xref: /netbsd-src/sys/dev/pci/piixpm.c (revision e39ef1d61eee3ccba837ee281f1e098c864487aa)
1 /* $NetBSD: piixpm.c,v 1.38 2012/01/07 15:59:46 pgoyette Exp $ */
2 /*	$OpenBSD: piixpm.c,v 1.20 2006/02/27 08:25:02 grange Exp $	*/
3 
4 /*
5  * Copyright (c) 2005, 2006 Alexander Yurchenko <grange@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 /*
21  * Intel PIIX and compatible Power Management controller driver.
22  */
23 
24 #include <sys/cdefs.h>
25 __KERNEL_RCSID(0, "$NetBSD: piixpm.c,v 1.38 2012/01/07 15:59:46 pgoyette Exp $");
26 
27 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/device.h>
30 #include <sys/kernel.h>
31 #include <sys/rwlock.h>
32 #include <sys/proc.h>
33 
34 #include <sys/bus.h>
35 
36 #include <dev/pci/pcidevs.h>
37 #include <dev/pci/pcireg.h>
38 #include <dev/pci/pcivar.h>
39 
40 #include <dev/pci/piixpmreg.h>
41 
42 #include <dev/i2c/i2cvar.h>
43 
44 #include <dev/ic/acpipmtimer.h>
45 
46 #ifdef PIIXPM_DEBUG
47 #define DPRINTF(x) printf x
48 #else
49 #define DPRINTF(x)
50 #endif
51 
52 #define PIIXPM_IS_CSB5(id) \
53 	(PCI_VENDOR((id)) == PCI_VENDOR_SERVERWORKS && \
54 	PCI_PRODUCT((id)) == PCI_PRODUCT_SERVERWORKS_CSB5)
55 #define PIIXPM_DELAY	200
56 #define PIIXPM_TIMEOUT	1
57 
58 #define PIIXPM_INDIRECTIO_BASE	0xcd6
59 #define PIIXPM_INDIRECTIO_SIZE	2
60 #define PIIXPM_INDIRECTIO_INDEX	0
61 #define PIIXPM_INDIRECTIO_DATA	1
62 
63 #define SB800_PM_SMBUS0EN_LO	0x2c
64 #define SB800_PM_SMBUS0EN_HI	0x2d
65 
66 #define SB800_PM_SMBUS0EN_ENABLE	0x0001
67 #define SB800_PM_SMBUS0EN_BADDR		0xffe0
68 
69 struct piixpm_softc {
70 	device_t		sc_dev;
71 
72 	bus_space_tag_t		sc_smb_iot;
73 	bus_space_handle_t	sc_smb_ioh;
74 	void *			sc_smb_ih;
75 	int			sc_poll;
76 
77 	bus_space_tag_t		sc_pm_iot;
78 	bus_space_handle_t	sc_pm_ioh;
79 
80 	pci_chipset_tag_t	sc_pc;
81 	pcitag_t		sc_pcitag;
82 	pcireg_t		sc_id;
83 
84 	struct i2c_controller	sc_i2c_tag;
85 	krwlock_t		sc_i2c_rwlock;
86 	struct {
87 		i2c_op_t     op;
88 		void *      buf;
89 		size_t       len;
90 		int          flags;
91 		volatile int error;
92 	}			sc_i2c_xfer;
93 
94 	pcireg_t		sc_devact[2];
95 };
96 
97 static int	piixpm_match(device_t, cfdata_t, void *);
98 static void	piixpm_attach(device_t, device_t, void *);
99 
100 static bool	piixpm_suspend(device_t, const pmf_qual_t *);
101 static bool	piixpm_resume(device_t, const pmf_qual_t *);
102 
103 static int	piixpm_sb800_init(struct piixpm_softc *,
104     struct pci_attach_args *);
105 static void	piixpm_csb5_reset(void *);
106 static int	piixpm_i2c_acquire_bus(void *, int);
107 static void	piixpm_i2c_release_bus(void *, int);
108 static int	piixpm_i2c_exec(void *, i2c_op_t, i2c_addr_t, const void *,
109     size_t, void *, size_t, int);
110 
111 static int	piixpm_intr(void *);
112 
113 CFATTACH_DECL_NEW(piixpm, sizeof(struct piixpm_softc),
114     piixpm_match, piixpm_attach, NULL, NULL);
115 
