xref: /freebsd/sys/dev/acpica/acpi_cmbat.c (revision 8fa113e5fc65fe6abc757f0089f477a87ee4d185)
1 /*-
2  * Copyright (c) 2000 Munehiro Matsuda
3  * Copyright (c) 2000 Takanori Watanabe
4  * Copyright (c) 2000 Mitsuru IWASAKI <iwasaki@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #include "opt_acpi.h"
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/bus.h>
35 #include <sys/ioccom.h>
36 #include <sys/conf.h>
37 
38 #include <machine/bus.h>
39 #include <machine/resource.h>
40 #include <sys/rman.h>
41 #include <sys/malloc.h>
42 
43 #include  "acpi.h"
44 
45 #include <dev/acpica/acpivar.h>
46 #include <dev/acpica/acpiio.h>
47 
48 MALLOC_DEFINE(M_ACPICMBAT, "acpicmbat", "ACPI control method battery data");
49 
50 #define	CMBAT_POLLRATE	(60 * hz)
51 
52 /*
53  * Hooks for the ACPI CA debugging infrastructure
54  */
55 #define	_COMPONENT	ACPI_BATTERY
56 MODULE_NAME("BATTERY")
57 
58 #define	ACPI_BATTERY_BST_CHANGE 0x80
59 #define	ACPI_BATTERY_BIF_CHANGE 0x81
60 
61 #define	PKG_GETINT(res, tmp, idx, dest, label) do {			\
62 	tmp = &res->Package.Elements[idx];				\
63 	if (tmp == NULL) {						\
64 		ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),	\
65 		    __func__ ": PKG_GETINT error, idx = %d\n.", idx);	\
66 		goto label;						\
67 	}								\
68 	if (tmp->Type != ACPI_TYPE_INTEGER)				\
69 		goto label;						\
70 	dest = tmp->Integer.Value;					\
71 } while (0)
72 
73 #define	PKG_GETSTR(res, tmp, idx, dest, size, label) do {              	\
74 	size_t	length;							\
75 	length = size;							\
76 	tmp = &res->Package.Elements[idx]; 				\
77 	if (tmp == NULL) {						\
78 		ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),	\
79 		    __func__ ": PKG_GETSTR error, idx = %d\n.", idx);	\
80 		goto label;						\
81 	}								\
82 	bzero(dest, sizeof(dest));					\
83 	switch (tmp->Type) {						\
84 	case ACPI_TYPE_STRING:						\
85 		if (tmp->String.Length < length) {			\
86 			length = tmp->String.Length;			\
87 		}							\
88 		strncpy(dest, tmp->String.Pointer, length);		\
89 		break;							\
90 	case ACPI_TYPE_BUFFER:						\
91 		if (tmp->Buffer.Length < length) {			\
92 			length = tmp->Buffer.Length;			\
93 		}							\
94 		strncpy(dest, tmp->Buffer.Pointer, length);		\
95 		break;							\
96 	default:							\
97 		goto label;						\
98 	}								\
99 	dest[sizeof(dest)-1] = '\0';					\
100 } while (0)
101 
102 struct acpi_cmbat_softc {
103 	device_t	dev;
104 
105 	struct acpi_bif	bif;
106 	struct acpi_bst	bst;
107 	ACPI_BUFFER	bif_buffer;
108 	ACPI_BUFFER	bst_buffer;
109 	struct timespec	bif_lastupdated;
110 	struct timespec	bst_lastupdated;
111 
112 	int		not_present;
113 	int		cap;
114 	int		min;
115 	int		full_charge_time;
116 
117 	struct callout_handle cmbat_timeout;
118 };
119 
120 static struct timespec	 acpi_cmbat_info_lastupdated;
121 
122 /* XXX: devclass_get_maxunit() don't give us the current allocated units... */
123 static int		 acpi_cmbat_units = 0;
124 
125 static void		 acpi_cmbat_timeout(void *);
126 static int		 acpi_cmbat_info_expired(struct timespec *);
127 static void		 acpi_cmbat_info_updated(struct timespec *);
128 static void		 acpi_cmbat_get_bst(void *);
129 static void		 acpi_cmbat_get_bif(void *);
130 static void		 acpi_cmbat_notify_handler(ACPI_HANDLE, UINT32, void *);
131 static int		 acpi_cmbat_probe(device_t);
132 static int		 acpi_cmbat_attach(device_t);
133 static int		 acpi_cmbat_resume(device_t);
134 static int		 acpi_cmbat_ioctl(u_long, caddr_t, void *);
135 static int		 acpi_cmbat_get_total_battinfo(struct acpi_battinfo *);
136 
137 /*
138  * Poll the battery info.
