xref: /netbsd-src/sys/dev/pcmcia/if_xi.c (revision 274254cdae52594c1aa480a736aef78313d15c9c)
1 /*	$NetBSD: if_xi.c,v 1.66 2009/03/14 15:36:20 dsl Exp $ */
2 /*	OpenBSD: if_xe.c,v 1.9 1999/09/16 11:28:42 niklas Exp 	*/
3 
4 /*
5  * Copyright (c) 2004 Charles M. Hannum.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by Charles M. Hannum.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  */
21 
22 /*
23  * Copyright (c) 1999 Niklas Hallqvist, Brandon Creighton, Job de Haas
24  * All rights reserved.
25  *
26  * Redistribution and use in source and binary forms, with or without
27  * modification, are permitted provided that the following conditions
28  * are met:
29  * 1. Redistributions of source code must retain the above copyright
30  *    notice, this list of conditions and the following disclaimer.
31  * 2. Redistributions in binary form must reproduce the above copyright
32  *    notice, this list of conditions and the following disclaimer in the
33  *    documentation and/or other materials provided with the distribution.
34  * 3. All advertising materials mentioning features or use of this software
35  *    must display the following acknowledgement:
36  *	This product includes software developed by Niklas Hallqvist,
37  *	Brandon Creighton and Job de Haas.
38  * 4. The name of the author may not be used to endorse or promote products
39  *    derived from this software without specific prior written permission
40  *
41  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
42  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
43  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
44  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
45  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
47  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
48  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
49  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
50  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
51  */
52 
53 /*
54  * A driver for Xircom CreditCard PCMCIA Ethernet adapters.
55  */
56 
57 #include <sys/cdefs.h>
58 __KERNEL_RCSID(0, "$NetBSD: if_xi.c,v 1.66 2009/03/14 15:36:20 dsl Exp $");
59 
60 #include "opt_inet.h"
61 #include "opt_ipx.h"
62 #include "bpfilter.h"
63 
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/device.h>
67 #include <sys/ioctl.h>
68 #include <sys/mbuf.h>
69 #include <sys/malloc.h>
70 #include <sys/socket.h>
71 #include <sys/kernel.h>
72 #include <sys/proc.h>
73 
74 #include <net/if.h>
75 #include <net/if_dl.h>
76 #include <net/if_media.h>
77 #include <net/if_types.h>
78 #include <net/if_ether.h>
79 
80 #ifdef INET
81 #include <netinet/in.h>
82 #include <netinet/in_systm.h>
83 #include <netinet/in_var.h>
84 #include <netinet/ip.h>
85 #include <netinet/if_inarp.h>
86 #endif
87 
88 #ifdef IPX
89 #include <netipx/ipx.h>
90 #include <netipx/ipx_if.h>
91 #endif
92 
93 
94 #if NBPFILTER > 0
95 #include <net/bpf.h>
96 #include <net/bpfdesc.h>
97 #endif
98 
99 /*
100  * Maximum number of bytes to read per interrupt.  Linux recommends
101  * somewhere between 2000-22000.
102  * XXX This is currently a hard maximum.
103  */
104 #define MAX_BYTES_INTR 12000
105 
106 #include <dev/mii/mii.h>
107 #include <dev/mii/miivar.h>
108 
109 #include <dev/pcmcia/pcmciareg.h>
110 #include <dev/pcmcia/pcmciavar.h>
111 #include <dev/pcmcia/pcmciadevs.h>
112 
113 #include <dev/pcmcia/if_xireg.h>
114 #include <dev/pcmcia/if_xivar.h>
115 
116 #ifdef __GNUC__
117 #define INLINE	inline
118 #else
119 #define INLINE
120 #endif	/* __GNUC__ */
121 
122 #define	XIDEBUG
123 #define	XIDEBUG_VALUE	0
124 
125 #ifdef XIDEBUG
126 #define DPRINTF(cat, x) if (xidebug & (cat)) printf x
127 
128 #define XID_CONFIG	0x01
129 #define XID_MII		0x02
130 #define XID_INTR	0x04
131 #define XID_FIFO	0x08
132 #define	XID_MCAST	0x10
133 
134 #ifdef XIDEBUG_VALUE
135 int xidebug = XIDEBUG_VALUE;
136 #else
137 int xidebug = 0;
138 #endif
139 #else
140 #define DPRINTF(cat, x) (void)0
141 #endif
142 
143 #define STATIC
144 
145 STATIC int xi_enable(struct xi_softc *);
146 STATIC void xi_disable(struct xi_softc *);
147 STATIC void xi_cycle_power(struct xi_softc *);
148 STATIC int xi_ether_ioctl(struct ifnet *, u_long cmd, void *);
149 STATIC void xi_full_reset(struct xi_softc *);
150 STATIC void xi_init(struct xi_softc *);
151 STATIC int xi_ioctl(struct ifnet *, u_long, void *);
152 STATIC int xi_mdi_read(struct device *, int, int);
153 STATIC void xi_mdi_write(struct device *, int, int, int);
154 STATIC int xi_mediachange(struct ifnet *);
155 STATIC u_int16_t xi_get(struct xi_softc *);
156 STATIC void xi_reset(struct xi_softc *);
157 STATIC void xi_set_address(struct xi_softc *);
158 STATIC void xi_start(struct ifnet *);
159 STATIC void xi_statchg(struct device *);
160 STATIC void xi_stop(struct xi_softc *);
161 STATIC void xi_watchdog(struct ifnet *);
162 
163 void
164 xi_attach(struct xi_softc *sc, u_int8_t *myea)
165 {
166 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
167 
168 #if 0
169 	/*
170 	 * Configuration as advised by DINGO documentation.
171 	 * Dingo has some extra configuration registers in the CCR space.