116 static int
117 piixpm_match(device_t parent, cfdata_t match, void *aux)
118 {
119 	struct pci_attach_args *pa;
120 
121 	pa = (struct pci_attach_args *)aux;
122 	switch (PCI_VENDOR(pa->pa_id)) {
123 	case PCI_VENDOR_INTEL:
124 		switch (PCI_PRODUCT(pa->pa_id)) {
125 		case PCI_PRODUCT_INTEL_82371AB_PMC:
126 		case PCI_PRODUCT_INTEL_82440MX_PMC:
127 			return 1;
128 		}
129 		break;
130 	case PCI_VENDOR_ATI:
131 		switch (PCI_PRODUCT(pa->pa_id)) {
132 		case PCI_PRODUCT_ATI_SB200_SMB:
133 		case PCI_PRODUCT_ATI_SB300_SMB:
134 		case PCI_PRODUCT_ATI_SB400_SMB:
135 		case PCI_PRODUCT_ATI_SB600_SMB:	/* matches SB600/SB700/SB800 */
136 			return 1;
137 		}
138 		break;
139 	case PCI_VENDOR_SERVERWORKS:
140 		switch (PCI_PRODUCT(pa->pa_id)) {
141 		case PCI_PRODUCT_SERVERWORKS_OSB4:
142 		case PCI_PRODUCT_SERVERWORKS_CSB5:
143 		case PCI_PRODUCT_SERVERWORKS_CSB6:
144 		case PCI_PRODUCT_SERVERWORKS_HT1000SB:
145 			return 1;
146 		}
147 	}
148 
149 	return 0;
150 }
151 
152 static void
153 piixpm_attach(device_t parent, device_t self, void *aux)
154 {
155 	struct piixpm_softc *sc = device_private(self);
156 	struct pci_attach_args *pa = aux;
157 	struct i2cbus_attach_args iba;
158 	pcireg_t base, conf;
159 	pcireg_t pmmisc;
160 	pci_intr_handle_t ih;
161 	char devinfo[256];
162 	const char *intrstr = NULL;
163 
164 	sc->sc_dev = self;
165 	sc->sc_id = pa->pa_id;
166 	sc->sc_pc = pa->pa_pc;
167 	sc->sc_pcitag = pa->pa_tag;
168 
169 	aprint_naive("\n");
170 
171 	pci_devinfo(pa->pa_id, pa->pa_class, 0, devinfo, sizeof(devinfo));
172 	aprint_normal(": %s (rev. 0x%02x)\n", devinfo,
173 	    PCI_REVISION(pa->pa_class));
174 
175 	if (!pmf_device_register(self, piixpm_suspend, piixpm_resume))
176 		aprint_error_dev(self, "couldn't establish power handler\n");
177 
178 	/* Read configuration */
179 	conf = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_HOSTC);
180 	DPRINTF(("%s: conf 0x%x\n", device_xname(self), conf));
181 
182 	if ((PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INTEL) ||
183 	    (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_INTEL_82371AB_PMC))
184 		goto nopowermanagement;
185 
186 	/* check whether I/O access to PM regs is enabled */
187 	pmmisc = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PMREGMISC);
188 	if (!(pmmisc & 1))
189 		goto nopowermanagement;
190 
191 	sc->sc_pm_iot = pa->pa_iot;
192 	/* Map I/O space */
193 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PM_BASE);
194 	if (bus_space_map(sc->sc_pm_iot, PCI_MAPREG_IO_ADDR(base),
195 	    PIIX_PM_SIZE, 0, &sc->sc_pm_ioh)) {
196 		aprint_error_dev(self, "can't map power management I/O space\n");
197 		goto nopowermanagement;
198 	}
199 
200 	/*
201 	 * Revision 0 and 1 are PIIX4, 2 is PIIX4E, 3 is PIIX4M.
202 	 * PIIX4 and PIIX4E have a bug in the timer latch, see Errata #20
203 	 * in the "Specification update" (document #297738).
