xref: /netbsd-src/sys/arch/i386/pci/viapcib.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /* $NetBSD: viapcib.c,v 1.6 2006/11/16 01:32:39 christos Exp $ */
2 /* $FreeBSD: src/sys/pci/viapm.c,v 1.10 2005/05/29 04:42:29 nyan Exp $ */
3 
4 /*-
5  * Copyright (c) 2005, 2006 Jared D. McNeill <jmcneill@invisible.ca>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions, and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 /*-
32  * Copyright (c) 2001 Alcove - Nicolas Souchu
33  * All rights reserved.
34  *
35  * Redistribution and use in source and binary forms, with or without
36  * modification, are permitted provided that the following conditions
37  * are met:
38  * 1. Redistributions of source code must retain the above copyright
39  *    notice, this list of conditions and the following disclaimer.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *    notice, this list of conditions and the following disclaimer in the
42  *    documentation and/or other materials provided with the distribution.
43  *
44  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
54  * SUCH DAMAGE.
55  */
56 
57 #include <sys/cdefs.h>
58 __KERNEL_RCSID(0, "$NetBSD: viapcib.c,v 1.6 2006/11/16 01:32:39 christos Exp $");
59 
60 #include <sys/types.h>
61 #include <sys/param.h>
62 #include <sys/systm.h>
63 #include <sys/device.h>
64 #include <sys/proc.h>
65 
66 #include <machine/bus.h>
67 
68 #include <dev/pci/pcireg.h>
69 #include <dev/pci/pcivar.h>
70 #include <dev/pci/pcidevs.h>
71 
72 #include <dev/i2c/i2cvar.h>
73 
74 #include <i386/pci/viapcibreg.h>
75 
76 /*#define VIAPCIB_DEBUG*/
77 
78 #ifdef	VIAPCIB_DEBUG
79 #define	DPRINTF(x)	printf x
80 #else
81 #define	DPRINTF(x)
82 #endif
83 
84 struct viapcib_softc {
85 	struct device	sc_dev;
86 	bus_space_tag_t	sc_iot;
87 	bus_space_handle_t sc_ioh;
88 	struct i2c_controller sc_i2c;
89 
90 	int sc_revision;
91 
92 	struct simplelock sc_lock;
93 };
94 
95 static int	viapcib_match(struct device *, struct cfdata *, void *);
96 static void	viapcib_attach(struct device *, struct device *, void *);
97 
98 static int	viapcib_clear(struct viapcib_softc *);
99 static int	viapcib_busy(struct viapcib_softc *);
100 
101 #define		viapcib_smbus_read(sc, o) \
102 	bus_space_read_1((sc)->sc_iot, (sc)->sc_ioh, (o))
103 #define		viapcib_smbus_write(sc, o, v) \
104 	bus_space_write_1((sc)->sc_iot, (sc)->sc_ioh, (o), (v))
105 
106 #define	VIAPCIB_SMBUS_TIMEOUT	10000
107 
108 static int	viapcib_acquire_bus(void *, int);
109 static void	viapcib_release_bus(void *, int);
110 static int	viapcib_exec(void *, i2c_op_t, i2c_addr_t, const void *,
111 			     size_t, void *, size_t, int);
112 
113 /* SMBus operations */
114 static int      viapcib_smbus_quick_write(void *, i2c_addr_t);
115 static int      viapcib_smbus_quick_read(void *, i2c_addr_t);
116 static int      viapcib_smbus_send_byte(void *, i2c_addr_t, uint8_t);
117 static int      viapcib_smbus_receive_byte(void *, i2c_addr_t,
118                                            uint8_t *);
119 static int      viapcib_smbus_read_byte(void *, i2c_addr_t, uint8_t,
120 					int8_t *);
121 static int      viapcib_smbus_write_byte(void *, i2c_addr_t, uint8_t,
