xref: /netbsd-src/sys/dev/pci/piixpm.c (revision 627f7eb200a4419d89b531d55fccd2ee3ffdcde0)
1 /* $NetBSD: piixpm.c,v 1.63 2020/01/14 15:42:03 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 1.63 2020/01/14 15:42:03 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/condvar.h>
33 #include <sys/proc.h>
34 
35 #include <sys/bus.h>
36 
37 #include <dev/pci/pcidevs.h>
38 #include <dev/pci/pcireg.h>
39 #include <dev/pci/pcivar.h>
40 
41 #include <dev/pci/piixpmreg.h>
42 
43 #include <dev/i2c/i2cvar.h>
44 
45 #include <dev/ic/acpipmtimer.h>
46 
47 #ifdef PIIXPM_DEBUG
48 #define DPRINTF(x) printf x
49 #else
50 #define DPRINTF(x)
51 #endif
52 
53 #define PIIXPM_IS_CSB5(sc)						      \
54 	(PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_SERVERWORKS &&		      \
55 	PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_SERVERWORKS_CSB5)
56 #define PIIXPM_DELAY	200
57 #define PIIXPM_TIMEOUT	1
58 
59 #define PIIXPM_IS_SB800GRP(sc)						      \
60 	((PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_ATI) &&			      \
61 	    ((PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_ATI_SB600_SMB) &&	      \
62 		((sc)->sc_rev >= 0x40)))
63 
64 #define PIIXPM_IS_HUDSON(sc)						      \
65 	((PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_AMD) &&			      \
66 	    (PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_AMD_HUDSON_SMB))
67 
68 #define PIIXPM_IS_KERNCZ(sc)						      \
69 	((PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_AMD) &&			      \
70 	    (PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_AMD_KERNCZ_SMB))
71 
72 #define PIIXPM_IS_FCHGRP(sc)	(PIIXPM_IS_HUDSON(sc) || PIIXPM_IS_KERNCZ(sc))
73 
74 #define PIIX_SB800_TIMEOUT 500
75 
76 struct piixpm_smbus {
77 	int			sda;
78 	int			sda_save;
79 	struct			piixpm_softc *softc;
80 };
81 
82 struct piixpm_softc {
83 	device_t		sc_dev;
84 
85 	bus_space_tag_t		sc_iot;
86 #define	sc_pm_iot sc_iot
87 #define sc_smb_iot sc_iot
88 	bus_space_handle_t	sc_pm_ioh;
89 	bus_space_handle_t	sc_sb800_ioh;
90 	bus_space_handle_t	sc_smb_ioh;
91 	void *			sc_smb_ih;
92 	int			sc_poll;
93 	bool			sc_sb800_selen; /* Use SMBUS0SEL */
94 
95 	pci_chipset_tag_t	sc_pc;
96 	pcitag_t		sc_pcitag;
97 	pcireg_t		sc_id;
98 	pcireg_t		sc_rev;
99 
100 	int			sc_numbusses;
101 	device_t		sc_i2c_device[4];
102 	struct piixpm_smbus	sc_busses[4];
103 	struct i2c_controller	sc_i2c_tags[4];
104 
105 	kmutex_t		sc_exec_lock;
106 	kcondvar_t		sc_exec_wait;
107 
108 	struct {
109 		i2c_op_t	op;
110 		void *		buf;
111 		size_t		len;
112 		int		flags;
113 		int             error;
114 		bool            done;
115 	}			sc_i2c_xfer;
116 
117 	pcireg_t		sc_devact[2];
118 };
119 
120 static int	piixpm_match(device_t, cfdata_t, void *);
121 static void	piixpm_attach(device_t, device_t, void *);
122 static int	piixpm_rescan(device_t, const char *, const int *);
123 static void	piixpm_chdet(device_t, device_t);
124 
125 static bool	piixpm_suspend(device_t, const pmf_qual_t *);
126 static bool	piixpm_resume(device_t, const pmf_qual_t *);
127 
128 static int	piixpm_sb800_init(struct piixpm_softc *);
129 static void	piixpm_csb5_reset(void *);
130 static int	piixpm_i2c_sb800_acquire_bus(void *, int);
131 static void	piixpm_i2c_sb800_release_bus(void *, int);
