xref: /titanic_50/usr/src/uts/sun4u/snowbird/io/todds1307/todds1307.c (revision 356f72340a69936724c69f2f87fffa6f5887f885)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 
27 #include <sys/types.h>
28 #include <sys/conf.h>
29 #include <sys/devops.h>
30 #include <sys/kmem.h>
31 #include <sys/open.h>
32 #include <sys/file.h>
33 #include <sys/note.h>
34 #include <sys/ddi.h>
35 #include <sys/sunddi.h>
36 
37 #include <sys/modctl.h>
38 #include <sys/stat.h>
39 #include <sys/clock.h>
40 #include <sys/reboot.h>
41 #include <sys/machsystm.h>
42 #include <sys/poll.h>
43 #include <sys/pbio.h>
44 #include <sys/sysmacros.h>
45 
46 /* Added for prom interface */
47 #include <sys/promif.h>
48 #include <sys/promimpl.h>
49 
50 #include <sys/i2c/misc/i2c_svc.h>
51 #include <sys/todds1307.h>
52 
53 #define	I2C_DELAY	20000
54 #define	DS1307_DEVICE_TYPE	"rtc"
55 
56 /*
57  * Driver enrty routines
58  */
59 static int todds1307_attach(dev_info_t *, ddi_attach_cmd_t);
60 static int todds1307_detach(dev_info_t *, ddi_detach_cmd_t);
61 static int todds1307_getinfo(dev_info_t *, ddi_info_cmd_t, void *, void **);
62 
63 /*
64  * tod_ops entry routines
65  */
66 static timestruc_t	todds1307_get(void);
67 static void		todds1307_set(timestruc_t);
68 static uint_t		todds1307_set_watchdog_timer(uint_t);
69 static uint_t		todds1307_clear_watchdog_timer(void);
70 static void		todds1307_set_power_alarm(timestruc_t);
71 static void		todds1307_clear_power_alarm(void);
72 static int todds1307_setup_prom();
73 static void todds1307_rele_prom();
74 static int todds1307_prom_getdate(struct rtc_t *rtc);
75 static int todds1307_prom_setdate(struct rtc_t *rtc);
76 
77 /*
78  * Local functions
79  */
80 static int	todds1307_read_rtc(struct rtc_t *);
81 static int	todds1307_write_rtc(struct rtc_t *);
82 
83 /* Anchor for soft state structure */
84 static void	*ds1307_statep;
85 static int	instance = -1;
86 static int	todds1307_attach_done = 0;
87 static kmutex_t	todds1307_rd_lock;
88 static ihandle_t todds1307_ihandle = 0;
89 
90 /* one second time out */
91 #define	I2c_CYCLIC_TIMEOUT	1000000000
92 uint_t i2c_cyclic_timeout = I2c_CYCLIC_TIMEOUT;
93 static int sync_clock_once = 1;
94 static 	struct	rtc_t	 soft_rtc;
95 
96 /*
97  * For debugging only
98  */
99 static unsigned char int2bcd(int num);
100 static int bcd2int(unsigned char num);
101 
102 /*
103  * cp_ops structure
104  */
105 static struct cb_ops ds1307_cbops = {
106 	nodev,				/* open */
107 	nodev,				/* close */
108 	nodev,				/* strategy */
109 	nodev,				/* print */
110 	nodev,				/* dump */
111 	nodev,				/* read */
112 	nodev,				/* write */
113 	nodev,				/* ioctl */
114 	nodev,				/* devmap */
115 	nodev,				/* mmap */
116 	nodev,				/* segmap */
117 	NULL,				/* poll */
118 	ddi_prop_op,			/* cb_prop_op */
119 	NULL,				/* streamtab */
