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viapcib.c revision 1.1
      1 /* $NetBSD: viapcib.c,v 1.1 2006/03/17 12:19:49 jmcneill 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 (at) 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 1.1 2006/03/17 12:19:49 jmcneill 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, void *opaque)
    142 {
    143 	struct pci_attach_args *pa;
    144 
    145 	pa = (struct pci_attach_args *)opaque;
    146 
    147 	if (PCI_VENDOR(pa->pa_id) != PCI_VENDOR_VIATECH)
    148 		return 0;
    149 
    150 	switch (PCI_PRODUCT(pa->pa_id)) {
    151 	case PCI_PRODUCT_VIATECH_VT8235:
    152 		return 2; /* match above generic pcib(4) */
    153 	}
    154 
    155 	return 0;
    156 }
    157 
    158 static void
    159 viapcib_attach(struct device *parent, struct device *self, void *opaque)
    160 {
    161 	struct viapcib_softc *sc;
    162 	struct pci_attach_args *pa;
    163 	pcireg_t addr, val;
    164 
    165 	sc = (struct viapcib_softc *)self;
    166 	pa = (struct pci_attach_args *)opaque;
    167 
    168 	/* XXX Only the 8235 is supported for now */
    169 	sc->sc_iot = pa->pa_iot;
    170 	addr = pci_conf_read(pa->pa_pc, pa->pa_tag, SMB_BASE3);
    171 	addr &= 0xfff0;
    172 	if (bus_space_map(sc->sc_iot, addr, 8, 0, &sc->sc_ioh)) {
    173 		printf(": failed to map SMBus I/O space\n");
    174 		addr = 0;
    175 		goto core_pcib;
    176 	}
    177 
    178 	simple_lock_init(&sc->sc_lock);
    179 
    180 	val = pci_conf_read(pa->pa_pc, pa->pa_tag, SMB_HOST_CONFIG);
    181 	if ((val & 1) == 0) {
    182 		printf(": SMBus is disabled\n");
    183 		addr = 0;
    184 		/* XXX We can enable the SMBus here by writing 1 to
    185 		 * SMB_HOST_CONFIG, but do we want to?
    186 		 */
    187 		goto core_pcib;
    188 	}
    189 
    190 #ifdef VIAPCIB_DEBUG
    191 	switch (val & 0x0e) {
    192 	case 8:
    193 		printf(": interrupting at irq 9\n");
    194 		break;
    195 	case 0:
    196 		printf(": interrupting at SMI#\n");
    197 		break;
    198 	default:
    199 		printf(": interrupt misconfigured\n");
    200 		break;
    201 	}
    202 #endif /* !VIAPCIB_DEBUG */
    203 
    204 	val = pci_conf_read(pa->pa_pc, pa->pa_tag, SMB_REVISION);
    205 	sc->sc_revision = val;
    206 
    207 core_pcib:
    208 	pcibattach(parent, self, opaque);
    209 
    210 	if (addr != 0) {
    211 		struct i2cbus_attach_args iba;
    212 		uint8_t b;
    213 
    214 		printf("%s: SMBus found at 0x%x (revision 0x%x)\n",
    215 		    sc->sc_dev.dv_xname, addr, sc->sc_revision);
    216 
    217 		/* Disable slave function */
    218 		b = viapcib_smbus_read(sc, SMBSLVCNT);
    219 		viapcib_smbus_write(sc, SMBSLVCNT, b & ~1);
    220 
    221 		memset(&sc->sc_i2c, 0, sizeof(sc->sc_i2c));
    222 		iba.iba_name = "iic";
    223 #ifdef I2C_TYPE_SMBUS
    224 		iba.iba_type = I2C_TYPE_SMBUS;
    225 #endif
    226 		iba.iba_tag = &sc->sc_i2c;
    227 		iba.iba_tag->ic_cookie = (void *)sc;
    228 		iba.iba_tag->ic_acquire_bus = viapcib_acquire_bus;
    229 		iba.iba_tag->ic_release_bus = viapcib_release_bus;
    230 		iba.iba_tag->ic_exec = viapcib_exec;
    231 
    232 		config_found(&sc->sc_dev, &iba, iicbus_print);
    233 	}
    234 
    235 	return;
    236 }
    237 
    238 static int
    239 viapcib_wait(struct viapcib_softc *sc)
    240 {
    241 	int rv, timeout;
    242 	uint8_t val;
    243 
    244 	timeout = VIAPCIB_SMBUS_TIMEOUT;
    245 	rv = 0;
    246 
    247 	while (timeout--) {
