xref: /netbsd-src/sys/dev/pci/piixpm.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /* $NetBSD: piixpm.c,v 1.47 2015/12/10 05:29:41 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 1.47 2015/12/10 05:29:41 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/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 	}
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 	pcireg_t base, conf;
158 	pcireg_t pmmisc;
159 	pci_intr_handle_t ih;
160 	const char *intrstr = NULL;
161 	int i, flags;
162 	char intrbuf[PCI_INTRSTR_LEN];
163 
164 	sc->sc_dev = self;
165 	sc->sc_iot = pa->pa_iot;
166 	sc->sc_id = pa->pa_id;
167 	sc->sc_pc = pa->pa_pc;
168 	sc->sc_pcitag = pa->pa_tag;
169 	sc->sc_numbusses = 1;
170 
171 	pci_aprint_devinfo(pa, NULL);
172 
173 	if (!pmf_device_register(self, piixpm_suspend, piixpm_resume))
174 		aprint_error_dev(self, "couldn't establish power handler\n");
175 
176 	/* Read configuration */
177 	conf = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_HOSTC);
178 	DPRINTF(("%s: conf 0x%x\n", device_xname(self), conf));
179 
180 	if ((PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INTEL) ||
181 	    (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_INTEL_82371AB_PMC))
182 		goto nopowermanagement;
183 
184 	/* check whether I/O access to PM regs is enabled */
185 	pmmisc = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PMREGMISC);
186 	if (!(pmmisc & 1))
187 		goto nopowermanagement;
188 
189 	/* Map I/O space */
190 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PM_BASE);
191 	if (bus_space_map(sc->sc_pm_iot, PCI_MAPREG_IO_ADDR(base),
192 	    PIIX_PM_SIZE, 0, &sc->sc_pm_ioh)) {
193 		aprint_error_dev(self, "can't map power management I/O space\n");
194 		goto nopowermanagement;
195 	}
196 
197 	/*
198 	 * Revision 0 and 1 are PIIX4, 2 is PIIX4E, 3 is PIIX4M.
199 	 * PIIX4 and PIIX4E have a bug in the timer latch, see Errata #20
200 	 * in the "Specification update" (document #297738).
201 	 */
202 	acpipmtimer_attach(self, sc->sc_pm_iot, sc->sc_pm_ioh,
203 			   PIIX_PM_PMTMR,
204 		(PCI_REVISION(pa->pa_class) < 3) ? ACPIPMT_BADLATCH : 0 );
205 
206 nopowermanagement:
207 
208 	/* SB800 rev 0x40+ needs special initialization */
209 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_ATI &&
210 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_ATI_SB600_SMB &&
211 	    PCI_REVISION(pa->pa_class) >= 0x40) {
212 		if (piixpm_sb800_init(sc) == 0) {
213 			sc->sc_numbusses = 4;
214 			goto attach_i2c;
215 		}
216 		aprint_normal_dev(self, "SMBus disabled\n");
217 		return;
218 	}
219 
220 	if ((conf & PIIX_SMB_HOSTC_HSTEN) == 0) {
221 		aprint_normal_dev(self, "SMBus disabled\n");
222 		return;
223 	}
224 
225 	/* Map I/O space */
226 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_BASE) & 0xffff;
227 	if (bus_space_map(sc->sc_smb_iot, PCI_MAPREG_IO_ADDR(base),
228 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
229 		aprint_error_dev(self, "can't map smbus I/O space\n");
230 		return;
231 	}
232 
233 	sc->sc_poll = 1;
234 	aprint_normal_dev(self, "");
235 	if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_SMI) {
236 		/* No PCI IRQ */
237 		aprint_normal("interrupting at SMI, ");
238 	} else if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_IRQ) {
239 		/* Install interrupt handler */
240 		if (pci_intr_map(pa, &ih) == 0) {
241 			intrstr = pci_intr_string(pa->pa_pc, ih, intrbuf, sizeof(intrbuf));
242 			sc->sc_smb_ih = pci_intr_establish(pa->pa_pc, ih, IPL_BIO,
243 			    piixpm_intr, sc);
244 			if (sc->sc_smb_ih != NULL) {
245 				aprint_normal("interrupting at %s", intrstr);
246 				sc->sc_poll = 0;
247 			}
248 		}
249 	}
250 	if (sc->sc_poll)
251 		aprint_normal("polling");
252 
253 	aprint_normal("\n");
254 
255 attach_i2c:
256 	for (i = 0; i < sc->sc_numbusses; i++)
