xref: /openbsd-src/sys/dev/pci/amdpm.c (revision f80bdd3b253c6dadc369d53ac62b52569e28b16c)
1 /*	$OpenBSD: amdpm.c,v 1.17 2006/03/09 00:39:04 dlg Exp $	*/
2 
3 /*
4  * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 /*-
20  * Copyright (c) 2002 The NetBSD Foundation, Inc.
21  * All rights reserved.
22  *
23  * This code is derived from software contributed to The NetBSD Foundation
24  * by Enami Tsugutomo.
25  *
26  * Redistribution and use in source and binary forms, with or without
27  * modification, are permitted provided that the following conditions
28  * are met:
29  * 1. Redistributions of source code must retain the above copyright
30  *    notice, this list of conditions and the following disclaimer.
31  * 2. Redistributions in binary form must reproduce the above copyright
32  *    notice, this list of conditions and the following disclaimer in the
33  *    documentation and/or other materials provided with the distribution.
34  * 3. All advertising materials mentioning features or use of this software
35  *    must display the following acknowledgement:
36  *	This product includes software developed by the NetBSD
37  *	Foundation, Inc. and its contributors.
38  * 4. Neither the name of The NetBSD Foundation nor the names of its
39  *    contributors may be used to endorse or promote products derived
40  *    from this software without specific prior written permission.
41  *
42  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
43  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
44  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
45  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
46  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
47  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
48  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
49  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
50  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
51  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
52  * POSSIBILITY OF SUCH DAMAGE.
53  */
54 
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/device.h>
58 #include <sys/kernel.h>
59 #include <sys/lock.h>
60 #include <sys/proc.h>
61 #include <sys/timeout.h>
62 #ifdef __HAVE_TIMECOUNTER
63 #include <sys/timetc.h>
64 #endif
65 
66 #include <machine/bus.h>
67 
68 #include <dev/pci/pcivar.h>
69 #include <dev/pci/pcireg.h>
70 #include <dev/pci/pcidevs.h>
71 
72 #include <dev/rndvar.h>
73 #include <dev/i2c/i2cvar.h>
74 
75 #ifdef AMDPM_DEBUG
76 #define DPRINTF(x...) printf(x)
77 #else
78 #define DPRINTF(x...)
79 #endif
80 
81 #define AMDPM_SMBUS_DELAY	100
82 #define AMDPM_SMBUS_TIMEOUT	1
83 
84 #ifdef __HAVE_TIMECOUNTER
85 u_int amdpm_get_timecount(struct timecounter *tc);
86 
87 #ifndef AMDPM_FREQUENCY
88 #define AMDPM_FREQUENCY 3579545
89 #endif
90 
91 static struct timecounter amdpm_timecounter = {
92 	amdpm_get_timecount,	/* get_timecount */
93 	0,			/* no poll_pps */
94 	0xffffff,		/* counter_mask */
95 	AMDPM_FREQUENCY,	/* frequency */
96 	"AMDPM",		/* name */
97 	1000			/* quality */
98 };
99 #endif
100 
101 #define	AMDPM_CONFREG	0x40
102 
