xref: /netbsd-src/sys/dev/pci/piixpm.c (revision fdd524d4ccd2bb0c6f67401e938dabf773eb0372)
1 /* $NetBSD: piixpm.c,v 1.49 2016/07/11 11:31:51 msaitoh 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 1.49 2016/07/11 11:31:51 msaitoh 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/mutex.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 struct piixpm_smbus {
59 	int			sda;
60 	struct			piixpm_softc *softc;
61 };
62 
63 struct piixpm_softc {
64 	device_t		sc_dev;
65 
66 	bus_space_tag_t		sc_iot;
67 #define	sc_pm_iot sc_iot
68 #define sc_smb_iot sc_iot
69 	bus_space_handle_t	sc_pm_ioh;
70 	bus_space_handle_t	sc_sb800_ioh;
71 	bus_space_handle_t	sc_smb_ioh;
72 	void *			sc_smb_ih;
73 	int			sc_poll;
74 
75 	pci_chipset_tag_t	sc_pc;
76 	pcitag_t		sc_pcitag;
77 	pcireg_t		sc_id;
78 
79 	int			sc_numbusses;
80 	device_t		sc_i2c_device[4];
81 	struct piixpm_smbus	sc_busses[4];
82 	struct i2c_controller	sc_i2c_tags[4];
83 
84 	kmutex_t		sc_i2c_mutex;
85 	struct {
86 		i2c_op_t	op;
87 		void *		buf;
88 		size_t		len;
89 		int		flags;
90 		volatile int	error;
91 	}			sc_i2c_xfer;
92 
93 	pcireg_t		sc_devact[2];
94 };
95 
96 static int	piixpm_match(device_t, cfdata_t, void *);
97 static void	piixpm_attach(device_t, device_t, void *);
98 static int	piixpm_rescan(device_t, const char *, const int *);
99 static void	piixpm_chdet(device_t, device_t);
100 
101 static bool	piixpm_suspend(device_t, const pmf_qual_t *);
102 static bool	piixpm_resume(device_t, const pmf_qual_t *);
103 
104 static int	piixpm_sb800_init(struct piixpm_softc *);
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_DECL3_NEW(piixpm, sizeof(struct piixpm_softc),
114     piixpm_match, piixpm_attach, NULL, NULL, piixpm_rescan, piixpm_chdet, 0);
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 	case PCI_VENDOR_AMD:
148 		switch (PCI_PRODUCT(pa->pa_id)) {
149 		case PCI_PRODUCT_AMD_HUDSON_SMB:
150 			return 1;
151 		}
152 	}
153 
154 	return 0;
155 }
156 
157 static void
158 piixpm_attach(device_t parent, device_t self, void *aux)
159 {
160 	struct piixpm_softc *sc = device_private(self);
161 	struct pci_attach_args *pa = aux;
162 	pcireg_t base, conf;
163 	pcireg_t pmmisc;
164 	pci_intr_handle_t ih;
165 	const char *intrstr = NULL;
166 	int i, flags;
167 	char intrbuf[PCI_INTRSTR_LEN];
168 
169 	sc->sc_dev = self;
170 	sc->sc_iot = pa->pa_iot;
171 	sc->sc_id = pa->pa_id;
172 	sc->sc_pc = pa->pa_pc;
173 	sc->sc_pcitag = pa->pa_tag;
174 	sc->sc_numbusses = 1;
175 
176 	pci_aprint_devinfo(pa, NULL);
177 
178 	if (!pmf_device_register(self, piixpm_suspend, piixpm_resume))
179 		aprint_error_dev(self, "couldn't establish power handler\n");
180 
181 	/* Read configuration */
182 	conf = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_HOSTC);
183 	DPRINTF(("%s: conf 0x%x\n", device_xname(self), conf));
184 
185 	if ((PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INTEL) ||
186 	    (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_INTEL_82371AB_PMC))
187 		goto nopowermanagement;
188 
189 	/* check whether I/O access to PM regs is enabled */
190 	pmmisc = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PMREGMISC);
191 	if (!(pmmisc & 1))
192 		goto nopowermanagement;
193 
194 	/* Map I/O space */
195 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PM_BASE);
196 	if (bus_space_map(sc->sc_pm_iot, PCI_MAPREG_IO_ADDR(base),
197 	    PIIX_PM_SIZE, 0, &sc->sc_pm_ioh)) {
198 		aprint_error_dev(self,
199 		    "can't map power management I/O space\n");
200 		goto nopowermanagement;
201 	}
202 
203 	/*
204 	 * Revision 0 and 1 are PIIX4, 2 is PIIX4E, 3 is PIIX4M.