257 		sc->sc_i2c_device[i] = NULL;
258 
259 	flags = 0;
260 	mutex_init(&sc->sc_i2c_mutex, MUTEX_DEFAULT, IPL_NONE);
261 	piixpm_rescan(self, "i2cbus", &flags);
262 }
263 
264 static int
265 piixpm_rescan(device_t self, const char *ifattr, const int *flags)
266 {
267 	struct piixpm_softc *sc = device_private(self);
268 	struct i2cbus_attach_args iba;
269 	int i;
270 
271 	if (!ifattr_match(ifattr, "i2cbus"))
272 		return 0;
273 
274 	/* Attach I2C bus */
275 
276 	for (i = 0; i < sc->sc_numbusses; i++) {
277 		if (sc->sc_i2c_device[i])
278 			continue;
279 		sc->sc_busses[i].sda = i;
280 		sc->sc_busses[i].softc = sc;
281 		sc->sc_i2c_tags[i].ic_cookie = &sc->sc_busses[i];
282 		sc->sc_i2c_tags[i].ic_acquire_bus = piixpm_i2c_acquire_bus;
283 		sc->sc_i2c_tags[i].ic_release_bus = piixpm_i2c_release_bus;
284 		sc->sc_i2c_tags[i].ic_exec = piixpm_i2c_exec;
285 		memset(&iba, 0, sizeof(iba));
286 		iba.iba_type = I2C_TYPE_SMBUS;
287 		iba.iba_tag = &sc->sc_i2c_tags[i];
288 		sc->sc_i2c_device[i] = config_found_ia(self, ifattr, &iba,
289 						    iicbus_print);
290 	}
291 
292 	return 0;
293 }
294 
295 static void
296 piixpm_chdet(device_t self, device_t child)
297 {
298 	struct piixpm_softc *sc = device_private(self);
299 	int i;
300 
301 	for (i = 0; i < sc->sc_numbusses; i++) {
302 		if (sc->sc_i2c_device[i] == child) {
303 			sc->sc_i2c_device[i] = NULL;
304 			break;
305 		}
306 	}
307 }
308 
309 
310 static bool
311 piixpm_suspend(device_t dv, const pmf_qual_t *qual)
312 {
313 	struct piixpm_softc *sc = device_private(dv);
314 
315 	sc->sc_devact[0] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
316 	    PIIX_DEVACTA);
317 	sc->sc_devact[1] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
318 	    PIIX_DEVACTB);
319 
320 	return true;
321 }
322 
323 static bool
324 piixpm_resume(device_t dv, const pmf_qual_t *qual)
325 {
326 	struct piixpm_softc *sc = device_private(dv);
327 
328 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTA,
329 	    sc->sc_devact[0]);
330 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTB,
331 	    sc->sc_devact[1]);
332 
333 	return true;
334 }
335 
336 /*
337  * Extract SMBus base address from SB800 Power Management (PM) registers.
338  * The PM registers can be accessed either through indirect I/O (CD6/CD7) or
339  * direct mapping if AcpiMMioDecodeEn is enabled. Since this function is only
340  * called once it uses indirect I/O for simplicity.
341  */
342 static int
343 piixpm_sb800_init(struct piixpm_softc *sc)
344 {
345 	bus_space_tag_t iot = sc->sc_iot;
346 	bus_space_handle_t ioh;	/* indirect I/O handle */
347 	uint16_t val, base_addr;
348 
349 	/* Fetch SMB base address */
350 	if (bus_space_map(iot,
351 	    PIIXPM_INDIRECTIO_BASE, PIIXPM_INDIRECTIO_SIZE, 0, &ioh)) {
352 		device_printf(sc->sc_dev, "couldn't map indirect I/O space\n");
353 		return EBUSY;
354 	}
355 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
356 	    SB800_PM_SMBUS0EN_LO);
357 	val = bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA);
358 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
359 	    SB800_PM_SMBUS0EN_HI);
360 	val |= bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA) << 8;
361 	sc->sc_sb800_ioh = ioh;
362 
363 	if ((val & SB800_PM_SMBUS0EN_ENABLE) == 0)
364 		return ENOENT;
365 
366 	base_addr = val & SB800_PM_SMBUS0EN_BADDR;
367 
368 	aprint_debug_dev(sc->sc_dev, "SMBus @ 0x%04x\n", base_addr);
369 
370 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SELEN);
371 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_DATA, 1); /* SMBUS0SEL */
372 
373 	if (bus_space_map(iot, PCI_MAPREG_IO_ADDR(base_addr),
374 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
375 		aprint_error_dev(sc->sc_dev, "can't map smbus I/O space\n");
376 		return EBUSY;