103 /* 0x40: General Configuration 1 Register */
104 #define	AMDPM_RNGEN	0x00000080	/* random number generator enable */
105 #define	AMDPM_STOPTMR	0x00000040	/* stop free-running timer */
106 
107 /* 0x41: General Configuration 2 Register */
108 #define	AMDPM_PMIOEN	0x00008000	/* system management IO space enable */
109 #define	AMDPM_TMRRST	0x00004000	/* reset free-running timer */
110 #define	AMDPM_TMR32	0x00000800	/* extended (32 bit) timer enable */
111 
112 /* 0x42: SCI Interrupt Configuration Register */
113 /* 0x43: Previous Power State Register */
114 
115 #define	AMDPM_PMPTR	0x58		/* PMxx System Management IO space
116 					   Pointer */
117 #define NFPM_PMPTR	0x14		/* nForce System Management IO space
118 					   POinter */
119 #define	AMDPM_PMBASE(x)	((x) & 0xff00)	/* PMxx base address */
120 #define	AMDPM_PMSIZE	256		/* PMxx space size */
121 
122 /* Registers in PMxx space */
123 #define	AMDPM_TMR	0x08		/* 24/32 bit timer register */
124 
125 #define	AMDPM_RNGDATA	0xf0		/* 32 bit random data register */
126 #define	AMDPM_RNGSTAT	0xf4		/* RNG status register */
127 #define	AMDPM_RNGDONE	0x00000001	/* Random number generation complete */
128 
129 #define AMDPM_SMB_REGS  0xe0		/* offset of SMB register space */
130 #define AMDPM_SMB_SIZE  0xf		/* size of SMB register space */
131 #define AMDPM_SMBSTAT	0x0		/* SMBus status */
132 #define AMDPM_SMBSTAT_ABRT	(1 << 0)	/* transfer abort */
133 #define AMDPM_SMBSTAT_COL	(1 << 1)	/* collision */
134 #define AMDPM_SMBSTAT_PRERR	(1 << 2)	/* protocol error */
135 #define AMDPM_SMBSTAT_HBSY	(1 << 3)	/* host controller busy */
136 #define AMDPM_SMBSTAT_CYC	(1 << 4)	/* cycle complete */
137 #define AMDPM_SMBSTAT_TO	(1 << 5)	/* timeout */
138 #define AMDPM_SMBSTAT_SNP	(1 << 8)	/* snoop address match */
139 #define AMDPM_SMBSTAT_SLV	(1 << 9)	/* slave address match */
140 #define AMDPM_SMBSTAT_SMBA	(1 << 10)	/* SMBALERT# asserted */
141 #define AMDPM_SMBSTAT_BSY	(1 << 11)	/* bus busy */
142 #define AMDPM_SMBSTAT_BITS	"\020\001ABRT\002COL\003PRERR\004HBSY\005CYC\006TO\011SNP\012SLV\013SMBA\014BSY"
143 #define AMDPM_SMBCTL	0x2		/* SMBus control */
144 #define AMDPM_SMBCTL_CMD_QUICK	0		/* QUICK command */
145 #define AMDPM_SMBCTL_CMD_BYTE	1		/* BYTE command */
146 #define AMDPM_SMBCTL_CMD_BDATA	2		/* BYTE DATA command */
147 #define AMDPM_SMBCTL_CMD_WDATA	3		/* WORD DATA command */
148 #define AMDPM_SMBCTL_CMD_PCALL	4		/* PROCESS CALL command */
149 #define AMDPM_SMBCTL_CMD_BLOCK	5		/* BLOCK command */
150 #define AMDPM_SMBCTL_START	(1 << 3)	/* start transfer */
151 #define AMDPM_SMBCTL_CYCEN	(1 << 4)	/* intr on cycle complete */
152 #define AMDPM_SMBCTL_ABORT	(1 << 5)	/* abort transfer */
153 #define AMDPM_SMBCTL_SNPEN	(1 << 8)	/* intr on snoop addr match */
154 #define AMDPM_SMBCTL_SLVEN	(1 << 9)	/* intr on slave addr match */
155 #define AMDPM_SMBCTL_SMBAEN	(1 << 10)	/* intr on SMBALERT# */
156 #define AMDPM_SMBADDR	0x4		/* SMBus address */
157 #define AMDPM_SMBADDR_READ	(1 << 0)	/* read direction */
158 #define AMDPM_SMBADDR_ADDR(x)	(((x) & 0x7f) << 1) /* 7-bit address */
159 #define AMDPM_SMBDATA	0x6		/* SMBus data */
160 #define AMDPM_SMBCMD	0x8		/* SMBus command */