205 	 * PIIX4 and PIIX4E have a bug in the timer latch, see Errata #20
206 	 * in the "Specification update" (document #297738).
207 	 */
208 	acpipmtimer_attach(self, sc->sc_pm_iot, sc->sc_pm_ioh,
209 			   PIIX_PM_PMTMR,
210 		(PCI_REVISION(pa->pa_class) < 3) ? ACPIPMT_BADLATCH : 0 );
211 
212 nopowermanagement:
213 
214 	/* SB800 rev 0x40+ and AMD HUDSON need special initialization */
215 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_AMD &&
216 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_HUDSON_SMB) {
217 		if (piixpm_sb800_init(sc) == 0) {
218 			goto attach_i2c;
219 		}
220 		aprint_normal_dev(self, "SMBus initialization failed\n");
221 		return;
222 	}
223 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_ATI &&
224 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_ATI_SB600_SMB &&
225 	    PCI_REVISION(pa->pa_class) >= 0x40) {
226 		if (piixpm_sb800_init(sc) == 0) {
227 			sc->sc_numbusses = 4;
228 			goto attach_i2c;
229 		}
230 		aprint_normal_dev(self, "SMBus initialization failed\n");
231 		return;
232 	}
233 
234 	if ((conf & PIIX_SMB_HOSTC_HSTEN) == 0) {
235 		aprint_normal_dev(self, "SMBus disabled\n");
236 		return;
237 	}
238 
239 	/* Map I/O space */
240 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_BASE) & 0xffff;
241 	if (bus_space_map(sc->sc_smb_iot, PCI_MAPREG_IO_ADDR(base),
242 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
243 		aprint_error_dev(self, "can't map smbus I/O space\n");
244 		return;
245 	}
246 
247 	sc->sc_poll = 1;
248 	aprint_normal_dev(self, "");
249 	if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_SMI) {
250 		/* No PCI IRQ */
251 		aprint_normal("interrupting at SMI, ");
252 	} else if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_IRQ) {
253 		/* Install interrupt handler */
254 		if (pci_intr_map(pa, &ih) == 0) {
255 			intrstr = pci_intr_string(pa->pa_pc, ih, intrbuf,
256 			    sizeof(intrbuf));
257 			sc->sc_smb_ih = pci_intr_establish(pa->pa_pc, ih,
258 			    IPL_BIO, piixpm_intr, sc);
259 			if (sc->sc_smb_ih != NULL) {
260 				aprint_normal("interrupting at %s", intrstr);
261 				sc->sc_poll = 0;
262 			}
263 		}
264 	}
265 	if (sc->sc_poll)
266 		aprint_normal("polling");
267 
268 	aprint_normal("\n");
269 
270 attach_i2c:
271 	for (i = 0; i < sc->sc_numbusses; i++)
272 		sc->sc_i2c_device[i] = NULL;
273 
274 	flags = 0;
275 	mutex_init(&sc->sc_i2c_mutex, MUTEX_DEFAULT, IPL_NONE);
276 	piixpm_rescan(self, "i2cbus", &flags);
277 }
278 
279 static int
280 piixpm_rescan(device_t self, const char *ifattr, const int *flags)
281 {
282 	struct piixpm_softc *sc = device_private(self);
283 	struct i2cbus_attach_args iba;
284 	int i;
285 
286 	if (!ifattr_match(ifattr, "i2cbus"))
287 		return 0;
288 
289 	/* Attach I2C bus */
290 
291 	for (i = 0; i < sc->sc_numbusses; i++) {
292 		if (sc->sc_i2c_device[i])
293 			continue;
294 		sc->sc_busses[i].sda = i;
295 		sc->sc_busses[i].softc = sc;
296 		sc->sc_i2c_tags[i].ic_cookie = &sc->sc_busses[i];
297 		sc->sc_i2c_tags[i].ic_acquire_bus = piixpm_i2c_acquire_bus;
298 		sc->sc_i2c_tags[i].ic_release_bus = piixpm_i2c_release_bus;
299 		sc->sc_i2c_tags[i].ic_exec = piixpm_i2c_exec;
300 		memset(&iba, 0, sizeof(iba));
301 		iba.iba_type = I2C_TYPE_SMBUS;
302 		iba.iba_tag = &sc->sc_i2c_tags[i];
303 		sc->sc_i2c_device[i] = config_found_ia(self, ifattr, &iba,
304 						    iicbus_print);
305 	}
306 
307 	return 0;
308 }
309 
310 static void
311 piixpm_chdet(device_t self, device_t child)
312 {
313 	struct piixpm_softc *sc = device_private(self);
314 	int i;
315 
316 	for (i = 0; i < sc->sc_numbusses; i++) {
317 		if (sc->sc_i2c_device[i] == child) {
318 			sc->sc_i2c_device[i] = NULL;
319 			break;
320 		}
321 	}
322 }
323 
324 
325 static bool
326 piixpm_suspend(device_t dv, const pmf_qual_t *qual)
327 {
328 	struct piixpm_softc *sc = device_private(dv);
329 