377 	}
378 	aprint_normal_dev(sc->sc_dev, "polling (SB800)\n");
379 	sc->sc_poll = 1;
380 
381 	return 0;
382 }
383 
384 static void
385 piixpm_csb5_reset(void *arg)
386 {
387 	struct piixpm_softc *sc = arg;
388 	pcireg_t base, hostc, pmbase;
389 
390 	base = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE);
391 	hostc = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC);
392 
393 	pmbase = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE);
394 	pmbase |= PIIX_PM_BASE_CSB5_RESET;
395 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
396 	pmbase &= ~PIIX_PM_BASE_CSB5_RESET;
397 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
398 
399 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE, base);
400 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC, hostc);
401 
402 	(void) tsleep(&sc, PRIBIO, "csb5reset", hz/2);
403 }
404 
405 static int
406 piixpm_i2c_acquire_bus(void *cookie, int flags)
407 {
408 	struct piixpm_smbus *smbus = cookie;
409 	struct piixpm_softc *sc = smbus->softc;
410 
411 	if (!cold)
412 		mutex_enter(&sc->sc_i2c_mutex);
413 
414 	if (smbus->sda > 0)	/* SB800 */
415 	{
416 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
417 		    PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
418 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
419 		    PIIXPM_INDIRECTIO_DATA, smbus->sda << 1);
420 	}
421 
422 	return 0;
423 }
424 
425 static void
426 piixpm_i2c_release_bus(void *cookie, int flags)
427 {
428 	struct piixpm_smbus *smbus = cookie;
429 	struct piixpm_softc *sc = smbus->softc;
430 
431 	if (smbus->sda > 0)	/* SB800 */
432 	{
433 		/*
434 		 * HP Microserver hangs after reboot if not set to SDA0.
435 		 * Also add shutdown hook?
436 		 */
437 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
438 		    PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
439 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
440 		    PIIXPM_INDIRECTIO_DATA, 0);
441 	}
442 
443 	if (!cold)
444 		mutex_exit(&sc->sc_i2c_mutex);
445 }
446 
447 static int
448 piixpm_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr,
449     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
450 {
451 	struct piixpm_smbus *smbus = cookie;
452 	struct piixpm_softc *sc = smbus->softc;
453 	const u_int8_t *b;
454 	u_int8_t ctl = 0, st;
455 	int retries;
456 
457 	DPRINTF(("%s: exec: op %d, addr 0x%x, cmdlen %zu, len %zu, flags 0x%x\n",
458 	    device_xname(sc->sc_dev), op, addr, cmdlen, len, flags));
459 
460 	/* Clear status bits */
461 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS,
462 	    PIIX_SMB_HS_INTR | PIIX_SMB_HS_DEVERR |
463 	    PIIX_SMB_HS_BUSERR | PIIX_SMB_HS_FAILED);
464 	bus_space_barrier(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, 1,
465 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
466 
467 	/* Wait for bus to be idle */
468 	for (retries = 100; retries > 0; retries--) {
469 		st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
470 		    PIIX_SMB_HS);
471 		if (!(st & PIIX_SMB_HS_BUSY))
472 			break;
473 		DELAY(PIIXPM_DELAY);
474 	}
475 	DPRINTF(("%s: exec: st 0x%d\n", device_xname(sc->sc_dev), st & 0xff));
476 	if (st & PIIX_SMB_HS_BUSY)
477 		return (1);
478 
479 	if (cold || sc->sc_poll)
480 		flags |= I2C_F_POLL;
481 
482 	if (!I2C_OP_STOP_P(op) || cmdlen > 1 || len > 2 ||
483 	    (cmdlen == 0 && len > 1))
484 		return (1);
485 
486 	/* Setup transfer */
487 	sc->sc_i2c_xfer.op = op;
488 	sc->sc_i2c_xfer.buf = buf;
489 	sc->sc_i2c_xfer.len = len;
490 	sc->sc_i2c_xfer.flags = flags;
491 	sc->sc_i2c_xfer.error = 0;
492 
493 	/* Set slave address and transfer direction */
494 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_TXSLVA,
495 	    PIIX_SMB_TXSLVA_ADDR(addr) |
496 	    (I2C_OP_READ_P(op) ? PIIX_SMB_TXSLVA_READ : 0));
497 
498 	b = cmdbuf;