132 static int	piixpm_i2c_exec(void *, i2c_op_t, i2c_addr_t, const void *,
133     size_t, void *, size_t, int);
134 
135 static int	piixpm_intr(void *);
136 
137 CFATTACH_DECL3_NEW(piixpm, sizeof(struct piixpm_softc),
138     piixpm_match, piixpm_attach, NULL, NULL, piixpm_rescan, piixpm_chdet, 0);
139 
140 static int
141 piixpm_match(device_t parent, cfdata_t match, void *aux)
142 {
143 	struct pci_attach_args *pa;
144 
145 	pa = (struct pci_attach_args *)aux;
146 	switch (PCI_VENDOR(pa->pa_id)) {
147 	case PCI_VENDOR_INTEL:
148 		switch (PCI_PRODUCT(pa->pa_id)) {
149 		case PCI_PRODUCT_INTEL_82371AB_PMC:
150 		case PCI_PRODUCT_INTEL_82440MX_PMC:
151 			return 1;
152 		}
153 		break;
154 	case PCI_VENDOR_ATI:
155 		switch (PCI_PRODUCT(pa->pa_id)) {
156 		case PCI_PRODUCT_ATI_SB200_SMB:
157 		case PCI_PRODUCT_ATI_SB300_SMB:
158 		case PCI_PRODUCT_ATI_SB400_SMB:
159 		case PCI_PRODUCT_ATI_SB600_SMB:	/* matches SB600/SB700/SB800 */
160 			return 1;
161 		}
162 		break;
163 	case PCI_VENDOR_SERVERWORKS:
164 		switch (PCI_PRODUCT(pa->pa_id)) {
165 		case PCI_PRODUCT_SERVERWORKS_OSB4:
166 		case PCI_PRODUCT_SERVERWORKS_CSB5:
167 		case PCI_PRODUCT_SERVERWORKS_CSB6:
168 		case PCI_PRODUCT_SERVERWORKS_HT1000SB:
169 		case PCI_PRODUCT_SERVERWORKS_HT1100SB:
170 			return 1;
171 		}
172 		break;
173 	case PCI_VENDOR_AMD:
174 		switch (PCI_PRODUCT(pa->pa_id)) {
175 		case PCI_PRODUCT_AMD_HUDSON_SMB:
176 		case PCI_PRODUCT_AMD_KERNCZ_SMB:
177 			return 1;
178 		}
179 		break;
180 	}
181 
182 	return 0;
183 }
184 
185 static void
186 piixpm_attach(device_t parent, device_t self, void *aux)
187 {
188 	struct piixpm_softc *sc = device_private(self);
189 	struct pci_attach_args *pa = aux;
190 	pcireg_t base, conf;
191 	pcireg_t pmmisc;
192 	pci_intr_handle_t ih;
193 	bool usesmi = false;
194 	const char *intrstr = NULL;
195 	int i, flags;
196 	char intrbuf[PCI_INTRSTR_LEN];
197 
198 	sc->sc_dev = self;
199 	sc->sc_iot = pa->pa_iot;
200 	sc->sc_id = pa->pa_id;
201 	sc->sc_rev = PCI_REVISION(pa->pa_class);
202 	sc->sc_pc = pa->pa_pc;
203 	sc->sc_pcitag = pa->pa_tag;
204 	sc->sc_numbusses = 1;
205 
206 	pci_aprint_devinfo(pa, NULL);
207 
208 	mutex_init(&sc->sc_exec_lock, MUTEX_DEFAULT, IPL_BIO);
209 	cv_init(&sc->sc_exec_wait, device_xname(self));
210 
211 	if (!pmf_device_register(self, piixpm_suspend, piixpm_resume))
212 		aprint_error_dev(self, "couldn't establish power handler\n");
213 
214 	if ((PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INTEL) ||
215 	    (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_INTEL_82371AB_PMC))
216 		goto nopowermanagement;
217 
218 	/* check whether I/O access to PM regs is enabled */
219 	pmmisc = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PMREGMISC);
220 	if (!(pmmisc & 1))
221 		goto nopowermanagement;
222 
223 	/* Map I/O space */
224 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PM_BASE);
225 	if (base == 0 || bus_space_map(sc->sc_pm_iot, PCI_MAPREG_IO_ADDR(base),
226 	    PIIX_PM_SIZE, 0, &sc->sc_pm_ioh)) {
227 		aprint_error_dev(self,
228 		    "can't map power management I/O space\n");
229 		goto nopowermanagement;
230 	}
231 
232 	/*
233 	 * Revision 0 and 1 are PIIX4, 2 is PIIX4E, 3 is PIIX4M.
