1/*	$NetBSD: ds1307.c,v 1.40 2023/01/24 07:09:48 mlelstv Exp $	*/
2
3/*
4 * Copyright (c) 2003 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Steve C. Woodford and Jason R. Thorpe for Wasabi Systems, Inc.
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 * 3. All advertising materials mentioning features or use of this software
18 *    must display the following acknowledgement:
19 *      This product includes software developed for the NetBSD Project by
20 *      Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 *    or promote products derived from this software without specific prior
23 *    written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38#include <sys/cdefs.h>
39__KERNEL_RCSID(0, "$NetBSD: ds1307.c,v 1.40 2023/01/24 07:09:48 mlelstv Exp $");
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/device.h>
44#include <sys/kernel.h>
45#include <sys/fcntl.h>
46#include <sys/uio.h>
47#include <sys/conf.h>
48#include <sys/event.h>
49
50#include <dev/clock_subr.h>
51
52#include <dev/i2c/i2cvar.h>
53#include <dev/i2c/ds1307reg.h>
54#include <dev/sysmon/sysmonvar.h>
55
56#include "ioconf.h"
57#include "opt_dsrtc.h"
58
59struct dsrtc_model {
60	const i2c_addr_t *dm_valid_addrs;
61	uint16_t dm_model;
62	uint8_t dm_ch_reg;
63	uint8_t dm_ch_value;
64	uint8_t dm_vbaten_reg;
65	uint8_t dm_vbaten_value;
66	uint8_t dm_rtc_start;
67	uint8_t dm_rtc_size;
68	uint8_t dm_nvram_start;
69	uint8_t dm_nvram_size;
70	uint8_t dm_flags;
71#define	DSRTC_FLAG_CLOCK_HOLD		0x01
72#define	DSRTC_FLAG_BCD			0x02
73#define	DSRTC_FLAG_TEMP			0x04
74#define DSRTC_FLAG_VBATEN		0x08
75#define	DSRTC_FLAG_YEAR_START_2K	0x10
76#define	DSRTC_FLAG_CLOCK_HOLD_REVERSED	0x20
77};
78
79static const i2c_addr_t ds1307_valid_addrs[] = { DS1307_ADDR, 0 };
80static const struct dsrtc_model ds1307_model = {
81	.dm_valid_addrs = ds1307_valid_addrs,
82	.dm_model = 1307,
83	.dm_ch_reg = DSXXXX_SECONDS,
84	.dm_ch_value = DS1307_SECONDS_CH,
85	.dm_rtc_start = DS1307_RTC_START,
86	.dm_rtc_size = DS1307_RTC_SIZE,
87	.dm_nvram_start = DS1307_NVRAM_START,
88	.dm_nvram_size = DS1307_NVRAM_SIZE,
89	.dm_flags = DSRTC_FLAG_BCD | DSRTC_FLAG_CLOCK_HOLD,
90};
91
92static const struct dsrtc_model ds1339_model = {
93	.dm_valid_addrs = ds1307_valid_addrs,
94	.dm_model = 1339,
95	.dm_rtc_start = DS1339_RTC_START,
96	.dm_rtc_size = DS1339_RTC_SIZE,
97	.dm_flags = DSRTC_FLAG_BCD,
98};
99
100static const struct dsrtc_model ds1340_model = {
101	.dm_valid_addrs = ds1307_valid_addrs,
102	.dm_model = 1340,
103	.dm_ch_reg = DSXXXX_SECONDS,
104	.dm_ch_value = DS1340_SECONDS_EOSC,
105	.dm_rtc_start = DS1340_RTC_START,
106	.dm_rtc_size = DS1340_RTC_SIZE,
107	.dm_flags = DSRTC_FLAG_BCD,
108};
109
110static const struct dsrtc_model ds1672_model = {
111	.dm_valid_addrs = ds1307_valid_addrs,
112	.dm_model = 1672,
113	.dm_rtc_start = DS1672_RTC_START,
114	.dm_rtc_size = DS1672_RTC_SIZE,
115	.dm_ch_reg = DS1672_CONTROL,
116	.dm_ch_value = DS1672_CONTROL_CH,
117	.dm_flags = 0,
118};
119
120static const struct dsrtc_model ds3231_model = {
121	.dm_valid_addrs = ds1307_valid_addrs,
122	.dm_model = 3231,