499 	if (cmdlen > 0)
500 		/* Set command byte */
501 		bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
502 		    PIIX_SMB_HCMD, b[0]);
503 
504 	if (I2C_OP_WRITE_P(op)) {
505 		/* Write data */
506 		b = buf;
507 		if (cmdlen == 0 && len == 1)
508 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
509 			    PIIX_SMB_HCMD, b[0]);
510 		else if (len > 0)
511 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
512 			    PIIX_SMB_HD0, b[0]);
513 		if (len > 1)
514 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
515 			    PIIX_SMB_HD1, b[1]);
516 	}
517 
518 	/* Set SMBus command */
519 	if (cmdlen == 0) {
520 		if (len == 0)
521 			ctl = PIIX_SMB_HC_CMD_QUICK;
522 		else
523 			ctl = PIIX_SMB_HC_CMD_BYTE;
524 	} else if (len == 1)
525 		ctl = PIIX_SMB_HC_CMD_BDATA;
526 	else if (len == 2)
527 		ctl = PIIX_SMB_HC_CMD_WDATA;
528 
529 	if ((flags & I2C_F_POLL) == 0)
530 		ctl |= PIIX_SMB_HC_INTREN;
531 
532 	/* Start transaction */
533 	ctl |= PIIX_SMB_HC_START;
534 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC, ctl);
535 
536 	if (flags & I2C_F_POLL) {
537 		/* Poll for completion */
538 		if (PIIXPM_IS_CSB5(sc->sc_id))
539 			DELAY(2*PIIXPM_DELAY);
540 		else
541 			DELAY(PIIXPM_DELAY);
542 		for (retries = 1000; retries > 0; retries--) {
543 			st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
544 			    PIIX_SMB_HS);
545 			if ((st & PIIX_SMB_HS_BUSY) == 0)
546 				break;
547 			DELAY(PIIXPM_DELAY);
548 		}
549 		if (st & PIIX_SMB_HS_BUSY)
550 			goto timeout;
551 		piixpm_intr(sc);
552 	} else {
553 		/* Wait for interrupt */
554 		if (tsleep(sc, PRIBIO, "iicexec", PIIXPM_TIMEOUT * hz))
555 			goto timeout;
556 	}
557 
558 	if (sc->sc_i2c_xfer.error)
559 		return (1);
560 
561 	return (0);
562 
563 timeout:
564 	/*
565 	 * Transfer timeout. Kill the transaction and clear status bits.
566 	 */
567 	aprint_error_dev(sc->sc_dev, "timeout, status 0x%x\n", st);
568 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC,
569 	    PIIX_SMB_HC_KILL);
570 	DELAY(PIIXPM_DELAY);
571 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
572 	if ((st & PIIX_SMB_HS_FAILED) == 0)
573 		aprint_error_dev(sc->sc_dev, "transaction abort failed, status 0x%x\n", st);
574 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
575 	/*
576 	 * CSB5 needs hard reset to unlock the smbus after timeout.
577 	 */
578 	if (PIIXPM_IS_CSB5(sc->sc_id))
579 		piixpm_csb5_reset(sc);
580 	return (1);
581 }
582 
583 static int
584 piixpm_intr(void *arg)
585 {
586 	struct piixpm_softc *sc = arg;
587 	u_int8_t st;
588 	u_int8_t *b;
589 	size_t len;
590 
591 	/* Read status */
592 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
593 	if ((st & PIIX_SMB_HS_BUSY) != 0 || (st & (PIIX_SMB_HS_INTR |
594 	    PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
595 	    PIIX_SMB_HS_FAILED)) == 0)
596 		/* Interrupt was not for us */
597 		return (0);
598 
599 	DPRINTF(("%s: intr st 0x%d\n", device_xname(sc->sc_dev), st & 0xff));
600 
601 	/* Clear status bits */
602 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
603 
604 	/* Check for errors */
605 	if (st & (PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
606 	    PIIX_SMB_HS_FAILED)) {
607 		sc->sc_i2c_xfer.error = 1;
608 		goto done;
609 	}
610 
611 	if (st & PIIX_SMB_HS_INTR) {
612 		if (I2C_OP_WRITE_P(sc->sc_i2c_xfer.op))
613 			goto done;
614 
615 		/* Read data */
616 		b = sc->sc_i2c_xfer.buf;
617 		len = sc->sc_i2c_xfer.len;
618 		if (len > 0)
619 			b[0] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
620 			    PIIX_SMB_HD0);
621 		if (len > 1)
622 			b[1] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
623 			    PIIX_SMB_HD1);
624 	}
625 
626 done:
627 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0)
628 		wakeup(sc);
629 	return (1);
630 }
631