234 	 * PIIX4 and PIIX4E have a bug in the timer latch, see Errata #20
235 	 * in the "Specification update" (document #297738).
236 	 */
237 	acpipmtimer_attach(self, sc->sc_pm_iot, sc->sc_pm_ioh, PIIX_PM_PMTMR,
238 	    (PCI_REVISION(pa->pa_class) < 3) ? ACPIPMT_BADLATCH : 0);
239 
240 nopowermanagement:
241 
242 	/* SB800 rev 0x40+, AMD HUDSON and newer need special initialization */
243 	if (PIIXPM_IS_FCHGRP(sc) || PIIXPM_IS_SB800GRP(sc)) {
244 		if (piixpm_sb800_init(sc) == 0) {
245 			/* Read configuration */
246 			conf = bus_space_read_1(sc->sc_iot,
247 			    sc->sc_smb_ioh, SB800_SMB_HOSTC);
248 			usesmi = ((conf & SB800_SMB_HOSTC_IRQ) == 0);
249 			goto setintr;
250 		}
251 		aprint_normal_dev(self, "SMBus initialization failed\n");
252 		return;
253 	}
254 
255 	/* Read configuration */
256 	conf = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_HOSTC);
257 	DPRINTF(("%s: conf 0x%08x\n", device_xname(self), conf));
258 
259 	if ((conf & PIIX_SMB_HOSTC_HSTEN) == 0) {
260 		aprint_normal_dev(self, "SMBus disabled\n");
261 		return;
262 	}
263 	usesmi = (conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_SMI;
264 
265 	/* Map I/O space */
266 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_BASE) & 0xffff;
267 	if (base == 0 ||
268 	    bus_space_map(sc->sc_smb_iot, PCI_MAPREG_IO_ADDR(base),
269 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
270 		aprint_error_dev(self, "can't map smbus I/O space\n");
271 		return;
272 	}
273 
274 setintr:
275 	sc->sc_poll = 1;
276 	aprint_normal_dev(self, "");
277 	if (usesmi) {
278 		/* No PCI IRQ */
279 		aprint_normal("interrupting at SMI, ");
280 	} else {
281 		if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_IRQ) {
282 			/* Install interrupt handler */
283 			if (pci_intr_map(pa, &ih) == 0) {
284 				intrstr = pci_intr_string(pa->pa_pc, ih,
285 				    intrbuf, sizeof(intrbuf));
286 				pci_intr_setattr(pa->pa_pc, &ih,
287 				    PCI_INTR_MPSAFE, true);
288 				sc->sc_smb_ih = pci_intr_establish_xname(
289 					pa->pa_pc, ih, IPL_BIO, piixpm_intr,
290 					sc, device_xname(sc->sc_dev));
291 				if (sc->sc_smb_ih != NULL) {
292 					aprint_normal("interrupting at %s",
293 					    intrstr);
294 					sc->sc_poll = 0;
295 				}
296 			}
297 		}
298 		if (sc->sc_poll)
299 			aprint_normal("polling");
300 	}
301 
302 	aprint_normal("\n");
303 
304 	for (i = 0; i < sc->sc_numbusses; i++)
305 		sc->sc_i2c_device[i] = NULL;
306 
307 	flags = 0;
308 	piixpm_rescan(self, "i2cbus", &flags);
309 }
310 
311 static int
312 piixpm_iicbus_print(void *aux, const char *pnp)
313 {
314 	struct i2cbus_attach_args *iba = aux;
315 	struct i2c_controller *tag = iba->iba_tag;