120 	D_NEW | D_MP,			/* Driver compatibility flag */
121 	CB_REV,				/* rev */
122 	nodev,				/* int (*cb_aread)() */
123 	nodev				/* int (*cb_awrite)() */
124 };
125 
126 /*
127  * dev_ops structure
128  */
129 static struct dev_ops ds1307_ops = {
130 	DEVO_REV,		/* devo_rev */
131 	0,			/* refcnt - reference cnt always set to 0 */
132 	todds1307_getinfo,	/* getinfo - Maybe requred */
133 	nulldev,		/* identify */
134 	nulldev,		/* probe */
135 	todds1307_attach,	/* attach */
136 	todds1307_detach,	/* detach */
137 	nodev,			/* reset */
138 	&ds1307_cbops,		/* cb_ops - ds1307 does not need this(?) */
139 	NULL,			/* bus_ops */
140 	NULL,			/* power */
141 	ddi_quiesce_not_needed,		/* quiesce */
142 };
143 
144 static struct modldrv todds1307_modldrv = {
145 	&mod_driverops,		/* Type of module. This one is a driver */
146 	"tod driver for DS1307 v1.12",	/* Name of the module */
147 	&ds1307_ops,			/* Pointer to dev_ops */
148 };
149 
150 /*
151  * Module linkage structure
152  */
153 static struct modlinkage todds1307_modlinkage = {
154 	MODREV_1,
155 	&todds1307_modldrv,
156 	0
157 };
158 
159 int
160 _init(void)
161 {
162 	int error;
163 
164 	if (strcmp(tod_module_name, "todds1307") == 0) {
165 		if ((error = ddi_soft_state_init(&ds1307_statep,
166 		    sizeof (ds1307_state_t), 0)) != DDI_SUCCESS) {
167 			return (error);
168 		}
169 
170 		tod_ops.tod_get = todds1307_get;
171 		tod_ops.tod_set = todds1307_set;
172 		tod_ops.tod_set_watchdog_timer = todds1307_set_watchdog_timer;
173 		tod_ops.tod_clear_watchdog_timer =
174 		    todds1307_clear_watchdog_timer;
175 		tod_ops.tod_set_power_alarm = todds1307_set_power_alarm;
176 		tod_ops.tod_clear_power_alarm = todds1307_clear_power_alarm;
177 	}
178 
179 	(void) todds1307_setup_prom();
180 
181 	/*
182 	 * Install the module
183 	 */
184 	if ((error = mod_install(&todds1307_modlinkage)) != 0) {
185 		ddi_soft_state_fini(&ds1307_statep);
186 		return (error);
187 	}
188 	mutex_init(&todds1307_rd_lock, NULL, MUTEX_DEFAULT, NULL);
189 
190 	return (0);
191 }
192 
193 int
194 _fini(void)
195 {
196 	int error = 0;
197 
198 	if (strcmp(tod_module_name, "todds1307") == 0) {
199 		error = EBUSY;
200 	} else {
201 		if ((error = mod_remove(&todds1307_modlinkage)) == 0) {
202 			ddi_soft_state_fini(&ds1307_statep);
203 			mutex_destroy(&todds1307_rd_lock);
204 			todds1307_rele_prom();
205 		}
206 	}
207 
208 	return (error);
209 }
210 
211 int
212 _info(struct modinfo *modinfop)
213 {
214 	return (mod_info(&todds1307_modlinkage, modinfop));
215 }
216 
217 /*
218  * cyclical call to get tod.
219  */
220 static void
221 todds1307_cyclic(void *arg)
222 {
223 
224 	(void) todds1307_read_rtc((struct rtc_t *)arg);
225 
226 }
227 
228 /*
229  * register ds1307 client device with i2c services, and
230  * allocate & initialize soft state structure.