    248 		val = viapcib_smbus_read(sc, SMBHSTSTS);
    249 		if (!(val & SMBHSTSTS_BUSY) && (val & SMBHSTSTS_INTR))
    250 			break;
    251 		DELAY(10);
    252 	}
    253 
    254 	if (timeout == 0)
    255 		rv = EBUSY;
    256 
    257 	if ((val & SMBHSTSTS_FAILED) || (val & SMBHSTSTS_COLLISION) ||
    258 	    (val & SMBHSTSTS_ERROR))
    259 		rv = EIO;
    260 
    261 	viapcib_clear(sc);
    262 
    263 	return rv;
    264 }
    265 
    266 static int
    267 viapcib_clear(struct viapcib_softc *sc)
    268 {
    269 	viapcib_smbus_write(sc, SMBHSTSTS,
    270 	    (SMBHSTSTS_FAILED | SMBHSTSTS_COLLISION | SMBHSTSTS_ERROR |
    271 	     SMBHSTSTS_INTR));
    272 	DELAY(10);
    273 
    274 	return 0;
    275 }
    276 
    277 static int
    278 viapcib_busy(struct viapcib_softc *sc)
    279 {
    280 	uint8_t val;
    281 
    282 	val = viapcib_smbus_read(sc, SMBHSTSTS);
    283 
    284 	return (val & SMBHSTSTS_BUSY);
    285 }
    286 
    287 static int
    288 viapcib_acquire_bus(void *opaque, int flags)
    289 {
    290 	struct viapcib_softc *sc;
    291 
    292 	DPRINTF(("viapcib_i2c_acquire_bus(%p, 0x%x)\n", opaque, flags));
    293 
    294 	sc = (struct viapcib_softc *)opaque;
    295 
    296 	simple_lock(&sc->sc_lock);
    297 
    298 	return 0;
    299 }
    300 
    301 static void
    302 viapcib_release_bus(void *opaque, int flags)
    303 {
    304 	struct viapcib_softc *sc;
    305 
    306 	DPRINTF(("viapcib_i2c_release_bus(%p, 0x%x)\n", opaque, flags));
    307 
    308 	sc = (struct viapcib_softc *)opaque;
    309 
    310 	simple_unlock(&sc->sc_lock);
    311 
    312 	return;
    313 }
    314 
    315 static int
    316 viapcib_exec(void *opaque, i2c_op_t op, i2c_addr_t addr, const void *vcmd,
    317     size_t cmdlen, void *vbuf, size_t buflen, int flags)
    318 {
    319 	struct viapcib_softc *sc;
    320 	uint8_t cmd;
    321 	int rv = -1;
    322 
    323 	DPRINTF(("viapcib_exec(%p, 0x%x, 0x%x, %p, %d, %p, %d, 0x%x)\n",
    324 	    opaque, op, addr, vcmd, cmdlen, vbuf, buflen, flags));
    325 
    326 	sc = (struct viapcib_softc *)opaque;
    327 
    328 	if (op != I2C_OP_READ_WITH_STOP &&
    329 	    op != I2C_OP_WRITE_WITH_STOP)
    330 		return -1;
    331 
    332 	if (cmdlen > 0)
    333 		cmd = *(uint8_t *)(__UNCONST(vcmd)); /* XXX */
    334 
    335 	switch (cmdlen) {
    336 	case 0:
    337 		switch (buflen) {
    338 		case 0:
    339 			/* SMBus quick read/write */
    340 			if (I2C_OP_READ_P(op))
    341 				rv = viapcib_smbus_quick_read(sc, addr);
    342 			else
    343 				rv = viapcib_smbus_quick_write(sc, addr);
    344 
    345 			return rv;
    346 		case 1:
    347 			/* SMBus send/receive byte */
    348 			if (I2C_OP_READ_P(op))
    349 				rv = viapcib_smbus_send_byte(sc, addr,
    350 				    *(uint8_t *)vbuf);
    351 			else
    352 				rv = viapcib_smbus_receive_byte(sc, addr,
    353 				    (uint8_t *)vbuf);
    354 			return rv;
    355 		default:
    356 			return -1;
    357 		}
    358 	case 1:
    359 		switch (buflen) {
    360 		case 0:
    361 			return -1;
    362 		case 1:
    363 			/* SMBus read/write byte */
    364 			if (I2C_OP_READ_P(op))
    365 				rv = viapcib_smbus_read_byte(sc, addr,
    366 				    cmd, (uint8_t *)vbuf);
    367 			else
    368 				rv = viapcib_smbus_write_byte(sc, addr,
    369 				    cmd, *(uint8_t *)vbuf);
    370 			return rv;
    371 		case 2:
    372 			/* SMBus read/write word */
    373 			if (I2C_OP_READ_P(op))