316 	struct piixpm_smbus *bus = tag->ic_cookie;
317 	struct piixpm_softc *sc = bus->softc;
318 
319 	iicbus_print(aux, pnp);
320 	if (sc->sc_numbusses != 0)
321 		aprint_normal(" port %d", bus->sda);
322 
323 	return UNCONF;
324 }
325 static int
326 piixpm_rescan(device_t self, const char *ifattr, const int *flags)
327 {
328 	struct piixpm_softc *sc = device_private(self);
329 	struct i2cbus_attach_args iba;
330 	int i;
331 
332 	if (!ifattr_match(ifattr, "i2cbus"))
333 		return 0;
334 
335 	/* Attach I2C bus */
336 
337 	for (i = 0; i < sc->sc_numbusses; i++) {
338 		struct i2c_controller *tag = &sc->sc_i2c_tags[i];
339 
340 		if (sc->sc_i2c_device[i])
341 			continue;
342 		sc->sc_busses[i].sda = i;
343 		sc->sc_busses[i].softc = sc;
344 		iic_tag_init(tag);
345 		tag->ic_cookie = &sc->sc_busses[i];
346 		if (PIIXPM_IS_SB800GRP(sc) || PIIXPM_IS_FCHGRP(sc)) {
347 			tag->ic_acquire_bus = piixpm_i2c_sb800_acquire_bus;
348 			tag->ic_release_bus = piixpm_i2c_sb800_release_bus;
349 		} else {
350 			tag->ic_acquire_bus = NULL;
351 			tag->ic_release_bus = NULL;
352 		}
353 		tag->ic_exec = piixpm_i2c_exec;
354 		memset(&iba, 0, sizeof(iba));
355 		iba.iba_tag = tag;
356 		sc->sc_i2c_device[i] = config_found_ia(self, ifattr, &iba,
357 		    piixpm_iicbus_print);
358 	}
359 
360 	return 0;
361 }
362 
363 static void
364 piixpm_chdet(device_t self, device_t child)
365 {
366 	struct piixpm_softc *sc = device_private(self);
367 	int i;
368 
369 	for (i = 0; i < sc->sc_numbusses; i++) {
370 		if (sc->sc_i2c_device[i] == child) {
371 			sc->sc_i2c_device[i] = NULL;
372 			break;
373 		}
374 	}
375 }
376 
377 
378 static bool
379 piixpm_suspend(device_t dv, const pmf_qual_t *qual)
380 {
381 	struct piixpm_softc *sc = device_private(dv);
382 
383 	sc->sc_devact[0] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
384 	    PIIX_DEVACTA);
385 	sc->sc_devact[1] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
386 	    PIIX_DEVACTB);
387 
388 	return true;
389 }
390 
391 static bool
392 piixpm_resume(device_t dv, const pmf_qual_t *qual)
393 {
394 	struct piixpm_softc *sc = device_private(dv);
395 
396 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTA,
397 	    sc->sc_devact[0]);
398 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTB,
399 	    sc->sc_devact[1]);
400 
401 	return true;
402 }
403 
404 /*
405  * Extract SMBus base address from SB800 Power Management (PM) registers.
406  * The PM registers can be accessed either through indirect I/O (CD6/CD7) or
407  * direct mapping if AcpiMMioDecodeEn is enabled. Since this function is only
408  * called once it uses indirect I/O for simplicity.