139  */
140 static void
141 acpi_cmbat_timeout(void *context)
142 {
143 	device_t	dev;
144 	struct acpi_cmbat_softc *sc;
145 
146 	dev = (device_t)context;
147 	sc = device_get_softc(dev);
148 
149 	AcpiOsQueueForExecution(OSD_PRIORITY_LO, acpi_cmbat_get_bif, dev);
150 	sc->cmbat_timeout = timeout(acpi_cmbat_timeout, dev, CMBAT_POLLRATE);
151 }
152 
153 static __inline int
154 acpi_cmbat_info_expired(struct timespec *lastupdated)
155 {
156 	struct timespec	curtime;
157 
158 	if (lastupdated == NULL) {
159 		return (1);
160 	}
161 
162 	if (!timespecisset(lastupdated)) {
163 		return (1);
164 	}
165 
166 	getnanotime(&curtime);
167 	timespecsub(&curtime, lastupdated);
168 	return ((curtime.tv_sec < 0 || curtime.tv_sec > acpi_battery_get_info_expire()));
169 }
170 
171 
172 static __inline void
173 acpi_cmbat_info_updated(struct timespec *lastupdated)
174 {
175 
176 	if (lastupdated != NULL) {
177 		getnanotime(lastupdated);
178 	}
179 }
180 
181 static void
182 acpi_cmbat_get_bst(void *context)
183 {
184 	device_t	dev;
185 	struct acpi_cmbat_softc *sc;
186 	ACPI_STATUS	as;
187 	ACPI_OBJECT	*res, *tmp;
188 	ACPI_HANDLE	h;
189 
190 	dev = context;
191 	sc = device_get_softc(dev);
192 	h = acpi_get_handle(dev);
193 
194 	if (!acpi_cmbat_info_expired(&sc->bst_lastupdated)) {
195 		return;
196 	}
197 
198 	untimeout(acpi_cmbat_timeout, (caddr_t)dev, sc->cmbat_timeout);
199 retry:
200 	if (sc->bst_buffer.Length == 0) {
201 		if (sc->bst_buffer.Pointer != NULL) {
202 			free(sc->bst_buffer.Pointer, M_ACPICMBAT);
203 			sc->bst_buffer.Pointer = NULL;
204 		}
205 		as = AcpiEvaluateObject(h, "_BST", NULL, &sc->bst_buffer);
206 		if (as != AE_BUFFER_OVERFLOW) {
207 			ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),
208 			    "couldn't find _BST - %s\n", AcpiFormatException(as));
209 			goto end;
210 		}
211 
212 		sc->bst_buffer.Pointer = malloc(sc->bst_buffer.Length, M_ACPICMBAT, M_NOWAIT);
213 		if (sc->bst_buffer.Pointer == NULL) {
214 			device_printf(dev, "malloc failed");
215 			goto end;
216 		}
217 	}
218 
219 	bzero(sc->bst_buffer.Pointer, sc->bst_buffer.Length);
220 	as = AcpiEvaluateObject(h, "_BST", NULL, &sc->bst_buffer);
221 
222 	if (as == AE_BUFFER_OVERFLOW) {
223 		if (sc->bst_buffer.Pointer != NULL) {
224 			free(sc->bst_buffer.Pointer, M_ACPICMBAT);
225 			sc->bst_buffer.Pointer = NULL;
226 		}
227 		ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),
228 		    "bst size changed to %d\n", sc->bst_buffer.Length);
229 		sc->bst_buffer.Length = 0;
230 		goto retry;
231 	} else if (as != AE_OK) {
232 		ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),
233 		    "couldn't find _BST - %s\n", AcpiFormatException(as));
234 		goto end;
235 	}
236 
237 	res = (ACPI_OBJECT *)sc->bst_buffer.Pointer;
238 
239 	if ((res->Type != ACPI_TYPE_PACKAGE) || (res->Package.Count != 4)) {
240 		ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),
241 		    "battery status corrupted\n");
242 		goto end;
243 	}
244 
245 	PKG_GETINT(res, tmp, 0, sc->bst.state, end);
246 	PKG_GETINT(res, tmp, 1, sc->bst.rate, end);
247 	PKG_GETINT(res, tmp, 2, sc->bst.cap, end);
248 	PKG_GETINT(res, tmp, 3, sc->bst.volt, end);
249 	acpi_cmbat_info_updated(&sc->bst_lastupdated);
250 end:
251 	sc->cmbat_timeout = timeout(acpi_cmbat_timeout, dev, CMBAT_POLLRATE);
252 }
253 
254 static void
255 acpi_cmbat_get_bif(void *context)
256 {
257 	device_t	dev;
258 	struct acpi_cmbat_softc *sc;
259 	ACPI_STATUS	as;
260 	ACPI_OBJECT	*res, *tmp;
261 	ACPI_HANDLE	h;
262 
263 	dev = context;