172 	 */
173 	if (sc->sc_chipset >= XI_CHIPSET_DINGO) {
174 		struct pcmcia_mem_handle pcmh;
175 		int ccr_window;
176 		bus_size_t ccr_offset;
177 
178 		/* get access to the DINGO CCR space */
179 		if (pcmcia_mem_alloc(psc->sc_pf, PCMCIA_CCR_SIZE_DINGO,
180 			&pcmh)) {
181 			DPRINTF(XID_CONFIG, ("xi: bad mem alloc\n"));
182 			goto fail;
183 		}
184 		if (pcmcia_mem_map(psc->sc_pf, PCMCIA_MEM_ATTR,
185 			psc->sc_pf->ccr_base, PCMCIA_CCR_SIZE_DINGO,
186 			&pcmh, &ccr_offset, &ccr_window)) {
187 			DPRINTF(XID_CONFIG, ("xi: bad mem map\n"));
188 			pcmcia_mem_free(psc->sc_pf, &pcmh);
189 			goto fail;
190 		}
191 
192 		/* enable the second function - usually modem */
193 		bus_space_write_1(pcmh.memt, pcmh.memh,
194 		    ccr_offset + PCMCIA_CCR_DCOR0, PCMCIA_CCR_DCOR0_SFINT);
195 		bus_space_write_1(pcmh.memt, pcmh.memh,
196 		    ccr_offset + PCMCIA_CCR_DCOR1,
197 		    PCMCIA_CCR_DCOR1_FORCE_LEVIREQ | PCMCIA_CCR_DCOR1_D6);
198 		bus_space_write_1(pcmh.memt, pcmh.memh,
199 		    ccr_offset + PCMCIA_CCR_DCOR2, 0);
200 		bus_space_write_1(pcmh.memt, pcmh.memh,
201 		    ccr_offset + PCMCIA_CCR_DCOR3, 0);
202 		bus_space_write_1(pcmh.memt, pcmh.memh,
203 		    ccr_offset + PCMCIA_CCR_DCOR4, 0);
204 
205 		/* We don't need them anymore and can free them (I think). */
206 		pcmcia_mem_unmap(psc->sc_pf, ccr_window);
207 		pcmcia_mem_free(psc->sc_pf, &pcmh);
208 	}
209 #endif
210 
211 	/* Reset and initialize the card. */
212 	xi_full_reset(sc);
213 
214 	printf("%s: MAC address %s\n", device_xname(&sc->sc_dev), ether_sprintf(myea));
215 
216 	ifp = &sc->sc_ethercom.ec_if;
217 	/* Initialize the ifnet structure. */
218 	strlcpy(ifp->if_xname, device_xname(&sc->sc_dev), IFNAMSIZ);
219 	ifp->if_softc = sc;
220 	ifp->if_start = xi_start;
221 	ifp->if_ioctl = xi_ioctl;
222 	ifp->if_watchdog = xi_watchdog;
223 	ifp->if_flags =
224 	    IFF_BROADCAST | IFF_NOTRAILERS | IFF_SIMPLEX | IFF_MULTICAST;
225 	IFQ_SET_READY(&ifp->if_snd);
226 
227 	/* 802.1q capability */
228 	sc->sc_ethercom.ec_capabilities |= ETHERCAP_VLAN_MTU;
229 
230 	/* Attach the interface. */
231 	if_attach(ifp);
232 	ether_ifattach(ifp, myea);
233 
234 	/*
235 	 * Initialize our media structures and probe the MII.
236 	 */
237 	sc->sc_mii.mii_ifp = ifp;
238 	sc->sc_mii.mii_readreg = xi_mdi_read;
239 	sc->sc_mii.mii_writereg = xi_mdi_write;
240 	sc->sc_mii.mii_statchg = xi_statchg;
241 	sc->sc_ethercom.ec_mii = &sc->sc_mii;
242 	ifmedia_init(&sc->sc_mii.mii_media, 0, xi_mediachange,
243 	    ether_mediastatus);
244 	DPRINTF(XID_MII | XID_CONFIG,
245 	    ("xi: bmsr %x\n", xi_mdi_read(&sc->sc_dev, 0, 1)));
246 
247 	mii_attach(&sc->sc_dev, &sc->sc_mii, 0xffffffff, MII_PHY_ANY,
248 		MII_OFFSET_ANY, 0);
249 	if (LIST_FIRST(&sc->sc_mii.mii_phys) == NULL)
250 		ifmedia_add(&sc->sc_mii.mii_media, IFM_ETHER | IFM_AUTO, 0,
251 		    NULL);
252 	ifmedia_set(&sc->sc_mii.mii_media, IFM_ETHER | IFM_AUTO);
253 
254 #if NRND > 0
255 	rnd_attach_source(&sc->sc_rnd_source, device_xname(&sc->sc_dev), RND_TYPE_NET, 0);
256 #endif
257 }
258 
259 int
260 xi_detach(struct device *self, int flags)
261 {
262 	struct xi_softc *sc = (void *)self;
263 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
264 
265 	DPRINTF(XID_CONFIG, ("xi_detach()\n"));
266 
267 	xi_disable(sc);
268 
269 #if NRND > 0
270 	rnd_detach_source(&sc->sc_rnd_source);
271 #endif
272 
273 	mii_detach(&sc->sc_mii, MII_PHY_ANY, MII_OFFSET_ANY);
274 	ifmedia_delete_instance(&sc->sc_mii.mii_media, IFM_INST_ANY);
275 	ether_ifdetach(ifp);
276 	if_detach(ifp);
277 
278 	return 0;
279 }
280 
281 int
282 xi_activate(struct device *self, enum devact act)
283 {
284 	struct xi_softc *sc = (void *)self;
285 	int s, rv = 0;
286 
287 	DPRINTF(XID_CONFIG, ("xi_activate()\n"));
288 
289 	s = splnet();
290 	switch (act) {
291 	case DVACT_ACTIVATE:
292 		rv = EOPNOTSUPP;
293 		break;
294 
295 	case DVACT_DEACTIVATE:
296 		if_deactivate(&sc->sc_ethercom.ec_if);
297 		break;
298 	}
299 	splx(s);
300 	return (rv);
301 }
302 
303 int
304 xi_intr(void *arg)
305 {
306 	struct xi_softc *sc = arg;
307 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
308 	u_int8_t esr, rsr, isr, rx_status;
309 	u_int16_t tx_status, recvcount = 0, tempint;