409  */
410 static int
411 piixpm_sb800_init(struct piixpm_softc *sc)
412 {
413 	bus_space_tag_t iot = sc->sc_iot;
414 	bus_space_handle_t ioh;	/* indirect I/O handle */
415 	uint16_t val, base_addr;
416 	bool enabled;
417 
418 	if (PIIXPM_IS_KERNCZ(sc) ||
419 	    (PIIXPM_IS_HUDSON(sc) && (sc->sc_rev >= 0x1f)))
420 		sc->sc_numbusses = 2;
421 	else
422 		sc->sc_numbusses = 4;
423 
424 	/* Fetch SMB base address */
425 	if (bus_space_map(iot,
426 	    SB800_INDIRECTIO_BASE, SB800_INDIRECTIO_SIZE, 0, &ioh)) {
427 		device_printf(sc->sc_dev, "couldn't map indirect I/O space\n");
428 		return EBUSY;
429 	}
430 	if (PIIXPM_IS_FCHGRP(sc)) {
431 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
432 		    AMDFCH41_PM_DECODE_EN0);
433 		val = bus_space_read_1(iot, ioh, SB800_INDIRECTIO_DATA);
434 		enabled = val & AMDFCH41_SMBUS_EN;
435 		if (!enabled)
436 			return ENOENT;
437 
438 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
439 		    AMDFCH41_PM_DECODE_EN1);
440 		val = bus_space_read_1(iot, ioh, SB800_INDIRECTIO_DATA) << 8;
441 		base_addr = val;
442 	} else {
443 		uint8_t data;
444 
445 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
446 		    SB800_PM_SMBUS0EN_LO);
447 		val = bus_space_read_1(iot, ioh, SB800_INDIRECTIO_DATA);
448 		enabled = val & SB800_PM_SMBUS0EN_ENABLE;
449 		if (!enabled)
450 			return ENOENT;
451 
452 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
453 		    SB800_PM_SMBUS0EN_HI);
454 		val |= bus_space_read_1(iot, ioh, SB800_INDIRECTIO_DATA) << 8;
455 		base_addr = val & SB800_PM_SMBUS0EN_BADDR;
456 
457 		bus_space_write_1(iot, ioh, SB800_INDIRECTIO_INDEX,
458 		    SB800_PM_SMBUS0SELEN);
459 		data = bus_space_read_1(iot, ioh, SB800_INDIRECTIO_DATA);
460 		if ((data & SB800_PM_USE_SMBUS0SEL) != 0)
461 			sc->sc_sb800_selen = true;
462 	}
463 
464 	sc->sc_sb800_ioh = ioh;
465 	aprint_debug_dev(sc->sc_dev, "SMBus @ 0x%04x\n", base_addr);
466 
467 	if (bus_space_map(iot, PCI_MAPREG_IO_ADDR(base_addr),
468 	    SB800_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
469 		aprint_error_dev(sc->sc_dev, "can't map smbus I/O space\n");
470 		return EBUSY;
471 	}
472 
473 	return 0;
474 }
475 
476 static void
477 piixpm_csb5_reset(void *arg)
478 {
479 	struct piixpm_softc *sc = arg;
480 	pcireg_t base, hostc, pmbase;
481 
482 	base = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE);
483 	hostc = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC);
484 
485 	pmbase = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE);
486 	pmbase |= PIIX_PM_BASE_CSB5_RESET;
487 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
488 	pmbase &= ~PIIX_PM_BASE_CSB5_RESET;
489 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
490 
491 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE, base);
492 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC, hostc);
493 
494 	(void) tsleep(&sc, PRIBIO, "csb5reset", hz/2);
495 }
496 
497 static int
498 piixpm_i2c_sb800_acquire_bus(void *cookie, int flags)
499 {
500 	struct piixpm_smbus *smbus = cookie;