161 
162 
163 struct amdpm_softc {
164 	struct device sc_dev;
165 
166 	pci_chipset_tag_t sc_pc;
167 	pcitag_t sc_tag;
168 
169 	bus_space_tag_t sc_iot;
170 	bus_space_handle_t sc_ioh;		/* PMxx space */
171 	bus_space_handle_t sc_i2c_ioh;		/* I2C space */
172 	int sc_poll;
173 
174 	struct timeout sc_rnd_ch;
175 
176 	struct i2c_controller sc_i2c_tag;
177 	struct lock sc_i2c_lock;
178 	struct {
179 		i2c_op_t op;
180 		void *buf;
181 		size_t len;
182 		int flags;
183 		volatile int error;
184 	} sc_i2c_xfer;
185 };
186 
187 int	amdpm_match(struct device *, void *, void *);
188 void	amdpm_attach(struct device *, struct device *, void *);
189 void	amdpm_rnd_callout(void *);
190 
191 int	amdpm_i2c_acquire_bus(void *, int);
192 void	amdpm_i2c_release_bus(void *, int);
193 int	amdpm_i2c_exec(void *, i2c_op_t, i2c_addr_t, const void *, size_t,
194 	    void *, size_t, int);
195 
196 int	amdpm_intr(void *);
197 
198 struct cfattach amdpm_ca = {
199 	sizeof(struct amdpm_softc), amdpm_match, amdpm_attach
200 };
201 
202 struct cfdriver amdpm_cd = {
203 	NULL, "amdpm", DV_DULL
204 };
205 
206 const struct pci_matchid amdpm_ids[] = {
207 	{ PCI_VENDOR_AMD, PCI_PRODUCT_AMD_PBC756_PMC },
208 	{ PCI_VENDOR_AMD, PCI_PRODUCT_AMD_766_PMC },
209 	{ PCI_VENDOR_AMD, PCI_PRODUCT_AMD_PBC768_PMC },
210 	{ PCI_VENDOR_AMD, PCI_PRODUCT_AMD_8111_PMC },
211 	{ PCI_VENDOR_NVIDIA, PCI_PRODUCT_NVIDIA_NFORCE_SMB }
212 };
213 
214 int
215 amdpm_match(struct device *parent, void *match, void *aux)
216 {
217 	return (pci_matchbyid(aux, amdpm_ids,
218 	    sizeof(amdpm_ids) / sizeof(amdpm_ids[0])));
219 }
220 
221 void
222 amdpm_attach(struct device *parent, struct device *self, void *aux)
223 {
224 	struct amdpm_softc *sc = (struct amdpm_softc *) self;
225 	struct pci_attach_args *pa = aux;
226 	struct i2cbus_attach_args iba;
227 	pcireg_t cfg_reg, reg;
228 	int i;
229 
230 	sc->sc_pc = pa->pa_pc;
231 	sc->sc_tag = pa->pa_tag;
232 	sc->sc_iot = pa->pa_iot;
233 	sc->sc_poll = 1; /* XXX */
234 
235 
236 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_AMD)  {
237 		cfg_reg = pci_conf_read(pa->pa_pc, pa->pa_tag, AMDPM_CONFREG);
238 		if ((cfg_reg & AMDPM_PMIOEN) == 0) {
239 			printf(": PMxx space isn't enabled\n");
240 			return;
241 		}
242 
243 		reg = pci_conf_read(pa->pa_pc, pa->pa_tag, AMDPM_PMPTR);
244 		if (bus_space_map(sc->sc_iot, AMDPM_PMBASE(reg), AMDPM_PMSIZE, 0,
245 		    &sc->sc_ioh)) {
246 			printf(": failed to map PMxx space\n");
247 			return;
248 		}
249 		if (bus_space_subregion(sc->sc_iot, sc->sc_ioh, AMDPM_SMB_REGS,
250 		    AMDPM_SMB_SIZE, &sc->sc_i2c_ioh)) {
251 			printf(": failed to map I2C subregion\n");
252 			return;
253 		}
254 
255 #ifdef __HAVE_TIMECOUNTER
256 		if ((cfg_reg & AMDPM_TMRRST) == 0 &&
257 		    (cfg_reg & AMDPM_STOPTMR) == 0 &&
258 		    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_PBC768_PMC) {
259 			printf(": %d-bit timer at %dHz",
260 			    (cfg_reg & AMDPM_TMR32) ? 32 : 24,
261 			    amdpm_timecounter.tc_frequency);
262 
263 			amdpm_timecounter.tc_priv = sc;
264 			if (cfg_reg & AMDPM_TMR32)