310 
311 	DPRINTF(XID_CONFIG, ("xi_intr()\n"));
312 
313 	if (sc->sc_enabled == 0 ||
314 	    !device_is_active(&sc->sc_dev))
315 		return (0);
316 
317 	ifp->if_timer = 0;	/* turn watchdog timer off */
318 
319 	PAGE(sc, 0);
320 	if (sc->sc_chipset >= XI_CHIPSET_MOHAWK) {
321 		/* Disable interrupt (Linux does it). */
322 		bus_space_write_1(sc->sc_bst, sc->sc_bsh, CR, 0);
323 	}
324 
325 	esr = bus_space_read_1(sc->sc_bst, sc->sc_bsh, ESR);
326 	isr = bus_space_read_1(sc->sc_bst, sc->sc_bsh, ISR0);
327 	rsr = bus_space_read_1(sc->sc_bst, sc->sc_bsh, RSR);
328 
329 	/* Check to see if card has been ejected. */
330 	if (isr == 0xff) {
331 #ifdef DIAGNOSTIC
332 		printf("%s: interrupt for dead card\n", device_xname(&sc->sc_dev));
333 #endif
334 		goto end;
335 	}
336 	DPRINTF(XID_INTR, ("xi: isr=%02x\n", isr));
337 
338 	PAGE(sc, 0x40);
339 	rx_status =
340 	    bus_space_read_1(sc->sc_bst, sc->sc_bsh, RXST0);
341 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, RXST0, ~rx_status & 0xff);
342 	tx_status =
343 	    bus_space_read_1(sc->sc_bst, sc->sc_bsh, TXST0);
344 	tx_status |=
345 	    bus_space_read_1(sc->sc_bst, sc->sc_bsh, TXST1) << 8;
346 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, TXST0, 0);
347 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, TXST1, 0);
348 	DPRINTF(XID_INTR, ("xi: rx_status=%02x tx_status=%04x\n", rx_status,
349 	    tx_status));
350 
351 	PAGE(sc, 0);
352 	while (esr & FULL_PKT_RCV) {
353 		if (!(rsr & RSR_RX_OK))
354 			break;
355 
356 		/* Compare bytes read this interrupt to hard maximum. */
357 		if (recvcount > MAX_BYTES_INTR) {
358 			DPRINTF(XID_INTR,
359 			    ("xi: too many bytes this interrupt\n"));
360 			ifp->if_iqdrops++;
361 			/* Drop packet. */
362 			bus_space_write_2(sc->sc_bst, sc->sc_bsh, DO0,
363 			    DO_SKIP_RX_PKT);
364 		}
365 		tempint = xi_get(sc);	/* XXX doesn't check the error! */
366 		recvcount += tempint;
367 		ifp->if_ibytes += tempint;
368 		esr = bus_space_read_1(sc->sc_bst, sc->sc_bsh, ESR);
369 		rsr = bus_space_read_1(sc->sc_bst, sc->sc_bsh, RSR);
370 	}
371 
372 	/* Packet too long? */
373 	if (rsr & RSR_TOO_LONG) {
374 		ifp->if_ierrors++;
375 		DPRINTF(XID_INTR, ("xi: packet too long\n"));
376 	}
377 
378 	/* CRC error? */
379 	if (rsr & RSR_CRCERR) {
380 		ifp->if_ierrors++;
381 		DPRINTF(XID_INTR, ("xi: CRC error detected\n"));
382 	}
383 
384 	/* Alignment error? */
385 	if (rsr & RSR_ALIGNERR) {
386 		ifp->if_ierrors++;
387 		DPRINTF(XID_INTR, ("xi: alignment error detected\n"));
388 	}
389 
390 	/* Check for rx overrun. */
391 	if (rx_status & RX_OVERRUN) {
392 		ifp->if_ierrors++;
393 		bus_space_write_1(sc->sc_bst, sc->sc_bsh, CR, CLR_RX_OVERRUN);
394 		DPRINTF(XID_INTR, ("xi: overrun cleared\n"));
395 	}
396 
397 	/* Try to start more packets transmitting. */
398 	if (IFQ_IS_EMPTY(&ifp->if_snd) == 0)
399 		xi_start(ifp);
400 
401 	/* Detected excessive collisions? */
402 	if ((tx_status & EXCESSIVE_COLL) && ifp->if_opackets > 0) {
403 		DPRINTF(XID_INTR, ("xi: excessive collisions\n"));
404 		bus_space_write_1(sc->sc_bst, sc->sc_bsh, CR, RESTART_TX);
405 		ifp->if_oerrors++;
406 	}
407 
408 	if ((tx_status & TX_ABORT) && ifp->if_opackets > 0)
409 		ifp->if_oerrors++;
410 
411 	/* have handled the interrupt */
412 #if NRND > 0
413 	rnd_add_uint32(&sc->sc_rnd_source, tx_status);
414 #endif
415 
416 end:
417 	/* Reenable interrupts. */
418 	PAGE(sc, 0);
419 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, CR, ENABLE_INT);
420 
421 	return (1);
422 }
423 
424 /*
425  * Pull a packet from the card into an mbuf chain.
426  */
427 STATIC u_int16_t
428 xi_get(struct xi_softc *sc)
429 {
430 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
431 	struct mbuf *top, **mp, *m;
432 	u_int16_t pktlen, len, recvcount = 0;
433 	u_int8_t *data;
434 
435 	DPRINTF(XID_CONFIG, ("xi_get()\n"));
436 
437 	PAGE(sc, 0);
438 	pktlen =
439 	    bus_space_read_2(sc->sc_bst, sc->sc_bsh, RBC0) & RBC_COUNT_MASK;
440 
441 	DPRINTF(XID_CONFIG, ("xi_get: pktlen=%d\n", pktlen));
442 
443 	if (pktlen == 0) {
444 		/*
445 		 * XXX At least one CE2 sets RBC0 == 0 occasionally, and only
446 		 * when MPE is set.  It is not known why.
