xref: /freebsd/sys/dev/amdpm/amdpm.c (revision a0ee8cc6)
1 /*-
2  * Copyright (c) 2000 Matthew C. Forman
3  *
4  * Based (heavily) on alpm.c which is:
5  *
6  * Copyright (c) 1998, 1999 Nicolas Souchu
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  * Power management function/SMBus function support for the AMD 756 chip.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 #include <sys/bus.h>
40 #include <sys/kernel.h>
41 #include <sys/lock.h>
42 #include <sys/module.h>
43 #include <sys/mutex.h>
44 #include <sys/systm.h>
45 
46 #include <machine/bus.h>
47 #include <machine/resource.h>
48 #include <sys/rman.h>
49 
50 #include <dev/pci/pcivar.h>
51 #include <dev/pci/pcireg.h>
52 
53 #include <dev/smbus/smbconf.h>
54 #include "smbus_if.h"
55 
56 #define AMDPM_DEBUG(x)	if (amdpm_debug) (x)
57 
58 #ifdef DEBUG
59 static int amdpm_debug = 1;
60 #else
61 static int amdpm_debug = 0;
62 #endif
63 
64 #define AMDPM_VENDORID_AMD 0x1022
65 #define AMDPM_DEVICEID_AMD756PM 0x740b
66 #define AMDPM_DEVICEID_AMD766PM 0x7413
67 #define AMDPM_DEVICEID_AMD768PM 0x7443
68 #define AMDPM_DEVICEID_AMD8111PM 0x746B
69 
70 /* nVidia nForce chipset */
71 #define AMDPM_VENDORID_NVIDIA 0x10de
72 #define AMDPM_DEVICEID_NF_SMB 0x01b4
73 
74 /* PCI Configuration space registers */
75 #define AMDPCI_PMBASE 0x58
76 #define NFPCI_PMBASE  0x14
77 
78 #define AMDPCI_GEN_CONFIG_PM 0x41
79 #define AMDPCI_PMIOEN (1<<7)
80 
81 #define AMDPCI_SCIINT_CONFIG_PM 0x42
82 #define AMDPCI_SCISEL_IRQ11 11
83 
84 #define AMDPCI_REVID 0x08
85 
86 /*
87  * I/O registers.
88  * Base address programmed via AMDPCI_PMBASE.
89  */
90 
91 #define AMDSMB_GLOBAL_STATUS (0x00)
92 #define AMDSMB_GS_TO_STS (1<<5)
93 #define AMDSMB_GS_HCYC_STS (1<<4)
94 #define AMDSMB_GS_HST_STS (1<<3)
95 #define AMDSMB_GS_PRERR_STS (1<<2)
96 #define AMDSMB_GS_COL_STS (1<<1)
97 #define AMDSMB_GS_ABRT_STS (1<<0)
98 #define AMDSMB_GS_CLEAR_STS (AMDSMB_GS_TO_STS|AMDSMB_GS_HCYC_STS|AMDSMB_GS_PRERR_STS|AMDSMB_GS_COL_STS|AMDSMB_GS_ABRT_STS)
99 
100 #define AMDSMB_GLOBAL_ENABLE (0x02)
101 #define AMDSMB_GE_ABORT (1<<5)
102 #define AMDSMB_GE_HCYC_EN (1<<4)
103 #define AMDSMB_GE_HOST_STC (1<<3)
104 #define AMDSMB_GE_CYC_QUICK 0
105 #define AMDSMB_GE_CYC_BYTE 1
106 #define AMDSMB_GE_CYC_BDATA 2
107 #define AMDSMB_GE_CYC_WDATA 3
108 #define AMDSMB_GE_CYC_PROCCALL 4
109 #define AMDSMB_GE_CYC_BLOCK 5
110 
111 #define	LSB		0x1	/* XXX: Better name: Read/Write? */
112 
113 #define AMDSMB_HSTADDR  (0x04)
114 #define AMDSMB_HSTDATA  (0x06)
115 #define AMDSMB_HSTCMD   (0x08)
116 #define AMDSMB_HSTDFIFO (0x09)
117 #define AMDSMB_HSLVDATA (0x0A)
118 #define AMDSMB_HSLVDA   (0x0C)
119 #define AMDSMB_HSLVDDR  (0x0E)
120 #define AMDSMB_SNPADDR  (0x0F)
121 
122 struct amdpm_softc {
123 	int base;
124 	int rid;
125 	struct resource *res;
126 	device_t smbus;
127 	struct mtx lock;
128 };
129 
130 #define	AMDPM_LOCK(amdpm)		mtx_lock(&(amdpm)->lock)
131 #define	AMDPM_UNLOCK(amdpm)		mtx_unlock(&(amdpm)->lock)
132 #define	AMDPM_LOCK_ASSERT(amdpm)	mtx_assert(&(amdpm)->lock, MA_OWNED)
