xref: /netbsd-src/sys/dev/pci/piixpm.c (revision 7330f729ccf0bd976a06f95fad452fe774fc7fd1)
1 /* $NetBSD: piixpm.c,v 1.54 2019/07/13 09:24:17 msaitoh Exp $ */
2 /*	$OpenBSD: piixpm.c,v 1.39 2013/10/01 20:06:02 sf 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 1.54 2019/07/13 09:24:17 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(sc)						      \
53 	(PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_SERVERWORKS &&		      \
54 	PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_SERVERWORKS_CSB5)
55 #define PIIXPM_DELAY	200
56 #define PIIXPM_TIMEOUT	1
57 
58 #define PIIXPM_IS_SB800GRP(sc)						      \
59 	((PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_ATI) &&			      \
60 	    ((PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_ATI_SB600_SMB) &&	      \
61 		((sc)->sc_rev >= 0x40)))
62 
63 #define PIIXPM_IS_HUDSON(sc)						      \
64 	((PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_AMD) &&			      \
65 	    (PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_AMD_HUDSON_SMB))
66 
67 #define PIIXPM_IS_KERNCZ(sc)						      \
68 	((PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_AMD) &&			      \
69 	    (PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_AMD_KERNCZ_SMB))
70 
71 #define PIIXPM_IS_FCHGRP(sc)	(PIIXPM_IS_HUDSON(sc) || PIIXPM_IS_KERNCZ(sc))
72 
73 struct piixpm_smbus {
74 	int			sda;
75 	struct			piixpm_softc *softc;
76 };
77 
78 struct piixpm_softc {
79 	device_t		sc_dev;
80 
81 	bus_space_tag_t		sc_iot;
82 #define	sc_pm_iot sc_iot
83 #define sc_smb_iot sc_iot
84 	bus_space_handle_t	sc_pm_ioh;
85 	bus_space_handle_t	sc_sb800_ioh;
86 	bus_space_handle_t	sc_smb_ioh;
87 	void *			sc_smb_ih;
88 	int			sc_poll;
89 
90 	pci_chipset_tag_t	sc_pc;
91 	pcitag_t		sc_pcitag;
92 	pcireg_t		sc_id;
93 	pcireg_t		sc_rev;
94 
95 	int			sc_numbusses;
96 	device_t		sc_i2c_device[4];
97 	struct piixpm_smbus	sc_busses[4];
98 	struct i2c_controller	sc_i2c_tags[4];
99 
100 	kmutex_t		sc_i2c_mutex;
101 	struct {
102 		i2c_op_t	op;
103 		void *		buf;
104 		size_t		len;
105 		int		flags;
106 		volatile int	error;
107 	}			sc_i2c_xfer;
108 
109 	pcireg_t		sc_devact[2];
110 };
111 
112 static int	piixpm_match(device_t, cfdata_t, void *);
113 static void	piixpm_attach(device_t, device_t, void *);
114 static int	piixpm_rescan(device_t, const char *, const int *);
115 static void	piixpm_chdet(device_t, device_t);
116 
117 static bool	piixpm_suspend(device_t, const pmf_qual_t *);
118 static bool	piixpm_resume(device_t, const pmf_qual_t *);
119 
120 static int	piixpm_sb800_init(struct piixpm_softc *);
121 static void	piixpm_csb5_reset(void *);
122 static int	piixpm_i2c_acquire_bus(void *, int);
123 static void	piixpm_i2c_release_bus(void *, int);
124 static int	piixpm_i2c_exec(void *, i2c_op_t, i2c_addr_t, const void *,
125     size_t, void *, size_t, int);
126 
127 static int	piixpm_intr(void *);
128 
129 CFATTACH_DECL3_NEW(piixpm, sizeof(struct piixpm_softc),