447 		 */
448 		return (0);
449 	}
450 
451 	/* XXX should this be incremented now ? */
452 	recvcount += pktlen;
453 
454 	MGETHDR(m, M_DONTWAIT, MT_DATA);
455 	if (m == NULL)
456 		return (recvcount);
457 	m->m_pkthdr.rcvif = ifp;
458 	m->m_pkthdr.len = pktlen;
459 	len = MHLEN;
460 	top = NULL;
461 	mp = &top;
462 
463 	while (pktlen > 0) {
464 		if (top) {
465 			MGET(m, M_DONTWAIT, MT_DATA);
466 			if (m == NULL) {
467 				m_freem(top);
468 				return (recvcount);
469 			}
470 			len = MLEN;
471 		}
472 		if (pktlen >= MINCLSIZE) {
473 			MCLGET(m, M_DONTWAIT);
474 			if (!(m->m_flags & M_EXT)) {
475 				m_freem(m);
476 				m_freem(top);
477 				return (recvcount);
478 			}
479 			len = MCLBYTES;
480 		}
481 		if (top == NULL) {
482 			char *newdata = (char *)ALIGN(m->m_data +
483 			    sizeof(struct ether_header)) -
484 			    sizeof(struct ether_header);
485 			len -= newdata - m->m_data;
486 			m->m_data = newdata;
487 		}
488 		len = min(pktlen, len);
489 		data = mtod(m, u_int8_t *);
490 		if (len > 1) {
491 		        len &= ~1;
492 			bus_space_read_multi_2(sc->sc_bst, sc->sc_bsh, EDP,
493 			    (u_int16_t *)data, len>>1);
494 		} else
495 			*data = bus_space_read_1(sc->sc_bst, sc->sc_bsh, EDP);
496 		m->m_len = len;
497 		pktlen -= len;
498 		*mp = m;
499 		mp = &m->m_next;
500 	}
501 
502 	/* Skip Rx packet. */
503 	bus_space_write_2(sc->sc_bst, sc->sc_bsh, DO0, DO_SKIP_RX_PKT);
504 
505 	if (top == NULL)
506 		return recvcount;
507 
508 	/* Trim the CRC off the end of the packet. */
509 	m_adj(top, -ETHER_CRC_LEN);
510 
511 	ifp->if_ipackets++;
512 
513 #if NBPFILTER > 0
514 	if (ifp->if_bpf)
515 		bpf_mtap(ifp->if_bpf, top);
516 #endif
517 
518 	(*ifp->if_input)(ifp, top);
519 	return (recvcount);
520 }
521 
522 /*
523  * Serial management for the MII.
524  * The DELAY's below stem from the fact that the maximum frequency
525  * acceptable on the MDC pin is 2.5 MHz and fast processors can easily
526  * go much faster than that.
527  */
528 
529 /* Let the MII serial management be idle for one period. */
530 static INLINE void xi_mdi_idle(struct xi_softc *);
531 static INLINE void
532 xi_mdi_idle(struct xi_softc *sc)
533 {
534 	bus_space_tag_t bst = sc->sc_bst;
535 	bus_space_handle_t bsh = sc->sc_bsh;
536 
537 	/* Drive MDC low... */
538 	bus_space_write_1(bst, bsh, GP2, MDC_LOW);
539 	DELAY(1);
540 
541 	/* and high again. */
542 	bus_space_write_1(bst, bsh, GP2, MDC_HIGH);
543 	DELAY(1);
544 }
545 
546 /* Pulse out one bit of data. */
547 static INLINE void xi_mdi_pulse(struct xi_softc *, int);
548 static INLINE void
549 xi_mdi_pulse(struct xi_softc *sc, int data)
550 {
551 	bus_space_tag_t bst = sc->sc_bst;
552 	bus_space_handle_t bsh = sc->sc_bsh;
553 	u_int8_t bit = data ? MDIO_HIGH : MDIO_LOW;
554 
555 	/* First latch the data bit MDIO with clock bit MDC low...*/
556 	bus_space_write_1(bst, bsh, GP2, bit | MDC_LOW);
557 	DELAY(1);
558 
559 	/* then raise the clock again, preserving the data bit. */
560 	bus_space_write_1(bst, bsh, GP2, bit | MDC_HIGH);
561 	DELAY(1);
562 }
563 
564 /* Probe one bit of data. */
565 static INLINE int xi_mdi_probe(struct xi_softc *sc);
566 static INLINE int
567 xi_mdi_probe(struct xi_softc *sc)
568 {
569 	bus_space_tag_t bst = sc->sc_bst;
570 	bus_space_handle_t bsh = sc->sc_bsh;
571 	u_int8_t x;
572 
573 	/* Pull clock bit MDCK low... */
574 	bus_space_write_1(bst, bsh, GP2, MDC_LOW);
575 	DELAY(1);
576 
577 	/* Read data and drive clock high again. */
578 	x = bus_space_read_1(bst, bsh, GP2);
579 	bus_space_write_1(bst, bsh, GP2, MDC_HIGH);
580 	DELAY(1);
581 
582 	return (x & MDIO);
583 }
584 
585 /* Pulse out a sequence of data bits. */
586 static INLINE void xi_mdi_pulse_bits(struct xi_softc *, u_int32_t, int);
587 static INLINE void
588 xi_mdi_pulse_bits(struct xi_softc *sc, u_int32_t data, int len)
589 {
590 	u_int32_t mask;
591 
592 	for (mask = 1 << (len - 1); mask; mask >>= 1)
593 		xi_mdi_pulse(sc, data & mask);
594 }
595 
596 /* Read a PHY register. */
597 STATIC int
598 xi_mdi_read(struct device *self, int phy, int reg)
599 {
600 	struct xi_softc *sc = (struct xi_softc *)self;
601 	int i;
602 	u_int32_t mask;
603 	u_int32_t data = 0;
604 
605 	PAGE(sc, 2);
606 	for (i = 0; i < 32; i++)	/* Synchronize. */