264 	sc = device_get_softc(dev);
265 	h = acpi_get_handle(dev);
266 
267 	if (!acpi_cmbat_info_expired(&sc->bif_lastupdated)) {
268 		return;
269 	}
270 
271 	untimeout(acpi_cmbat_timeout, (caddr_t)dev, sc->cmbat_timeout);
272 retry:
273 	if (sc->bif_buffer.Length == 0) {
274 		if (sc->bif_buffer.Pointer != NULL) {
275 			free(sc->bif_buffer.Pointer, M_ACPICMBAT);
276 			sc->bif_buffer.Pointer = NULL;
277 		}
278 		as = AcpiEvaluateObject(h, "_BIF", NULL, &sc->bif_buffer);
279 		if (as != AE_BUFFER_OVERFLOW) {
280 			ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),
281 			    "couldn't find _BIF - %s\n", AcpiFormatException(as));
282 			goto end;
283 		}
284 
285 		sc->bif_buffer.Pointer = malloc(sc->bif_buffer.Length, M_ACPICMBAT, M_NOWAIT);
286 		if (sc->bif_buffer.Pointer == NULL) {
287 			device_printf(dev, "malloc failed");
288 			goto end;
289 		}
290 	}
291 
292 	bzero(sc->bif_buffer.Pointer, sc->bif_buffer.Length);
293 	as = AcpiEvaluateObject(h, "_BIF", NULL, &sc->bif_buffer);
294 
295 	if (as == AE_BUFFER_OVERFLOW) {
296 		if (sc->bif_buffer.Pointer != NULL) {
297 			free(sc->bif_buffer.Pointer, M_ACPICMBAT);
298 			sc->bif_buffer.Pointer = NULL;
299 		}
300 		ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),
301 		    "bif size changed to %d\n", sc->bif_buffer.Length);
302 		sc->bif_buffer.Length = 0;
303 		goto retry;
304 	} else if (as != AE_OK) {
305 		ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),
306 		    "couldn't find _BIF - %s\n", AcpiFormatException(as));
307 		goto end;
308 	}
309 
310 	res = (ACPI_OBJECT *)sc->bif_buffer.Pointer;
311 
312 	if ((res->Type != ACPI_TYPE_PACKAGE) || (res->Package.Count != 13)) {
313 		ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),
314 		    "battery info corrupted\n");
315 		goto end;
316 	}
317 
318 	PKG_GETINT(res, tmp,  0, sc->bif.unit, end);
319 	PKG_GETINT(res, tmp,  1, sc->bif.dcap, end);
320 	PKG_GETINT(res, tmp,  2, sc->bif.lfcap, end);
321 	PKG_GETINT(res, tmp,  3, sc->bif.btech, end);
322 	PKG_GETINT(res, tmp,  4, sc->bif.dvol, end);
323 	PKG_GETINT(res, tmp,  5, sc->bif.wcap, end);
324 	PKG_GETINT(res, tmp,  6, sc->bif.lcap, end);
325 	PKG_GETINT(res, tmp,  7, sc->bif.gra1, end);
326 	PKG_GETINT(res, tmp,  8, sc->bif.gra2, end);
327 	PKG_GETSTR(res, tmp,  9, sc->bif.model, ACPI_CMBAT_MAXSTRLEN, end);
328 	PKG_GETSTR(res, tmp, 10, sc->bif.serial, ACPI_CMBAT_MAXSTRLEN, end);
329 	PKG_GETSTR(res, tmp, 11, sc->bif.type, ACPI_CMBAT_MAXSTRLEN, end);
330 	PKG_GETSTR(res, tmp, 12, sc->bif.oeminfo, ACPI_CMBAT_MAXSTRLEN, end);
331 	acpi_cmbat_info_updated(&sc->bif_lastupdated);
332 end:
333 	sc->cmbat_timeout = timeout(acpi_cmbat_timeout, dev, CMBAT_POLLRATE);
334 }
335 
336 static void
337 acpi_cmbat_notify_handler(ACPI_HANDLE h, UINT32 notify, void *context)
338 {
339 	device_t	dev;
340 	struct acpi_cmbat_softc	*sc;
341 
342 	dev = (device_t)context;
343 	if ((sc = device_get_softc(dev)) == NULL) {
344 		return;
345 	}
346 
347 	switch (notify) {
348 	case ACPI_BATTERY_BST_CHANGE:
349 		timespecclear(&sc->bst_lastupdated);
350 		break;
351 	case ACPI_BATTERY_BIF_CHANGE:
352 		timespecclear(&sc->bif_lastupdated);
353 		AcpiOsQueueForExecution(OSD_PRIORITY_LO, acpi_cmbat_get_bif, dev);
354 		break;
355 	default:
356 		break;
357 	}
358 }
359 
360 static int
361 acpi_cmbat_probe(device_t dev)
362 {
363 
364 	if ((acpi_get_type(dev) == ACPI_TYPE_DEVICE) &&
365 	    !acpi_disabled("cmbat") &&
366 	    acpi_MatchHid(dev, "PNP0C0A")) {
367 		/*
368 		 * Set device description.