123	.dm_rtc_start = DS3232_RTC_START,
124	.dm_rtc_size = DS3232_RTC_SIZE,
125	.dm_flags = DSRTC_FLAG_BCD | DSRTC_FLAG_TEMP,
126};
127
128static const struct dsrtc_model ds3232_model = {
129	.dm_valid_addrs = ds1307_valid_addrs,
130	.dm_model = 3232,
131	.dm_rtc_start = DS3232_RTC_START,
132	.dm_rtc_size = DS3232_RTC_SIZE,
133	.dm_nvram_start = DS3232_NVRAM_START,
134	.dm_nvram_size = DS3232_NVRAM_SIZE,
135	/*
136	 * XXX
137	 * the DS3232 likely has the temperature sensor too but I can't
138	 * easily verify or test that right now
139	 */
140	.dm_flags = DSRTC_FLAG_BCD,
141};
142
143static const i2c_addr_t mcp7940_valid_addrs[] = { MCP7940_ADDR, 0 };
144static const struct dsrtc_model mcp7940_model = {
145	.dm_valid_addrs = mcp7940_valid_addrs,
146	.dm_model = 7940,
147	.dm_rtc_start = DS1307_RTC_START,
148	.dm_rtc_size = DS1307_RTC_SIZE,
149	.dm_ch_reg = DSXXXX_SECONDS,
150	.dm_ch_value = DS1307_SECONDS_CH,
151	.dm_vbaten_reg = DSXXXX_DAY,
152	.dm_vbaten_value = MCP7940_TOD_DAY_VBATEN,
153	.dm_nvram_start = MCP7940_NVRAM_START,
154	.dm_nvram_size = MCP7940_NVRAM_SIZE,
155	.dm_flags = DSRTC_FLAG_BCD | DSRTC_FLAG_CLOCK_HOLD |
156		DSRTC_FLAG_VBATEN | DSRTC_FLAG_CLOCK_HOLD_REVERSED,
157};
158
159static const struct device_compatible_entry compat_data[] = {
160	{ .compat = "dallas,ds1307",		.data = &ds1307_model },
161	{ .compat = "maxim,ds1307",		.data = &ds1307_model },
162	{ .compat = "i2c-ds1307",		.data = &ds1307_model },
163
164	{ .compat = "dallas,ds1339",		.data = &ds1339_model },
165	{ .compat = "maxim,ds1339",		.data = &ds1339_model },
166
167	{ .compat = "dallas,ds1340",		.data = &ds1340_model },
168	{ .compat = "maxim,ds1340",		.data = &ds1340_model },
169
170	{ .compat = "dallas,ds1672",		.data = &ds1672_model },
171	{ .compat = "maxim,ds1672",		.data = &ds1672_model },
172
173	{ .compat = "dallas,ds3231",		.data = &ds3231_model },
174	{ .compat = "maxim,ds3231",		.data = &ds3231_model },
175
176	{ .compat = "dallas,ds3232",		.data = &ds3232_model },
177	{ .compat = "maxim,ds3232",		.data = &ds3232_model },
178
179	{ .compat = "microchip,mcp7940",	.data = &mcp7940_model },
180
181	DEVICE_COMPAT_EOL
182};
183
184struct dsrtc_softc {
185	device_t sc_dev;
186	i2c_tag_t sc_tag;
187	uint8_t sc_address;
188	bool sc_open;
189	struct dsrtc_model sc_model;
190	struct todr_chip_handle sc_todr;
191	struct sysmon_envsys *sc_sme;
192	envsys_data_t sc_sensor;
193};
194
195static void	dsrtc_attach(device_t, device_t, void *);
196static int	dsrtc_match(device_t, cfdata_t, void *);
197
198CFATTACH_DECL_NEW(dsrtc, sizeof(struct dsrtc_softc),
199    dsrtc_match, dsrtc_attach, NULL, NULL);
200
201dev_type_open(dsrtc_open);
202dev_type_close(dsrtc_close);
203dev_type_read(dsrtc_read);
204dev_type_write(dsrtc_write);
205
206const struct cdevsw dsrtc_cdevsw = {
207	.d_open = dsrtc_open,
208	.d_close = dsrtc_close,
209	.d_read = dsrtc_read,
210	.d_write = dsrtc_write,
211	.d_ioctl = noioctl,
212	.d_stop = nostop,
213	.d_tty = notty,
214	.d_poll = nopoll,
215	.d_mmap = nommap,
216	.d_kqfilter = nokqfilter,
217	.d_discard = nodiscard,