231  */
232 static int
233 todds1307_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
234 {
235 	static ds1307_state_t	*statep = NULL;
236 	i2c_transfer_t	*i2c_tp = NULL;
237 	uint8_t tempVal = (uint8_t)0;
238 	switch (cmd) {
239 
240 		case DDI_ATTACH:
241 			break;
242 		case DDI_RESUME:
243 			return (DDI_SUCCESS);
244 		default:
245 			return (DDI_FAILURE);
246 	}
247 
248 	if (instance != -1) {
249 		return (DDI_FAILURE);
250 	}
251 
252 	instance = ddi_get_instance(dip);
253 
254 	/*
255 	 * Allocate soft state structure
256 	 */
257 	if (ddi_soft_state_zalloc(ds1307_statep, instance) != DDI_SUCCESS) {
258 		return (DDI_FAILURE);
259 	}
260 
261 	statep = ddi_get_soft_state(ds1307_statep, instance);
262 	if (statep == NULL) {
263 		return (DDI_FAILURE);
264 	}
265 
266 	statep->dip = dip;
267 
268 	if (i2c_client_register(dip, &statep->ds1307_i2c_hdl) != I2C_SUCCESS) {
269 		ddi_soft_state_free(ds1307_statep, instance);
270 		delay(drv_usectohz(I2C_DELAY));
271 		return (DDI_FAILURE);
272 	}
273 
274 	/* check and initialize the oscillator */
275 
276 	(void) i2c_transfer_alloc(statep->ds1307_i2c_hdl,
277 	    &i2c_tp, 1, 1, I2C_SLEEP);
278 	i2c_tp->i2c_version = I2C_XFER_REV;
279 	i2c_tp->i2c_flags = I2C_WR_RD;
280 	i2c_tp->i2c_wbuf[0] = (uchar_t)0x00; /* Read 00h */
281 	i2c_tp->i2c_wlen = 1;
282 	i2c_tp->i2c_rlen = 1;
283 
284 	if ((i2c_transfer(statep->ds1307_i2c_hdl, i2c_tp)) != I2C_SUCCESS) {
285 		(void) i2c_transfer_free(statep->ds1307_i2c_hdl, i2c_tp);
286 		ddi_soft_state_free(ds1307_statep, instance);
287 		delay(drv_usectohz(I2C_DELAY));
288 		return (DDI_FAILURE);
289 	}
290 
291 	tempVal = i2c_tp->i2c_rbuf[0];
292 
293 	(void) i2c_transfer_free(statep->ds1307_i2c_hdl, i2c_tp);
294 
295 	if (tempVal & 0x80) {			 /* check Oscillator */
296 		(void) i2c_transfer_alloc(statep->ds1307_i2c_hdl, &i2c_tp,
297 		    2, 1, I2C_SLEEP);
298 		i2c_tp->i2c_version = I2C_XFER_REV;
299 		i2c_tp->i2c_flags = I2C_WR;
300 		i2c_tp->i2c_wbuf[0] = 0x00;
301 		i2c_tp->i2c_wbuf[1] =
302 		    (uchar_t)(i2c_tp->i2c_rbuf[0]& 0x7f);
303 		i2c_tp->i2c_wlen = 2;
304 					/* Enable oscillator */
305 		if ((i2c_transfer(statep->ds1307_i2c_hdl, i2c_tp))
306 		    != I2C_SUCCESS) {
307 			(void) i2c_transfer_free(statep->ds1307_i2c_hdl,
308 			    i2c_tp);
309 			ddi_soft_state_free(ds1307_statep, instance);
310 			return (DDI_FAILURE);
311 		}
312 		(void) i2c_transfer_free(statep->ds1307_i2c_hdl, i2c_tp);
313 	}
314 
315 	/*
316 	 * Create a periodical handler to read TOD.
317 	 */
318 	ASSERT(statep->cycid == NULL);
319 	statep->cycid = ddi_periodic_add(todds1307_cyclic, &soft_rtc,
320 	    i2c_cyclic_timeout, DDI_IPL_1);
321 
322 	statep->state = TOD_ATTACHED;
323 	todds1307_attach_done = 1;
324 	ddi_report_dev(dip);
325 
326 	return (DDI_SUCCESS);
327 }
328 
329 /*
330  * Unregister ds1307 client device with i2c services and free
331  * soft state structure.
332  */
333 /*ARGSUSED*/
334 static int
335 todds1307_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
336 {
337 	switch (cmd) {
338 
339 	/*
340 	 * Once attached, do not allow detach because the system constantly
341 	 * calling todds1307_get() to get the time.  If the driver is detached
342 	 * and the system try to get the time, the system will have memory
343 	 * problem.
344 	 *
345 	 *	ds1307_state_t	*statep = NULL;
346 	 *	case DDI_DETACH:
347 	 *		if ((statep = ddi_get_soft_state(ds1307_statep,
348 	 *					instance)) == NULL) {
349 	 *			return (ENOMEM);
350 	 *		}
351 	 *		i2c_client_unregister(statep->ds1307_i2c_hdl);
352 	 *		ddi_soft_state_free(ds1307_statep, instance);
353 	 *		return (DDI_SUCCESS);
354 	 */
355 		case DDI_SUSPEND:
356 			return (DDI_SUCCESS);
357 
358 		default:
359 			return (DDI_FAILURE);
360 	}
361 }
362 
363 /* *********************** tod_ops entry points ******************** */
364 
365 /*
366  * Read the current time from the DS1307 chip and convert to UNIX form.