    374 				rv = viapcib_smbus_read_word(sc, addr,
    375 				    cmd, (uint16_t *)vbuf);
    376 			else
    377 				rv = viapcib_smbus_write_word(sc, addr,
    378 				    cmd, *(uint16_t *)vbuf);
    379 			return rv;
    380 		default:
    381 			/* SMBus read/write block */
    382 			if (I2C_OP_READ_P(op))
    383 				rv = viapcib_smbus_block_read(sc, addr,
    384 				    cmd, buflen, vbuf);
    385 			else
    386 				rv = viapcib_smbus_block_write(sc, addr,
    387 				    cmd, buflen, vbuf);
    388 			return rv;
    389 		}
    390 	}
    391 
    392 	return -1; /* XXX ??? */
    393 }
    394 
    395 static int
    396 viapcib_smbus_quick_write(void *opaque, i2c_addr_t slave)
    397 {
    398 	struct viapcib_softc *sc;
    399 
    400 	sc = (struct viapcib_softc *)opaque;
    401 
    402 	DPRINTF(("viapcib_smbus_quick_write(%p, 0x%x)\n", opaque, slave));
    403 
    404 	viapcib_clear(sc);
    405 	if (viapcib_busy(sc))
    406 		return EBUSY;
    407 
    408 	viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
    409 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_QUICK);
    410 	if (viapcib_wait(sc))
    411 		return EBUSY;
    412 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_QUICK | SMBHSTCNT_START);
    413 
    414 	return viapcib_wait(sc);
    415 }
    416 
    417 static int
    418 viapcib_smbus_quick_read(void *opaque, i2c_addr_t slave)
    419 {
    420 	struct viapcib_softc *sc;
    421 
    422 	sc = (struct viapcib_softc *)opaque;
    423 
    424 	DPRINTF(("viapcib_smbus_quick_read(%p, 0x%x)\n", opaque, slave));
    425 
    426 	viapcib_clear(sc);
    427 	if (viapcib_busy(sc))
    428 		return EBUSY;
    429 
    430 	viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
    431 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_QUICK);
    432 	if (viapcib_wait(sc))
    433 		return EBUSY;
    434 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_QUICK | SMBHSTCNT_START);
    435 
    436 	return viapcib_wait(sc);
    437 }
    438 
    439 static int
    440 viapcib_smbus_send_byte(void *opaque, i2c_addr_t slave, uint8_t byte)
    441 {
    442 	struct viapcib_softc *sc;
    443 
    444 	sc = (struct viapcib_softc *)opaque;
    445 
    446 	DPRINTF(("viapcib_smbus_send_byte(%p, 0x%x, 0x%x)\n", opaque,
    447 	    slave, byte));
    448 
    449 	viapcib_clear(sc);
    450 	if (viapcib_busy(sc))
    451 		return EBUSY;
    452 
    453 	viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
    454 	viapcib_smbus_write(sc, SMBHSTCMD, byte);
    455 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_SENDRECV);
    456 	if (viapcib_wait(sc))
    457 		return EBUSY;
    458 	viapcib_smbus_write(sc, SMBHSTCNT,
    459 	    SMBHSTCNT_START | SMBHSTCNT_SENDRECV);
    460 
    461 	return viapcib_wait(sc);
    462 }
    463 
    464 static int
    465 viapcib_smbus_receive_byte(void *opaque, i2c_addr_t slave, uint8_t *pbyte)
    466 {
    467 	struct viapcib_softc *sc;
    468 	int rv;
    469 
    470 	sc = (struct viapcib_softc *)opaque;
    471 
    472 	DPRINTF(("viapcib_smbus_receive_byte(%p, 0x%x, %p)\n", opaque,
    473 	    slave, pbyte));
    474 
    475 	viapcib_clear(sc);
    476 	if (viapcib_busy(sc))
    477 		return EBUSY;
    478 
    479 	viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
    480 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_SENDRECV);
    481 	if (viapcib_wait(sc))
    482 		return EBUSY;
    483 	viapcib_smbus_write(sc, SMBHSTCNT,