122 					 int8_t);
123 static int      viapcib_smbus_read_word(void *, i2c_addr_t, uint8_t,
124 					int16_t *);
125 static int      viapcib_smbus_write_word(void *, i2c_addr_t, uint8_t,
126 					 int16_t);
127 static int      viapcib_smbus_block_write(void *, i2c_addr_t, uint8_t,
128 					  int, void *);
129 static int      viapcib_smbus_block_read(void *, i2c_addr_t, uint8_t,
130 					 int, void *);
131 /* XXX Should be moved to smbus layer */
132 #define	SMB_MAXBLOCKSIZE	32
133 
134 /* from arch/i386/pci/pcib.c */
135 extern void	pcibattach(struct device *, struct device *, void *);
136 
137 CFATTACH_DECL(viapcib, sizeof(struct viapcib_softc), viapcib_match,
138     viapcib_attach, NULL, NULL);
139 
140 static int
141 viapcib_match(struct device *parent, struct cfdata *match,
142     void *opaque)
143 {
144 	struct pci_attach_args *pa;
145 
146 	pa = (struct pci_attach_args *)opaque;
147 
148 	if (PCI_VENDOR(pa->pa_id) != PCI_VENDOR_VIATECH)
149 		return 0;
150 
151 	switch (PCI_PRODUCT(pa->pa_id)) {
152 	case PCI_PRODUCT_VIATECH_VT8235:
153 	case PCI_PRODUCT_VIATECH_VT8237:
154 		return 2; /* match above generic pcib(4) */
155 	}
156 
157 	return 0;
158 }
159 
160 static void
161 viapcib_attach(struct device *parent, struct device *self, void *opaque)
162 {
163 	struct viapcib_softc *sc;
164 	struct pci_attach_args *pa;
165 	pcireg_t addr, val;
166 
167 	sc = (struct viapcib_softc *)self;
168 	pa = (struct pci_attach_args *)opaque;
169 
170 	/* XXX Only the 8235 is supported for now */
171 	sc->sc_iot = pa->pa_iot;
172 	addr = pci_conf_read(pa->pa_pc, pa->pa_tag, SMB_BASE3);
173 	addr &= 0xfff0;
174 	if (bus_space_map(sc->sc_iot, addr, 8, 0, &sc->sc_ioh)) {
175 		printf(": failed to map SMBus I/O space\n");
176 		addr = 0;
177 		goto core_pcib;
178 	}
179 
180 	simple_lock_init(&sc->sc_lock);
181 
182 	val = pci_conf_read(pa->pa_pc, pa->pa_tag, SMB_HOST_CONFIG);
183 	if ((val & 1) == 0) {
184 		printf(": SMBus is disabled\n");
185 		addr = 0;
186 		/* XXX We can enable the SMBus here by writing 1 to
187 		 * SMB_HOST_CONFIG, but do we want to?
188 		 */
189 		goto core_pcib;
190 	}
191 
192 #ifdef VIAPCIB_DEBUG
193 	switch (val & 0x0e) {
194 	case 8:
195 		printf(": interrupting at irq 9\n");
196 		break;
197 	case 0:
198 		printf(": interrupting at SMI#\n");
199 		break;
200 	default:
201 		printf(": interrupt misconfigured\n");
202 		break;
203 	}
204 #endif /* !VIAPCIB_DEBUG */
205 
206 	val = pci_conf_read(pa->pa_pc, pa->pa_tag, SMB_REVISION);
207 	sc->sc_revision = val;
208 
209 core_pcib:
210 	pcibattach(parent, self, opaque);
211 
212 	if (addr != 0) {
213 		struct i2cbus_attach_args iba;
214 		uint8_t b;
215 
216 		printf("%s: SMBus found at 0x%x (revision 0x%x)\n",
217 		    sc->sc_dev.dv_xname, addr, sc->sc_revision);
218 
219 		/* Disable slave function */
220 		b = viapcib_smbus_read(sc, SMBSLVCNT);
221 		viapcib_smbus_write(sc, SMBSLVCNT, b & ~1);
222 
223 		memset(&sc->sc_i2c, 0, sizeof(sc->sc_i2c));
224 #ifdef I2C_TYPE_SMBUS
225 		iba.iba_type = I2C_TYPE_SMBUS;
226 #endif
227 		iba.iba_tag = &sc->sc_i2c;
228 		iba.iba_tag->ic_cookie = (void *)sc;