501 	struct piixpm_softc *sc = smbus->softc;
502 	uint8_t sctl, old_sda, index, mask, reg;
503 	int i;
504 
505 	sctl = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_SC);
506 	for (i = 0; i < PIIX_SB800_TIMEOUT; i++) {
507 		/* Try to acquire the host semaphore */
508 		sctl &= ~PIIX_SMB_SC_SEMMASK;
509 		bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_SC,
510 		    sctl | PIIX_SMB_SC_HOSTSEM);
511 
512 		sctl = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
513 		    PIIX_SMB_SC);
514 		if ((sctl & PIIX_SMB_SC_HOSTSEM) != 0)
515 			break;
516 
517 		delay(1000);
518 	}
519 	if (i >= PIIX_SB800_TIMEOUT) {
520 		device_printf(sc->sc_dev,
521 		    "Failed to acquire the host semaphore\n");
522 		return -1;
523 	}
524 
525 	if (PIIXPM_IS_KERNCZ(sc) ||
526 	    (PIIXPM_IS_HUDSON(sc) && (sc->sc_rev >= 0x1f))) {
527 		index = AMDFCH41_PM_PORT_INDEX;
528 		mask = AMDFCH41_SMBUS_PORTMASK;
529 	} else if (sc->sc_sb800_selen) {
530 		index = SB800_PM_SMBUS0SEL;
531 		mask = SB800_PM_SMBUS0_MASK_E;
532 	} else {
533 		index = SB800_PM_SMBUS0EN_LO;
534 		mask = SB800_PM_SMBUS0_MASK_C;
535 	}
536 
537 	bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
538 	    SB800_INDIRECTIO_INDEX, index);
539 	reg = bus_space_read_1(sc->sc_iot, sc->sc_sb800_ioh,
540 	    SB800_INDIRECTIO_DATA);
541 
542 	old_sda = __SHIFTOUT(reg, mask);
543 	if (smbus->sda != old_sda) {
544 		reg &= ~mask;
545 		reg |= __SHIFTIN(smbus->sda, mask);
546 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
547 		    SB800_INDIRECTIO_DATA, reg);
548 	}
549 
550 	/* Save the old port number */
551 	smbus->sda_save = old_sda;
552 
553 	return 0;
554 }
555 
556 static void
557 piixpm_i2c_sb800_release_bus(void *cookie, int flags)
558 {
559 	struct piixpm_smbus *smbus = cookie;
560 	struct piixpm_softc *sc = smbus->softc;
561 	uint8_t sctl, index, mask, reg;
562 
563 	if (PIIXPM_IS_KERNCZ(sc) ||
564 	    (PIIXPM_IS_HUDSON(sc) && (sc->sc_rev >= 0x1f))) {
565 		index = AMDFCH41_PM_PORT_INDEX;
566 		mask = AMDFCH41_SMBUS_PORTMASK;
567 	} else if (sc->sc_sb800_selen) {
568 		index = SB800_PM_SMBUS0SEL;
569 		mask = SB800_PM_SMBUS0_MASK_E;
570 	} else {
571 		index = SB800_PM_SMBUS0EN_LO;
572 		mask = SB800_PM_SMBUS0_MASK_C;
573 	}
574 
575 	bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
576 	    SB800_INDIRECTIO_INDEX, index);
577 	if (smbus->sda != smbus->sda_save) {
578 		/* Restore the port number */
579 		reg = bus_space_read_1(sc->sc_iot, sc->sc_sb800_ioh,
580 		    SB800_INDIRECTIO_DATA);
581 		reg &= ~mask;
582 		reg |= __SHIFTIN(smbus->sda_save, mask);
583 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
584 		    SB800_INDIRECTIO_DATA, reg);
585 	}
586 
587 	/* Relase the host semaphore */
588 	sctl = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_SC);
589 	sctl &= ~PIIX_SMB_SC_SEMMASK;
590 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_SC,
591 	    sctl | PIIX_SMB_SC_CLRHOSTSEM);
592 }
593 
594 static int
595 piixpm_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr,