369 		 */
370 		device_set_desc(dev, "Control method Battery");
371 		return (0);
372 	}
373 	return (ENXIO);
374 }
375 
376 static int
377 acpi_cmbat_attach(device_t dev)
378 {
379 	int		error;
380 	ACPI_HANDLE	handle;
381 	struct acpi_cmbat_softc *sc;
382 
383 	if ((sc = device_get_softc(dev)) == NULL) {
384 		return (ENXIO);
385 	}
386 
387 	handle = acpi_get_handle(dev);
388 
389 	AcpiInstallNotifyHandler(handle, ACPI_DEVICE_NOTIFY,
390 				 acpi_cmbat_notify_handler, dev);
391 
392 	bzero(&sc->bif_buffer, sizeof(sc->bif_buffer));
393 	bzero(&sc->bst_buffer, sizeof(sc->bst_buffer));
394 	sc->dev = dev;
395 
396 	timespecclear(&sc->bif_lastupdated);
397 	timespecclear(&sc->bst_lastupdated);
398 
399 	if (acpi_cmbat_units == 0) {
400 		if ((error = acpi_register_ioctl(ACPIIO_CMBAT_GET_BIF,
401 				acpi_cmbat_ioctl, NULL)) != 0) {
402 			return (error);
403 		}
404 		if ((error = acpi_register_ioctl(ACPIIO_CMBAT_GET_BST,
405 				acpi_cmbat_ioctl, NULL)) != 0) {
406 			return (error);
407 		}
408 	}
409 
410 	if ((error = acpi_battery_register(ACPI_BATT_TYPE_CMBAT,
411 			acpi_cmbat_units)) != 0) {
412 		return (error);
413 	}
414 
415 	acpi_cmbat_units++;
416 	timespecclear(&acpi_cmbat_info_lastupdated);
417 
418 	AcpiOsQueueForExecution(OSD_PRIORITY_LO, acpi_cmbat_get_bif, dev);
419 	return (0);
420 }
421 
422 static int
423 acpi_cmbat_resume(device_t dev)
424 {
425 
426 	AcpiOsQueueForExecution(OSD_PRIORITY_LO, acpi_cmbat_get_bif, dev);
427 	return (0);
428 }
429 
430 static device_method_t acpi_cmbat_methods[] = {
431 	/* Device interface */
432 	DEVMETHOD(device_probe,		acpi_cmbat_probe),
433 	DEVMETHOD(device_attach,	acpi_cmbat_attach),
434 	DEVMETHOD(device_resume,	acpi_cmbat_resume),
435 
436 	{0, 0}
437 };
438 
439 static driver_t acpi_cmbat_driver = {
440 	"acpi_cmbat",
441 	acpi_cmbat_methods,
442 	sizeof(struct acpi_cmbat_softc),
443 };
444 
445 static devclass_t acpi_cmbat_devclass;
446 DRIVER_MODULE(acpi_cmbat, acpi, acpi_cmbat_driver, acpi_cmbat_devclass, 0, 0);
447 
448 static int
449 acpi_cmbat_ioctl(u_long cmd, caddr_t addr, void *arg)
450 {
451 	device_t	dev;
452 	union acpi_battery_ioctl_arg *ioctl_arg;
453 	struct acpi_cmbat_softc *sc;
454 	struct acpi_bif	*bifp;
455 	struct acpi_bst	*bstp;
456 
457 	ioctl_arg = (union acpi_battery_ioctl_arg *)addr;
458 	if ((dev = devclass_get_device(acpi_cmbat_devclass,
459 			ioctl_arg->unit)) == NULL) {
460 		return (ENXIO);
461 	}
462 
463 	if ((sc = device_get_softc(dev)) == NULL) {
464 		return (ENXIO);
465 	}
466 
467 	switch (cmd) {
468 	case ACPIIO_CMBAT_GET_BIF:
469 		acpi_cmbat_get_bif(dev);
470 		bifp = &ioctl_arg->bif;
471 		bifp->unit = sc->bif.unit;
472 		bifp->dcap = sc->bif.dcap;
473 		bifp->lfcap = sc->bif.lfcap;
474 		bifp->btech = sc->bif.btech;
