xref: /netbsd-src/sys/dev/pci/piixpm.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /* $NetBSD: piixpm.c,v 1.45 2014/06/22 09:48:20 hannken 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 1.45 2014/06/22 09:48:20 hannken 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 	struct piixpm_smbus	sc_busses[4];
80 	struct i2c_controller	sc_i2c_tags[4];
81 
82 	kmutex_t		sc_i2c_mutex;
83 	struct {
84 		i2c_op_t	op;
85 		void *		buf;
86 		size_t		len;
87 		int		flags;
88 		volatile int	error;
89 	}			sc_i2c_xfer;
90 
91 	pcireg_t		sc_devact[2];
92 };
93 
94 static int	piixpm_match(device_t, cfdata_t, void *);
95 static void	piixpm_attach(device_t, device_t, void *);
96 
97 static bool	piixpm_suspend(device_t, const pmf_qual_t *);
98 static bool	piixpm_resume(device_t, const pmf_qual_t *);
99 
100 static int	piixpm_sb800_init(struct piixpm_softc *);
101 static void	piixpm_csb5_reset(void *);
102 static int	piixpm_i2c_acquire_bus(void *, int);
103 static void	piixpm_i2c_release_bus(void *, int);
104 static int	piixpm_i2c_exec(void *, i2c_op_t, i2c_addr_t, const void *,
105     size_t, void *, size_t, int);
106 
107 static int	piixpm_intr(void *);
108 
109 CFATTACH_DECL_NEW(piixpm, sizeof(struct piixpm_softc),
110     piixpm_match, piixpm_attach, NULL, NULL);
111 
112 static int
113 piixpm_match(device_t parent, cfdata_t match, void *aux)
114 {
115 	struct pci_attach_args *pa;
116 
117 	pa = (struct pci_attach_args *)aux;
118 	switch (PCI_VENDOR(pa->pa_id)) {
119 	case PCI_VENDOR_INTEL:
120 		switch (PCI_PRODUCT(pa->pa_id)) {
121 		case PCI_PRODUCT_INTEL_82371AB_PMC:
122 		case PCI_PRODUCT_INTEL_82440MX_PMC:
123 			return 1;
124 		}
125 		break;
126 	case PCI_VENDOR_ATI:
127 		switch (PCI_PRODUCT(pa->pa_id)) {
128 		case PCI_PRODUCT_ATI_SB200_SMB:
129 		case PCI_PRODUCT_ATI_SB300_SMB:
130 		case PCI_PRODUCT_ATI_SB400_SMB:
131 		case PCI_PRODUCT_ATI_SB600_SMB:	/* matches SB600/SB700/SB800 */
132 			return 1;
133 		}
134 		break;
135 	case PCI_VENDOR_SERVERWORKS:
136 		switch (PCI_PRODUCT(pa->pa_id)) {
137 		case PCI_PRODUCT_SERVERWORKS_OSB4:
138 		case PCI_PRODUCT_SERVERWORKS_CSB5:
139 		case PCI_PRODUCT_SERVERWORKS_CSB6:
140 		case PCI_PRODUCT_SERVERWORKS_HT1000SB:
141 			return 1;
142 		}
143 	}
144 
145 	return 0;
146 }
147 
148 static void
149 piixpm_attach(device_t parent, device_t self, void *aux)
150 {
151 	struct piixpm_softc *sc = device_private(self);
152 	struct pci_attach_args *pa = aux;
153 	struct i2cbus_attach_args iba;
154 	pcireg_t base, conf;
155 	pcireg_t pmmisc;
156 	pci_intr_handle_t ih;
157 	const char *intrstr = NULL;
158 	int i, numbusses = 1;
159 	char intrbuf[PCI_INTRSTR_LEN];
160 
161 	sc->sc_dev = self;
162 	sc->sc_iot = pa->pa_iot;
163 	sc->sc_id = pa->pa_id;
164 	sc->sc_pc = pa->pa_pc;
165 	sc->sc_pcitag = pa->pa_tag;
166 
167 	pci_aprint_devinfo(pa, NULL);
168 
169 	if (!pmf_device_register(self, piixpm_suspend, piixpm_resume))
170 		aprint_error_dev(self, "couldn't establish power handler\n");
171 
172 	/* Read configuration */
173 	conf = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_HOSTC);
174 	DPRINTF(("%s: conf 0x%x\n", device_xname(self), conf));
175 
176 	if ((PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INTEL) ||
177 	    (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_INTEL_82371AB_PMC))
178 		goto nopowermanagement;
179 
180 	/* check whether I/O access to PM regs is enabled */
181 	pmmisc = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PMREGMISC);
182 	if (!(pmmisc & 1))
183 		goto nopowermanagement;
184 
185 	/* Map I/O space */
186 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PM_BASE);
187 	if (bus_space_map(sc->sc_pm_iot, PCI_MAPREG_IO_ADDR(base),
188 	    PIIX_PM_SIZE, 0, &sc->sc_pm_ioh)) {
189 		aprint_error_dev(self, "can't map power management I/O space\n");
190 		goto nopowermanagement;
191 	}
192 
193 	/*
194 	 * Revision 0 and 1 are PIIX4, 2 is PIIX4E, 3 is PIIX4M.