607 		xi_mdi_pulse(sc, 1);
608 	xi_mdi_pulse_bits(sc, 0x06, 4); /* Start + Read opcode */
609 	xi_mdi_pulse_bits(sc, phy, 5);	/* PHY address */
610 	xi_mdi_pulse_bits(sc, reg, 5);	/* PHY register */
611 	xi_mdi_idle(sc);		/* Turn around. */
612 	xi_mdi_probe(sc);		/* Drop initial zero bit. */
613 
614 	for (mask = 1 << 15; mask; mask >>= 1) {
615 		if (xi_mdi_probe(sc))
616 			data |= mask;
617 	}
618 	xi_mdi_idle(sc);
619 
620 	DPRINTF(XID_MII,
621 	    ("xi_mdi_read: phy %d reg %d -> %x\n", phy, reg, data));
622 
623 	return (data);
624 }
625 
626 /* Write a PHY register. */
627 STATIC void
628 xi_mdi_write(struct device *self, int phy, int reg, int value)
629 {
630 	struct xi_softc *sc = (struct xi_softc *)self;
631 	int i;
632 
633 	PAGE(sc, 2);
634 	for (i = 0; i < 32; i++)	/* Synchronize. */
635 		xi_mdi_pulse(sc, 1);
636 	xi_mdi_pulse_bits(sc, 0x05, 4); /* Start + Write opcode */
637 	xi_mdi_pulse_bits(sc, phy, 5);	/* PHY address */
638 	xi_mdi_pulse_bits(sc, reg, 5);	/* PHY register */
639 	xi_mdi_pulse_bits(sc, 0x02, 2); /* Turn around. */
640 	xi_mdi_pulse_bits(sc, value, 16);	/* Write the data */
641 	xi_mdi_idle(sc);		/* Idle away. */
642 
643 	DPRINTF(XID_MII,
644 	    ("xi_mdi_write: phy %d reg %d val %x\n", phy, reg, value));
645 }
646 
647 STATIC void
648 xi_statchg(struct device *self)
649 {
650 	/* XXX Update ifp->if_baudrate */
651 }
652 
653 /*
654  * Change media according to request.
655  */
656 STATIC int
657 xi_mediachange(struct ifnet *ifp)
658 {
659 	int s;
660 
661 	DPRINTF(XID_CONFIG, ("xi_mediachange()\n"));
662 
663 	if (ifp->if_flags & IFF_UP) {
664 		s = splnet();
665 		xi_init(ifp->if_softc);
666 		splx(s);
667 	}
668 	return (0);
669 }
670 
671 STATIC void
672 xi_reset(struct xi_softc *sc)
673 {
674 	int s;
675 
676 	DPRINTF(XID_CONFIG, ("xi_reset()\n"));
677 
678 	s = splnet();
679 	xi_stop(sc);
680 	xi_init(sc);
681 	splx(s);
682 }
683 
684 STATIC void
685 xi_watchdog(struct ifnet *ifp)
686 {
687 	struct xi_softc *sc = ifp->if_softc;
688 
689 	printf("%s: device timeout\n", device_xname(&sc->sc_dev));
690 	++ifp->if_oerrors;
691 
692 	xi_reset(sc);
693 }
694 
695 STATIC void
696 xi_stop(register struct xi_softc *sc)
697 {
698 	bus_space_tag_t bst = sc->sc_bst;
699 	bus_space_handle_t bsh = sc->sc_bsh;
700 
701 	DPRINTF(XID_CONFIG, ("xi_stop()\n"));
702 
703 	PAGE(sc, 0x40);
704 	bus_space_write_1(bst, bsh, CMD0, DISABLE_RX);
705 
706 	/* Disable interrupts. */
707 	PAGE(sc, 0);
708 	bus_space_write_1(bst, bsh, CR, 0);
709 
710 	PAGE(sc, 1);
711 	bus_space_write_1(bst, bsh, IMR0, 0);
712 
713 	/* Cancel watchdog timer. */
714 	sc->sc_ethercom.ec_if.if_timer = 0;
715 }
716 
717 STATIC int
718 xi_enable(struct xi_softc *sc)
719 {
720 	int error;
721 
722 	if (!sc->sc_enabled) {
723 		error = (*sc->sc_enable)(sc);
724 		if (error)
725 			return (error);
726 		sc->sc_enabled = 1;
727 		xi_full_reset(sc);
728 	}
729 	return (0);
730 }
731 
732 STATIC void
733 xi_disable(struct xi_softc *sc)
734 {
735 
736 	if (sc->sc_enabled) {
737 		sc->sc_enabled = 0;
738 		(*sc->sc_disable)(sc);
739 	}
740 }
741 
742 STATIC void
743 xi_init(struct xi_softc *sc)
744 {
745 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
746 	bus_space_tag_t bst = sc->sc_bst;
747 	bus_space_handle_t bsh = sc->sc_bsh;
748 
749 	DPRINTF(XID_CONFIG, ("xi_init()\n"));
750 
751 	/* Setup the ethernet interrupt mask. */
752 	PAGE(sc, 1);
753 	bus_space_write_1(bst, bsh, IMR0,
754 	    ISR_TX_OFLOW | ISR_PKT_TX | ISR_MAC_INT | /* ISR_RX_EARLY | */
755 	    ISR_RX_FULL | ISR_RX_PKT_REJ | ISR_FORCED_INT);
756 	if (sc->sc_chipset < XI_CHIPSET_DINGO) {
757 		/* XXX What is this?  Not for Dingo at least. */
758 		/* Unmask TX underrun detection */
759 		bus_space_write_1(bst, bsh, IMR1, 1);
760 	}
761 
762 	/* Enable interrupts. */
763 	PAGE(sc, 0);
764 	bus_space_write_1(bst, bsh, CR, ENABLE_INT);
765 
766 	xi_set_address(sc);
767 
768 	PAGE(sc, 0x40);
769 	bus_space_write_1(bst, bsh, CMD0, ENABLE_RX | ONLINE);
770 
771 	PAGE(sc, 0);
772 
773 	/* Set current media. */
774 	mii_mediachg(&sc->sc_mii);
775 
776 	ifp->if_flags |= IFF_RUNNING;
777 	ifp->if_flags &= ~IFF_OACTIVE;
778 
779 	xi_start(ifp);
780 }
781 
782 /*
783  * Start outputting on the interface.