229 		iba.iba_tag->ic_acquire_bus = viapcib_acquire_bus;
230 		iba.iba_tag->ic_release_bus = viapcib_release_bus;
231 		iba.iba_tag->ic_exec = viapcib_exec;
232 
233 		config_found_ia(&sc->sc_dev, "i2cbus", &iba, iicbus_print);
234 	}
235 
236 	return;
237 }
238 
239 static int
240 viapcib_wait(struct viapcib_softc *sc)
241 {
242 	int rv, timeout;
243 	uint8_t val;
244 
245 	timeout = VIAPCIB_SMBUS_TIMEOUT;
246 	rv = 0;
247 
248 	while (timeout--) {
249 		val = viapcib_smbus_read(sc, SMBHSTSTS);
250 		if (!(val & SMBHSTSTS_BUSY) && (val & SMBHSTSTS_INTR))
251 			break;
252 		DELAY(10);
253 	}
254 
255 	if (timeout == 0)
256 		rv = EBUSY;
257 
258 	if ((val & SMBHSTSTS_FAILED) || (val & SMBHSTSTS_COLLISION) ||
259 	    (val & SMBHSTSTS_ERROR))
260 		rv = EIO;
261 
262 	viapcib_clear(sc);
263 
264 	return rv;
265 }
266 
267 static int
268 viapcib_clear(struct viapcib_softc *sc)
269 {
270 	viapcib_smbus_write(sc, SMBHSTSTS,
271 	    (SMBHSTSTS_FAILED | SMBHSTSTS_COLLISION | SMBHSTSTS_ERROR |
272 	     SMBHSTSTS_INTR));
273 	DELAY(10);
274 
275 	return 0;
276 }
277 
278 static int
279 viapcib_busy(struct viapcib_softc *sc)
280 {
281 	uint8_t val;
282 
283 	val = viapcib_smbus_read(sc, SMBHSTSTS);
284 
285 	return (val & SMBHSTSTS_BUSY);
286 }
287 
288 static int
289 viapcib_acquire_bus(void *opaque, int flags)
290 {
291 	struct viapcib_softc *sc;
292 
293 	DPRINTF(("viapcib_i2c_acquire_bus(%p, 0x%x)\n", opaque, flags));
294 
295 	sc = (struct viapcib_softc *)opaque;
296 
297 	simple_lock(&sc->sc_lock);
298 
299 	return 0;
300 }
301 
302 static void
303 viapcib_release_bus(void *opaque, int flags)
304 {
305 	struct viapcib_softc *sc;
306 
307 	DPRINTF(("viapcib_i2c_release_bus(%p, 0x%x)\n", opaque, flags));
308 
309 	sc = (struct viapcib_softc *)opaque;
310 
311 	simple_unlock(&sc->sc_lock);
312 
313 	return;
314 }
315 
316 static int
317 viapcib_exec(void *opaque, i2c_op_t op, i2c_addr_t addr, const void *vcmd,
318     size_t cmdlen, void *vbuf, size_t buflen, int flags)
319 {
320 	struct viapcib_softc *sc;
321 	uint8_t cmd;
322 	int rv = -1;
323 
324 	DPRINTF(("viapcib_exec(%p, 0x%x, 0x%x, %p, %d, %p, %d, 0x%x)\n",
325 	    opaque, op, addr, vcmd, cmdlen, vbuf, buflen, flags));
326 
327 	sc = (struct viapcib_softc *)opaque;
328 
329 	if (op != I2C_OP_READ_WITH_STOP &&
330 	    op != I2C_OP_WRITE_WITH_STOP)
331 		return -1;
332 
333 	if (cmdlen > 0)
334 		cmd = *(uint8_t *)(__UNCONST(vcmd)); /* XXX */
335 
336 	switch (cmdlen) {
337 	case 0:
338 		switch (buflen) {
339 		case 0:
340 			/* SMBus quick read/write */
341 			if (I2C_OP_READ_P(op))
342 				rv = viapcib_smbus_quick_read(sc, addr);
343 			else
344 				rv = viapcib_smbus_quick_write(sc, addr);
345 
346 			return rv;
347 		case 1:
348 			/* SMBus send/receive byte */
349 			if (I2C_OP_READ_P(op))
350 				rv = viapcib_smbus_send_byte(sc, addr,
351 				    *(uint8_t *)vbuf);
352 			else
353 				rv = viapcib_smbus_receive_byte(sc, addr,
354 				    (uint8_t *)vbuf);
355 			return rv;
356 		default:
357 			return -1;
358 		}
359 	case 1:
360 		switch (buflen) {
361 		case 0:
362 			return -1;
363 		case 1:
364 			/* SMBus read/write byte */
365 			if (I2C_OP_READ_P(op))