133 
134 #define AMDPM_SMBINB(amdpm,register) \
135 	(bus_read_1(amdpm->res, register))
136 #define AMDPM_SMBOUTB(amdpm,register,value) \
137 	(bus_write_1(amdpm->res, register, value))
138 #define AMDPM_SMBINW(amdpm,register) \
139 	(bus_read_2(amdpm->res, register))
140 #define AMDPM_SMBOUTW(amdpm,register,value) \
141 	(bus_write_2(amdpm->res, register, value))
142 
143 static int	amdpm_detach(device_t dev);
144 
145 static int
146 amdpm_probe(device_t dev)
147 {
148 	u_long base;
149 	u_int16_t vid;
150 	u_int16_t did;
151 
152 	vid = pci_get_vendor(dev);
153 	did = pci_get_device(dev);
154 	if ((vid == AMDPM_VENDORID_AMD) &&
155 	    ((did == AMDPM_DEVICEID_AMD756PM) ||
156 	     (did == AMDPM_DEVICEID_AMD766PM) ||
157 	     (did == AMDPM_DEVICEID_AMD768PM) ||
158 	     (did == AMDPM_DEVICEID_AMD8111PM))) {
159 		device_set_desc(dev, "AMD 756/766/768/8111 Power Management Controller");
160 
161 		/*
162 		 * We have to do this, since the BIOS won't give us the
163 		 * resource info (not mine, anyway).
164 		 */
165 		base = pci_read_config(dev, AMDPCI_PMBASE, 4);
166 		base &= 0xff00;
167 		bus_set_resource(dev, SYS_RES_IOPORT, AMDPCI_PMBASE,
168 				 base+0xe0, 32);
169 		return (BUS_PROBE_DEFAULT);
170 	}
171 
172 	if ((vid == AMDPM_VENDORID_NVIDIA) &&
173 	    (did == AMDPM_DEVICEID_NF_SMB)) {
174 		device_set_desc(dev, "nForce SMBus Controller");
175 
176 		/*
177 		* We have to do this, since the BIOS won't give us the
178 		* resource info (not mine, anyway).
179 		*/
180 		base = pci_read_config(dev, NFPCI_PMBASE, 4);
181 		base &= 0xff00;
182 		bus_set_resource(dev, SYS_RES_IOPORT, NFPCI_PMBASE,
183 				 base, 32);
184 
185 		return (BUS_PROBE_DEFAULT);
186 	}
187 
188 	return ENXIO;
189 }
190 
191 static int
192 amdpm_attach(device_t dev)
193 {
194 	struct amdpm_softc *amdpm_sc = device_get_softc(dev);
195 	u_char val_b;
196 
197 	/* Enable I/O block access */
198 	val_b = pci_read_config(dev, AMDPCI_GEN_CONFIG_PM, 1);
199 	pci_write_config(dev, AMDPCI_GEN_CONFIG_PM, val_b | AMDPCI_PMIOEN, 1);
200 
201 	/* Allocate I/O space */
202 	if (pci_get_vendor(dev) == AMDPM_VENDORID_AMD)
203 		amdpm_sc->rid = AMDPCI_PMBASE;
204 	else
205 		amdpm_sc->rid = NFPCI_PMBASE;
206 	amdpm_sc->res = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
207 		&amdpm_sc->rid, RF_ACTIVE);
208 
209 	if (amdpm_sc->res == NULL) {
210 		device_printf(dev, "could not map i/o space\n");
211 		return (ENXIO);
212 	}
213 
214 	mtx_init(&amdpm_sc->lock, device_get_nameunit(dev), "amdpm", MTX_DEF);
215 
216 	/* Allocate a new smbus device */
217 	amdpm_sc->smbus = device_add_child(dev, "smbus", -1);
218 	if (!amdpm_sc->smbus) {
219 		amdpm_detach(dev);
220 		return (EINVAL);
221 	}
222 
223 	bus_generic_attach(dev);
224 
225 	return (0);
226 }
227 
228 static int
229 amdpm_detach(device_t dev)
230 {
231 	struct amdpm_softc *amdpm_sc = device_get_softc(dev);
232 
233 	if (amdpm_sc->smbus) {
234 		device_delete_child(dev, amdpm_sc->smbus);
235 		amdpm_sc->smbus = NULL;
236 	}
