_match(struct mii_softc *mii, const char *name)
655 {
656 
657 	return (strcmp(device_get_name(device_get_parent(mii->mii_dev)),
658 	    name) == 0);
659 }
660 
661 int
662 mii_dev_mac_match(device_t parent, const char *name)
663 {
664 
665 	return (strcmp(device_get_name(device_get_parent(
666 	    device_get_parent(parent))), name) == 0);
667 }
668 
669 void *
670 mii_phy_mac_softc(struct mii_softc *mii)
671 {
672 
673 	return (device_get_softc(device_get_parent(mii->mii_dev)));
674 }
675 
676 void *
677 mii_dev_mac_softc(device_t parent)
678 {
679 
680 	return (device_get_softc(device_get_parent(device_get_parent(parent))));
681 }
682