367  * Should be called with tod_clock held.
368  */
369 
370 static timestruc_t
371 todds1307_get(void)
372 {
373 	timestruc_t	ts;
374 	todinfo_t	tod;
375 	struct	rtc_t	rtc;
376 
377 	ASSERT(MUTEX_HELD(&tod_lock));
378 
379 	if (sync_clock_once) {
380 		(void) todds1307_read_rtc(&soft_rtc);
381 		sync_clock_once = 0;
382 	} else {
383 		tod_status_set(TOD_GET_FAILED);
384 		return (hrestime);
385 	}
386 
387 	bcopy(&soft_rtc, &rtc, sizeof (rtc));
388 
389 	/*
390 	 * 00 - 68 = 2000 thru 2068
391 	 * 69-99 = 1969 thru 1999
392 	 */
393 	tod.tod_year    = rtc.rtc_year;
394 	if (rtc.rtc_year <= 68)
395 		tod.tod_year += 100;
396 	tod.tod_month	= rtc.rtc_mon;
397 	tod.tod_day	= rtc.rtc_dom;
398 	tod.tod_dow	= rtc.rtc_dow;
399 	tod.tod_hour	= rtc.rtc_hrs;
400 	tod.tod_min	= rtc.rtc_min;
401 	tod.tod_sec	= rtc.rtc_sec;
402 
403 	/* read was successful so ensure failure flag is clear */
404 	tod_status_clear(TOD_GET_FAILED);
405 
406 	ts.tv_sec = tod_to_utc(tod);
407 	ts.tv_nsec = 0;
408 	return (ts);
409 }
410 
411 /*
412  * Program DS1307 with the specified time.
413  * Must be called with tod_lock held. The TOD
414  * chip supports date from 1969-2068 only. We must
415  * reject requests to set date below 2000.
416  */
417 static void
418 todds1307_set(timestruc_t ts)
419 {
420 	struct rtc_t	rtc;
421 	todinfo_t	tod = utc_to_tod(ts.tv_sec);
422 	int		year;
423 
424 
425 	ASSERT(MUTEX_HELD(&tod_lock));
426 
427 	/*
428 	 * Year is base 1900, valid year range 1969-2068
429 	 */
430 	if ((tod.tod_year < 69) || (tod.tod_year > 168))
431 		return;
432 
433 	year = tod.tod_year;
434 	if (year >= 100)
435 		year -= 100;
436 
437 	rtc.rtc_year	= int2bcd(year);
438 	rtc.rtc_mon	= int2bcd(tod.tod_month);
439 	rtc.rtc_dom	= int2bcd(tod.tod_day);
440 	rtc.rtc_dow	= int2bcd(tod.tod_dow);
441 	rtc.rtc_hrs	= int2bcd(tod.tod_hour);
442 	rtc.rtc_min	= int2bcd(tod.tod_min);
443 	rtc.rtc_sec	= int2bcd(tod.tod_sec);
444 
445 	(void) todds1307_write_rtc(&rtc);
446 }
447 
448 /* ARGSUSED */
449 static void
450 todds1307_set_power_alarm(timestruc_t ts)
451 {
452 	ASSERT(MUTEX_HELD(&tod_lock));
453 }
454 
455 /* ARGSUSED */
456 static void
457 todds1307_clear_power_alarm(void)
458 {
459 	ASSERT(MUTEX_HELD(&tod_lock));
460 }
461 
462 /* ARGSUSED */
463 static uint_t
464 todds1307_set_watchdog_timer(uint_t timeoutval)
465 {
466 	ASSERT(MUTEX_HELD(&tod_lock));
467 	return (0);
468 }
469 
470 /* ARGSUSED */
471 static uint_t
472 todds1307_clear_watchdog_timer(void)
473 {
474 	ASSERT(MUTEX_HELD(&tod_lock));
475 	return (0);
476 }
477 
478 /* ********************** Local functions ***************************** */
479 
480 static char tod_read[7] = {-1, -1, -1, -1, -1, -1, -1};
481 static int
482 todds1307_read_rtc(struct rtc_t *rtc)
483 {
484 	static	ds1307_state_t	*statep = NULL;
485 	i2c_transfer_t	*i2c_tp = NULL;