784  * Always called as splnet().
785  */
786 STATIC void
787 xi_start(struct ifnet *ifp)
788 {
789 	struct xi_softc *sc = ifp->if_softc;
790 	bus_space_tag_t bst = sc->sc_bst;
791 	bus_space_handle_t bsh = sc->sc_bsh;
792 	unsigned int s, len, pad = 0;
793 	struct mbuf *m0, *m;
794 	u_int16_t space;
795 
796 	DPRINTF(XID_CONFIG, ("xi_start()\n"));
797 
798 	/* Don't transmit if interface is busy or not running. */
799 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING) {
800 		DPRINTF(XID_CONFIG, ("xi: interface busy or not running\n"));
801 		return;
802 	}
803 
804 	/* Peek at the next packet. */
805 	IFQ_POLL(&ifp->if_snd, m0);
806 	if (m0 == 0)
807 		return;
808 
809 	/* We need to use m->m_pkthdr.len, so require the header. */
810 	if (!(m0->m_flags & M_PKTHDR))
811 		panic("xi_start: no header mbuf");
812 
813 	len = m0->m_pkthdr.len;
814 
815 #if 1
816 	/* Pad to ETHER_MIN_LEN - ETHER_CRC_LEN. */
817 	if (len < ETHER_MIN_LEN - ETHER_CRC_LEN)
818 		pad = ETHER_MIN_LEN - ETHER_CRC_LEN - len;
819 #else
820 	pad = 0;
821 #endif
822 
823 	PAGE(sc, 0);
824 
825 	bus_space_write_2(bst, bsh, TRS, (u_int16_t)len + pad + 2);
826 	space = bus_space_read_2(bst, bsh, TSO) & 0x7fff;
827 	if (len + pad + 2 > space) {
828 		DPRINTF(XID_FIFO,
829 		    ("xi: not enough space in output FIFO (%d > %d)\n",
830 		    len + pad + 2, space));
831 		return;
832 	}
833 
834 	IFQ_DEQUEUE(&ifp->if_snd, m0);
835 
836 #if NBPFILTER > 0
837 	if (ifp->if_bpf)
838 		bpf_mtap(ifp->if_bpf, m0);
839 #endif
840 
841 	/*
842 	 * Do the output at splhigh() so that an interrupt from another device
843 	 * won't cause a FIFO underrun.
844 	 */
845 	s = splhigh();
846 
847 	bus_space_write_2(bst, bsh, EDP, (u_int16_t)len + pad);
848 	for (m = m0; m; ) {
849 		if (m->m_len > 1)
850 			bus_space_write_multi_2(bst, bsh, EDP,
851 			    mtod(m, u_int16_t *), m->m_len>>1);
852 		if (m->m_len & 1) {
853 			DPRINTF(XID_CONFIG, ("xi: XXX odd!\n"));
854 			bus_space_write_1(bst, bsh, EDP,
855 			    *(mtod(m, u_int8_t *) + m->m_len - 1));
856 		}
857 		MFREE(m, m0);
858 		m = m0;
859 	}
860 	DPRINTF(XID_CONFIG, ("xi: len=%d pad=%d total=%d\n", len, pad, len+pad+4));
861 	if (sc->sc_chipset >= XI_CHIPSET_MOHAWK)
862 		bus_space_write_1(bst, bsh, CR, TX_PKT | ENABLE_INT);
863 	else {
864 		for (; pad > 1; pad -= 2)
865 			bus_space_write_2(bst, bsh, EDP, 0);
866 		if (pad == 1)
867 			bus_space_write_1(bst, bsh, EDP, 0);
868 	}
869 
870 	splx(s);
871 
872 	ifp->if_timer = 5;
873 	++ifp->if_opackets;
874 }
875 
876 STATIC int
877 xi_ether_ioctl(struct ifnet *ifp, u_long cmd, void *data)
878 {
879 	struct ifaddr *ifa = (struct ifaddr *)data;
880 	struct xi_softc *sc = ifp->if_softc;
881 	int error;
882 
883 	DPRINTF(XID_CONFIG, ("xi_ether_ioctl()\n"));
884 
885 	switch (cmd) {
886 	case SIOCINITIFADDR:
887 		if ((error = xi_enable(sc)) != 0)
888 			break;
889 
890 		ifp->if_flags |= IFF_UP;
891 
892 		xi_init(sc);
893 		switch (ifa->ifa_addr->sa_family) {
894 #ifdef INET
895 		case AF_INET:
896 			arp_ifinit(ifp, ifa);
897 			break;
898 #endif	/* INET */
899 
900 
901 		default:
902 			break;
903 		}
904 		break;
905 
906 	default:
907 		return (EINVAL);
908 	}
909 
910 	return (0);
911 }
912 
913 STATIC int
914 xi_ioctl(struct ifnet *ifp, u_long cmd, void *data)
915 {
916 	struct xi_softc *sc = ifp->if_softc;
917 	int s, error = 0;
918 
919 	DPRINTF(XID_CONFIG, ("xi_ioctl()\n"));
920 
921 	s = splnet();
922 
923 	switch (cmd) {
924 	case SIOCINITIFADDR:
925 		error = xi_ether_ioctl(ifp, cmd, data);
926 		break;
927 
928 	case SIOCSIFFLAGS:
929 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
930 			break;
931 		/* XXX re-use ether_ioctl() */
932 		switch (ifp->if_flags & (IFF_UP|IFF_RUNNING)) {
933 		case IFF_RUNNING:
934 			/*
935 			 * If interface is marked down and it is running,
936 			 * stop it.
937 			 */
938 			xi_stop(sc);
939 			ifp->if_flags &= ~IFF_RUNNING;
940 			xi_disable(sc);
941 			break;
942 		case IFF_UP:
943 			/*
944 			 * If interface is marked up and it is stopped,
945 			 * start it.