218	.d_flag = D_OTHER
219};
220
221static int dsrtc_gettime_ymdhms(struct todr_chip_handle *, struct clock_ymdhms *);
222static int dsrtc_settime_ymdhms(struct todr_chip_handle *, struct clock_ymdhms *);
223static int dsrtc_clock_read_ymdhms(struct dsrtc_softc *, struct clock_ymdhms *);
224static int dsrtc_clock_write_ymdhms(struct dsrtc_softc *, struct clock_ymdhms *);
225
226static int dsrtc_gettime_timeval(struct todr_chip_handle *, struct timeval *);
227static int dsrtc_settime_timeval(struct todr_chip_handle *, struct timeval *);
228static int dsrtc_clock_read_timeval(struct dsrtc_softc *, time_t *);
229static int dsrtc_clock_write_timeval(struct dsrtc_softc *, time_t);
230
231static int dsrtc_read_temp(struct dsrtc_softc *, uint32_t *);
232static void dsrtc_refresh(struct sysmon_envsys *, envsys_data_t *);
233
234static const struct dsrtc_model *
235dsrtc_model_by_number(u_int model)
236{
237	const struct device_compatible_entry *dce;
238	const struct dsrtc_model *dm;
239
240	/* no model given, assume it's a DS1307 */
241	if (model == 0)
242		return &ds1307_model;
243
244	for (dce = compat_data; dce->compat != NULL; dce++) {
245		dm = dce->data;
246		if (dm->dm_model == model)
247			return dm;
248	}
249	return NULL;
250}
251
252static const struct dsrtc_model *
253dsrtc_model_by_compat(const struct i2c_attach_args *ia)
254{
255	const struct dsrtc_model *dm = NULL;
256	const struct device_compatible_entry *dce;
257
258	if ((dce = iic_compatible_lookup(ia, compat_data)) != NULL)
259		dm = dce->data;
260
261	return dm;
262}
263
264static bool
265dsrtc_is_valid_addr_for_model(const struct dsrtc_model *dm, i2c_addr_t addr)
266{
267
268	for (int i = 0; dm->dm_valid_addrs[i] != 0; i++) {
269		if (addr == dm->dm_valid_addrs[i])
270			return true;
271	}
272	return false;
273}
274
275static int
276dsrtc_match(device_t parent, cfdata_t cf, void *arg)
277{
278	struct i2c_attach_args *ia = arg;
279	const struct dsrtc_model *dm;
280	int match_result;
281
282	if (iic_use_direct_match(ia, cf, compat_data, &match_result))
283		return match_result;
284
285	dm = dsrtc_model_by_number(cf->cf_flags & 0xffff);
286	if (dm == NULL)
287		return 0;
288
289	if (dsrtc_is_valid_addr_for_model(dm, ia->ia_addr))
290		return I2C_MATCH_ADDRESS_ONLY;
291
292	return 0;
293}
294
295static void
296dsrtc_attach(device_t parent, device_t self, void *arg)
297{
298	struct dsrtc_softc *sc = device_private(self);
299	struct i2c_attach_args *ia = arg;
300	const struct dsrtc_model *dm;
301	prop_dictionary_t dict = device_properties(self);
302	bool base_2k = FALSE;
303
304	if ((dm = dsrtc_model_by_compat(ia)) == NULL)
305		dm = dsrtc_model_by_number(device_cfdata(self)->cf_flags);
306
307	if (dm == NULL) {
308		aprint_error(": unable to determine model!\n");
309		return;
310	}
311
312	aprint_naive(": Real-time Clock%s\n",
313	    dm->dm_nvram_size > 0 ? "/NVRAM" : "");
314	aprint_normal(": DS%u Real-time Clock%s\n", dm->dm_model,
315	    dm->dm_nvram_size > 0 ? "/NVRAM" : "");
316
317	sc->sc_tag = ia->ia_tag;
318	sc->sc_address = ia->ia_addr;
319	sc->sc_model = *dm;