596     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
597 {
598 	struct piixpm_smbus *smbus = cookie;
599 	struct piixpm_softc *sc = smbus->softc;
600 	const uint8_t *b;
601 	uint8_t ctl = 0, st;
602 	int retries;
603 
604 	DPRINTF(("%s: exec: op %d, addr 0x%02x, cmdlen %zu, len %zu, "
605 		"flags 0x%x\n",
606 		device_xname(sc->sc_dev), op, addr, cmdlen, len, flags));
607 
608 	mutex_enter(&sc->sc_exec_lock);
609 
610 	/* Clear status bits */
611 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS,
612 	    PIIX_SMB_HS_INTR | PIIX_SMB_HS_DEVERR |
613 	    PIIX_SMB_HS_BUSERR | PIIX_SMB_HS_FAILED);
614 	bus_space_barrier(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, 1,
615 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
616 
617 	/* Wait for bus to be idle */
618 	for (retries = 100; retries > 0; retries--) {
619 		st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
620 		    PIIX_SMB_HS);
621 		if (!(st & PIIX_SMB_HS_BUSY))
622 			break;
623 		DELAY(PIIXPM_DELAY);
624 	}
625 	DPRINTF(("%s: exec: st %#x\n", device_xname(sc->sc_dev), st & 0xff));
626 	if (st & PIIX_SMB_HS_BUSY) {
627 		mutex_exit(&sc->sc_exec_lock);
628 		return (EBUSY);
629 	}
630 
631 	if (sc->sc_poll)
632 		flags |= I2C_F_POLL;
633 
634 	if (!I2C_OP_STOP_P(op) || cmdlen > 1 || len > 2 ||
635 	    (cmdlen == 0 && len > 1)) {
636 		mutex_exit(&sc->sc_exec_lock);
637 		return (EINVAL);
638 	}
639 
640 	/* Setup transfer */
641 	sc->sc_i2c_xfer.op = op;
642 	sc->sc_i2c_xfer.buf = buf;
643 	sc->sc_i2c_xfer.len = len;
644 	sc->sc_i2c_xfer.flags = flags;
645 	sc->sc_i2c_xfer.error = 0;
646 	sc->sc_i2c_xfer.done = false;
647 
648 	/* Set slave address and transfer direction */
649 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_TXSLVA,
650 	    PIIX_SMB_TXSLVA_ADDR(addr) |
651 	    (I2C_OP_READ_P(op) ? PIIX_SMB_TXSLVA_READ : 0));
652 
653 	b = cmdbuf;
654 	if (cmdlen > 0)
655 		/* Set command byte */
656 		bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
657 		    PIIX_SMB_HCMD, b[0]);
658 
659 	if (I2C_OP_WRITE_P(op)) {
660 		/* Write data */
661 		b = buf;
662 		if (cmdlen == 0 && len == 1)
663 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
664 			    PIIX_SMB_HCMD, b[0]);
665 		else if (len > 0)
666 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
667 			    PIIX_SMB_HD0, b[0]);
668 		if (len > 1)
669 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
670 			    PIIX_SMB_HD1, b[1]);
671 	}
672 
673 	/* Set SMBus command */
674 	if (cmdlen == 0) {
675 		if (len == 0)
676 			ctl = PIIX_SMB_HC_CMD_QUICK;
677 		else
678 			ctl = PIIX_SMB_HC_CMD_BYTE;
679 	} else if (len == 1)
680 		ctl = PIIX_SMB_HC_CMD_BDATA;
681 	else if (len == 2)
682 		ctl = PIIX_SMB_HC_CMD_WDATA;
683 	else
684 		panic("%s: unexpected len %zu", __func__, len);
685 
686 	if ((flags & I2C_F_POLL) == 0)
687 		ctl |= PIIX_SMB_HC_INTREN;
688 
689 	/* Start transaction */
690 	ctl |= PIIX_SMB_HC_START;
691 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC, ctl);
692 
693 	if (flags & I2C_F_POLL) {