195 	 * PIIX4 and PIIX4E have a bug in the timer latch, see Errata #20
196 	 * in the "Specification update" (document #297738).
197 	 */
198 	acpipmtimer_attach(self, sc->sc_pm_iot, sc->sc_pm_ioh,
199 			   PIIX_PM_PMTMR,
200 		(PCI_REVISION(pa->pa_class) < 3) ? ACPIPMT_BADLATCH : 0 );
201 
202 nopowermanagement:
203 
204 	/* SB800 rev 0x40+ needs special initialization */
205 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_ATI &&
206 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_ATI_SB600_SMB &&
207 	    PCI_REVISION(pa->pa_class) >= 0x40) {
208 		if (piixpm_sb800_init(sc) == 0) {
209 			numbusses = 4;
210 			goto attach_i2c;
211 		}
212 		aprint_normal_dev(self, "SMBus disabled\n");
213 		return;
214 	}
215 
216 	if ((conf & PIIX_SMB_HOSTC_HSTEN) == 0) {
217 		aprint_normal_dev(self, "SMBus disabled\n");
218 		return;
219 	}
220 
221 	/* Map I/O space */
222 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_BASE) & 0xffff;
223 	if (bus_space_map(sc->sc_smb_iot, PCI_MAPREG_IO_ADDR(base),
224 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
225 		aprint_error_dev(self, "can't map smbus I/O space\n");
226 		return;
227 	}
228 
229 	sc->sc_poll = 1;
230 	aprint_normal_dev(self, "");
231 	if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_SMI) {
232 		/* No PCI IRQ */
233 		aprint_normal("interrupting at SMI, ");
234 	} else if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_IRQ) {
235 		/* Install interrupt handler */
236 		if (pci_intr_map(pa, &ih) == 0) {
237 			intrstr = pci_intr_string(pa->pa_pc, ih, intrbuf, sizeof(intrbuf));
238 			sc->sc_smb_ih = pci_intr_establish(pa->pa_pc, ih, IPL_BIO,
239 			    piixpm_intr, sc);
240 			if (sc->sc_smb_ih != NULL) {
241 				aprint_normal("interrupting at %s", intrstr);
242 				sc->sc_poll = 0;
243 			}
244 		}
245 	}
246 	if (sc->sc_poll)
247 		aprint_normal("polling");
248 
249 	aprint_normal("\n");
250 
251 attach_i2c:
252 	/* Attach I2C bus */
253 	mutex_init(&sc->sc_i2c_mutex, MUTEX_DEFAULT, IPL_NONE);
254 
255 	for (i = 0; i < numbusses; i++) {
256 		sc->sc_busses[i].sda = i;
257 		sc->sc_busses[i].softc = sc;
258 		sc->sc_i2c_tags[i].ic_cookie = &sc->sc_busses[i];
259 		sc->sc_i2c_tags[i].ic_acquire_bus = piixpm_i2c_acquire_bus;
260 		sc->sc_i2c_tags[i].ic_release_bus = piixpm_i2c_release_bus;
261 		sc->sc_i2c_tags[i].ic_exec = piixpm_i2c_exec;
262 
263 		memset(&iba, 0, sizeof(iba));
264 		iba.iba_type = I2C_TYPE_SMBUS;
265 		iba.iba_tag = &sc->sc_i2c_tags[i];
266 		config_found_ia(self, "i2cbus", &iba, iicbus_print);
267 	}
268 }
269 
270 static bool
271 piixpm_suspend(device_t dv, const pmf_qual_t *qual)
272 {
273 	struct piixpm_softc *sc = device_private(dv);
274 
275 	sc->sc_devact[0] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
276 	    PIIX_DEVACTA);
277 	sc->sc_devact[1] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
278 	    PIIX_DEVACTB);
279 
280 	return true;
281 }
282 
283 static bool
284 piixpm_resume(device_t dv, const pmf_qual_t *qual)
285 {
286 	struct piixpm_softc *sc = device_private(dv);
287 
288 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTA,
289 	    sc->sc_devact[0]);
290 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTB,
291 	    sc->sc_devact[1]);
292 
293 	return true;
294 }
295 
296 /*
297  * Extract SMBus base address from SB800 Power Management (PM) registers.