265 				amdpm_timecounter.tc_counter_mask = 0xffffffffu;
266 			tc_init(&amdpm_timecounter);
267 		}
268 #endif
269 		if (PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_PBC768_PMC ||
270 		    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_8111_PMC) {
271 			if ((cfg_reg & AMDPM_RNGEN) ==0) {
272 				pci_conf_write(pa->pa_pc, pa->pa_tag,
273 				    AMDPM_CONFREG, cfg_reg | AMDPM_RNGEN);
274 				cfg_reg = pci_conf_read(pa->pa_pc, pa->pa_tag,
275 				    AMDPM_CONFREG);
276 			}
277 			if (cfg_reg & AMDPM_RNGEN) {
278 			/* Check to see if we can read data from the RNG. */
279 				(void) bus_space_read_4(sc->sc_iot, sc->sc_ioh,
280 				    AMDPM_RNGDATA);
281 				for (i = 1000; i--; ) {
282 					if (bus_space_read_1(sc->sc_iot,
283 					    sc->sc_ioh, AMDPM_RNGSTAT) &
284 					    AMDPM_RNGDONE)
285 						break;
286 					DELAY(10);
287 				}
288 				if (bus_space_read_1(sc->sc_iot, sc->sc_ioh,
289 				    AMDPM_RNGSTAT) & AMDPM_RNGDONE) {
290 					printf(": rng active");
291 					timeout_set(&sc->sc_rnd_ch,
292 					    amdpm_rnd_callout, sc);
293 					amdpm_rnd_callout(sc);
294 				}
295 			}
296 		}
297 	} else if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_NVIDIA) {
298 		reg = pci_conf_read(pa->pa_pc, pa->pa_tag, NFPM_PMPTR);
299 		if (bus_space_map(sc->sc_iot, AMDPM_PMBASE(reg), AMDPM_SMB_SIZE, 0,
300 		    &sc->sc_i2c_ioh)) {
301 			printf(": failed to map I2C subregion\n");
302 			return;
303 		}
304 	}
305 	printf("\n");
306 
307 	/* Attach I2C bus */
308 	lockinit(&sc->sc_i2c_lock, PRIBIO | PCATCH, "iiclk", 0, 0);
309 	sc->sc_i2c_tag.ic_cookie = sc;
310 	sc->sc_i2c_tag.ic_acquire_bus = amdpm_i2c_acquire_bus;
311 	sc->sc_i2c_tag.ic_release_bus = amdpm_i2c_release_bus;
312 	sc->sc_i2c_tag.ic_exec = amdpm_i2c_exec;
313 
314 	bzero(&iba, sizeof(iba));
315 	iba.iba_name = "iic";
316 	iba.iba_tag = &sc->sc_i2c_tag;
317 	config_found(self, &iba, iicbus_print);
318 }
319 
320 void
321 amdpm_rnd_callout(void *v)
322 {
323 	struct amdpm_softc *sc = v;
324 	u_int32_t reg;
325 
326 	if ((bus_space_read_4(sc->sc_iot, sc->sc_ioh, AMDPM_RNGSTAT) &
327 	    AMDPM_RNGDONE) != 0) {
328 		reg = bus_space_read_4(sc->sc_iot, sc->sc_ioh, AMDPM_RNGDATA);
329 		add_true_randomness(reg);
330 	}
331 	timeout_add(&sc->sc_rnd_ch, 1);
332 }
333 
334 #ifdef __HAVE_TIMECOUNTER
335 u_int
336 amdpm_get_timecount(struct timecounter *tc)
337 {
338 	struct amdpm_softc *sc = tc->tc_priv;
339 	u_int u2;
340 #if 0
341 	u_int u1, u3;
342 #endif
343 
344 	u2 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, AMDPM_TMR);
345 #if 0
346 	u3 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, AMDPM_TMR);
347 	do {
348 		u1 = u2;
349 		u2 = u3;
350 		u3 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, AMDPM_TMR);
351 	} while (u1 > u2 || u2 > u3);
352 #endif
353 	return (u2);
354 }
355 #endif
356 
357 int
358 amdpm_i2c_acquire_bus(void *cookie, int flags)
359 {
360 	struct amdpm_softc *sc = cookie;
361 
362 	if (cold || sc->sc_poll || (flags & I2C_F_POLL))
363 		return (0);
364 
365 	return (lockmgr(&sc->sc_i2c_lock, LK_EXCLUSIVE, NULL));
366 }
367 
368 void
369 amdpm_i2c_release_bus(void *cookie, int flags)