130     piixpm_match, piixpm_attach, NULL, NULL, piixpm_rescan, piixpm_chdet, 0);
131 
132 static int
133 piixpm_match(device_t parent, cfdata_t match, void *aux)
134 {
135 	struct pci_attach_args *pa;
136 
137 	pa = (struct pci_attach_args *)aux;
138 	switch (PCI_VENDOR(pa->pa_id)) {
139 	case PCI_VENDOR_INTEL:
140 		switch (PCI_PRODUCT(pa->pa_id)) {
141 		case PCI_PRODUCT_INTEL_82371AB_PMC:
142 		case PCI_PRODUCT_INTEL_82440MX_PMC:
143 			return 1;
144 		}
145 		break;
146 	case PCI_VENDOR_ATI:
147 		switch (PCI_PRODUCT(pa->pa_id)) {
148 		case PCI_PRODUCT_ATI_SB200_SMB:
149 		case PCI_PRODUCT_ATI_SB300_SMB:
150 		case PCI_PRODUCT_ATI_SB400_SMB:
151 		case PCI_PRODUCT_ATI_SB600_SMB:	/* matches SB600/SB700/SB800 */
152 			return 1;
153 		}
154 		break;
155 	case PCI_VENDOR_SERVERWORKS:
156 		switch (PCI_PRODUCT(pa->pa_id)) {
157 		case PCI_PRODUCT_SERVERWORKS_OSB4:
158 		case PCI_PRODUCT_SERVERWORKS_CSB5:
159 		case PCI_PRODUCT_SERVERWORKS_CSB6:
160 		case PCI_PRODUCT_SERVERWORKS_HT1000SB:
161 		case PCI_PRODUCT_SERVERWORKS_HT1100SB:
162 			return 1;
163 		}
164 		break;
165 	case PCI_VENDOR_AMD:
166 		switch (PCI_PRODUCT(pa->pa_id)) {
167 		case PCI_PRODUCT_AMD_HUDSON_SMB:
168 		case PCI_PRODUCT_AMD_KERNCZ_SMB:
169 			return 1;
170 		}
171 		break;
172 	}
173 
174 	return 0;
175 }
176 
177 static void
178 piixpm_attach(device_t parent, device_t self, void *aux)
179 {
180 	struct piixpm_softc *sc = device_private(self);
181 	struct pci_attach_args *pa = aux;
182 	pcireg_t base, conf;
183 	pcireg_t pmmisc;
184 	pci_intr_handle_t ih;
185 	bool usesmi = false;
186 	const char *intrstr = NULL;
187 	int i, flags;
188 	char intrbuf[PCI_INTRSTR_LEN];
189 
190 	sc->sc_dev = self;
191 	sc->sc_iot = pa->pa_iot;
192 	sc->sc_id = pa->pa_id;
193 	sc->sc_rev = PCI_REVISION(pa->pa_class);
194 	sc->sc_pc = pa->pa_pc;
195 	sc->sc_pcitag = pa->pa_tag;
196 	sc->sc_numbusses = 1;
197 
198 	pci_aprint_devinfo(pa, NULL);
199 
200 	if (!pmf_device_register(self, piixpm_suspend, piixpm_resume))
201 		aprint_error_dev(self, "couldn't establish power handler\n");
202 
203 	if ((PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INTEL) ||
204 	    (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_INTEL_82371AB_PMC))
205 		goto nopowermanagement;
206 
207 	/* check whether I/O access to PM regs is enabled */
208 	pmmisc = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PMREGMISC);
209 	if (!(pmmisc & 1))
210 		goto nopowermanagement;
211 
212 	/* Map I/O space */
213 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PM_BASE);
214 	if (base == 0 || bus_space_map(sc->sc_pm_iot, PCI_MAPREG_IO_ADDR(base),
215 	    PIIX_PM_SIZE, 0, &sc->sc_pm_ioh)) {
216 		aprint_error_dev(self,
217 		    "can't map power management I/O space\n");
218 		goto nopowermanagement;
219 	}
220 
221 	/*
222 	 * Revision 0 and 1 are PIIX4, 2 is PIIX4E, 3 is PIIX4M.
223 	 * PIIX4 and PIIX4E have a bug in the timer latch, see Errata #20
224 	 * in the "Specification update" (document #297738).