320	sc->sc_dev = self;
321	sc->sc_open = 0;
322	sc->sc_todr.cookie = sc;
323
324	if (dm->dm_flags & DSRTC_FLAG_BCD) {
325		sc->sc_todr.todr_gettime_ymdhms = dsrtc_gettime_ymdhms;
326		sc->sc_todr.todr_settime_ymdhms = dsrtc_settime_ymdhms;
327	} else {
328		sc->sc_todr.todr_gettime = dsrtc_gettime_timeval;
329		sc->sc_todr.todr_settime = dsrtc_settime_timeval;
330	}
331	sc->sc_todr.todr_setwen = NULL;
332
333#ifdef DSRTC_YEAR_START_2K
334	sc->sc_model.dm_flags |= DSRTC_FLAG_YEAR_START_2K;
335#endif
336
337	prop_dictionary_get_bool(dict, "base_year_is_2000", &base_2k);
338	if (base_2k) sc->sc_model.dm_flags |= DSRTC_FLAG_YEAR_START_2K;
339
340
341	todr_attach(&sc->sc_todr);
342	if ((sc->sc_model.dm_flags & DSRTC_FLAG_TEMP) != 0) {
343		int error;
344
345		sc->sc_sme = sysmon_envsys_create();
346		sc->sc_sme->sme_name = device_xname(self);
347		sc->sc_sme->sme_cookie = sc;
348		sc->sc_sme->sme_refresh = dsrtc_refresh;
349
350		sc->sc_sensor.units =  ENVSYS_STEMP;
351		sc->sc_sensor.state = ENVSYS_SINVALID;
352		sc->sc_sensor.flags = 0;
353		(void)strlcpy(sc->sc_sensor.desc, "temperature",
354		    sizeof(sc->sc_sensor.desc));
355
356		if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
357			aprint_error_dev(self, "unable to attach sensor\n");
358			goto bad;
359		}
360
361		error = sysmon_envsys_register(sc->sc_sme);
362		if (error) {
363			aprint_error_dev(self,
364			    "error %d registering with sysmon\n", error);
365			goto bad;
366		}
367	}
368	return;
369bad:
370	sysmon_envsys_destroy(sc->sc_sme);
371}
372
373/*ARGSUSED*/
374int
375dsrtc_open(dev_t dev, int flag, int fmt, struct lwp *l)
376{
377	struct dsrtc_softc *sc;
378
379	if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
380		return ENXIO;
381
382	/* XXX: Locking */
383	if (sc->sc_open)
384		return EBUSY;
385
386	sc->sc_open = true;
387	return 0;
388}
389
390/*ARGSUSED*/
391int
392dsrtc_close(dev_t dev, int flag, int fmt, struct lwp *l)
393{
394	struct dsrtc_softc *sc;
395
396	if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
397		return ENXIO;
398
399	sc->sc_open = false;
400	return 0;
401}
402
403/*ARGSUSED*/
404int
405dsrtc_read(dev_t dev, struct uio *uio, int flags)
406{
407	struct dsrtc_softc *sc;
408	int error;
409
410	if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
411		return ENXIO;
412
413	const struct dsrtc_model * const dm = &sc->sc_model;
414	if (uio->uio_offset < 0 || uio->uio_offset >= dm->dm_nvram_size)
415		return EINVAL;
416
417	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
418		return error;
419
420	while (uio->uio_resid && uio->uio_offset < dm->dm_nvram_size) {
421		uint8_t ch, cmd;
422		const u_int a = uio->uio_offset;
423		cmd = a + dm->dm_nvram_start;
424		if ((error = iic_exec(sc->sc_tag,
425		    uio->uio_resid > 1 ? I2C_OP_READ : I2C_OP_READ_WITH_STOP,
426		    sc->sc_address, &cmd, 1, &ch, 1, 0)) != 0) {
427			iic_release_bus(sc->sc_tag, 0);
428			aprint_error_dev(sc->sc_dev,
429			    "%s: read failed at 0x%x: %d\n",
430			    __func__, a, error);
431			return error;
432		}
433		if ((error = uiomove(&ch, 1, uio)) != 0) {