486 	int i2c_cmd_status = I2C_FAILURE;
487 	int counter = 4;
488 
489 	if (!todds1307_attach_done) {
490 		return (todds1307_prom_getdate(rtc));
491 	}
492 
493 	statep = ddi_get_soft_state(ds1307_statep, instance);
494 	if (statep == NULL) {
495 		cmn_err(CE_WARN, "todds1307: ddi_get_soft_state failed");
496 		return (DDI_FAILURE);
497 	}
498 
499 	mutex_enter(&todds1307_rd_lock);
500 
501 	/*
502 	 * Allocate 1 byte for write buffer and 7 bytes for read buffer to
503 	 * to accomodate sec, min, hrs, dayOfWeek, dayOfMonth, year
504 	 */
505 	if ((i2c_transfer_alloc(statep->ds1307_i2c_hdl, &i2c_tp, 1,
506 	    7, I2C_SLEEP)) != I2C_SUCCESS) {
507 		mutex_exit(&todds1307_rd_lock);
508 		return (DDI_FAILURE);
509 	}
510 
511 	do {
512 		i2c_tp->i2c_version = I2C_XFER_REV;
513 		i2c_tp->i2c_flags = I2C_WR_RD;
514 		i2c_tp->i2c_wbuf[0] = (uchar_t)0x00; /* Start from reg 0x00 */
515 		i2c_tp->i2c_wlen = 1;	/* Write one byte address */
516 		i2c_tp->i2c_rlen = 7;	/* Read 7 regs */
517 
518 		if ((i2c_cmd_status = i2c_transfer(statep->ds1307_i2c_hdl,
519 		    i2c_tp)) != I2C_SUCCESS) {
520 			drv_usecwait(I2C_DELAY);
521 			goto done;
522 		}
523 		/* for first read, need to get valid data */
524 		while (tod_read[0] == -1 && counter > 0) {
525 		/* move data to static buffer */
526 		bcopy(i2c_tp->i2c_rbuf, tod_read, 7);
527 
528 		/* now read again */
529 		/* Start reading reg from 0x00 */
530 		i2c_tp->i2c_wbuf[0] = (uchar_t)0x00;
531 		i2c_tp->i2c_wlen = 1;	/* Write one byte address */
532 		i2c_tp->i2c_rlen = 7;	/* Read 7 regs */
533 		if ((i2c_cmd_status = i2c_transfer(statep->ds1307_i2c_hdl,
534 		    i2c_tp)) != I2C_SUCCESS) {
535 			drv_usecwait(I2C_DELAY);
536 			goto done;
537 		}
538 		/* if they are not the same, then read again */
539 		if (bcmp(tod_read, i2c_tp->i2c_rbuf, 7) != 0) {
540 			tod_read[0] = -1;
541 			counter--;
542 		}
543 	}
544 
545 	} while (i2c_tp->i2c_rbuf[0] == 0x59 &&
546 	    /* if seconds register is 0x59 (BCD), add data should match */
547 	    bcmp(&tod_read[1], &i2c_tp->i2c_rbuf[1], 6) != 0 &&
548 	    counter-- > 0);
549 
550 	if (counter < 0)
551 		cmn_err(CE_WARN, "i2ctod: TOD Chip failed ??");
552 
553 	/* move data to static buffer */
554 	bcopy(i2c_tp->i2c_rbuf, tod_read, 7);
555 
556 
557 	rtc->rtc_year	= bcd2int(i2c_tp->i2c_rbuf[6]);
558 	rtc->rtc_mon	= bcd2int(i2c_tp->i2c_rbuf[5]);
559 	rtc->rtc_dom	= bcd2int(i2c_tp->i2c_rbuf[4]);
560 	rtc->rtc_dow	= bcd2int(i2c_tp->i2c_rbuf[3]);
561 	rtc->rtc_hrs	= bcd2int(i2c_tp->i2c_rbuf[2]);
562 	rtc->rtc_min	= bcd2int(i2c_tp->i2c_rbuf[1]);
563 	rtc->rtc_sec	= bcd2int(i2c_tp->i2c_rbuf[0]);
564 
565 done:
566 	(void) i2c_transfer_free(statep->ds1307_i2c_hdl, i2c_tp);
567 
568 	mutex_exit(&todds1307_rd_lock);
569 	return (i2c_cmd_status);
570 }
571 
572 
573 static int
574 todds1307_write_rtc(struct rtc_t *rtc)