370 {
371 	struct amdpm_softc *sc = cookie;
372 
373 	if (cold || sc->sc_poll || (flags & I2C_F_POLL))
374 		return;
375 
376 	lockmgr(&sc->sc_i2c_lock, LK_RELEASE, NULL);
377 }
378 
379 int
380 amdpm_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr,
381     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
382 {
383 	struct amdpm_softc *sc = cookie;
384 	u_int8_t *b;
385 	u_int16_t st, ctl, data;
386 	int retries;
387 
388 	DPRINTF("%s: exec: op %d, addr 0x%x, cmdlen %d, len %d, flags 0x%x\n",
389 	    sc->sc_dev.dv_xname, op, addr, cmdlen, len, flags);
390 
391 	/* Wait for bus to be idle */
392 	for (retries = 100; retries > 0; retries--) {
393 		st = bus_space_read_2(sc->sc_iot, sc->sc_i2c_ioh, AMDPM_SMBSTAT);
394 		if (!(st & AMDPM_SMBSTAT_BSY))
395 			break;
396 		DELAY(AMDPM_SMBUS_DELAY);
397 	}
398 	DPRINTF("%s: exec: st 0x%b\n", sc->sc_dev.dv_xname, st,
399 	    AMDPM_SMBSTAT_BITS);
400 	if (st & AMDPM_SMBSTAT_BSY)
401 		return (1);
402 
403 	if (cold || sc->sc_poll)
404 		flags |= I2C_F_POLL;
405 
406 	if (!I2C_OP_STOP_P(op) || cmdlen > 1 || len > 2)
407 		return (1);
408 
409 	/* Setup transfer */
410 	sc->sc_i2c_xfer.op = op;
411 	sc->sc_i2c_xfer.buf = buf;
412 	sc->sc_i2c_xfer.len = len;
413 	sc->sc_i2c_xfer.flags = flags;
414 	sc->sc_i2c_xfer.error = 0;
415 
416 	/* Set slave address and transfer direction */
417 	bus_space_write_2(sc->sc_iot, sc->sc_i2c_ioh, AMDPM_SMBADDR,
418 	    AMDPM_SMBADDR_ADDR(addr) |
419 	    (I2C_OP_READ_P(op) ? AMDPM_SMBADDR_READ : 0));
420 
421 	b = (void *)cmdbuf;
422 	if (cmdlen > 0)
423 		/* Set command byte */
424 		bus_space_write_1(sc->sc_iot, sc->sc_i2c_ioh, AMDPM_SMBCMD, b[0]);
425 
426 	if (I2C_OP_WRITE_P(op)) {
427 		/* Write data */
428 		data = 0;
429 		b = buf;
430 		if (len > 0)
431 			data = b[0];
432 		if (len > 1)
433 			data |= ((u_int16_t)b[1] << 8);
434 		if (len > 0)
435 			bus_space_write_2(sc->sc_iot, sc->sc_i2c_ioh,
436 			    AMDPM_SMBDATA, data);
437 	}
438 
439 	/* Set SMBus command */
440 	if (len == 0)
441 		ctl = AMDPM_SMBCTL_CMD_BYTE;
442 	else if (len == 1)
443 		ctl = AMDPM_SMBCTL_CMD_BDATA;
444 	else if (len == 2)
445 		ctl = AMDPM_SMBCTL_CMD_WDATA;
446 
447 	if ((flags & I2C_F_POLL) == 0)
448 		ctl |= AMDPM_SMBCTL_CYCEN;
449 
450 	/* Start transaction */
451 	ctl |= AMDPM_SMBCTL_START;
452 	bus_space_write_2(sc->sc_iot, sc->sc_i2c_ioh, AMDPM_SMBCTL, ctl);
453 
454 	if (flags & I2C_F_POLL) {
455 		/* Poll for completion */
456 		DELAY(AMDPM_SMBUS_DELAY);
457 		for (retries = 1000; retries > 0; retries--) {
458 			st = bus_space_read_2(sc->sc_iot, sc->sc_i2c_ioh,
459 			    AMDPM_SMBSTAT);
460 			if ((st & AMDPM_SMBSTAT_HBSY) == 0)
461 				break;
462 			DELAY(AMDPM_SMBUS_DELAY);
463 		}
464 		if (st & AMDPM_SMBSTAT_HBSY)
465 			goto timeout;
466 		amdpm_intr(sc);
467 	} else {
468 		/* Wait for interrupt */
469 		if (tsleep(sc, PRIBIO, "iicexec", AMDPM_SMBUS_TIMEOUT * hz))
470 			goto timeout;
471 	}
472 
473 	if (sc->sc_i2c_xfer.error)
474 		return (1);
475 
476 	return (0);
477 
478 timeout:
479 	/*
480 	 * Transfer timeout. Kill the transaction and clear status bits.