475 		bifp->dvol = sc->bif.dvol;
476 		bifp->wcap = sc->bif.wcap;
477 		bifp->lcap = sc->bif.lcap;
478 		bifp->gra1 = sc->bif.gra1;
479 		bifp->gra2 = sc->bif.gra2;
480 		strncpy(bifp->model, sc->bif.model, sizeof(sc->bif.model));
481 		strncpy(bifp->serial, sc->bif.serial, sizeof(sc->bif.serial));
482 		strncpy(bifp->type, sc->bif.type, sizeof(sc->bif.type));
483 		strncpy(bifp->oeminfo, sc->bif.oeminfo, sizeof(sc->bif.oeminfo));
484 		break;
485 
486 	case ACPIIO_CMBAT_GET_BST:
487 		acpi_cmbat_get_bst(dev);
488 		bstp = &ioctl_arg->bst;
489 		bstp->state = sc->bst.state;
490 		bstp->rate = sc->bst.rate;
491 		bstp->cap = sc->bst.cap;
492 		bstp->volt = sc->bst.volt;
493 		break;
494 	}
495 
496 	return (0);
497 }
498 
499 static int
500 acpi_cmbat_get_total_battinfo(struct acpi_battinfo *battinfo)
501 {
502 	int		i;
503 	int		error;
504 	int		batt_stat;
505 	int		valid_rate, valid_units;
506 	int		cap, min;
507 	int		total_cap, total_min, total_full;
508 	device_t	dev;
509 	struct acpi_cmbat_softc *sc;
510 	static int	bat_units = 0;
511 	static struct acpi_cmbat_softc **bat = NULL;
512 
513 	cap = min = -1;
514 	batt_stat = ACPI_BATT_STAT_NOT_PRESENT;
515 	error = 0;
516 
517 	/* Allocate array of softc pointers */
518 	if (bat_units != acpi_cmbat_units) {
519 		if (bat != NULL) {
520 			free(bat, M_ACPICMBAT);
521 			bat = NULL;
522 		}
523 		bat_units = 0;
524 	}
525 	if (bat == NULL) {
526 		bat_units = acpi_cmbat_units;
527 		bat = malloc(sizeof(struct acpi_cmbat_softc *) * bat_units,
528 			     M_ACPICMBAT, M_NOWAIT);
529 		if (bat == NULL) {
530 			error = ENOMEM;
531 			goto out;
532 		}
533 
534 		/* Collect softc pointers */
535 		for (i = 0; i < acpi_cmbat_units; i++) {
536 			if ((dev = devclass_get_device(acpi_cmbat_devclass, i)) == NULL) {
537 				error = ENXIO;
538 				goto out;
539 			}
540 
541 			if ((sc = device_get_softc(dev)) == NULL) {
542 				error = ENXIO;
543 				goto out;
544 			}
545 
546 			bat[i] = sc;
547 		}
548 	}
549 
550 	/* Get battery status, valid rate and valid units */
551 	batt_stat = valid_rate = valid_units = 0;
552 	for (i = 0; i < acpi_cmbat_units; i++) {
553 		bat[i]->not_present = 0;
554 		acpi_cmbat_get_bst(bat[i]->dev);
555 
556 		/* If battey not installed, we get strange values */
557 		if (bat[i]->bst.state >= ACPI_BATT_STAT_MAX ||
558 		    bat[i]->bst.cap == 0xffffffff ||
559 		    bat[i]->bst.volt == 0xffffffff ||
560 		    bat[i]->bif.lfcap == 0) {
561 			bat[i]->not_present = 1;
562 			continue;
563 		}
564 
565 		valid_units++;
566 
567 		bat[i]->cap = 100 * bat[i]->bst.cap / bat[i]->bif.lfcap;
568 
569 		batt_stat |= bat[i]->bst.state;
570 
571 		if (bat[i]->bst.rate > 0) {
572 			/*
573 			 * XXX Hack to calculate total battery time.