366 				rv = viapcib_smbus_read_byte(sc, addr,
367 				    cmd, (uint8_t *)vbuf);
368 			else
369 				rv = viapcib_smbus_write_byte(sc, addr,
370 				    cmd, *(uint8_t *)vbuf);
371 			return rv;
372 		case 2:
373 			/* SMBus read/write word */
374 			if (I2C_OP_READ_P(op))
375 				rv = viapcib_smbus_read_word(sc, addr,
376 				    cmd, (uint16_t *)vbuf);
377 			else
378 				rv = viapcib_smbus_write_word(sc, addr,
379 				    cmd, *(uint16_t *)vbuf);
380 			return rv;
381 		default:
382 			/* SMBus read/write block */
383 			if (I2C_OP_READ_P(op))
384 				rv = viapcib_smbus_block_read(sc, addr,
385 				    cmd, buflen, vbuf);
386 			else
387 				rv = viapcib_smbus_block_write(sc, addr,
388 				    cmd, buflen, vbuf);
389 			return rv;
390 		}
391 	}
392 
393 	return -1; /* XXX ??? */
394 }
395 
396 static int
397 viapcib_smbus_quick_write(void *opaque, i2c_addr_t slave)
398 {
399 	struct viapcib_softc *sc;
400 
401 	sc = (struct viapcib_softc *)opaque;
402 
403 	DPRINTF(("viapcib_smbus_quick_write(%p, 0x%x)\n", opaque, slave));
404 
405 	viapcib_clear(sc);
406 	if (viapcib_busy(sc))
407 		return EBUSY;
408 
409 	viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
410 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_QUICK);
411 	if (viapcib_wait(sc))
412 		return EBUSY;
413 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_QUICK | SMBHSTCNT_START);
414 
415 	return viapcib_wait(sc);
416 }
417 
418 static int
419 viapcib_smbus_quick_read(void *opaque, i2c_addr_t slave)
420 {
421 	struct viapcib_softc *sc;
422 
423 	sc = (struct viapcib_softc *)opaque;
424 
425 	DPRINTF(("viapcib_smbus_quick_read(%p, 0x%x)\n", opaque, slave));
426 
427 	viapcib_clear(sc);
428 	if (viapcib_busy(sc))
429 		return EBUSY;
430 
431 	viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
432 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_QUICK);
433 	if (viapcib_wait(sc))
434 		return EBUSY;
435 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_QUICK | SMBHSTCNT_START);
436 
437 	return viapcib_wait(sc);
438 }
439 
440 static int
441 viapcib_smbus_send_byte(void *opaque, i2c_addr_t slave, uint8_t byte)
442 {
443 	struct viapcib_softc *sc;
444 
445 	sc = (struct viapcib_softc *)opaque;
446 
447 	DPRINTF(("viapcib_smbus_send_byte(%p, 0x%x, 0x%x)\n", opaque,
448 	    slave, byte));
449 
450 	viapcib_clear(sc);
451 	if (viapcib_busy(sc))
452 		return EBUSY;
453 
454 	viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
455 	viapcib_smbus_write(sc, SMBHSTCMD, byte);
456 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_SENDRECV);
457 	if (viapcib_wait(sc))
458 		return EBUSY;
459 	viapcib_smbus_write(sc, SMBHSTCNT,
460 	    SMBHSTCNT_START | SMBHSTCNT_SENDRECV);
461 
462 	return viapcib_wait(sc);
463 }
464 
465 static int
466 viapcib_smbus_receive_byte(void *opaque, i2c_addr_t slave, uint8_t *pbyte)
467 {
468 	struct viapcib_softc *sc;
469 	int rv;
470 
471 	sc = (struct viapcib_softc *)opaque;
472 
473 	DPRINTF(("viapcib_smbus_receive_byte(%p, 0x%x, %p)\n", opaque,
474 	    slave, pbyte));
475 
476 	viapcib_clear(sc);
477 	if (viapcib_busy(sc))
478 		return EBUSY;
479 
480 	viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
