xref: /netbsd-src/sys/dev/pci/piixpm.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* $NetBSD: piixpm.c,v 1.52 2017/03/29 09:04:36 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 1.52 2017/03/29 09:04:36 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 		break;
148 	case PCI_VENDOR_AMD:
149 		switch (PCI_PRODUCT(pa->pa_id)) {
150 		case PCI_PRODUCT_AMD_HUDSON_SMB:
151 			return 1;
152 		}
153 		break;
154 	}
155 
156 	return 0;
157 }
158 
159 static void
160 piixpm_attach(device_t parent, device_t self, void *aux)
161 {
162 	struct piixpm_softc *sc = device_private(self);
163 	struct pci_attach_args *pa = aux;
164 	pcireg_t base, conf;
165 	pcireg_t pmmisc;
166 	pci_intr_handle_t ih;
167 	const char *intrstr = NULL;
168 	int i, flags;
169 	char intrbuf[PCI_INTRSTR_LEN];
170 
171 	sc->sc_dev = self;
172 	sc->sc_iot = pa->pa_iot;
173 	sc->sc_id = pa->pa_id;
174 	sc->sc_pc = pa->pa_pc;
175 	sc->sc_pcitag = pa->pa_tag;
176 	sc->sc_numbusses = 1;
177 
178 	pci_aprint_devinfo(pa, NULL);
179 
180 	if (!pmf_device_register(self, piixpm_suspend, piixpm_resume))
181 		aprint_error_dev(self, "couldn't establish power handler\n");
182 
183 	/* Read configuration */
184 	conf = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_HOSTC);
185 	DPRINTF(("%s: conf 0x%x\n", device_xname(self), conf));
186 
187 	if ((PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INTEL) ||
188 	    (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_INTEL_82371AB_PMC))
189 		goto nopowermanagement;
190 
191 	/* check whether I/O access to PM regs is enabled */
192 	pmmisc = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PMREGMISC);
193 	if (!(pmmisc & 1))
194 		goto nopowermanagement;
195 
196 	/* Map I/O space */
197 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PM_BASE);
198 	if (bus_space_map(sc->sc_pm_iot, PCI_MAPREG_IO_ADDR(base),
199 	    PIIX_PM_SIZE, 0, &sc->sc_pm_ioh)) {
200 		aprint_error_dev(self,
201 		    "can't map power management I/O space\n");
202 		goto nopowermanagement;
203 	}
204 
205 	/*
206 	 * Revision 0 and 1 are PIIX4, 2 is PIIX4E, 3 is PIIX4M.
207 	 * PIIX4 and PIIX4E have a bug in the timer latch, see Errata #20
208 	 * in the "Specification update" (document #297738).
209 	 */
210 	acpipmtimer_attach(self, sc->sc_pm_iot, sc->sc_pm_ioh,
211 			   PIIX_PM_PMTMR,
212 		(PCI_REVISION(pa->pa_class) < 3) ? ACPIPMT_BADLATCH : 0 );
213 
214 nopowermanagement:
215 
216 	/* SB800 rev 0x40+ and AMD HUDSON need special initialization */
217 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_AMD &&
218 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_HUDSON_SMB) {
219 		if (piixpm_sb800_init(sc) == 0) {
220 			goto attach_i2c;
221 		}
222 		aprint_normal_dev(self, "SMBus initialization failed\n");
223 		return;
224 	}
225 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_ATI &&
226 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_ATI_SB600_SMB &&
227 	    PCI_REVISION(pa->pa_class) >= 0x40) {
228 		if (piixpm_sb800_init(sc) == 0) {
229 			sc->sc_numbusses = 4;
230 			goto attach_i2c;
231 		}
232 		aprint_normal_dev(self, "SMBus initialization failed\n");
233 		return;
234 	}
235 
236 	if ((conf & PIIX_SMB_HOSTC_HSTEN) == 0) {
237 		aprint_normal_dev(self, "SMBus disabled\n");
238 		return;
239 	}
240 
241 	/* Map I/O space */
242 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_BASE) & 0xffff;
243 	if (bus_space_map(sc->sc_smb_iot, PCI_MAPREG_IO_ADDR(base),