434			iic_release_bus(sc->sc_tag, 0);
435			return error;
436		}
437	}
438
439	iic_release_bus(sc->sc_tag, 0);
440
441	return 0;
442}
443
444/*ARGSUSED*/
445int
446dsrtc_write(dev_t dev, struct uio *uio, int flags)
447{
448	struct dsrtc_softc *sc;
449	int error;
450
451	if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
452		return ENXIO;
453
454	const struct dsrtc_model * const dm = &sc->sc_model;
455	if (uio->uio_offset >= dm->dm_nvram_size)
456		return EINVAL;
457
458	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
459		return error;
460
461	while (uio->uio_resid && uio->uio_offset < dm->dm_nvram_size) {
462		uint8_t cmdbuf[2];
463		const u_int a = (int)uio->uio_offset;
464		cmdbuf[0] = a + dm->dm_nvram_start;
465		if ((error = uiomove(&cmdbuf[1], 1, uio)) != 0)
466			break;
467
468		if ((error = iic_exec(sc->sc_tag,
469		    uio->uio_resid ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
470		    sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
471			aprint_error_dev(sc->sc_dev,
472			    "%s: write failed at 0x%x: %d\n",
473			    __func__, a, error);
474			break;
475		}
476	}
477
478	iic_release_bus(sc->sc_tag, 0);
479
480	return error;
481}
482
483static int
484dsrtc_gettime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
485{
486	struct dsrtc_softc *sc = ch->cookie;
487	struct clock_ymdhms check;
488	int retries;
489
490	memset(dt, 0, sizeof(*dt));
491	memset(&check, 0, sizeof(check));
492
493	/*
494	 * Since we don't support Burst Read, we have to read the clock twice
495	 * until we get two consecutive identical results.
496	 */
497	retries = 5;
498	do {
499		dsrtc_clock_read_ymdhms(sc, dt);
500		dsrtc_clock_read_ymdhms(sc, &check);
501	} while (memcmp(dt, &check, sizeof(check)) != 0 && --retries);
502
503	return 0;
504}
505
506static int
507dsrtc_settime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
508{
509	struct dsrtc_softc *sc = ch->cookie;
510
511	if (dsrtc_clock_write_ymdhms(sc, dt) == 0)
512		return -1;
513
514	return 0;
515}
516
517static int
518dsrtc_clock_read_ymdhms(struct dsrtc_softc *sc, struct clock_ymdhms *dt)
519{
520	struct dsrtc_model * const dm = &sc->sc_model;
521	uint8_t bcd[DSXXXX_RTC_SIZE], cmdbuf[1];
522	int error;
523
524	KASSERT(DSXXXX_RTC_SIZE >= dm->dm_rtc_size);
525
526	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
527		aprint_error_dev(sc->sc_dev,
528		    "%s: failed to acquire I2C bus: %d\n",
529		    __func__, error);
530		return 0;
531	}
532
533	/* Read each RTC register in order. */
534	for (u_int i = 0; !error && i < dm->dm_rtc_size; i++) {
535		cmdbuf[0] = dm->dm_rtc_start + i;
536
537		error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
538		    sc->sc_address, cmdbuf, 1, &bcd[i], 1, 0);
539	}
540
541	/* Done with I2C */
542	iic_release_bus(sc->sc_tag, 0);
543
544	if (error != 0) {
545		aprint_error_dev(sc->sc_dev,
546		    "%s: failed to read rtc at 0x%x: %d\n",
547		    __func__, cmdbuf[0], error);
548		return 0;
549	}
550
551	/*
552	 * Convert the RTC's register values into something useable
553	 */