237 
238 	mtx_destroy(&amdpm_sc->lock);
239 	if (amdpm_sc->res)
240 		bus_release_resource(dev, SYS_RES_IOPORT, amdpm_sc->rid,
241 				     amdpm_sc->res);
242 
243 	return (0);
244 }
245 
246 static int
247 amdpm_callback(device_t dev, int index, void *data)
248 {
249 	int error = 0;
250 
251 	switch (index) {
252 	case SMB_REQUEST_BUS:
253 	case SMB_RELEASE_BUS:
254 		break;
255 	default:
256 		error = EINVAL;
257 	}
258 
259 	return (error);
260 }
261 
262 static int
263 amdpm_clear(struct amdpm_softc *sc)
264 {
265 
266 	AMDPM_LOCK_ASSERT(sc);
267 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_STATUS, AMDSMB_GS_CLEAR_STS);
268 	DELAY(10);
269 
270 	return (0);
271 }
272 
273 #if 0
274 static int
275 amdpm_abort(struct amdpm_softc *sc)
276 {
277 	u_short l;
278 
279 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
280 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE, l | AMDSMB_GE_ABORT);
281 
282 	return (0);
283 }
284 #endif
285 
286 static int
287 amdpm_idle(struct amdpm_softc *sc)
288 {
289 	u_short sts;
290 
291 	AMDPM_LOCK_ASSERT(sc);
292 	sts = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_STATUS);
293 
294 	AMDPM_DEBUG(printf("amdpm: busy? STS=0x%x\n", sts));
295 
296 	return (~(sts & AMDSMB_GS_HST_STS));
297 }
298 
299 /*
300  * Poll the SMBus controller
301  */
302 static int
303 amdpm_wait(struct amdpm_softc *sc)
304 {
305 	int count = 10000;
306 	u_short sts = 0;
307 	int error;
308 
309 	AMDPM_LOCK_ASSERT(sc);
310 	/* Wait for command to complete (SMBus controller is idle) */
311 	while(count--) {
312 		DELAY(10);
313 		sts = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_STATUS);
314 		if (!(sts & AMDSMB_GS_HST_STS))
315 			break;
316 	}
317 
318 	AMDPM_DEBUG(printf("amdpm: STS=0x%x (count=%d)\n", sts, count));
319 
320 	error = SMB_ENOERR;
321 
322 	if (!count)
323 		error |= SMB_ETIMEOUT;
324 
325 	if (sts & AMDSMB_GS_ABRT_STS)
326 		error |= SMB_EABORT;
327 
328 	if (sts & AMDSMB_GS_COL_STS)
329 		error |= SMB_ENOACK;
330 
331 	if (sts & AMDSMB_GS_PRERR_STS)
332 		error |= SMB_EBUSERR;
333 
334 	if (error != SMB_ENOERR)
335 		amdpm_clear(sc);
336 
337 	return (error);
338 }
339 
340 static int
341 amdpm_quick(device_t dev, u_char slave, int how)
342 {
343 	struct amdpm_softc *sc = (struct amdpm_softc *)device_get_softc(dev);
344 	int error;
345 	u_short l;
346 
347 	AMDPM_LOCK(sc);
348 	amdpm_clear(sc);
349 	if (!amdpm_idle(sc)) {
350 		AMDPM_UNLOCK(sc);
351 		return (EBUSY);
352 	}
353 
354 	switch (how) {
355 	case SMB_QWRITE:
356 		AMDPM_DEBUG(printf("amdpm: QWRITE to 0x%x", slave));
357 		AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave & ~LSB);
358 		break;
359 	case SMB_QREAD:
360 		AMDPM_DEBUG(printf("amdpm: QREAD to 0x%x", slave));
361 		AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave | LSB);
362 		break;
363 	default:
364 		panic("%s: unknown QUICK command (%x)!", __func__, how);
365 	}
366 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