225 	 */
226 	acpipmtimer_attach(self, sc->sc_pm_iot, sc->sc_pm_ioh, PIIX_PM_PMTMR,
227 	    (PCI_REVISION(pa->pa_class) < 3) ? ACPIPMT_BADLATCH : 0);
228 
229 nopowermanagement:
230 
231 	/* SB800 rev 0x40+, AMD HUDSON and newer need special initialization */
232 	if (PIIXPM_IS_FCHGRP(sc) || PIIXPM_IS_SB800GRP(sc)) {
233 		if (piixpm_sb800_init(sc) == 0) {
234 			sc->sc_numbusses = 4;
235 
236 			/* Read configuration */
237 			conf = pci_conf_read(pa->pa_pc, pa->pa_tag,
238 			    SB800_SMB_HOSTC);
239 			DPRINTF(("%s: conf 0x%08x\n", device_xname(self),
240 				conf));
241 
242 			usesmi = conf & SB800_SMB_HOSTC_SMI;
243 			goto setintr;
244 		}
245 		aprint_normal_dev(self, "SMBus initialization failed\n");
246 		return;
247 	}
248 
249 	/* Read configuration */
250 	conf = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_HOSTC);
251 	DPRINTF(("%s: conf 0x%08x\n", device_xname(self), conf));
252 
253 	if ((conf & PIIX_SMB_HOSTC_HSTEN) == 0) {
254 		aprint_normal_dev(self, "SMBus disabled\n");
255 		return;
256 	}
257 	usesmi = (conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_SMI;
258 
259 	/* Map I/O space */
260 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_BASE) & 0xffff;
261 	if (base == 0 ||
262 	    bus_space_map(sc->sc_smb_iot, PCI_MAPREG_IO_ADDR(base),
263 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
264 		aprint_error_dev(self, "can't map smbus I/O space\n");
265 		return;
266 	}
267 
268 setintr:
269 	sc->sc_poll = 1;
270 	aprint_normal_dev(self, "");
271 	if (usesmi) {
272 		/* No PCI IRQ */
273 		aprint_normal("interrupting at SMI, ");
274 	} else {
275 		if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_IRQ) {
276 			/* Install interrupt handler */
277 			if (pci_intr_map(pa, &ih) == 0) {
278 				intrstr = pci_intr_string(pa->pa_pc, ih,
279 				    intrbuf, sizeof(intrbuf));
280 				sc->sc_smb_ih = pci_intr_establish_xname(
281 					pa->pa_pc, ih, IPL_BIO, piixpm_intr,
282 					sc, device_xname(sc->sc_dev));
283 				if (sc->sc_smb_ih != NULL) {
284 					aprint_normal("interrupting at %s",
285 					    intrstr);
286 					sc->sc_poll = 0;
287 				}
288 			}
289 		}
290 		if (sc->sc_poll)
291 			aprint_normal("polling");
292 	}
293 
294 	aprint_normal("\n");
295 
296 	for (i = 0; i < sc->sc_numbusses; i++)
297 		sc->sc_i2c_device[i] = NULL;
298 
299 	flags = 0;
300 	mutex_init(&sc->sc_i2c_mutex, MUTEX_DEFAULT, IPL_NONE);
301 	piixpm_rescan(self, "i2cbus", &flags);
302 }
303 
304 static int
305 piixpm_iicbus_print(void *aux, const char *pnp)
306 {
307 	struct i2cbus_attach_args *iba = aux;
308 	struct i2c_controller *tag = iba->iba_tag;
309 	struct piixpm_smbus *bus = tag->ic_cookie;
310 	struct piixpm_softc *sc = bus->softc;
311 
312 	iicbus_print(aux, pnp);
313 	if (sc->sc_numbusses != 0)
314 		aprint_normal(" port %d", bus->sda);
315 
316 	return UNCONF;
317 }
318 static int
319 piixpm_rescan(device_t self, const char *ifattr, const int *flags)
320 {
321 	struct piixpm_softc *sc = device_private(self);
322 	struct i2cbus_attach_args iba;
323 	int i;
324 
325 	if (!ifattr_match(ifattr, "i2cbus"))
326 		return 0;
327 
328 	/* Attach I2C bus */
329 
330 	for (i = 0; i < sc->sc_numbusses; i++) {
331 		if (sc->sc_i2c_device[i])
332 			continue;
333 		sc->sc_busses[i].sda = i;
334 		sc->sc_busses[i].softc = sc;
335 		sc->sc_i2c_tags[i].ic_cookie = &sc->sc_busses[i];
336 		sc->sc_i2c_tags[i].ic_acquire_bus = piixpm_i2c_acquire_bus;
337 		sc->sc_i2c_tags[i].ic_release_bus = piixpm_i2c_release_bus;
338 		sc->sc_i2c_tags[i].ic_exec = piixpm_i2c_exec;
339 		memset(&iba, 0, sizeof(iba));
340 		iba.iba_type = I2C_TYPE_SMBUS;
341 		iba.iba_tag = &sc->sc_i2c_tags[i];
342 		sc->sc_i2c_device[i] = config_found_ia(self, ifattr, &iba,
343 		    piixpm_iicbus_print);
344 	}
345 
346 	return 0;
347 }
348 
349 static void
350 piixpm_chdet(device_t self, device_t child)
351 {
352 	struct piixpm_softc *sc = device_private(self);
353 	int i;
354 
355 	for (i = 0; i < sc->sc_numbusses; i++) {
356 		if (sc->sc_i2c_device[i] == child) {
357 			sc->sc_i2c_device[i] = NULL;
358 			break;
359 		}
360 	}
361 }
362 
363 
364 static bool
365 piixpm_suspend(device_t dv, const pmf_qual_t *qual)
366 {
367 	struct piixpm_softc *sc = device_private(dv);
368 
369 	sc->sc_devact[0] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
370 	    PIIX_DEVACTA);
371 	sc->sc_devact[1] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
372 	    PIIX_DEVACTB);
373 
374 	return true;
375 }
376 
377 static bool
378 piixpm_resume(device_t dv, const pmf_qual_t *qual)
379 {
380 	struct piixpm_softc *sc = device_private(dv);
381 
382 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTA,
383 	    sc->sc_devact[0]);
384 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTB,
385 	    sc->sc_devact[1]);
386 
387 	return true;
388 }
389 
390 /*
391  * Extract SMBus base address from SB800 Power Management (PM) registers.