554	dt->dt_sec = bcdtobin(bcd[DSXXXX_SECONDS] & DSXXXX_SECONDS_MASK);
555	dt->dt_min = bcdtobin(bcd[DSXXXX_MINUTES] & DSXXXX_MINUTES_MASK);
556
557	if ((bcd[DSXXXX_HOURS] & DSXXXX_HOURS_12HRS_MODE) != 0) {
558		dt->dt_hour = bcdtobin(bcd[DSXXXX_HOURS] &
559		    DSXXXX_HOURS_12MASK) % 12; /* 12AM -> 0, 12PM -> 12 */
560		if (bcd[DSXXXX_HOURS] & DSXXXX_HOURS_12HRS_PM)
561			dt->dt_hour += 12;
562	} else
563		dt->dt_hour = bcdtobin(bcd[DSXXXX_HOURS] &
564		    DSXXXX_HOURS_24MASK);
565
566	dt->dt_day = bcdtobin(bcd[DSXXXX_DATE] & DSXXXX_DATE_MASK);
567	dt->dt_mon = bcdtobin(bcd[DSXXXX_MONTH] & DSXXXX_MONTH_MASK);
568
569	/* XXX: Should be an MD way to specify EPOCH used by BIOS/Firmware */
570	if (sc->sc_model.dm_flags & DSRTC_FLAG_YEAR_START_2K)
571		dt->dt_year = bcdtobin(bcd[DSXXXX_YEAR]) + 2000;
572	else {
573		dt->dt_year = bcdtobin(bcd[DSXXXX_YEAR]) + POSIX_BASE_YEAR;
574		if (bcd[DSXXXX_MONTH] & DSXXXX_MONTH_CENTURY)
575			dt->dt_year += 100;
576	}
577
578	return 1;
579}
580
581static int
582dsrtc_clock_write_ymdhms(struct dsrtc_softc *sc, struct clock_ymdhms *dt)
583{
584	struct dsrtc_model * const dm = &sc->sc_model;
585	uint8_t bcd[DSXXXX_RTC_SIZE], cmdbuf[2];
586	int error, offset;
587
588	KASSERT(DSXXXX_RTC_SIZE >= dm->dm_rtc_size);
589
590	/*
591	 * Convert our time representation into something the DSXXXX
592	 * can understand.
593	 */
594	bcd[DSXXXX_SECONDS] = bintobcd(dt->dt_sec);
595	bcd[DSXXXX_MINUTES] = bintobcd(dt->dt_min);
596	bcd[DSXXXX_HOURS] = bintobcd(dt->dt_hour); /* DSXXXX_HOURS_12HRS_MODE=0 */
597	bcd[DSXXXX_DATE] = bintobcd(dt->dt_day);
598	bcd[DSXXXX_DAY] = bintobcd(dt->dt_wday);
599	bcd[DSXXXX_MONTH] = bintobcd(dt->dt_mon);
600
601	if (sc->sc_model.dm_flags & DSRTC_FLAG_YEAR_START_2K) {
602		offset = 2000;
603	} else {
604		offset = POSIX_BASE_YEAR;
605	}
606
607	bcd[DSXXXX_YEAR] = bintobcd((dt->dt_year - offset) % 100);
608	if (dt->dt_year - offset >= 100)
609		bcd[DSXXXX_MONTH] |= DSXXXX_MONTH_CENTURY;
610
611	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
612		aprint_error_dev(sc->sc_dev,
613		    "%s: failed to acquire I2C bus: %d\n",
614		    __func__, error);
615		return 0;
616	}
617
618	/* Stop the clock */
619	cmdbuf[0] = dm->dm_ch_reg;
620
621	if ((error = iic_exec(sc->sc_tag, I2C_OP_READ, sc->sc_address,
622	    cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
623		iic_release_bus(sc->sc_tag, 0);
624		aprint_error_dev(sc->sc_dev,
625		    "%s: failed to read Hold Clock: %d\n",
626		    __func__, error);
627		return 0;
628	}
629
630	if (sc->sc_model.dm_flags & DSRTC_FLAG_CLOCK_HOLD_REVERSED)
631		cmdbuf[1] &= ~dm->dm_ch_value;
632	else
633		cmdbuf[1] |= dm->dm_ch_value;
634
635	if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE, sc->sc_address,
636	    cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
637		iic_release_bus(sc->sc_tag, 0);
638		aprint_error_dev(sc->sc_dev,
639		    "%s: failed to write Hold Clock: %d\n",
640		    __func__, error);
641		return 0;
642	}
643
644	/*
645	 * Write registers in reverse order. The last write (to the Seconds
646	 * register) will undo the Clock Hold, above.