481 	 */
482 	printf("%s: timeout, status 0x%b\n", sc->sc_dev.dv_xname, st,
483 	    AMDPM_SMBSTAT_BITS);
484 	bus_space_write_2(sc->sc_iot, sc->sc_i2c_ioh, AMDPM_SMBCTL,
485 	    AMDPM_SMBCTL_ABORT);
486 	DELAY(AMDPM_SMBUS_DELAY);
487 	st = bus_space_read_2(sc->sc_iot, sc->sc_i2c_ioh, AMDPM_SMBSTAT);
488 	if ((st & AMDPM_SMBSTAT_ABRT) == 0)
489 		printf("%s: transaction abort failed, status 0x%b\n",
490 		    sc->sc_dev.dv_xname, st, AMDPM_SMBSTAT_BITS);
491 	bus_space_write_2(sc->sc_iot, sc->sc_i2c_ioh, AMDPM_SMBSTAT, st);
492 	return (1);
493 }
494 
495 int
496 amdpm_intr(void *arg)
497 {
498 	struct amdpm_softc *sc = arg;
499 	u_int16_t st, data;
500 	u_int8_t *b;
501 	size_t len;
502 
503 	/* Read status */
504 	st = bus_space_read_2(sc->sc_iot, sc->sc_i2c_ioh, AMDPM_SMBSTAT);
505 	if ((st & AMDPM_SMBSTAT_HBSY) != 0 || (st & (AMDPM_SMBSTAT_ABRT |
506 	    AMDPM_SMBSTAT_COL | AMDPM_SMBSTAT_PRERR | AMDPM_SMBSTAT_CYC |
507 	    AMDPM_SMBSTAT_TO | AMDPM_SMBSTAT_SNP | AMDPM_SMBSTAT_SLV |
508 	    AMDPM_SMBSTAT_SMBA)) == 0)
509 		/* Interrupt was not for us */
510 		return (0);
511 
512 	DPRINTF("%s: intr: st 0x%b\n", sc->sc_dev.dv_xname, st,
513 	    AMDPM_SMBSTAT_BITS);
514 
515 	/* Clear status bits */
516 	bus_space_write_2(sc->sc_iot, sc->sc_i2c_ioh, AMDPM_SMBSTAT, st);
517 
518 	/* Check for errors */
519 	if (st & (AMDPM_SMBSTAT_COL | AMDPM_SMBSTAT_PRERR |
520 	    AMDPM_SMBSTAT_TO)) {
521 		sc->sc_i2c_xfer.error = 1;
522 		goto done;
523 	}
524 
525 	if (st & AMDPM_SMBSTAT_CYC) {
526 		if (I2C_OP_WRITE_P(sc->sc_i2c_xfer.op))
527 			goto done;
528 
529 		/* Read data */
530 		b = sc->sc_i2c_xfer.buf;
531 		len = sc->sc_i2c_xfer.len;
532 		if (len > 0) {
533 			data = bus_space_read_2(sc->sc_iot, sc->sc_i2c_ioh,
534 			    AMDPM_SMBDATA);
535 			b[0] = data & 0xff;
536 		}
537 		if (len > 1)
538 			b[1] = (data >> 8) & 0xff;
539 	}
540 
541 done:
542 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0)
543 		wakeup(sc);
544 	return (1);
545 }
546