946 			 */
947 			if ((error = xi_enable(sc)) != 0)
948 				break;
949 			xi_init(sc);
950 			break;
951 		case IFF_UP|IFF_RUNNING:
952 			/*
953 			 * Reset the interface to pick up changes in any
954 			 * other flags that affect hardware registers.
955 			 */
956 			xi_set_address(sc);
957 			break;
958 		case 0:
959 			break;
960 		}
961 		break;
962 
963 	case SIOCADDMULTI:
964 	case SIOCDELMULTI:
965 		if (sc->sc_enabled == 0) {
966 			error = EIO;
967 			break;
968 		}
969 		/*FALLTHROUGH*/
970 	case SIOCSIFMEDIA:
971 	case SIOCGIFMEDIA:
972 		if ((error = ether_ioctl(ifp, cmd, data)) == ENETRESET) {
973 			/*
974 			 * Multicast list has changed; set the hardware
975 			 * filter accordingly.
976 			 */
977 			if (ifp->if_flags & IFF_RUNNING)
978 				xi_set_address(sc);
979 			error = 0;
980 		}
981 		break;
982 
983 	default:
984 		error = ether_ioctl(ifp, cmd, data);
985 		break;
986 	}
987 
988 	splx(s);
989 	return (error);
990 }
991 
992 STATIC void
993 xi_set_address(struct xi_softc *sc)
994 {
995 	bus_space_tag_t bst = sc->sc_bst;
996 	bus_space_handle_t bsh = sc->sc_bsh;
997 	struct ethercom *ether = &sc->sc_ethercom;
998 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
999 	struct ether_multistep step;
1000 	struct ether_multi *enm;
1001 	int page, num;
1002 	int i;
1003 	u_int8_t x;
1004 	const u_int8_t *enaddr;
1005 	u_int8_t indaddr[64];
1006 
1007 	DPRINTF(XID_CONFIG, ("xi_set_address()\n"));
1008 
1009 	enaddr = (const u_int8_t *)CLLADDR(ifp->if_sadl);
1010 	if (sc->sc_chipset >= XI_CHIPSET_MOHAWK)
1011 		for (i = 0; i < 6; i++)
1012 			indaddr[i] = enaddr[5 - i];
1013 	else
1014 		for (i = 0; i < 6; i++)
1015 			indaddr[i] = enaddr[i];
1016 	num = 1;
1017 
1018 	if (ether->ec_multicnt > 9) {
1019 		ifp->if_flags |= IFF_ALLMULTI;
1020 		goto done;
1021 	}
1022 
1023 	ETHER_FIRST_MULTI(step, ether, enm);
1024 	for (; enm; num++) {
1025 		if (memcmp(enm->enm_addrlo, enm->enm_addrhi,
1026 		    sizeof(enm->enm_addrlo)) != 0) {
1027 			/*
1028 			 * The multicast address is really a range;
1029 			 * it's easier just to accept all multicasts.
1030 			 * XXX should we be setting IFF_ALLMULTI here?
1031 			 */
1032 			ifp->if_flags |= IFF_ALLMULTI;
1033 			goto done;
1034 		}
1035 		if (sc->sc_chipset >= XI_CHIPSET_MOHAWK)
1036 			for (i = 0; i < 6; i++)
1037 				indaddr[num * 6 + i] = enm->enm_addrlo[5 - i];
1038 		else
1039 			for (i = 0; i < 6; i++)
1040 				indaddr[num * 6 + i] = enm->enm_addrlo[i];
1041 		ETHER_NEXT_MULTI(step, enm);
1042 	}
1043 	ifp->if_flags &= ~IFF_ALLMULTI;
1044 
1045 done:
1046 	if (num < 10)
1047 		memset(&indaddr[num * 6], 0xff, 6 * (10 - num));
1048 
1049 	for (page = 0; page < 8; page++) {
1050 #ifdef XIDEBUG
1051 		if (xidebug & XID_MCAST) {
1052 			printf("page %d before:", page);
1053 			for (i = 0; i < 8; i++)
1054 				printf(" %02x", indaddr[page * 8 + i]);
1055 			printf("\n");
1056 		}
1057 #endif
1058 
1059 		PAGE(sc, 0x50 + page);
1060 		bus_space_write_region_1(bst, bsh, IA, &indaddr[page * 8],
1061 		    page == 7 ? 4 : 8);
1062 		/*
1063 		 * XXX
1064 		 * Without this delay, the address registers on my CE2 get
1065 		 * trashed the first and I have to cycle it.  I have no idea
1066 		 * why.  - mycroft, 2004/08/09
1067 		 */
1068 		DELAY(50);
1069 
1070 #ifdef XIDEBUG
1071 		if (xidebug & XID_MCAST) {
1072 			bus_space_read_region_1(bst, bsh, IA,
1073 			    &indaddr[page * 8], page == 7 ? 4 : 8);
1074 			printf("page %d after: ", page);
1075 			for (i = 0; i < 8; i++)
1076 				printf(" %02x", indaddr[page * 8 + i]);
1077 			printf("\n");
1078 		}
1079 #endif
1080 	}
1081 
1082 	PAGE(sc, 0x42);
1083 	x = SWC1_IND_ADDR;
1084 	if (ifp->if_flags & IFF_PROMISC)
1085 		x |= SWC1_PROMISC;
1086 	if (ifp->if_flags & (IFF_ALLMULTI|IFF_PROMISC))
1087 		x |= SWC1_MCAST_PROM;
1088 	if (!LIST_FIRST(&sc->sc_mii.mii_phys))
1089 		x |= SWC1_AUTO_MEDIA;
1090 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, SWC1, x);
1091 }
1092 
1093 STATIC void
1094 xi_cycle_power(struct xi_softc *sc)
1095 {
1096 	bus_space_tag_t bst = sc->sc_bst;
1097 	bus_space_handle_t bsh = sc->sc_bsh;
1098 
1099 	DPRINTF(XID_CONFIG, ("xi_cycle_power()\n"));
1100 
1101 	PAGE(sc, 4);
1102 	DELAY(1);
1103 	bus_space_write_1(bst, bsh, GP1, 0);
1104 	tsleep(&xi_cycle_power, PWAIT, "xipwr1", hz * 40 / 1000);
1105 	if (sc->sc_chipset >= XI_CHIPSET_MOHAWK)
1106 		bus_space_write_1(bst, bsh, GP1, POWER_UP);
1107 	else
1108 		/* XXX What is bit 2 (aka AIC)? */
1109 		bus_space_write_1(bst, bsh, GP1, POWER_UP | 4);
1110 	tsleep(&xi_cycle_power, PWAIT, "xipwr2", hz * 20 / 1000);
1111 }
1112 
1113 STATIC void
1114 xi_full_reset(struct xi_softc *sc)
1115 {
1116 	bus_space_tag_t bst = sc->sc_bst;
1117 	bus_space_handle_t bsh = sc->sc_bsh;
1118 	u_int8_t x;
1119 
1120 	DPRINTF(XID_CONFIG, ("xi_full_reset()\n"));
1121 
1122 	/* Do an as extensive reset as possible on all functions. */
1123 	xi_cycle_power(sc);
1124 	bus_space_write_1(bst, bsh, CR, SOFT_RESET);
1125 	tsleep(&xi_full_reset, PWAIT, "xirst1", hz * 20 / 1000);
1126 	bus_space_write_1(bst, bsh, CR, 0);
1127 	tsleep(&xi_full_reset, PWAIT, "xirst2", hz * 20 / 1000);
1128 	PAGE(sc, 4);
1129 	if (sc->sc_chipset >= XI_CHIPSET_MOHAWK) {
1130 		/*
1131 		 * Drive GP1 low to power up ML6692 and GP2 high to power up
1132 		 * the 10MHz chip.  XXX What chip is that?  The phy?