647	 */
648	uint8_t op = I2C_OP_WRITE;
649	for (signed int i = dm->dm_rtc_size - 1; i >= 0; i--) {
650		cmdbuf[0] = dm->dm_rtc_start + i;
651		if ((dm->dm_flags & DSRTC_FLAG_VBATEN) &&
652				dm->dm_rtc_start + i == dm->dm_vbaten_reg)
653			bcd[i] |= dm->dm_vbaten_value;
654		if (dm->dm_rtc_start + i == dm->dm_ch_reg) {
655			op = I2C_OP_WRITE_WITH_STOP;
656			if (dm->dm_flags & DSRTC_FLAG_CLOCK_HOLD_REVERSED)
657				bcd[i] |= dm->dm_ch_value;
658		}
659		if ((error = iic_exec(sc->sc_tag, op, sc->sc_address,
660		    cmdbuf, 1, &bcd[i], 1, 0)) != 0) {
661			iic_release_bus(sc->sc_tag, 0);
662			aprint_error_dev(sc->sc_dev,
663			    "%s: failed to write rtc at 0x%x: %d\n",
664			    __func__, i, error);
665			/* XXX: Clock Hold is likely still asserted! */
666			return 0;
667		}
668	}
669	/*
670	 * If the clock hold register isn't the same register as seconds,
671	 * we need to reenable the clock.
672	 */
673	if (op != I2C_OP_WRITE_WITH_STOP) {
674		cmdbuf[0] = dm->dm_ch_reg;
675		if (dm->dm_flags & DSRTC_FLAG_CLOCK_HOLD_REVERSED)
676			cmdbuf[1] |= dm->dm_ch_value;
677		else
678			cmdbuf[1] &= ~dm->dm_ch_value;
679
680		if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
681		    sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
682			iic_release_bus(sc->sc_tag, 0);
683			aprint_error_dev(sc->sc_dev,
684			    "%s: failed to Hold Clock: %d\n",
685			    __func__, error);
686			return 0;
687		}
688	}
689
690	iic_release_bus(sc->sc_tag, 0);
691
692	return 1;
693}
694
695static int
696dsrtc_gettime_timeval(struct todr_chip_handle *ch, struct timeval *tv)
697{
698	struct dsrtc_softc *sc = ch->cookie;
699	struct timeval check;
700	int retries;
701
702	memset(tv, 0, sizeof(*tv));
703	memset(&check, 0, sizeof(check));
704
705	/*
706	 * Since we don't support Burst Read, we have to read the clock twice
707	 * until we get two consecutive identical results.
708	 */
709	retries = 5;
710	do {
711		dsrtc_clock_read_timeval(sc, &tv->tv_sec);
712		dsrtc_clock_read_timeval(sc, &check.tv_sec);
713	} while (memcmp(tv, &check, sizeof(check)) != 0 && --retries);
714
715	return 0;
716}
717
718static int
719dsrtc_settime_timeval(struct todr_chip_handle *ch, struct timeval *tv)
720{
721	struct dsrtc_softc *sc = ch->cookie;
722
723	if (dsrtc_clock_write_timeval(sc, tv->tv_sec) == 0)
724		return -1;
725
726	return 0;
727}
728
729/*
730 * The RTC probably has a nice Clock Burst Read/Write command, but we can't use
731 * it, since some I2C controllers don't support anything other than single-byte
732 * transfers.