330 	sc->sc_devact[0] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
331 	    PIIX_DEVACTA);
332 	sc->sc_devact[1] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
333 	    PIIX_DEVACTB);
334 
335 	return true;
336 }
337 
338 static bool
339 piixpm_resume(device_t dv, const pmf_qual_t *qual)
340 {
341 	struct piixpm_softc *sc = device_private(dv);
342 
343 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTA,
344 	    sc->sc_devact[0]);
345 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTB,
346 	    sc->sc_devact[1]);
347 
348 	return true;
349 }
350 
351 /*
352  * Extract SMBus base address from SB800 Power Management (PM) registers.
353  * The PM registers can be accessed either through indirect I/O (CD6/CD7) or
354  * direct mapping if AcpiMMioDecodeEn is enabled. Since this function is only
355  * called once it uses indirect I/O for simplicity.
356  */
357 static int
358 piixpm_sb800_init(struct piixpm_softc *sc)
359 {
360 	bus_space_tag_t iot = sc->sc_iot;
361 	bus_space_handle_t ioh;	/* indirect I/O handle */
362 	uint16_t val, base_addr;
363 
364 	/* Fetch SMB base address */
365 	if (bus_space_map(iot,
366 	    PIIXPM_INDIRECTIO_BASE, PIIXPM_INDIRECTIO_SIZE, 0, &ioh)) {
367 		device_printf(sc->sc_dev, "couldn't map indirect I/O space\n");
368 		return EBUSY;
369 	}
370 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
371 	    SB800_PM_SMBUS0EN_LO);
372 	val = bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA);
373 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
374 	    SB800_PM_SMBUS0EN_HI);
375 	val |= bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA) << 8;
376 	sc->sc_sb800_ioh = ioh;
377 
378 	if ((val & SB800_PM_SMBUS0EN_ENABLE) == 0)
379 		return ENOENT;
380 
381 	base_addr = val & SB800_PM_SMBUS0EN_BADDR;
382 
383 	aprint_debug_dev(sc->sc_dev, "SMBus @ 0x%04x\n", base_addr);
384 
385 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
386 	    SB800_PM_SMBUS0SELEN);
387 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_DATA, 1); /* SMBUS0SEL */
388 
389 	if (bus_space_map(iot, PCI_MAPREG_IO_ADDR(base_addr),
390 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
391 		aprint_error_dev(sc->sc_dev, "can't map smbus I/O space\n");
392 		return EBUSY;
393 	}
394 	aprint_normal_dev(sc->sc_dev, "polling (SB800)\n");
395 	sc->sc_poll = 1;
396 
397 	return 0;
398 }
399 
400 static void
401 piixpm_csb5_reset(void *arg)
402 {
403 	struct piixpm_softc *sc = arg;
404 	pcireg_t base, hostc, pmbase;
405 
406 	base = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE);
407 	hostc = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC);
408 
409 	pmbase = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE);
410 	pmbase |= PIIX_PM_BASE_CSB5_RESET;
411 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
412 	pmbase &= ~PIIX_PM_BASE_CSB5_RESET;
413 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
414 
415 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE, base);
416 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC, hostc);
417 
418 	(void) tsleep(&sc, PRIBIO, "csb5reset", hz/2);
419 }
420 
421 static int
422 piixpm_i2c_acquire_bus(void *cookie, int flags)
423 {
424 	struct piixpm_smbus *smbus = cookie;
425 	struct piixpm_softc *sc = smbus->softc;
426 
427 	if (!cold)
428 		mutex_enter(&sc->sc_i2c_mutex);
429 
430 	if (smbus->sda > 0)	/* SB800 */
431 	{
432 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
433 		    PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
434 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
435 		    PIIXPM_INDIRECTIO_DATA, smbus->sda << 1);
436 	}
437 
438 	return 0;
439 }
440 
441 static void
442 piixpm_i2c_release_bus(void *cookie, int flags)
443 {
444 	struct piixpm_smbus *smbus = cookie;
445 	struct piixpm_softc *sc = smbus->softc;
446 
447 	if (smbus->sda > 0)	/* SB800 */
448 	{
449 		/*
450 		 * HP Microserver hangs after reboot if not set to SDA0.