244 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
245 		aprint_error_dev(self, "can't map smbus I/O space\n");
246 		return;
247 	}
248 
249 	sc->sc_poll = 1;
250 	aprint_normal_dev(self, "");
251 	if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_SMI) {
252 		/* No PCI IRQ */
253 		aprint_normal("interrupting at SMI, ");
254 	} else if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_IRQ) {
255 		/* Install interrupt handler */
256 		if (pci_intr_map(pa, &ih) == 0) {
257 			intrstr = pci_intr_string(pa->pa_pc, ih, intrbuf,
258 			    sizeof(intrbuf));
259 			sc->sc_smb_ih = pci_intr_establish_xname(pa->pa_pc, ih,
260 			    IPL_BIO, piixpm_intr, sc, device_xname(sc->sc_dev));
261 			if (sc->sc_smb_ih != NULL) {
262 				aprint_normal("interrupting at %s", intrstr);
263 				sc->sc_poll = 0;
264 			}
265 		}
266 	}
267 	if (sc->sc_poll)
268 		aprint_normal("polling");
269 
270 	aprint_normal("\n");
271 
272 attach_i2c:
273 	for (i = 0; i < sc->sc_numbusses; i++)
274 		sc->sc_i2c_device[i] = NULL;
275 
276 	flags = 0;
277 	mutex_init(&sc->sc_i2c_mutex, MUTEX_DEFAULT, IPL_NONE);
278 	piixpm_rescan(self, "i2cbus", &flags);
279 }
280 
281 static int
282 piixpm_rescan(device_t self, const char *ifattr, const int *flags)
283 {
284 	struct piixpm_softc *sc = device_private(self);
285 	struct i2cbus_attach_args iba;
286 	int i;
287 
288 	if (!ifattr_match(ifattr, "i2cbus"))
289 		return 0;
290 
291 	/* Attach I2C bus */
292 
293 	for (i = 0; i < sc->sc_numbusses; i++) {
294 		if (sc->sc_i2c_device[i])
295 			continue;
296 		sc->sc_busses[i].sda = i;
297 		sc->sc_busses[i].softc = sc;
298 		sc->sc_i2c_tags[i].ic_cookie = &sc->sc_busses[i];
299 		sc->sc_i2c_tags[i].ic_acquire_bus = piixpm_i2c_acquire_bus;
300 		sc->sc_i2c_tags[i].ic_release_bus = piixpm_i2c_release_bus;
301 		sc->sc_i2c_tags[i].ic_exec = piixpm_i2c_exec;
302 		memset(&iba, 0, sizeof(iba));
303 		iba.iba_type = I2C_TYPE_SMBUS;
304 		iba.iba_tag = &sc->sc_i2c_tags[i];
305 		sc->sc_i2c_device[i] = config_found_ia(self, ifattr, &iba,
306 						    iicbus_print);
307 	}
308 
309 	return 0;
310 }
311 
312 static void
313 piixpm_chdet(device_t self, device_t child)
314 {
315 	struct piixpm_softc *sc = device_private(self);
316 	int i;
317 
318 	for (i = 0; i < sc->sc_numbusses; i++) {
319 		if (sc->sc_i2c_device[i] == child) {
320 			sc->sc_i2c_device[i] = NULL;
321 			break;
322 		}
323 	}
324 }
325 
326 
327 static bool
328 piixpm_suspend(device_t dv, const pmf_qual_t *qual)
329 {
330 	struct piixpm_softc *sc = device_private(dv);
331 
332 	sc->sc_devact[0] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
333 	    PIIX_DEVACTA);
334 	sc->sc_devact[1] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
335 	    PIIX_DEVACTB);
336 
337 	return true;
338 }
339 
340 static bool
341 piixpm_resume(device_t dv, const pmf_qual_t *qual)
342 {
343 	struct piixpm_softc *sc = device_private(dv);
344 
345 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTA,
346 	    sc->sc_devact[0]);
347 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTB,
348 	    sc->sc_devact[1]);
349 
350 	return true;
351 }
352 
353 /*
354  * Extract SMBus base address from SB800 Power Management (PM) registers.
355  * The PM registers can be accessed either through indirect I/O (CD6/CD7) or
356  * direct mapping if AcpiMMioDecodeEn is enabled. Since this function is only
357  * called once it uses indirect I/O for simplicity.