694 		/* Poll for completion */
695 		if (PIIXPM_IS_CSB5(sc))
696 			DELAY(2*PIIXPM_DELAY);
697 		else
698 			DELAY(PIIXPM_DELAY);
699 		for (retries = 1000; retries > 0; retries--) {
700 			st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
701 			    PIIX_SMB_HS);
702 			if ((st & PIIX_SMB_HS_BUSY) == 0)
703 				break;
704 			DELAY(PIIXPM_DELAY);
705 		}
706 		if (st & PIIX_SMB_HS_BUSY)
707 			goto timeout;
708 		piixpm_intr(sc);
709 	} else {
710 		/* Wait for interrupt */
711 		while (! sc->sc_i2c_xfer.done) {
712 			if (cv_timedwait(&sc->sc_exec_wait, &sc->sc_exec_lock,
713 					 PIIXPM_TIMEOUT * hz))
714 				goto timeout;
715 		}
716 	}
717 
718 	int error = sc->sc_i2c_xfer.error;
719 	mutex_exit(&sc->sc_exec_lock);
720 
721 	return (error);
722 
723 timeout:
724 	/*
725 	 * Transfer timeout. Kill the transaction and clear status bits.
726 	 */
727 	aprint_error_dev(sc->sc_dev, "timeout, status 0x%x\n", st);
728 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC,
729 	    PIIX_SMB_HC_KILL);
730 	DELAY(PIIXPM_DELAY);
731 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
732 	if ((st & PIIX_SMB_HS_FAILED) == 0)
733 		aprint_error_dev(sc->sc_dev,
734 		    "transaction abort failed, status 0x%x\n", st);
735 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
736 	/*
737 	 * CSB5 needs hard reset to unlock the smbus after timeout.
738 	 */
739 	if (PIIXPM_IS_CSB5(sc))
740 		piixpm_csb5_reset(sc);
741 	mutex_exit(&sc->sc_exec_lock);
742 	return (ETIMEDOUT);
743 }
744 
745 static int
746 piixpm_intr(void *arg)
747 {
748 	struct piixpm_softc *sc = arg;
749 	uint8_t st;
750 	uint8_t *b;
751 	size_t len;
752 
753 	/* Read status */
754 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
755 	if ((st & PIIX_SMB_HS_BUSY) != 0 || (st & (PIIX_SMB_HS_INTR |
756 	    PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
757 	    PIIX_SMB_HS_FAILED)) == 0)
758 		/* Interrupt was not for us */
759 		return (0);
760 
761 	DPRINTF(("%s: intr st %#x\n", device_xname(sc->sc_dev), st & 0xff));
762 
763 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0)
764 		mutex_enter(&sc->sc_exec_lock);
765 
766 	/* Clear status bits */
767 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
768 
769 	/* Check for errors */
770 	if (st & (PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
771 	    PIIX_SMB_HS_FAILED)) {
772 		sc->sc_i2c_xfer.error = EIO;
773 		goto done;
774 	}
775 
776 	if (st & PIIX_SMB_HS_INTR) {
777 		if (I2C_OP_WRITE_P(sc->sc_i2c_xfer.op))
778 			goto done;
779 
780 		/* Read data */
781 		b = sc->sc_i2c_xfer.buf;
782 		len = sc->sc_i2c_xfer.len;
783 		if (len > 0)
784 			b[0] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
785 			    PIIX_SMB_HD0);
786 		if (len > 1)
787 			b[1] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
788 			    PIIX_SMB_HD1);
789 	}
790 
791 done:
792 	sc->sc_i2c_xfer.done = true;
793 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0) {
794 		cv_signal(&sc->sc_exec_wait);
795 		mutex_exit(&sc->sc_exec_lock);
796 	}
797 	return (1);
798 }
799