    484 	    SMBHSTCNT_START | SMBHSTCNT_SENDRECV);
    485 
    486 	rv = viapcib_wait(sc);
    487 	if (rv == 0)
    488 		*pbyte = viapcib_smbus_read(sc, SMBHSTDAT0);
    489 
    490 	return rv;
    491 }
    492 
    493 static int
    494 viapcib_smbus_write_byte(void *opaque, i2c_addr_t slave, uint8_t cmd,
    495 		   int8_t byte)
    496 {
    497 	struct viapcib_softc *sc;
    498 
    499 	sc = (struct viapcib_softc *)opaque;
    500 
    501 	DPRINTF(("viapcib_smbus_write_byte(%p, 0x%x, 0x%x, 0x%x)\n", opaque,
    502 	    slave, cmd, byte));
    503 
    504 	viapcib_clear(sc);
    505 	if (viapcib_busy(sc))
    506 		return EBUSY;
    507 
    508 	viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
    509 	viapcib_smbus_write(sc, SMBHSTCMD, cmd);
    510 	viapcib_smbus_write(sc, SMBHSTDAT0, byte);
    511 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_BYTE);
    512 	if (viapcib_wait(sc))
    513 		return EBUSY;
    514 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_START | SMBHSTCNT_BYTE);
    515 
    516 	return viapcib_wait(sc);
    517 }
    518 
    519 static int
    520 viapcib_smbus_read_byte(void *opaque, i2c_addr_t slave, uint8_t cmd,
    521 		  int8_t *pbyte)
    522 {
    523 	struct viapcib_softc *sc;
    524 	int rv;
    525 
    526 	sc = (struct viapcib_softc *)opaque;
    527 
    528 	DPRINTF(("viapcib_smbus_read_byte(%p, 0x%x, 0x%x, %p)\n", opaque,
    529 	    slave, cmd, pbyte));
    530 
    531 	viapcib_clear(sc);
    532 	if (viapcib_busy(sc))
    533 		return EBUSY;
    534 
    535 	viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
    536 	viapcib_smbus_write(sc, SMBHSTCMD, cmd);
    537 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_BYTE);
    538 	if (viapcib_wait(sc))
    539 		return EBUSY;
    540 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_START | SMBHSTCNT_BYTE);
    541 	rv = viapcib_wait(sc);
    542 	if (rv == 0)
    543 		*pbyte = viapcib_smbus_read(sc, SMBHSTDAT0);
    544 
    545 	return rv;
    546 }
    547 
    548 static int
    549 viapcib_smbus_write_word(void *opaque, i2c_addr_t slave, uint8_t cmd,
    550 		   int16_t word)
    551 {
    552 	struct viapcib_softc *sc;
    553 
    554 	sc = (struct viapcib_softc *)opaque;
    555 
    556 	DPRINTF(("viapcib_smbus_write_word(%p, 0x%x, 0x%x, 0x%x)\n", opaque,
    557 	    slave, cmd, word));
    558 
    559 	viapcib_clear(sc);
    560 	if (viapcib_busy(sc))
    561 		return EBUSY;
    562 
    563 	viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
    564 	viapcib_smbus_write(sc, SMBHSTCMD, cmd);
    565 	viapcib_smbus_write(sc, SMBHSTDAT0, word & 0x00ff);
    566 	viapcib_smbus_write(sc, SMBHSTDAT1, (word & 0xff00) >> 8);
    567 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_WORD);
    568 	if (viapcib_wait(sc))
    569 		return EBUSY;
    570 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_START | SMBHSTCNT_WORD);
    571 
    572 	return viapcib_wait(sc);
    573 }
    574 
    575 static int
    576 viapcib_smbus_read_word(void *opaque, i2c_addr_t slave, uint8_t cmd,
    577 		  int16_t *pword)
    578 {
    579 	struct viapcib_softc *sc;
    580 	int rv;
    581 	int8_t high, low;
    582 
    583 	sc = (struct viapcib_softc *)opaque;
    584 
    585 	DPRINTF(("viapcib_smbus_read_word(%p, 0x%x, 0x%x, %p)\n", opaque,
    586 	    slave, cmd, pword));
    587 
    588 	viapcib_clear(sc);
    589 	if (viapcib_busy(sc))
    590 		return EBUSY;
    591 