358  */
359 static int
360 piixpm_sb800_init(struct piixpm_softc *sc)
361 {
362 	bus_space_tag_t iot = sc->sc_iot;
363 	bus_space_handle_t ioh;	/* indirect I/O handle */
364 	uint16_t val, base_addr;
365 
366 	/* Fetch SMB base address */
367 	if (bus_space_map(iot,
368 	    PIIXPM_INDIRECTIO_BASE, PIIXPM_INDIRECTIO_SIZE, 0, &ioh)) {
369 		device_printf(sc->sc_dev, "couldn't map indirect I/O space\n");
370 		return EBUSY;
371 	}
372 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
373 	    SB800_PM_SMBUS0EN_LO);
374 	val = bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA);
375 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
376 	    SB800_PM_SMBUS0EN_HI);
377 	val |= bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA) << 8;
378 	sc->sc_sb800_ioh = ioh;
379 
380 	if ((val & SB800_PM_SMBUS0EN_ENABLE) == 0)
381 		return ENOENT;
382 
383 	base_addr = val & SB800_PM_SMBUS0EN_BADDR;
384 
385 	aprint_debug_dev(sc->sc_dev, "SMBus @ 0x%04x\n", base_addr);
386 
387 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
388 	    SB800_PM_SMBUS0SELEN);
389 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_DATA, 1); /* SMBUS0SEL */
390 
391 	if (bus_space_map(iot, PCI_MAPREG_IO_ADDR(base_addr),
392 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
393 		aprint_error_dev(sc->sc_dev, "can't map smbus I/O space\n");
394 		return EBUSY;
395 	}
396 	aprint_normal_dev(sc->sc_dev, "polling (SB800)\n");
397 	sc->sc_poll = 1;
398 
399 	return 0;
400 }
401 
402 static void
403 piixpm_csb5_reset(void *arg)
404 {
405 	struct piixpm_softc *sc = arg;
406 	pcireg_t base, hostc, pmbase;
407 
408 	base = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE);
409 	hostc = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC);
410 
411 	pmbase = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE);
412 	pmbase |= PIIX_PM_BASE_CSB5_RESET;
413 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
414 	pmbase &= ~PIIX_PM_BASE_CSB5_RESET;
415 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
416 
417 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE, base);
418 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC, hostc);
419 
420 	(void) tsleep(&sc, PRIBIO, "csb5reset", hz/2);
421 }
422 
423 static int
424 piixpm_i2c_acquire_bus(void *cookie, int flags)
425 {
426 	struct piixpm_smbus *smbus = cookie;
427 	struct piixpm_softc *sc = smbus->softc;
428 
429 	if (!cold)
430 		mutex_enter(&sc->sc_i2c_mutex);
431 
432 	if (smbus->sda > 0)	/* SB800 */
433 	{
434 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
435 		    PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
436 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
437 		    PIIXPM_INDIRECTIO_DATA, smbus->sda << 1);
438 	}
439 
440 	return 0;
441 }
442 
443 static void
444 piixpm_i2c_release_bus(void *cookie, int flags)
445 {
446 	struct piixpm_smbus *smbus = cookie;
447 	struct piixpm_softc *sc = smbus->softc;
448 
449 	if (smbus->sda > 0)	/* SB800 */
450 	{
451 		/*
452 		 * HP Microserver hangs after reboot if not set to SDA0.
453 		 * Also add shutdown hook?
454 		 */
455 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
456 		    PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
457 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
458 		    PIIXPM_INDIRECTIO_DATA, 0);
459 	}
460 
461 	if (!cold)
462 		mutex_exit(&sc->sc_i2c_mutex);
463 }
464 
465 static int
466 piixpm_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr,
467     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
468 {
469 	struct piixpm_smbus *smbus = cookie;
470 	struct piixpm_softc *sc = smbus->softc;
471 	const u_int8_t *b;
472 	u_int8_t ctl = 0, st;
473 	int retries;
474 
475 	DPRINTF(("%s: exec: op %d, addr 0x%x, cmdlen %zu, len %zu, flags 0x%x\n",
476 	    device_xname(sc->sc_dev), op, addr, cmdlen, len, flags));
477 
478 	/* Clear status bits */
479 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS,
480 	    PIIX_SMB_HS_INTR | PIIX_SMB_HS_DEVERR |
481 	    PIIX_SMB_HS_BUSERR | PIIX_SMB_HS_FAILED);
482 	bus_space_barrier(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, 1,
483 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
484 
485 	/* Wait for bus to be idle */
486 	for (retries = 100; retries > 0; retries--) {
487 		st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
488 		    PIIX_SMB_HS);
489 		if (!(st & PIIX_SMB_HS_BUSY))
490 			break;
491 		DELAY(PIIXPM_DELAY);
492 	}
493 	DPRINTF(("%s: exec: st %#x\n", device_xname(sc->sc_dev), st & 0xff));