481 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_SENDRECV);
482 	if (viapcib_wait(sc))
483 		return EBUSY;
484 	viapcib_smbus_write(sc, SMBHSTCNT,
485 	    SMBHSTCNT_START | SMBHSTCNT_SENDRECV);
486 
487 	rv = viapcib_wait(sc);
488 	if (rv == 0)
489 		*pbyte = viapcib_smbus_read(sc, SMBHSTDAT0);
490 
491 	return rv;
492 }
493 
494 static int
495 viapcib_smbus_write_byte(void *opaque, i2c_addr_t slave, uint8_t cmd,
496 		   int8_t byte)
497 {
498 	struct viapcib_softc *sc;
499 
500 	sc = (struct viapcib_softc *)opaque;
501 
502 	DPRINTF(("viapcib_smbus_write_byte(%p, 0x%x, 0x%x, 0x%x)\n", opaque,
503 	    slave, cmd, byte));
504 
505 	viapcib_clear(sc);
506 	if (viapcib_busy(sc))
507 		return EBUSY;
508 
509 	viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
510 	viapcib_smbus_write(sc, SMBHSTCMD, cmd);
511 	viapcib_smbus_write(sc, SMBHSTDAT0, byte);
512 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_BYTE);
513 	if (viapcib_wait(sc))
514 		return EBUSY;
515 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_START | SMBHSTCNT_BYTE);
516 
517 	return viapcib_wait(sc);
518 }
519 
520 static int
521 viapcib_smbus_read_byte(void *opaque, i2c_addr_t slave, uint8_t cmd,
522 		  int8_t *pbyte)
523 {
524 	struct viapcib_softc *sc;
525 	int rv;
526 
527 	sc = (struct viapcib_softc *)opaque;
528 
529 	DPRINTF(("viapcib_smbus_read_byte(%p, 0x%x, 0x%x, %p)\n", opaque,
530 	    slave, cmd, pbyte));
531 
532 	viapcib_clear(sc);
533 	if (viapcib_busy(sc))
534 		return EBUSY;
535 
536 	viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
537 	viapcib_smbus_write(sc, SMBHSTCMD, cmd);
538 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_BYTE);
539 	if (viapcib_wait(sc))
540 		return EBUSY;
541 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_START | SMBHSTCNT_BYTE);
542 	rv = viapcib_wait(sc);
543 	if (rv == 0)
544 		*pbyte = viapcib_smbus_read(sc, SMBHSTDAT0);
545 
546 	return rv;
547 }
548 
549 static int
550 viapcib_smbus_write_word(void *opaque, i2c_addr_t slave, uint8_t cmd,
551 		   int16_t word)
552 {
553 	struct viapcib_softc *sc;
554 
555 	sc = (struct viapcib_softc *)opaque;
556 
557 	DPRINTF(("viapcib_smbus_write_word(%p, 0x%x, 0x%x, 0x%x)\n", opaque,
558 	    slave, cmd, word));
559 
560 	viapcib_clear(sc);
561 	if (viapcib_busy(sc))
562 		return EBUSY;
563 
564 	viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
565 	viapcib_smbus_write(sc, SMBHSTCMD, cmd);
566 	viapcib_smbus_write(sc, SMBHSTDAT0, word & 0x00ff);
567 	viapcib_smbus_write(sc, SMBHSTDAT1, (word & 0xff00) >> 8);
568 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_WORD);
569 	if (viapcib_wait(sc))
570 		return EBUSY;
571 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_START | SMBHSTCNT_WORD);
572 
573 	return viapcib_wait(sc);
574 }
575 
576 static int
577 viapcib_smbus_read_word(void *opaque, i2c_addr_t slave, uint8_t cmd,
578 		  int16_t *pword)
579 {
580 	struct viapcib_softc *sc;
581 	int rv;
582 	int8_t high, low;
583 
584 	sc = (struct viapcib_softc *)opaque;
585 
586 	DPRINTF(("viapcib_smbus_read_word(%p, 0x%x, 0x%x, %p)\n", opaque,
587 	    slave, cmd, pword));