575 {
576 	ds1307_state_t	*statep = NULL;
577 	i2c_transfer_t	*i2c_tp = NULL;
578 	int i2c_cmd_status = I2C_SUCCESS;
579 
580 
581 	if (!todds1307_attach_done) {
582 		return (todds1307_prom_setdate(rtc));
583 	}
584 
585 	statep = ddi_get_soft_state(ds1307_statep, instance);
586 	if (statep == NULL) {
587 		return (DDI_FAILURE);
588 	}
589 
590 	if ((i2c_cmd_status = i2c_transfer_alloc(statep->ds1307_i2c_hdl,
591 	    &i2c_tp, 8, 0, I2C_SLEEP)) != I2C_SUCCESS) {
592 		return (i2c_cmd_status);
593 	}
594 
595 	i2c_tp->i2c_version = I2C_XFER_REV;
596 	i2c_tp->i2c_flags = I2C_WR;
597 	i2c_tp->i2c_wbuf[0] = (uchar_t)0x00;
598 	i2c_tp->i2c_wbuf[1] = rtc->rtc_sec;
599 	i2c_tp->i2c_wbuf[2] = rtc->rtc_min;
600 	i2c_tp->i2c_wbuf[3] = rtc->rtc_hrs;
601 	i2c_tp->i2c_wbuf[4] = rtc->rtc_dow;
602 	i2c_tp->i2c_wbuf[5] = rtc->rtc_dom;
603 	i2c_tp->i2c_wbuf[6] = rtc->rtc_mon;
604 	i2c_tp->i2c_wbuf[7] = rtc->rtc_year;
605 	i2c_tp->i2c_wlen = 8;
606 
607 	if ((i2c_cmd_status = i2c_transfer(statep->ds1307_i2c_hdl,
608 	    i2c_tp)) != I2C_SUCCESS) {
609 		(void) i2c_transfer_free(statep->ds1307_i2c_hdl, i2c_tp);
610 		/* delay(drv_usectohz(I2C_DELAY)); */
611 		drv_usecwait(I2C_DELAY);
612 		return (i2c_cmd_status);
613 	}
614 
615 	tod_read[0] = -1;  /* invalidate saved data from read routine */
616 
617 	(void) i2c_transfer_free(statep->ds1307_i2c_hdl, i2c_tp);
618 
619 	return (i2c_cmd_status);
620 }
621 
622 
623 /*ARGSUSED*/
624 static int
625 todds1307_getinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
626     void **result)
627 {
628 	ds1307_state_t *softsp;
629 
630 	if (instance == -1) {
631 		return (DDI_FAILURE);
632 	}
633 
634 	switch (infocmd) {
635 	case DDI_INFO_DEVT2DEVINFO:
636 		if ((softsp = ddi_get_soft_state(ds1307_statep, instance))
637 		    == NULL)
638 			return (DDI_FAILURE);
639 		*result = (void *)softsp->dip;
640 		return (DDI_SUCCESS);
641 
642 	case DDI_INFO_DEVT2INSTANCE:
643 		*result = (void *)(uintptr_t)instance;
644 		return (DDI_SUCCESS);
645 
646 	default:
647 		return (DDI_FAILURE);
648 	}
649 }
650 
651 /*
652  * Conversion functions
653  */
654 static unsigned char
655 int2bcd(int num) {
656 	return (((num / 10) << 4)	/* tens BCD digit in high four bits */
657 	+ (num % 10));		/* units digit goes in low four bits */
658 }
659 
660 static int
661 bcd2int(unsigned char num) {
662 	return (((num >> 4) * 10)	/* 10 times high-order four bits */
663 	+ (num & 0x0f));		/* plus low-order four bits */
664 }
665 
666 /*
667  * Finds the device node with device_type "rtc" and opens it to
668  * execute the get-time method
669  */
670 static int
671 todds1307_setup_prom()
672 {
673 	pnode_t todnode;
674 	char tod1307_devpath[MAXNAMELEN];
675 
676 	if ((todnode = prom_findnode_bydevtype(prom_rootnode(),
677 	    DS1307_DEVICE_TYPE)) == OBP_NONODE)