204 	 */
205 	acpipmtimer_attach(self, sc->sc_pm_iot, sc->sc_pm_ioh,
206 			   PIIX_PM_PMTMR,
207 		(PCI_REVISION(pa->pa_class) < 3) ? ACPIPMT_BADLATCH : 0 );
208 
209 nopowermanagement:
210 
211 	/* SB800 rev 0x40+ needs special initialization */
212 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_ATI &&
213 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_ATI_SB600_SMB &&
214 	    PCI_REVISION(pa->pa_class) >= 0x40) {
215 		if (piixpm_sb800_init(sc, pa) == 0)
216 			goto attach_i2c;
217 		aprint_normal_dev(self, "SMBus disabled\n");
218 		return;
219 	}
220 
221 	if ((conf & PIIX_SMB_HOSTC_HSTEN) == 0) {
222 		aprint_normal_dev(self, "SMBus disabled\n");
223 		return;
224 	}
225 
226 	/* Map I/O space */
227 	sc->sc_smb_iot = pa->pa_iot;
228 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_BASE) & 0xffff;
229 	if (bus_space_map(sc->sc_smb_iot, PCI_MAPREG_IO_ADDR(base),
230 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
231 		aprint_error_dev(self, "can't map smbus I/O space\n");
232 		return;
233 	}
234 
235 	sc->sc_poll = 1;
236 	aprint_normal_dev(self, "");
237 	if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_SMI) {
238 		/* No PCI IRQ */
239 		aprint_normal("interrupting at SMI, ");
240 	} else if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_IRQ) {
241 		/* Install interrupt handler */
242 		if (pci_intr_map(pa, &ih) == 0) {
243 			intrstr = pci_intr_string(pa->pa_pc, ih);
244 			sc->sc_smb_ih = pci_intr_establish(pa->pa_pc, ih, IPL_BIO,
245 			    piixpm_intr, sc);
246 			if (sc->sc_smb_ih != NULL) {
247 				aprint_normal("interrupting at %s", intrstr);
248 				sc->sc_poll = 0;
249 			}
250 		}
251 	}
252 	if (sc->sc_poll)
253 		aprint_normal("polling");
254 
255 	aprint_normal("\n");
256 
257 attach_i2c:
258 	/* Attach I2C bus */
259 	rw_init(&sc->sc_i2c_rwlock);
260 	sc->sc_i2c_tag.ic_cookie = sc;
261 	sc->sc_i2c_tag.ic_acquire_bus = piixpm_i2c_acquire_bus;
262 	sc->sc_i2c_tag.ic_release_bus = piixpm_i2c_release_bus;
263 	sc->sc_i2c_tag.ic_exec = piixpm_i2c_exec;
264 
265 	memset(&iba, 0, sizeof(iba));
266 	iba.iba_type = I2C_TYPE_SMBUS;
267 	iba.iba_tag = &sc->sc_i2c_tag;
268 	config_found_ia(self, "i2cbus", &iba, iicbus_print);
269 
270 	return;
271 }
272 
273 static bool
274 piixpm_suspend(device_t dv, const pmf_qual_t *qual)
275 {
276 	struct piixpm_softc *sc = device_private(dv);
277 
278 	sc->sc_devact[0] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
279 	    PIIX_DEVACTA);
280 	sc->sc_devact[1] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
281 	    PIIX_DEVACTB);
282 
283 	return true;
284 }
285 
286 static bool
287 piixpm_resume(device_t dv, const pmf_qual_t *qual)
288 {
289 	struct piixpm_softc *sc = device_private(dv);
290 
291 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTA,
292 	    sc->sc_devact[0]);
293 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTB,
294 	    sc->sc_devact[1]);
295 
296 	return true;
297 }
298 
299 /*
300  * Extract SMBus base address from SB800 Power Management (PM) registers.
301  * The PM registers can be accessed either through indirect I/O (CD6/CD7) or
302  * direct mapping if AcpiMMioDecodeEn is enabled. Since this function is only
303  * called once it uses indirect I/O for simplicity.