494 	if (st & PIIX_SMB_HS_BUSY)
495 		return (1);
496 
497 	if (cold || sc->sc_poll)
498 		flags |= I2C_F_POLL;
499 
500 	if (!I2C_OP_STOP_P(op) || cmdlen > 1 || len > 2 ||
501 	    (cmdlen == 0 && len > 1))
502 		return (1);
503 
504 	/* Setup transfer */
505 	sc->sc_i2c_xfer.op = op;
506 	sc->sc_i2c_xfer.buf = buf;
507 	sc->sc_i2c_xfer.len = len;
508 	sc->sc_i2c_xfer.flags = flags;
509 	sc->sc_i2c_xfer.error = 0;
510 
511 	/* Set slave address and transfer direction */
512 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_TXSLVA,
513 	    PIIX_SMB_TXSLVA_ADDR(addr) |
514 	    (I2C_OP_READ_P(op) ? PIIX_SMB_TXSLVA_READ : 0));
515 
516 	b = cmdbuf;
517 	if (cmdlen > 0)
518 		/* Set command byte */
519 		bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
520 		    PIIX_SMB_HCMD, b[0]);
521 
522 	if (I2C_OP_WRITE_P(op)) {
523 		/* Write data */
524 		b = buf;
525 		if (cmdlen == 0 && len == 1)
526 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
527 			    PIIX_SMB_HCMD, b[0]);
528 		else if (len > 0)
529 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
530 			    PIIX_SMB_HD0, b[0]);
531 		if (len > 1)
532 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
533 			    PIIX_SMB_HD1, b[1]);
534 	}
535 
536 	/* Set SMBus command */
537 	if (cmdlen == 0) {
538 		if (len == 0)
539 			ctl = PIIX_SMB_HC_CMD_QUICK;
540 		else
541 			ctl = PIIX_SMB_HC_CMD_BYTE;
542 	} else if (len == 1)
543 		ctl = PIIX_SMB_HC_CMD_BDATA;
544 	else if (len == 2)
545 		ctl = PIIX_SMB_HC_CMD_WDATA;
546 
547 	if ((flags & I2C_F_POLL) == 0)
548 		ctl |= PIIX_SMB_HC_INTREN;
549 
550 	/* Start transaction */
551 	ctl |= PIIX_SMB_HC_START;
552 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC, ctl);
553 
554 	if (flags & I2C_F_POLL) {
555 		/* Poll for completion */
556 		if (PIIXPM_IS_CSB5(sc->sc_id))
557 			DELAY(2*PIIXPM_DELAY);
558 		else
559 			DELAY(PIIXPM_DELAY);
560 		for (retries = 1000; retries > 0; retries--) {
561 			st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
562 			    PIIX_SMB_HS);
563 			if ((st & PIIX_SMB_HS_BUSY) == 0)
564 				break;
565 			DELAY(PIIXPM_DELAY);
566 		}
567 		if (st & PIIX_SMB_HS_BUSY)
568 			goto timeout;
569 		piixpm_intr(sc);
570 	} else {
571 		/* Wait for interrupt */
572 		if (tsleep(sc, PRIBIO, "iicexec", PIIXPM_TIMEOUT * hz))
573 			goto timeout;
574 	}
575 
576 	if (sc->sc_i2c_xfer.error)
577 		return (1);
578 
579 	return (0);
580 
581 timeout:
582 	/*
583 	 * Transfer timeout. Kill the transaction and clear status bits.
584 	 */
585 	aprint_error_dev(sc->sc_dev, "timeout, status 0x%x\n", st);
586 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC,
587 	    PIIX_SMB_HC_KILL);
588 	DELAY(PIIXPM_DELAY);
589 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
590 	if ((st & PIIX_SMB_HS_FAILED) == 0)
591 		aprint_error_dev(sc->sc_dev,
592 		    "transaction abort failed, status 0x%x\n", st);
593 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
594 	/*
595 	 * CSB5 needs hard reset to unlock the smbus after timeout.
596 	 */
597 	if (PIIXPM_IS_CSB5(sc->sc_id))
598 		piixpm_csb5_reset(sc);
599 	return (1);
600 }
601 
602 static int
603 piixpm_intr(void *arg)
604 {
605 	struct piixpm_softc *sc = arg;
606 	u_int8_t st;
607 	u_int8_t *b;
608 	size_t len;
609 
610 	/* Read status */
611 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
612 	if ((st & PIIX_SMB_HS_BUSY) != 0 || (st & (PIIX_SMB_HS_INTR |
613 	    PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
614 	    PIIX_SMB_HS_FAILED)) == 0)
615 		/* Interrupt was not for us */
616 		return (0);
617 
618 	DPRINTF(("%s: intr st %#x\n", device_xname(sc->sc_dev), st & 0xff));
619 
620 	/* Clear status bits */
621 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
622 
623 	/* Check for errors */
624 	if (st & (PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
625 	    PIIX_SMB_HS_FAILED)) {
626 		sc->sc_i2c_xfer.error = 1;
627 		goto done;
628 	}
629 
630 	if (st & PIIX_SMB_HS_INTR) {
631 		if (I2C_OP_WRITE_P(sc->sc_i2c_xfer.op))
632 			goto done;
633 
634 		/* Read data */
635 		b = sc->sc_i2c_xfer.buf;
636 		len = sc->sc_i2c_xfer.len;
637 		if (len > 0)
638 			b[0] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
639 			    PIIX_SMB_HD0);
640 		if (len > 1)
641 			b[1] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
642 			    PIIX_SMB_HD1);
643 	}
644 
645 done:
646 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0)
647 		wakeup(sc);
648 	return (1);
649 }
650