678 		return (DDI_FAILURE);
679 
680 	/*
681 	 * We now have the phandle of the rtc node, we need to open the
682 	 * node and get the ihandle
683 	 */
684 	if (prom_phandle_to_path(todnode, tod1307_devpath,
685 	    sizeof (tod1307_devpath)) < 0) {
686 		cmn_err(CE_WARN, "prom_phandle_to_path failed");
687 		return (DDI_FAILURE);
688 	}
689 
690 	/*
691 	 * Now open the node and store it's ihandle
692 	 */
693 	if ((todds1307_ihandle = prom_open(tod1307_devpath)) == NULL) {
694 		cmn_err(CE_WARN, "prom_open failed");
695 		return (DDI_FAILURE);
696 	}
697 
698 	return (DDI_SUCCESS);
699 }
700 
701 /*
702  * Closes the prom interface
703  */
704 static void
705 todds1307_rele_prom()
706 {
707 	(void) prom_close(todds1307_ihandle);
708 }
709 
710 /*
711  * Read the date using "get-time" method in rtc node
712  * PROM returns 1969-1999 when reading 69-99 and
713  * 2000-2068 when reading 00-68
714  */
715 static int
716 todds1307_prom_getdate(struct rtc_t *rtc)
717 {
718 	int year;
719 	cell_t ci[12];
720 
721 	ci[0] = p1275_ptr2cell("call-method");  /* Service name */
722 	ci[1] = 2; /* # of arguments */
723 	ci[2] = 7; /* # of result cells */
724 	ci[3] = p1275_ptr2cell("get-time");
725 	ci[4] = p1275_ihandle2cell(todds1307_ihandle);
726 
727 	promif_preprom();
728 	(void) p1275_cif_handler(&ci);
729 	promif_postprom();
730 
731 	year 		= p1275_cell2int(ci[6]);
732 	rtc->rtc_mon	= p1275_cell2int(ci[7]);
733 	rtc->rtc_dom	= p1275_cell2int(ci[8]);
734 	rtc->rtc_dow	= 0;
735 	rtc->rtc_hrs	= p1275_cell2int(ci[9]);
736 	rtc->rtc_min	= p1275_cell2int(ci[10]);
737 	rtc->rtc_sec	= p1275_cell2int(ci[11]);
738 	if (year >= 2000)
739 		year -= 2000;
740 	else
741 		year -= 1900;
742 	rtc->rtc_year	= year;
743 
744 	return (DDI_SUCCESS);
745 }
746 
747 /*
748  * Read the date using "set-time" method in rtc node
749  * For values 00 - 68, write 2000-2068, and for 69-99,
750  * write 1969-1999
751  */
752 static int
753 todds1307_prom_setdate(struct rtc_t *rtc)
754 {
755 	int year;
756 	cell_t ci[12];
757 
758 	year = rtc->rtc_year;
759 
760 	if ((year < 0) || (year > 99))
761 		return (DDI_FAILURE);
762 
763 	if (year <= 68)
764 		year = rtc->rtc_year + 2000;
765 	else
766 		year = rtc->rtc_year + 1900;
767 
768 	ci[0] = p1275_ptr2cell("call-method");  /* Service name */
769 	ci[1] = 8; /* # of arguments */
770 	ci[2] = 0; /* # of result cells */
771 	ci[3] = p1275_ptr2cell("set-time");
772 	ci[4] = p1275_ihandle2cell(todds1307_ihandle);
773 	ci[5] = p1275_int2cell(year);
774 	ci[6] = p1275_int2cell(rtc->rtc_mon);
775 	ci[7] = p1275_int2cell(rtc->rtc_dom);
776 	ci[8] = p1275_int2cell(rtc->rtc_hrs);
777 	ci[9] = p1275_int2cell(rtc->rtc_min);
778 	ci[10] = p1275_int2cell(rtc->rtc_sec);
779 
780 	promif_preprom();
781 	(void) p1275_cif_handler(&ci);
782 	promif_postprom();
783 
784 	return (DDI_SUCCESS);
785 }
786