304  */
305 static int
306 piixpm_sb800_init(struct piixpm_softc *sc, struct pci_attach_args *pa)
307 {
308 	bus_space_tag_t iot = pa->pa_iot;
309 	bus_space_handle_t ioh;	/* indirect I/O handle */
310 	uint16_t val, base_addr;
311 
312 	/* Fetch SMB base address */
313 	if (bus_space_map(iot,
314 	    PIIXPM_INDIRECTIO_BASE, PIIXPM_INDIRECTIO_SIZE, 0, &ioh)) {
315 		device_printf(sc->sc_dev, "couldn't map indirect I/O space\n");
316 		return EBUSY;
317 	}
318 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
319 	    SB800_PM_SMBUS0EN_LO);
320 	val = bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA);
321 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
322 	    SB800_PM_SMBUS0EN_HI);
323 	val |= bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA) << 8;
324 	bus_space_unmap(iot, ioh, 2);
325 
326 	if ((val & SB800_PM_SMBUS0EN_ENABLE) == 0)
327 		return ENOENT;
328 
329 	base_addr = val & SB800_PM_SMBUS0EN_BADDR;
330 
331 	aprint_debug_dev(sc->sc_dev, "SMBus @ 0x%04x\n", base_addr);
332 
333 	sc->sc_smb_iot = iot;
334 	if (bus_space_map(sc->sc_smb_iot, PCI_MAPREG_IO_ADDR(base_addr),
335 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
336 		aprint_error_dev(sc->sc_dev, "can't map smbus I/O space\n");
337 		return EBUSY;
338 	}
339 	sc->sc_poll = 1;
340 
341 	return 0;
342 }
343 
344 static void
345 piixpm_csb5_reset(void *arg)
346 {
347 	struct piixpm_softc *sc = arg;
348 	pcireg_t base, hostc, pmbase;
349 
350 	base = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE);
351 	hostc = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC);
352 
353 	pmbase = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE);
354 	pmbase |= PIIX_PM_BASE_CSB5_RESET;
355 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
356 	pmbase &= ~PIIX_PM_BASE_CSB5_RESET;
357 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
358 
359 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE, base);
360 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC, hostc);
361 
362 	(void) tsleep(&sc, PRIBIO, "csb5reset", hz/2);
363 }
364 
365 static int
366 piixpm_i2c_acquire_bus(void *cookie, int flags)
367 {
368 	struct piixpm_softc *sc = cookie;
369 
370 	if (cold || sc->sc_poll || (flags & I2C_F_POLL))
371 		return (0);
372 
373 	rw_enter(&sc->sc_i2c_rwlock, RW_WRITER);
374 	return 0;
375 }
376 
377 static void
378 piixpm_i2c_release_bus(void *cookie, int flags)
379 {
380 	struct piixpm_softc *sc = cookie;
381 
382 	if (cold || sc->sc_poll || (flags & I2C_F_POLL))
383 		return;
384 
385 	rw_exit(&sc->sc_i2c_rwlock);
386 }
387 
388 static int
389 piixpm_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr,
390     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
391 {
392 	struct piixpm_softc *sc = cookie;
393 	const u_int8_t *b;
394 	u_int8_t ctl = 0, st;
395 	int retries;
396 
397 	DPRINTF(("%s: exec: op %d, addr 0x%x, cmdlen %zu, len %zu, flags 0x%x\n",
398 	    device_xname(sc->sc_dev), op, addr, cmdlen, len, flags));
399 
400 	/* Wait for bus to be idle */
401 	for (retries = 100; retries > 0; retries--) {
402 		st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
403 		    PIIX_SMB_HS);
404 		if (!(st & PIIX_SMB_HS_BUSY))
405 			break;
406 		DELAY(PIIXPM_DELAY);
407 	}
408 	DPRINTF(("%s: exec: st 0x%d\n", device_xname(sc->sc_dev), st & 0xff));
409 	if (st & PIIX_SMB_HS_BUSY)
410 		return (1);
411 
412 	if (cold || sc->sc_poll)
413 		flags |= I2C_F_POLL;
414 
415 	if (!I2C_OP_STOP_P(op) || cmdlen > 1 || len > 2 ||
416 	    (cmdlen == 0 && len > 1))
417 		return (1);
418 
419 	/* Setup transfer */
420 	sc->sc_i2c_xfer.op = op;
421 	sc->sc_i2c_xfer.buf = buf;
422 	sc->sc_i2c_xfer.len = len;
423 	sc->sc_i2c_xfer.flags = flags;
424 	sc->sc_i2c_xfer.error = 0;
425 
426 	/* Set slave address and transfer direction */
427 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_TXSLVA,
428 	    PIIX_SMB_TXSLVA_ADDR(addr) |