392  * The PM registers can be accessed either through indirect I/O (CD6/CD7) or
393  * direct mapping if AcpiMMioDecodeEn is enabled. Since this function is only
394  * called once it uses indirect I/O for simplicity.
395  */
396 static int
397 piixpm_sb800_init(struct piixpm_softc *sc)
398 {
399 	bus_space_tag_t iot = sc->sc_iot;
400 	bus_space_handle_t ioh;	/* indirect I/O handle */
401 	uint16_t val, base_addr;
402 	bool enabled;
403 
404 	/* Fetch SMB base address */
405 	if (bus_space_map(iot,
406 	    SB800_INDIRECTIO_BASE, SB800_INDIRECTIO_SIZE, 0, &ioh)) {
407 		device_printf(sc->sc_dev, "couldn't map indirect I/O space\n");
408 		return EBUSY;
409 	}
410 	if (PIIXPM_IS_FCHGRP(sc)) {
411 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
412 		    AMDFCH41_PM_DECODE_EN0);
413 		val = bus_space_read_1(iot, ioh, SB800_INDIRECTIO_DATA);
414 		enabled = val & AMDFCH41_SMBUS_EN;
415 		if (!enabled)
416 			return ENOENT;
417 
418 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
419 		    AMDFCH41_PM_DECODE_EN1);
420 		val = bus_space_read_1(iot, ioh, SB800_INDIRECTIO_DATA) << 8;
421 		base_addr = val;
422 	} else {
423 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
424 		    SB800_PM_SMBUS0EN_LO);
425 		val = bus_space_read_1(iot, ioh, SB800_INDIRECTIO_DATA);
426 		enabled = val & SB800_PM_SMBUS0EN_ENABLE;
427 		if (!enabled)
428 			return ENOENT;
429 
430 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
431 		    SB800_PM_SMBUS0EN_HI);
432 		val |= bus_space_read_1(iot, ioh, SB800_INDIRECTIO_DATA) << 8;
433 		base_addr = val & SB800_PM_SMBUS0EN_BADDR;
434 
435 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
436 		    SB800_PM_SMBUS0SELEN);
437 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_DATA,
438 		    SB800_PM_SMBUS0EN_ENABLE);
439 	}
440 
441 	sc->sc_sb800_ioh = ioh;
442 	aprint_debug_dev(sc->sc_dev, "SMBus @ 0x%04x\n", base_addr);
443 
444 	if (bus_space_map(iot, PCI_MAPREG_IO_ADDR(base_addr),
445 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
446 		aprint_error_dev(sc->sc_dev, "can't map smbus I/O space\n");
447 		return EBUSY;
448 	}
449 
450 	return 0;
451 }
452 
453 static void
454 piixpm_csb5_reset(void *arg)
455 {
456 	struct piixpm_softc *sc = arg;
457 	pcireg_t base, hostc, pmbase;
458 
459 	base = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE);
460 	hostc = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC);
461 
462 	pmbase = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE);
463 	pmbase |= PIIX_PM_BASE_CSB5_RESET;
464 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
465 	pmbase &= ~PIIX_PM_BASE_CSB5_RESET;
466 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
467 
468 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE, base);
469 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC, hostc);
470 
471 	(void) tsleep(&sc, PRIBIO, "csb5reset", hz/2);
472 }
473 
474 static int
475 piixpm_i2c_acquire_bus(void *cookie, int flags)
476 {
477 	struct piixpm_smbus *smbus = cookie;
478 	struct piixpm_softc *sc = smbus->softc;
479 
480 	if (!cold)
481 		mutex_enter(&sc->sc_i2c_mutex);
482 
483 	if (PIIXPM_IS_KERNCZ(sc)) {
484 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
485 		    SB800_INDIRECTIO_INDEX, AMDFCH41_PM_PORT_INDEX);
486 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
487 		    SB800_INDIRECTIO_DATA, smbus->sda << 3);
488 	} else if (PIIXPM_IS_SB800GRP(sc) || PIIXPM_IS_HUDSON(sc)) {