298  * The PM registers can be accessed either through indirect I/O (CD6/CD7) or
299  * direct mapping if AcpiMMioDecodeEn is enabled. Since this function is only
300  * called once it uses indirect I/O for simplicity.
301  */
302 static int
303 piixpm_sb800_init(struct piixpm_softc *sc)
304 {
305 	bus_space_tag_t iot = sc->sc_iot;
306 	bus_space_handle_t ioh;	/* indirect I/O handle */
307 	uint16_t val, base_addr;
308 
309 	/* Fetch SMB base address */
310 	if (bus_space_map(iot,
311 	    PIIXPM_INDIRECTIO_BASE, PIIXPM_INDIRECTIO_SIZE, 0, &ioh)) {
312 		device_printf(sc->sc_dev, "couldn't map indirect I/O space\n");
313 		return EBUSY;
314 	}
315 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
316 	    SB800_PM_SMBUS0EN_LO);
317 	val = bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA);
318 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX,
319 	    SB800_PM_SMBUS0EN_HI);
320 	val |= bus_space_read_1(iot, ioh, PIIXPM_INDIRECTIO_DATA) << 8;
321 	sc->sc_sb800_ioh = ioh;
322 
323 	if ((val & SB800_PM_SMBUS0EN_ENABLE) == 0)
324 		return ENOENT;
325 
326 	base_addr = val & SB800_PM_SMBUS0EN_BADDR;
327 
328 	aprint_debug_dev(sc->sc_dev, "SMBus @ 0x%04x\n", base_addr);
329 
330 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SELEN);
331 	bus_space_write_1(iot, ioh, PIIXPM_INDIRECTIO_DATA, 1); /* SMBUS0SEL */
332 
333 	if (bus_space_map(iot, PCI_MAPREG_IO_ADDR(base_addr),
334 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
335 		aprint_error_dev(sc->sc_dev, "can't map smbus I/O space\n");
336 		return EBUSY;
337 	}
338 	aprint_normal_dev(sc->sc_dev, "polling (SB800)\n");
339 	sc->sc_poll = 1;
340 
341 	return 0;
342 }
343 
344 static void
345 piixpm_csb5_reset(void *arg)
346 {
347 	struct piixpm_softc *sc = arg;
348 	pcireg_t base, hostc, pmbase;
349 
350 	base = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE);
351 	hostc = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC);
352 
353 	pmbase = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE);
354 	pmbase |= PIIX_PM_BASE_CSB5_RESET;
355 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
356 	pmbase &= ~PIIX_PM_BASE_CSB5_RESET;
357 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
358 
359 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE, base);
360 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC, hostc);
361 
362 	(void) tsleep(&sc, PRIBIO, "csb5reset", hz/2);
363 }
364 
365 static int
366 piixpm_i2c_acquire_bus(void *cookie, int flags)
367 {
368 	struct piixpm_smbus *smbus = cookie;
369 	struct piixpm_softc *sc = smbus->softc;
370 
371 	if (!cold)
372 		mutex_enter(&sc->sc_i2c_mutex);
373 
374 	if (smbus->sda > 0)	/* SB800 */
375 	{
376 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
377 		    PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
378 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
379 		    PIIXPM_INDIRECTIO_DATA, smbus->sda << 1);
380 	}
381 
382 	return 0;
383 }
384 
385 static void
386 piixpm_i2c_release_bus(void *cookie, int flags)
387 {
388 	struct piixpm_smbus *smbus = cookie;
389 	struct piixpm_softc *sc = smbus->softc;
390 
391 	if (smbus->sda > 0)	/* SB800 */
392 	{
393 		/*
394 		 * HP Microserver hangs after reboot if not set to SDA0.