367 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE, (l & 0xfff8) | AMDSMB_GE_CYC_QUICK | AMDSMB_GE_HOST_STC);
368 
369 	error = amdpm_wait(sc);
370 
371 	AMDPM_DEBUG(printf(", error=0x%x\n", error));
372 	AMDPM_UNLOCK(sc);
373 
374 	return (error);
375 }
376 
377 static int
378 amdpm_sendb(device_t dev, u_char slave, char byte)
379 {
380 	struct amdpm_softc *sc = (struct amdpm_softc *)device_get_softc(dev);
381 	int error;
382 	u_short l;
383 
384 	AMDPM_LOCK(sc);
385 	amdpm_clear(sc);
386 	if (!amdpm_idle(sc)) {
387 		AMDPM_UNLOCK(sc);
388 		return (SMB_EBUSY);
389 	}
390 
391 	AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave & ~LSB);
392 	AMDPM_SMBOUTW(sc, AMDSMB_HSTDATA, byte);
393 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
394 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE, (l & 0xfff8) | AMDSMB_GE_CYC_BYTE | AMDSMB_GE_HOST_STC);
395 
396 	error = amdpm_wait(sc);
397 
398 	AMDPM_DEBUG(printf("amdpm: SENDB to 0x%x, byte=0x%x, error=0x%x\n", slave, byte, error));
399 	AMDPM_UNLOCK(sc);
400 
401 	return (error);
402 }
403 
404 static int
405 amdpm_recvb(device_t dev, u_char slave, char *byte)
406 {
407 	struct amdpm_softc *sc = (struct amdpm_softc *)device_get_softc(dev);
408 	int error;
409 	u_short l;
410 
411 	AMDPM_LOCK(sc);
412 	amdpm_clear(sc);
413 	if (!amdpm_idle(sc)) {
414 		AMDPM_UNLOCK(sc);
415 		return (SMB_EBUSY);
416 	}
417 
418 	AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave | LSB);
419 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
420 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE, (l & 0xfff8) | AMDSMB_GE_CYC_BYTE | AMDSMB_GE_HOST_STC);
421 
422 	if ((error = amdpm_wait(sc)) == SMB_ENOERR)
423 		*byte = AMDPM_SMBINW(sc, AMDSMB_HSTDATA);
424 
425 	AMDPM_DEBUG(printf("amdpm: RECVB from 0x%x, byte=0x%x, error=0x%x\n", slave, *byte, error));
426 	AMDPM_UNLOCK(sc);
427 
428 	return (error);
429 }
430 
431 static int
432 amdpm_writeb(device_t dev, u_char slave, char cmd, char byte)
433 {
434 	struct amdpm_softc *sc = (struct amdpm_softc *)device_get_softc(dev);
435 	int error;
436 	u_short l;
437 
438 	AMDPM_LOCK(sc);
439 	amdpm_clear(sc);
440 	if (!amdpm_idle(sc)) {
441 		AMDPM_UNLOCK(sc);
442 		return (SMB_EBUSY);
443 	}
444 
445 	AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave & ~LSB);
446 	AMDPM_SMBOUTW(sc, AMDSMB_HSTDATA, byte);
447 	AMDPM_SMBOUTB(sc, AMDSMB_HSTCMD, cmd);
448 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
449 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE, (l & 0xfff8) | AMDSMB_GE_CYC_BDATA | AMDSMB_GE_HOST_STC);
450 
451 	error = amdpm_wait(sc);
452 
453 	AMDPM_DEBUG(printf("amdpm: WRITEB to 0x%x, cmd=0x%x, byte=0x%x, error=0x%x\n", slave, cmd, byte, error));
454 	AMDPM_UNLOCK(sc);
455 
456 	return (error);
457 }
458 
459 static int
460 amdpm_readb(device_t dev, u_char slave, char cmd, char *byte)
461 {
462 	struct amdpm_softc *sc = (struct amdpm_softc *)device_get_softc(dev);
463 	int error;
464 	u_short l;
465 
466 	AMDPM_LOCK(sc);
467 	amdpm_clear(sc);
468 	if (!amdpm_idle(sc)) {