574 			 * Systems with 2 or more battries, they may get used
575 			 * one by one, thus bst.rate is set only to the one
576 			 * in use. For remaining batteries bst.rate = 0, which
577 			 * makes it impossible to calculate remaining time.
578 			 * Some other systems may need sum of bst.rate in
579 			 * dis-charging state.
580 			 * There for we sum up the bst.rate that is valid
581 			 * (in dis-charging state), and use the sum to
582 			 * calcutate remaining batteries' time.
583 			 */
584 			if (bat[i]->bst.state & ACPI_BATT_STAT_DISCHARG) {
585 				valid_rate += bat[i]->bst.rate;
586 			}
587 		}
588 	}
589 
590 	/* Calculate total battery capacity and time */
591 	total_cap = total_min = total_full = 0;
592 	for (i = 0; i < acpi_cmbat_units; i++) {
593 		if (bat[i]->not_present) {
594 			continue;
595 		}
596 
597 		if (valid_rate > 0) {
598 			/* Use the sum of bst.rate */
599 			bat[i]->min = 60 * bat[i]->bst.cap / valid_rate;
600 		} else if (bat[i]->full_charge_time > 0) {
601 			bat[i]->min = (bat[i]->full_charge_time * bat[i]->cap) / 100;
602 		} else {
603 			/* Couldn't find valid rate and full battery time */
604 			bat[i]->min = 0;
605 		}
606 		total_min += bat[i]->min;
607 		total_cap += bat[i]->cap;
608 		total_full += bat[i]->full_charge_time;
609 	}
610 
611 	/* Battery life */
612 	if (valid_units == 0) {
613 		cap = -1;
614 		batt_stat = ACPI_BATT_STAT_NOT_PRESENT;
615 	} else {
616 		cap = total_cap / valid_units;
617 	}
618 
619 	/* Battery time */
620 	if (valid_units == 0) {
621 		min = -1;
622 	} else if (valid_rate == 0 || (batt_stat & ACPI_BATT_STAT_CHARGING)) {
623 		if (total_full == 0) {
624 			min = -1;
625 		} else {
626 			min = (total_full * cap) / 100;
627 		}
628 	} else {
629 		min = total_min;
630 	}
631 
632 	acpi_cmbat_info_updated(&acpi_cmbat_info_lastupdated);
633 out:
634 	battinfo->cap = cap;
635 	battinfo->min = min;
636 	battinfo->state = batt_stat;
637 
638 	return (error);
639 }
640 
641 /*
642  * Public interfaces.
643  */
644 
645 int
646 acpi_cmbat_get_battinfo(int unit, struct acpi_battinfo *battinfo)
647 {
648 	int		error;
649 	device_t	dev;
650 	struct acpi_cmbat_softc *sc;
651 
652 	if (unit == -1) {
653 		return (acpi_cmbat_get_total_battinfo(battinfo));
654 	}
655 
656 	if (acpi_cmbat_info_expired(&acpi_cmbat_info_lastupdated)) {
657 		error = acpi_cmbat_get_total_battinfo(battinfo);
658 		if (error) {
659 			goto out;
660 		}
661 	}
662 
663 	error = 0;
664 	if (unit >= acpi_cmbat_units) {
665 		error = ENXIO;
666 		goto out;
667 	}
668 
669 	if ((dev = devclass_get_device(acpi_cmbat_devclass, unit)) == NULL) {
670 		error = ENXIO;
671 		goto out;
672 	}
673 
674 	if ((sc = device_get_softc(dev)) == NULL) {
675 		error = ENXIO;
676 		goto out;
677 	}
678 
679 	if (sc->not_present) {
680 		battinfo->cap = -1;
681 		battinfo->min = -1;
682 		battinfo->state = ACPI_BATT_STAT_NOT_PRESENT;
683 	} else {
684 		battinfo->cap = sc->cap;
685 		battinfo->min = sc->min;
686 		battinfo->state = sc->bst.state;
687 	}
688 out:
689 	return (error);
690 }
691 
692