395 		 * Also add shutdown hook?
396 		 */
397 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
398 		    PIIXPM_INDIRECTIO_INDEX, SB800_PM_SMBUS0SEL);
399 		bus_space_write_1(sc->sc_iot, sc->sc_sb800_ioh,
400 		    PIIXPM_INDIRECTIO_DATA, 0);
401 	}
402 
403 	if (!cold)
404 		mutex_exit(&sc->sc_i2c_mutex);
405 }
406 
407 static int
408 piixpm_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr,
409     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
410 {
411 	struct piixpm_smbus *smbus = cookie;
412 	struct piixpm_softc *sc = smbus->softc;
413 	const u_int8_t *b;
414 	u_int8_t ctl = 0, st;
415 	int retries;
416 
417 	DPRINTF(("%s: exec: op %d, addr 0x%x, cmdlen %zu, len %zu, flags 0x%x\n",
418 	    device_xname(sc->sc_dev), op, addr, cmdlen, len, flags));
419 
420 	/* Clear status bits */
421 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS,
422 	    PIIX_SMB_HS_INTR | PIIX_SMB_HS_DEVERR |
423 	    PIIX_SMB_HS_BUSERR | PIIX_SMB_HS_FAILED);
424 	bus_space_barrier(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, 1,
425 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
426 
427 	/* Wait for bus to be idle */
428 	for (retries = 100; retries > 0; retries--) {
429 		st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
430 		    PIIX_SMB_HS);
431 		if (!(st & PIIX_SMB_HS_BUSY))
432 			break;
433 		DELAY(PIIXPM_DELAY);
434 	}
435 	DPRINTF(("%s: exec: st 0x%d\n", device_xname(sc->sc_dev), st & 0xff));
436 	if (st & PIIX_SMB_HS_BUSY)
437 		return (1);
438 
439 	if (cold || sc->sc_poll)
440 		flags |= I2C_F_POLL;
441 
442 	if (!I2C_OP_STOP_P(op) || cmdlen > 1 || len > 2 ||
443 	    (cmdlen == 0 && len > 1))
444 		return (1);
445 
446 	/* Setup transfer */
447 	sc->sc_i2c_xfer.op = op;
448 	sc->sc_i2c_xfer.buf = buf;
449 	sc->sc_i2c_xfer.len = len;
450 	sc->sc_i2c_xfer.flags = flags;
451 	sc->sc_i2c_xfer.error = 0;
452 
453 	/* Set slave address and transfer direction */
454 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_TXSLVA,
455 	    PIIX_SMB_TXSLVA_ADDR(addr) |
456 	    (I2C_OP_READ_P(op) ? PIIX_SMB_TXSLVA_READ : 0));
457 
458 	b = cmdbuf;
459 	if (cmdlen > 0)
460 		/* Set command byte */
461 		bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
462 		    PIIX_SMB_HCMD, b[0]);
463 
464 	if (I2C_OP_WRITE_P(op)) {
465 		/* Write data */
466 		b = buf;
467 		if (cmdlen == 0 && len == 1)
468 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
469 			    PIIX_SMB_HCMD, b[0]);
470 		else if (len > 0)
471 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
472 			    PIIX_SMB_HD0, b[0]);
473 		if (len > 1)
474 			bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh,
475 			    PIIX_SMB_HD1, b[1]);
476 	}
477 
478 	/* Set SMBus command */
479 	if (cmdlen == 0) {
480 		if (len == 0)
481 			ctl = PIIX_SMB_HC_CMD_QUICK;
482 		else
483 			ctl = PIIX_SMB_HC_CMD_BYTE;
484 	} else if (len == 1)
485 		ctl = PIIX_SMB_HC_CMD_BDATA;
486 	else if (len == 2)
487 		ctl = PIIX_SMB_HC_CMD_WDATA;
488 