469 		AMDPM_UNLOCK(sc);
470 		return (SMB_EBUSY);
471 	}
472 
473 	AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave | LSB);
474 	AMDPM_SMBOUTB(sc, AMDSMB_HSTCMD, cmd);
475 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
476 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE, (l & 0xfff8) | AMDSMB_GE_CYC_BDATA | AMDSMB_GE_HOST_STC);
477 
478 	if ((error = amdpm_wait(sc)) == SMB_ENOERR)
479 		*byte = AMDPM_SMBINW(sc, AMDSMB_HSTDATA);
480 
481 	AMDPM_DEBUG(printf("amdpm: READB from 0x%x, cmd=0x%x, byte=0x%x, error=0x%x\n", slave, cmd, *byte, error));
482 	AMDPM_UNLOCK(sc);
483 
484 	return (error);
485 }
486 
487 static int
488 amdpm_writew(device_t dev, u_char slave, char cmd, short word)
489 {
490 	struct amdpm_softc *sc = (struct amdpm_softc *)device_get_softc(dev);
491 	int error;
492 	u_short l;
493 
494 	AMDPM_LOCK(sc);
495 	amdpm_clear(sc);
496 	if (!amdpm_idle(sc)) {
497 		AMDPM_UNLOCK(sc);
498 		return (SMB_EBUSY);
499 	}
500 
501 	AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave & ~LSB);
502 	AMDPM_SMBOUTW(sc, AMDSMB_HSTDATA, word);
503 	AMDPM_SMBOUTB(sc, AMDSMB_HSTCMD, cmd);
504 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
505 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE, (l & 0xfff8) | AMDSMB_GE_CYC_WDATA | AMDSMB_GE_HOST_STC);
506 
507 	error = amdpm_wait(sc);
508 
509 	AMDPM_DEBUG(printf("amdpm: WRITEW to 0x%x, cmd=0x%x, word=0x%x, error=0x%x\n", slave, cmd, word, error));
510 	AMDPM_UNLOCK(sc);
511 
512 	return (error);
513 }
514 
515 static int
516 amdpm_readw(device_t dev, u_char slave, char cmd, short *word)
517 {
518 	struct amdpm_softc *sc = (struct amdpm_softc *)device_get_softc(dev);
519 	int error;
520 	u_short l;
521 
522 	AMDPM_LOCK(sc);
523 	amdpm_clear(sc);
524 	if (!amdpm_idle(sc)) {
525 		AMDPM_UNLOCK(sc);
526 		return (SMB_EBUSY);
527 	}
528 
529 	AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave | LSB);
530 	AMDPM_SMBOUTB(sc, AMDSMB_HSTCMD, cmd);
531 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
532 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE, (l & 0xfff8) | AMDSMB_GE_CYC_WDATA | AMDSMB_GE_HOST_STC);
533 
534 	if ((error = amdpm_wait(sc)) == SMB_ENOERR)
535 		*word = AMDPM_SMBINW(sc, AMDSMB_HSTDATA);
536 
537 	AMDPM_DEBUG(printf("amdpm: READW from 0x%x, cmd=0x%x, word=0x%x, error=0x%x\n", slave, cmd, *word, error));
538 	AMDPM_UNLOCK(sc);
539 
540 	return (error);
541 }
542 
543 static int
544 amdpm_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf)
545 {
546 	struct amdpm_softc *sc = (struct amdpm_softc *)device_get_softc(dev);
547 	u_char i;
548 	int error;
549 	u_short l;
550 
551 	if (count < 1 || count > 32)
552 		return (SMB_EINVAL);
553 
554 	AMDPM_LOCK(sc);
555 	amdpm_clear(sc);
556 	if (!amdpm_idle(sc)) {
557 		AMDPM_UNLOCK(sc);
558 		return (SMB_EBUSY);
559 	}
560 
561 	AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave & ~LSB);
562 
563 	/*
564 	 * Do we have to reset the internal 32-byte buffer?
565 	 * Can't see how to do this from the data sheet.