489 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
490 		    SB800_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
491 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
492 		    SB800_INDIRECTIO_DATA, smbus->sda << 1);
493 	}
494 
495 	return 0;
496 }
497 
498 static void
499 piixpm_i2c_release_bus(void *cookie, int flags)
500 {
501 	struct piixpm_smbus *smbus = cookie;
502 	struct piixpm_softc *sc = smbus->softc;
503 
504 	if (PIIXPM_IS_KERNCZ(sc)) {
505 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
506 		    SB800_INDIRECTIO_INDEX, AMDFCH41_PM_PORT_INDEX);
507 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
508 		    SB800_INDIRECTIO_DATA, 0);
509 	} else if (PIIXPM_IS_SB800GRP(sc) || PIIXPM_IS_HUDSON(sc)) {
510 		/*
511 		 * HP Microserver hangs after reboot if not set to SDA0.
512 		 * Also add shutdown hook?
513 		 */
514 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
515 		    SB800_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
516 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
517 		    SB800_INDIRECTIO_DATA, 0);
518 	}
519 
520 	if (!cold)
521 		mutex_exit(&sc->sc_i2c_mutex);
522 }
523 
524 static int
525 piixpm_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr,
526     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
527 {
528 	struct piixpm_smbus *smbus = cookie;
529 	struct piixpm_softc *sc = smbus->softc;
530 	const uint8_t *b;
531 	uint8_t ctl = 0, st;
532 	int retries;
533 
534 	DPRINTF(("%s: exec: op %d, addr 0x%02x, cmdlen %zu, len %zu, "
535 		"flags 0x%x\n",
536 		device_xname(sc->sc_dev), op, addr, cmdlen, len, flags));
537 
538 	/* Clear status bits */
539 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS,
540 	    PIIX_SMB_HS_INTR | PIIX_SMB_HS_DEVERR |
541 	    PIIX_SMB_HS_BUSERR | PIIX_SMB_HS_FAILED);
542 	bus_space_barrier(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, 1,
543 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
544 
545 	/* Wait for bus to be idle */
546 	for (retries = 100; retries > 0; retries--) {
547 		st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
548 		    PIIX_SMB_HS);
549 		if (!(st & PIIX_SMB_HS_BUSY))
550 			break;
551 		DELAY(PIIXPM_DELAY);
552 	}
553 	DPRINTF(("%s: exec: st %#x\n", device_xname(sc->sc_dev), st & 0xff));
554 	if (st & PIIX_SMB_HS_BUSY)
555 		return (1);
556 
557 	if (cold || sc->sc_poll)
558 		flags |= I2C_F_POLL;
559 
560 	if (!I2C_OP_STOP_P(op) || cmdlen > 1 || len > 2 ||
561 	    (cmdlen == 0 && len > 1))
562 		return (1);
563 
564 	/* Setup transfer */
565 	sc->sc_i2c_xfer.op = op;
566 	sc->sc_i2c_xfer.buf = buf;
567 	sc->sc_i2c_xfer.len = len;
568 	sc->sc_i2c_xfer.flags = flags;
569 	sc->sc_i2c_xfer.error = 0;
570 
571 	/* Set slave address and transfer direction */
572 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_TXSLVA,
573 	    PIIX_SMB_TXSLVA_ADDR(addr) |
574 	    (I2C_OP_READ_P(op) ? PIIX_SMB_TXSLVA_READ : 0));
575 
576 	b = cmdbuf;
577 	if (cmdlen > 0)
578 		/* Set command byte */
579 		bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
580 		    PIIX_SMB_HCMD, b[0]);
581 
582 	if (I2C_OP_WRITE_P(op)) {
583 		/* Write data */
584 		b = buf;
585 		if (cmdlen == 0 && len == 1)
586 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
587 			    PIIX_SMB_HCMD, b[0]);
588 		else if (len > 0)
589 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