489 	if ((flags & I2C_F_POLL) == 0)
490 		ctl |= PIIX_SMB_HC_INTREN;
491 
492 	/* Start transaction */
493 	ctl |= PIIX_SMB_HC_START;
494 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC, ctl);
495 
496 	if (flags & I2C_F_POLL) {
497 		/* Poll for completion */
498 		if (PIIXPM_IS_CSB5(sc->sc_id))
499 			DELAY(2*PIIXPM_DELAY);
500 		else
501 			DELAY(PIIXPM_DELAY);
502 		for (retries = 1000; retries > 0; retries--) {
503 			st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
504 			    PIIX_SMB_HS);
505 			if ((st & PIIX_SMB_HS_BUSY) == 0)
506 				break;
507 			DELAY(PIIXPM_DELAY);
508 		}
509 		if (st & PIIX_SMB_HS_BUSY)
510 			goto timeout;
511 		piixpm_intr(sc);
512 	} else {
513 		/* Wait for interrupt */
514 		if (tsleep(sc, PRIBIO, "iicexec", PIIXPM_TIMEOUT * hz))
515 			goto timeout;
516 	}
517 
518 	if (sc->sc_i2c_xfer.error)
519 		return (1);
520 
521 	return (0);
522 
523 timeout:
524 	/*
525 	 * Transfer timeout. Kill the transaction and clear status bits.
526 	 */
527 	aprint_error_dev(sc->sc_dev, "timeout, status 0x%x\n", st);
528 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HC,
529 	    PIIX_SMB_HC_KILL);
530 	DELAY(PIIXPM_DELAY);
531 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
532 	if ((st & PIIX_SMB_HS_FAILED) == 0)
533 		aprint_error_dev(sc->sc_dev, "transaction abort failed, status 0x%x\n", st);
534 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
535 	/*
536 	 * CSB5 needs hard reset to unlock the smbus after timeout.
537 	 */
538 	if (PIIXPM_IS_CSB5(sc->sc_id))
539 		piixpm_csb5_reset(sc);
540 	return (1);
541 }
542 
543 static int
544 piixpm_intr(void *arg)
545 {
546 	struct piixpm_softc *sc = arg;
547 	u_int8_t st;
548 	u_int8_t *b;
549 	size_t len;
550 
551 	/* Read status */
552 	st = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
553 	if ((st & PIIX_SMB_HS_BUSY) != 0 || (st & (PIIX_SMB_HS_INTR |
554 	    PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
555 	    PIIX_SMB_HS_FAILED)) == 0)
556 		/* Interrupt was not for us */
557 		return (0);
558 
559 	DPRINTF(("%s: intr st 0x%d\n", device_xname(sc->sc_dev), st & 0xff));
560 
561 	/* Clear status bits */
562 	bus_space_write_1(sc->sc_smb_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
563 
564 	/* Check for errors */
565 	if (st & (PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
566 	    PIIX_SMB_HS_FAILED)) {
567 		sc->sc_i2c_xfer.error = 1;
568 		goto done;
569 	}
570 
571 	if (st & PIIX_SMB_HS_INTR) {
572 		if (I2C_OP_WRITE_P(sc->sc_i2c_xfer.op))
573 			goto done;
574 
575 		/* Read data */
576 		b = sc->sc_i2c_xfer.buf;
577 		len = sc->sc_i2c_xfer.len;
578 		if (len > 0)
579 			b[0] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
580 			    PIIX_SMB_HD0);
581 		if (len > 1)
582 			b[1] = bus_space_read_1(sc->sc_smb_iot, sc->sc_smb_ioh,
583 			    PIIX_SMB_HD1);
584 	}
585 
586 done:
587 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0)
588 		wakeup(sc);
589 	return (1);
590 }
591