588 
589 	viapcib_clear(sc);
590 	if (viapcib_busy(sc))
591 		return EBUSY;
592 
593 	viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
594 	viapcib_smbus_write(sc, SMBHSTCMD, cmd);
595 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_WORD);
596 	if (viapcib_wait(sc))
597 		return EBUSY;
598 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_START | SMBHSTCNT_WORD);
599 
600 	rv = viapcib_wait(sc);
601 	if (rv == 0) {
602 		low = viapcib_smbus_read(sc, SMBHSTDAT0);
603 		high = viapcib_smbus_read(sc, SMBHSTDAT1);
604 		*pword = ((high & 0xff) << 8) | (low & 0xff);
605 	}
606 
607 	return rv;
608 }
609 
610 static int
611 viapcib_smbus_block_write(void *opaque, i2c_addr_t slave, uint8_t cmd,
612 		    int cnt, void *data)
613 {
614 	struct viapcib_softc *sc;
615 	int8_t *buf;
616 	int remain, len, i;
617 	int rv;
618 
619 	sc = (struct viapcib_softc *)opaque;
620 	buf = (int8_t *)data;
621 	rv = 0;
622 
623 	DPRINTF(("viapcib_smbus_block_write(%p, 0x%x, 0x%x, %d, %p)\n",
624 	    opaque, slave, cmd, cnt, data));
625 
626 	viapcib_clear(sc);
627 	if (viapcib_busy(sc))
628 		return EBUSY;
629 
630 	remain = cnt;
631 	while (remain) {
632 		len = min(remain, SMB_MAXBLOCKSIZE);
633 
634 		viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
635 		viapcib_smbus_write(sc, SMBHSTCMD, cmd);
636 		viapcib_smbus_write(sc, SMBHSTDAT0, len);
637 		i = viapcib_smbus_read(sc, SMBHSTCNT);
638 		/* XXX FreeBSD does this, but it looks wrong */
639 		for (i = 0; i < len; i++) {
640 			viapcib_smbus_write(sc, SMBBLKDAT,
641 			    buf[cnt - remain + i]);
642 		}
643 		viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_BLOCK);
644 		if (viapcib_wait(sc))
645 			return EBUSY;
646 		viapcib_smbus_write(sc, SMBHSTCNT,
647 		    SMBHSTCNT_START | SMBHSTCNT_BLOCK);
648 		if (viapcib_wait(sc))
649 			return EBUSY;
650 
651 		remain -= len;
652 	}
653 
654 	return rv;
655 }
656 
657 static int
658 viapcib_smbus_block_read(void *opaque, i2c_addr_t slave, uint8_t cmd,
659 			 int cnt, void *data)
660 {
661 	struct viapcib_softc *sc;
662 	int8_t *buf;
663 	int remain, len, i;
664 	int rv;
665 
666 	sc = (struct viapcib_softc *)opaque;
667 	buf = (int8_t *)data;
668 	rv = 0;
669 
670 	DPRINTF(("viapcib_smbus_block_read(%p, 0x%x, 0x%x, %d, %p)\n",
671 	    opaque, slave, cmd, cnt, data));
672 
673 	viapcib_clear(sc);
674 	if (viapcib_busy(sc))
675 		return EBUSY;
676 
677 	remain = cnt;
678 	while (remain) {
679 		viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
680 		viapcib_smbus_write(sc, SMBHSTCMD, cmd);
681 		viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_BLOCK);
682 		if (viapcib_wait(sc))
683 			return EBUSY;
684 		viapcib_smbus_write(sc, SMBHSTCNT,
685 		    SMBHSTCNT_START | SMBHSTCNT_BLOCK);
686 		if (viapcib_wait(sc))
687 			return EBUSY;
688 
689 		len = viapcib_smbus_read(sc, SMBHSTDAT0);
690 		i = viapcib_smbus_read(sc, SMBHSTCNT);
691 
692 		len = min(len, remain);
693 
694 		/* FreeBSD does this too... */
695 		for (i = 0; i < len; i++) {
696 			buf[cnt - remain + i] =
697 			    viapcib_smbus_read(sc, SMBBLKDAT);
698 		}
699 
700 		remain -= len;
701 	}
702 
703 	return rv;
704 }
705