429 	    (I2C_OP_READ_P(op) ? PIIX_SMB_TXSLVA_READ : 0));
430 
431 	b = cmdbuf;
432 	if (cmdlen > 0)
433 		/* Set command byte */
434 		bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
435 		    PIIX_SMB_HCMD, b[0]);
436 
437 	if (I2C_OP_WRITE_P(op)) {
438 		/* Write data */
439 		b = buf;
440 		if (cmdlen == 0 && len == 1)
441 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
442 			    PIIX_SMB_HCMD, b[0]);
443 		else if (len > 0)
444 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
445 			    PIIX_SMB_HD0, b[0]);
446 		if (len > 1)
447 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
448 			    PIIX_SMB_HD1, b[1]);
449 	}
450 
451 	/* Set SMBus command */
452 	if (cmdlen == 0) {
453 		if (len == 0)
454 			ctl = PIIX_SMB_HC_CMD_QUICK;
455 		else
456 			ctl = PIIX_SMB_HC_CMD_BYTE;
457 	} else if (len == 1)
458 		ctl = PIIX_SMB_HC_CMD_BDATA;
459 	else if (len == 2)
460 		ctl = PIIX_SMB_HC_CMD_WDATA;
461 
462 	if ((flags & I2C_F_POLL) == 0)
463 		ctl |= PIIX_SMB_HC_INTREN;
464 
465 	/* Start transaction */
466 	ctl |= PIIX_SMB_HC_START;
467 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC, ctl);
468 
469 	if (flags & I2C_F_POLL) {
470 		/* Poll for completion */
471 		if (PIIXPM_IS_CSB5(sc->sc_id))
472 			DELAY(2*PIIXPM_DELAY);
473 		else
474 			DELAY(PIIXPM_DELAY);
475 		for (retries = 1000; retries > 0; retries--) {
476 			st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
477 			    PIIX_SMB_HS);
478 			if ((st & PIIX_SMB_HS_BUSY) == 0)
479 				break;
480 			DELAY(PIIXPM_DELAY);
481 		}
482 		if (st & PIIX_SMB_HS_BUSY)
483 			goto timeout;
484 		piixpm_intr(sc);
485 	} else {
486 		/* Wait for interrupt */
487 		if (tsleep(sc, PRIBIO, "iicexec", PIIXPM_TIMEOUT * hz))
488 			goto timeout;
489 	}
490 
491 	if (sc->sc_i2c_xfer.error)
492 		return (1);
493 
494 	return (0);
495 
496 timeout:
497 	/*
498 	 * Transfer timeout. Kill the transaction and clear status bits.
499 	 */
500 	aprint_error_dev(sc->sc_dev, "timeout, status 0x%x\n", st);
501 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC,
502 	    PIIX_SMB_HC_KILL);
503 	DELAY(PIIXPM_DELAY);
504 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
505 	if ((st & PIIX_SMB_HS_FAILED) == 0)
506 		aprint_error_dev(sc->sc_dev, "transaction abort failed, status 0x%x\n", st);
507 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
508 	/*
509 	 * CSB5 needs hard reset to unlock the smbus after timeout.
510 	 */
511 	if (PIIXPM_IS_CSB5(sc->sc_id))
512 		piixpm_csb5_reset(sc);
513 	return (1);
514 }
515 
516 static int
517 piixpm_intr(void *arg)
518 {
519 	struct piixpm_softc *sc = arg;
520 	u_int8_t st;
521 	u_int8_t *b;
522 	size_t len;
523 
524 	/* Read status */
525 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
526 	if ((st & PIIX_SMB_HS_BUSY) != 0 || (st & (PIIX_SMB_HS_INTR |
527 	    PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
528 	    PIIX_SMB_HS_FAILED)) == 0)
529 		/* Interrupt was not for us */
530 		return (0);
531 
532 	DPRINTF(("%s: intr st 0x%d\n", device_xname(sc->sc_dev), st & 0xff));
533 
534 	/* Clear status bits */
535 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
536 
537 	/* Check for errors */
538 	if (st & (PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
539 	    PIIX_SMB_HS_FAILED)) {
540 		sc->sc_i2c_xfer.error = 1;
541 		goto done;
542 	}
543 
544 	if (st & PIIX_SMB_HS_INTR) {
545 		if (I2C_OP_WRITE_P(sc->sc_i2c_xfer.op))
546 			goto done;
547 
548 		/* Read data */
549 		b = sc->sc_i2c_xfer.buf;
550 		len = sc->sc_i2c_xfer.len;
551 		if (len > 0)
552 			b[0] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
553 			    PIIX_SMB_HD0);
554 		if (len > 1)
555 			b[1] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
556 			    PIIX_SMB_HD1);
557 	}
558 
559 done:
560 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0)
561 		wakeup(sc);
562 	return (1);
563 }
564