451 		 * Also add shutdown hook?
452 		 */
453 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
454 		    PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
455 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
456 		    PIIXPM_INDIRECTIO_DATA, 0);
457 	}
458 
459 	if (!cold)
460 		mutex_exit(&sc->sc_i2c_mutex);
461 }
462 
463 static int
464 piixpm_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr,
465     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
466 {
467 	struct piixpm_smbus *smbus = cookie;
468 	struct piixpm_softc *sc = smbus->softc;
469 	const u_int8_t *b;
470 	u_int8_t ctl = 0, st;
471 	int retries;
472 
473 	DPRINTF(("%s: exec: op %d, addr 0x%x, cmdlen %zu, len %zu, flags 0x%x\n",
474 	    device_xname(sc->sc_dev), op, addr, cmdlen, len, flags));
475 
476 	/* Clear status bits */
477 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS,
478 	    PIIX_SMB_HS_INTR | PIIX_SMB_HS_DEVERR |
479 	    PIIX_SMB_HS_BUSERR | PIIX_SMB_HS_FAILED);
480 	bus_space_barrier(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, 1,
481 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
482 
483 	/* Wait for bus to be idle */
484 	for (retries = 100; retries > 0; retries--) {
485 		st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
486 		    PIIX_SMB_HS);
487 		if (!(st & PIIX_SMB_HS_BUSY))
488 			break;
489 		DELAY(PIIXPM_DELAY);
490 	}
491 	DPRINTF(("%s: exec: st 0x%d\n", device_xname(sc->sc_dev), st & 0xff));
492 	if (st & PIIX_SMB_HS_BUSY)
493 		return (1);
494 
495 	if (cold || sc->sc_poll)
496 		flags |= I2C_F_POLL;
497 
498 	if (!I2C_OP_STOP_P(op) || cmdlen > 1 || len > 2 ||
499 	    (cmdlen == 0 && len > 1))
500 		return (1);
501 
502 	/* Setup transfer */
503 	sc->sc_i2c_xfer.op = op;
504 	sc->sc_i2c_xfer.buf = buf;
505 	sc->sc_i2c_xfer.len = len;
506 	sc->sc_i2c_xfer.flags = flags;
507 	sc->sc_i2c_xfer.error = 0;
508 
509 	/* Set slave address and transfer direction */
510 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_TXSLVA,
511 	    PIIX_SMB_TXSLVA_ADDR(addr) |
512 	    (I2C_OP_READ_P(op) ? PIIX_SMB_TXSLVA_READ : 0));
513 
514 	b = cmdbuf;
515 	if (cmdlen > 0)
516 		/* Set command byte */
517 		bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
518 		    PIIX_SMB_HCMD, b[0]);
519 
520 	if (I2C_OP_WRITE_P(op)) {
521 		/* Write data */
522 		b = buf;
523 		if (cmdlen == 0 && len == 1)
524 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
525 			    PIIX_SMB_HCMD, b[0]);
526 		else if (len > 0)
527 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
528 			    PIIX_SMB_HD0, b[0]);
529 		if (len > 1)
530 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
531 			    PIIX_SMB_HD1, b[1]);
532 	}
533 
534 	/* Set SMBus command */
535 	if (cmdlen == 0) {
536 		if (len == 0)
537 			ctl = PIIX_SMB_HC_CMD_QUICK;
538 		else
539 			ctl = PIIX_SMB_HC_CMD_BYTE;
540 	} else if (len == 1)
541 		ctl = PIIX_SMB_HC_CMD_BDATA;
542 	else if (len == 2)
543 		ctl = PIIX_SMB_HC_CMD_WDATA;