590 			    PIIX_SMB_HD0, b[0]);
591 		if (len > 1)
592 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
593 			    PIIX_SMB_HD1, b[1]);
594 	}
595 
596 	/* Set SMBus command */
597 	if (cmdlen == 0) {
598 		if (len == 0)
599 			ctl = PIIX_SMB_HC_CMD_QUICK;
600 		else
601 			ctl = PIIX_SMB_HC_CMD_BYTE;
602 	} else if (len == 1)
603 		ctl = PIIX_SMB_HC_CMD_BDATA;
604 	else if (len == 2)
605 		ctl = PIIX_SMB_HC_CMD_WDATA;
606 	else
607 		panic("%s: unexpected len %zu", __func__, len);
608 
609 	if ((flags & I2C_F_POLL) == 0)
610 		ctl |= PIIX_SMB_HC_INTREN;
611 
612 	/* Start transaction */
613 	ctl |= PIIX_SMB_HC_START;
614 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC, ctl);
615 
616 	if (flags & I2C_F_POLL) {
617 		/* Poll for completion */
618 		if (PIIXPM_IS_CSB5(sc))
619 			DELAY(2*PIIXPM_DELAY);
620 		else
621 			DELAY(PIIXPM_DELAY);
622 		for (retries = 1000; retries > 0; retries--) {
623 			st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
624 			    PIIX_SMB_HS);
625 			if ((st & PIIX_SMB_HS_BUSY) == 0)
626 				break;
627 			DELAY(PIIXPM_DELAY);
628 		}
629 		if (st & PIIX_SMB_HS_BUSY)
630 			goto timeout;
631 		piixpm_intr(sc);
632 	} else {
633 		/* Wait for interrupt */
634 		if (tsleep(sc, PRIBIO, "piixpm", PIIXPM_TIMEOUT * hz))
635 			goto timeout;
636 	}
637 
638 	if (sc->sc_i2c_xfer.error)
639 		return (1);
640 
641 	return (0);
642 
643 timeout:
644 	/*
645 	 * Transfer timeout. Kill the transaction and clear status bits.
646 	 */
647 	aprint_error_dev(sc->sc_dev, "timeout, status 0x%x\n", st);
648 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC,
649 	    PIIX_SMB_HC_KILL);
650 	DELAY(PIIXPM_DELAY);
651 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
652 	if ((st & PIIX_SMB_HS_FAILED) == 0)
653 		aprint_error_dev(sc->sc_dev,
654 		    "transaction abort failed, status 0x%x\n", st);
655 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
656 	/*
657 	 * CSB5 needs hard reset to unlock the smbus after timeout.
658 	 */
659 	if (PIIXPM_IS_CSB5(sc))
660 		piixpm_csb5_reset(sc);
661 	return (1);
662 }
663 
664 static int
665 piixpm_intr(void *arg)
666 {
667 	struct piixpm_softc *sc = arg;
668 	uint8_t st;
669 	uint8_t *b;
670 	size_t len;
671 
672 	/* Read status */
673 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
674 	if ((st & PIIX_SMB_HS_BUSY) != 0 || (st & (PIIX_SMB_HS_INTR |
675 	    PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
676 	    PIIX_SMB_HS_FAILED)) == 0)
677 		/* Interrupt was not for us */
678 		return (0);
679 
680 	DPRINTF(("%s: intr st %#x\n", device_xname(sc->sc_dev), st & 0xff));
681 
682 	/* Clear status bits */
683 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
684 
685 	/* Check for errors */
686 	if (st & (PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
687 	    PIIX_SMB_HS_FAILED)) {
688 		sc->sc_i2c_xfer.error = 1;
689 		goto done;
690 	}
691 
692 	if (st & PIIX_SMB_HS_INTR) {
693 		if (I2C_OP_WRITE_P(sc->sc_i2c_xfer.op))
694 			goto done;
695 
696 		/* Read data */
697 		b = sc->sc_i2c_xfer.buf;
698 		len = sc->sc_i2c_xfer.len;
699 		if (len > 0)
700 			b[0] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
701 			    PIIX_SMB_HD0);
702 		if (len > 1)
703 			b[1] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
704 			    PIIX_SMB_HD1);
705 	}
706 
707 done:
708 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0)
709 		wakeup(sc);
710 	return (1);
711 }
712