733 */
734static int
735dsrtc_clock_read_timeval(struct dsrtc_softc *sc, time_t *tp)
736{
737	const struct dsrtc_model * const dm = &sc->sc_model;
738	uint8_t buf[4];
739	int error;
740
741	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
742		aprint_error_dev(sc->sc_dev,
743		    "%s: failed to acquire I2C bus: %d\n",
744		    __func__, error);
745		return 0;
746	}
747
748	/* read all registers: */
749	uint8_t reg = dm->dm_rtc_start;
750	error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
751	     &reg, 1, buf, 4, 0);
752
753	/* Done with I2C */
754	iic_release_bus(sc->sc_tag, 0);
755
756	if (error != 0) {
757		aprint_error_dev(sc->sc_dev,
758		    "%s: failed to read rtc at 0x%x: %d\n",
759		    __func__, reg, error);
760		return 0;
761	}
762
763	uint32_t v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
764	*tp = v;
765
766	aprint_debug_dev(sc->sc_dev, "%s: cntr=0x%08"PRIx32"\n",
767	    __func__, v);
768
769	return 1;
770}
771
772static int
773dsrtc_clock_write_timeval(struct dsrtc_softc *sc, time_t t)
774{
775	const struct dsrtc_model * const dm = &sc->sc_model;
776	size_t buflen = dm->dm_rtc_size + 2;
777	/* XXX: the biggest dm_rtc_size we have now is 7, so we should be ok */
778	uint8_t buf[16];
779	int error;
780
781	KASSERT((dm->dm_flags & DSRTC_FLAG_CLOCK_HOLD) == 0);
782	KASSERT(dm->dm_ch_reg == dm->dm_rtc_start + 4);
783
784	buf[0] = dm->dm_rtc_start;
785	buf[1] = (t >> 0) & 0xff;
786	buf[2] = (t >> 8) & 0xff;
787	buf[3] = (t >> 16) & 0xff;
788	buf[4] = (t >> 24) & 0xff;
789	buf[5] = 0;
790
791	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
792		aprint_error_dev(sc->sc_dev,
793		    "%s: failed to acquire I2C bus: %d\n",
794		    __func__, error);
795		return 0;
796	}
797
798	error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
799	    &buf, buflen, NULL, 0, 0);
800
801	/* Done with I2C */
802	iic_release_bus(sc->sc_tag, 0);
803
804	/* send data */
805	if (error != 0) {
806		aprint_error_dev(sc->sc_dev,
807		    "%s: failed to set time: %d\n",
808		    __func__, error);
809		return 0;
810	}
811
812	return 1;
813}
814
815static int
816dsrtc_read_temp(struct dsrtc_softc *sc, uint32_t *temp)
817{
818	int error, tc;
819	uint8_t reg = DS3232_TEMP_MSB;
820	uint8_t buf[2];
821
822	if ((sc->sc_model.dm_flags & DSRTC_FLAG_TEMP) == 0)
823		return ENOTSUP;
824
825	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
826		aprint_error_dev(sc->sc_dev,
827		    "%s: failed to acquire I2C bus: %d\n",
828		    __func__, error);
829		return 0;
830	}
831
832	/* read temperature registers: */
833	error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
834	     &reg, 1, buf, 2, 0);
835
836	/* Done with I2C */
837	iic_release_bus(sc->sc_tag, 0);
838
839	if (error != 0) {
840		aprint_error_dev(sc->sc_dev,
841		    "%s: failed to read temperature: %d\n",
842		    __func__, error);
843		return 0;
844	}
845
846	/* convert to microkelvin */
847	tc = buf[0] * 1000000 + (buf[1] >> 6) * 250000;
848	*temp = tc + 273150000;
849	return 1;
850}
851
852static void
853dsrtc_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
854{
855	struct dsrtc_softc *sc = sme->sme_cookie;
856	uint32_t temp = 0;	/* XXX gcc */
857
858	if (dsrtc_read_temp(sc, &temp) == 0) {
859		edata->state = ENVSYS_SINVALID;
860		return;
861	}
862
863	edata->value_cur = temp;
864
865	edata->state = ENVSYS_SVALID;
866}
867