    592 	viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
    593 	viapcib_smbus_write(sc, SMBHSTCMD, cmd);
    594 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_WORD);
    595 	if (viapcib_wait(sc))
    596 		return EBUSY;
    597 	viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_START | SMBHSTCNT_WORD);
    598 
    599 	rv = viapcib_wait(sc);
    600 	if (rv == 0) {
    601 		low = viapcib_smbus_read(sc, SMBHSTDAT0);
    602 		high = viapcib_smbus_read(sc, SMBHSTDAT1);
    603 		*pword = ((high & 0xff) << 8) | (low & 0xff);
    604 	}
    605 
    606 	return rv;
    607 }
    608 
    609 static int
    610 viapcib_smbus_block_write(void *opaque, i2c_addr_t slave, uint8_t cmd,
    611 		    int cnt, void *data)
    612 {
    613 	struct viapcib_softc *sc;
    614 	int8_t *buf;
    615 	int remain, len, i;
    616 	int rv;
    617 
    618 	sc = (struct viapcib_softc *)opaque;
    619 	buf = (int8_t *)data;
    620 	rv = 0;
    621 
    622 	DPRINTF(("viapcib_smbus_block_write(%p, 0x%x, 0x%x, %d, %p)\n",
    623 	    opaque, slave, cmd, cnt, data));
    624 
    625 	viapcib_clear(sc);
    626 	if (viapcib_busy(sc))
    627 		return EBUSY;
    628 
    629 	remain = cnt;
    630 	while (remain) {
    631 		len = min(remain, SMB_MAXBLOCKSIZE);
    632 
    633 		viapcib_smbus_write(sc, SMBHSTADD, (slave & 0x7f) << 1);
    634 		viapcib_smbus_write(sc, SMBHSTCMD, cmd);
    635 		viapcib_smbus_write(sc, SMBHSTDAT0, len);
    636 		i = viapcib_smbus_read(sc, SMBHSTCNT);
    637 		/* XXX FreeBSD does this, but it looks wrong */
    638 		for (i = 0; i < len; i++) {
    639 			viapcib_smbus_write(sc, SMBBLKDAT,
    640 			    buf[cnt - remain + i]);
    641 		}
    642 		viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_BLOCK);
    643 		if (viapcib_wait(sc))
    644 			return EBUSY;
    645 		viapcib_smbus_write(sc, SMBHSTCNT,
    646 		    SMBHSTCNT_START | SMBHSTCNT_BLOCK);
    647 		if (viapcib_wait(sc))
    648 			return EBUSY;
    649 
    650 		remain -= len;
    651 	}
    652 
    653 	return rv;
    654 }
    655 
    656 static int
    657 viapcib_smbus_block_read(void *opaque, i2c_addr_t slave, uint8_t cmd,
    658 			 int cnt, void *data)
    659 {
    660 	struct viapcib_softc *sc;
    661 	int8_t *buf;
    662 	int remain, len, i;
    663 	int rv;
    664 
    665 	sc = (struct viapcib_softc *)opaque;
    666 	buf = (int8_t *)data;
    667 	rv = 0;
    668 
    669 	DPRINTF(("viapcib_smbus_block_read(%p, 0x%x, 0x%x, %d, %p)\n",
    670 	    opaque, slave, cmd, cnt, data));
    671 
    672 	viapcib_clear(sc);
    673 	if (viapcib_busy(sc))
    674 		return EBUSY;
    675 
    676 	remain = cnt;
    677 	while (remain) {
    678 		viapcib_smbus_write(sc, SMBHSTADD, ((slave & 0x7f) << 1) | 1);
    679 		viapcib_smbus_write(sc, SMBHSTCMD, cmd);
    680 		viapcib_smbus_write(sc, SMBHSTCNT, SMBHSTCNT_BLOCK);
    681 		if (viapcib_wait(sc))
    682 			return EBUSY;
    683 		viapcib_smbus_write(sc, SMBHSTCNT,
    684 		    SMBHSTCNT_START | SMBHSTCNT_BLOCK);
    685 		if (viapcib_wait(sc))
    686 			return EBUSY;
    687 
    688 		len = viapcib_smbus_read(sc, SMBHSTDAT0);
    689 		i = viapcib_smbus_read(sc, SMBHSTCNT);
    690 
    691 		len = min(len, remain);
    692 
    693 		/* FreeBSD does this too... */
    694 		for (i = 0; i < len; i++) {
    695 			buf[cnt - remain + i] =
    696 			    viapcib_smbus_read(sc, SMBBLKDAT);
    697 		}
    698 
    699 		remain -= len;
    700 	}
    701 
    702 	return rv;
    703 }
    704