544 
545 	if ((flags & I2C_F_POLL) == 0)
546 		ctl |= PIIX_SMB_HC_INTREN;
547 
548 	/* Start transaction */
549 	ctl |= PIIX_SMB_HC_START;
550 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC, ctl);
551 
552 	if (flags & I2C_F_POLL) {
553 		/* Poll for completion */
554 		if (PIIXPM_IS_CSB5(sc->sc_id))
555 			DELAY(2*PIIXPM_DELAY);
556 		else
557 			DELAY(PIIXPM_DELAY);
558 		for (retries = 1000; retries > 0; retries--) {
559 			st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
560 			    PIIX_SMB_HS);
561 			if ((st & PIIX_SMB_HS_BUSY) == 0)
562 				break;
563 			DELAY(PIIXPM_DELAY);
564 		}
565 		if (st & PIIX_SMB_HS_BUSY)
566 			goto timeout;
567 		piixpm_intr(sc);
568 	} else {
569 		/* Wait for interrupt */
570 		if (tsleep(sc, PRIBIO, "iicexec", PIIXPM_TIMEOUT * hz))
571 			goto timeout;
572 	}
573 
574 	if (sc->sc_i2c_xfer.error)
575 		return (1);
576 
577 	return (0);
578 
579 timeout:
580 	/*
581 	 * Transfer timeout. Kill the transaction and clear status bits.
582 	 */
583 	aprint_error_dev(sc->sc_dev, "timeout, status 0x%x\n", st);
584 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC,
585 	    PIIX_SMB_HC_KILL);
586 	DELAY(PIIXPM_DELAY);
587 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
588 	if ((st & PIIX_SMB_HS_FAILED) == 0)
589 		aprint_error_dev(sc->sc_dev,
590 		    "transaction abort failed, status 0x%x\n", st);
591 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
592 	/*
593 	 * CSB5 needs hard reset to unlock the smbus after timeout.
594 	 */
595 	if (PIIXPM_IS_CSB5(sc->sc_id))
596 		piixpm_csb5_reset(sc);
597 	return (1);
598 }
599 
600 static int
601 piixpm_intr(void *arg)
602 {
603 	struct piixpm_softc *sc = arg;
604 	u_int8_t st;
605 	u_int8_t *b;
606 	size_t len;
607 
608 	/* Read status */
609 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
610 	if ((st & PIIX_SMB_HS_BUSY) != 0 || (st & (PIIX_SMB_HS_INTR |
611 	    PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
612 	    PIIX_SMB_HS_FAILED)) == 0)
613 		/* Interrupt was not for us */
614 		return (0);
615 
616 	DPRINTF(("%s: intr st 0x%d\n", device_xname(sc->sc_dev), st & 0xff));
617 
618 	/* Clear status bits */
619 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
620 
621 	/* Check for errors */
622 	if (st & (PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
623 	    PIIX_SMB_HS_FAILED)) {
624 		sc->sc_i2c_xfer.error = 1;
625 		goto done;
626 	}
627 
628 	if (st & PIIX_SMB_HS_INTR) {
629 		if (I2C_OP_WRITE_P(sc->sc_i2c_xfer.op))
630 			goto done;
631 
632 		/* Read data */
633 		b = sc->sc_i2c_xfer.buf;
634 		len = sc->sc_i2c_xfer.len;
635 		if (len > 0)
636 			b[0] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
637 			    PIIX_SMB_HD0);
638 		if (len > 1)
639 			b[1] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
640 			    PIIX_SMB_HD1);
641 	}
642 
643 done:
644 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0)
645 		wakeup(sc);
646 	return (1);
647 }
648