1133 		 */
1134 		bus_space_write_1(bst, bsh, GP0, GP1_OUT | GP2_OUT | GP2_WR);
1135 	}
1136 	tsleep(&xi_full_reset, PWAIT, "xirst3", hz * 500 / 1000);
1137 
1138 	/* Get revision information.  XXX Symbolic constants. */
1139 	sc->sc_rev = bus_space_read_1(bst, bsh, BV) &
1140 	    ((sc->sc_chipset >= XI_CHIPSET_MOHAWK) ? 0x70 : 0x30) >> 4;
1141 	DPRINTF(XID_CONFIG, ("xi: rev=%02x\n", sc->sc_rev));
1142 
1143 	/* Media selection.  XXX Maybe manual overriding too? */
1144 	if (sc->sc_chipset < XI_CHIPSET_MOHAWK) {
1145 		/*
1146 		 * XXX I have no idea what this really does, it is from the
1147 		 * Linux driver.
1148 		 */
1149 		bus_space_write_1(bst, bsh, GP0, GP1_OUT);
1150 	}
1151 	tsleep(&xi_full_reset, PWAIT, "xirst4", hz * 40 / 1000);
1152 
1153 	/*
1154 	 * Disable source insertion.
1155 	 * XXX Dingo does not have this bit, but Linux does it unconditionally.
1156 	 */
1157 	if (sc->sc_chipset < XI_CHIPSET_DINGO) {
1158 		PAGE(sc, 0x42);
1159 		bus_space_write_1(bst, bsh, SWC0, 0x20);
1160 	}
1161 
1162 	/* Set the local memory dividing line. */
1163 	if (sc->sc_rev != 1) {
1164 		PAGE(sc, 2);
1165 		/* XXX Symbolic constant preferrable. */
1166 		bus_space_write_2(bst, bsh, RBS0, 0x2000);
1167 	}
1168 
1169 	/*
1170 	 * Apparently the receive byte pointer can be bad after a reset, so
1171 	 * we hardwire it correctly.
1172 	 */
1173 	PAGE(sc, 0);
1174 	bus_space_write_2(bst, bsh, DO0, DO_CHG_OFFSET);
1175 
1176 	/* Setup ethernet MAC registers. XXX Symbolic constants. */
1177 	PAGE(sc, 0x40);
1178 	bus_space_write_1(bst, bsh, RX0MSK,
1179 	    PKT_TOO_LONG | CRC_ERR | RX_OVERRUN | RX_ABORT | RX_OK);
1180 	bus_space_write_1(bst, bsh, TX0MSK,
1181 	    CARRIER_LOST | EXCESSIVE_COLL | TX_UNDERRUN | LATE_COLLISION |
1182 	    SQE | TX_ABORT | TX_OK);
1183 	if (sc->sc_chipset < XI_CHIPSET_DINGO)
1184 		/* XXX From Linux, dunno what 0xb0 means. */
1185 		bus_space_write_1(bst, bsh, TX1MSK, 0xb0);
1186 	bus_space_write_1(bst, bsh, RXST0, 0);
1187 	bus_space_write_1(bst, bsh, TXST0, 0);
1188 	bus_space_write_1(bst, bsh, TXST1, 0);
1189 
1190 	PAGE(sc, 2);
1191 
1192 	/* Enable MII function if available. */
1193 	x = 0;
1194 	if (LIST_FIRST(&sc->sc_mii.mii_phys))
1195 		x |= SELECT_MII;
1196 	bus_space_write_1(bst, bsh, MSR, x);
1197 	tsleep(&xi_full_reset, PWAIT, "xirst5", hz * 20 / 1000);
1198 
1199 	/* Configure the LED registers. */
1200 	/* XXX This is not good for 10base2. */
1201 	bus_space_write_1(bst, bsh, LED,
1202 	    (LED_TX_ACT << LED1_SHIFT) | (LED_10MB_LINK << LED0_SHIFT));
1203 	if (sc->sc_chipset >= XI_CHIPSET_DINGO)
1204 		bus_space_write_1(bst, bsh, LED3, LED_100MB_LINK << LED3_SHIFT);
1205 
1206 	/*
1207 	 * The Linux driver says this:
1208 	 * We should switch back to page 0 to avoid a bug in revision 0
1209 	 * where regs with offset below 8 can't be read after an access
1210 	 * to the MAC registers.
1211 	 */
1212 	PAGE(sc, 0);
1213 }
1214