566 	 */
567 	AMDPM_SMBOUTW(sc, AMDSMB_HSTDATA, count);
568 
569 	/* Fill the 32-byte internal buffer */
570 	for (i = 0; i < count; i++) {
571 		AMDPM_SMBOUTB(sc, AMDSMB_HSTDFIFO, buf[i]);
572 		DELAY(2);
573 	}
574 	AMDPM_SMBOUTB(sc, AMDSMB_HSTCMD, cmd);
575 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
576 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE,
577 	    (l & 0xfff8) | AMDSMB_GE_CYC_BLOCK | AMDSMB_GE_HOST_STC);
578 
579 	error = amdpm_wait(sc);
580 
581 	AMDPM_DEBUG(printf("amdpm: WRITEBLK to 0x%x, count=0x%x, cmd=0x%x, error=0x%x", slave, count, cmd, error));
582 	AMDPM_UNLOCK(sc);
583 
584 	return (error);
585 }
586 
587 static int
588 amdpm_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf)
589 {
590 	struct amdpm_softc *sc = (struct amdpm_softc *)device_get_softc(dev);
591 	u_char data, len, i;
592 	int error;
593 	u_short l;
594 
595 	if (*count < 1 || *count > 32)
596 		return (SMB_EINVAL);
597 
598 	AMDPM_LOCK(sc);
599 	amdpm_clear(sc);
600 	if (!amdpm_idle(sc)) {
601 		AMDPM_UNLOCK(sc);
602 		return (SMB_EBUSY);
603 	}
604 
605 	AMDPM_SMBOUTW(sc, AMDSMB_HSTADDR, slave | LSB);
606 
607 	AMDPM_SMBOUTB(sc, AMDSMB_HSTCMD, cmd);
608 
609 	l = AMDPM_SMBINW(sc, AMDSMB_GLOBAL_ENABLE);
610 	AMDPM_SMBOUTW(sc, AMDSMB_GLOBAL_ENABLE,
611 	    (l & 0xfff8) | AMDSMB_GE_CYC_BLOCK | AMDSMB_GE_HOST_STC);
612 
613 	if ((error = amdpm_wait(sc)) != SMB_ENOERR)
614 		goto error;
615 
616 	len = AMDPM_SMBINW(sc, AMDSMB_HSTDATA);
617 
618 	/* Read the 32-byte internal buffer */
619 	for (i = 0; i < len; i++) {
620 		data = AMDPM_SMBINB(sc, AMDSMB_HSTDFIFO);
621 		if (i < *count)
622 			buf[i] = data;
623 		DELAY(2);
624 	}
625 	*count = len;
626 
627 error:
628 	AMDPM_DEBUG(printf("amdpm: READBLK to 0x%x, count=0x%x, cmd=0x%x, error=0x%x", slave, *count, cmd, error));
629 	AMDPM_UNLOCK(sc);
630 
631 	return (error);
632 }
633 
634 static devclass_t amdpm_devclass;
635 
636 static device_method_t amdpm_methods[] = {
637 	/* Device interface */
638 	DEVMETHOD(device_probe,		amdpm_probe),
639 	DEVMETHOD(device_attach,	amdpm_attach),
640 	DEVMETHOD(device_detach,	amdpm_detach),
641 
642 	/* SMBus interface */
643 	DEVMETHOD(smbus_callback,	amdpm_callback),
644 	DEVMETHOD(smbus_quick,		amdpm_quick),
645 	DEVMETHOD(smbus_sendb,		amdpm_sendb),
646 	DEVMETHOD(smbus_recvb,		amdpm_recvb),
647 	DEVMETHOD(smbus_writeb,		amdpm_writeb),
648 	DEVMETHOD(smbus_readb,		amdpm_readb),
649 	DEVMETHOD(smbus_writew,		amdpm_writew),
650 	DEVMETHOD(smbus_readw,		amdpm_readw),
651 	DEVMETHOD(smbus_bwrite,		amdpm_bwrite),
652 	DEVMETHOD(smbus_bread,		amdpm_bread),
653 
654 	{ 0, 0 }
655 };
656 
657 static driver_t amdpm_driver = {
658 	"amdpm",
659 	amdpm_methods,
660 	sizeof(struct amdpm_softc),
661 };
662 
663 DRIVER_MODULE(amdpm, pci, amdpm_driver, amdpm_devclass, 0, 0);
664 DRIVER_MODULE(smbus, amdpm, smbus_driver, smbus_devclass, 0, 0);
665 
666 MODULE_DEPEND(amdpm, pci, 1, 1, 1);
667 MODULE_DEPEND(amdpm, smbus, SMBUS_MINVER, SMBUS_PREFVER, SMBUS_MAXVER);
668 MODULE_VERSION(amdpm, 1);
669