1 /*-
2 * Copyright (c) 2015 Luiz Otavio O Souza <loos@FreeBSD.org>
3 * Copyright (c) 2022 Mathew McBride <matt@traverse.com.au>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 /*
30 * Driver for Maxim DS1307 I2C real-time clock/calendar.
31 */
32
33 #include "opt_platform.h"
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/clock.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/sysctl.h>
42
43 #include <dev/iicbus/iicbus.h>
44 #include <dev/iicbus/iiconf.h>
45 #ifdef FDT
46 #include <dev/ofw/openfirm.h>
47 #include <dev/ofw/ofw_bus.h>
48 #include <dev/ofw/ofw_bus_subr.h>
49 #endif
50
51 #include <dev/iicbus/rtc/ds1307reg.h>
52
53 #include "clock_if.h"
54 #include "iicbus_if.h"
55
56 enum {
57 TYPE_DS1307,
58 TYPE_MAXIM1307,
59 TYPE_MICROCHIP_MCP7941X,
60 TYPE_EPSON_RX8035,
61 TYPE_COUNT
62 };
63
64 struct ds1307_softc {
65 device_t sc_dev;
66 struct intr_config_hook enum_hook;
67 uint32_t chiptype;
68 uint8_t sc_ctrl;
69 bool sc_use_ampm;
70 };
71
72 static void ds1307_start(void *);
73
74 #ifdef FDT
75 static const struct ofw_compat_data ds1307_compat_data[] = {
76 {"dallas,ds1307", TYPE_DS1307},
77 {"maxim,ds1307", TYPE_MAXIM1307},
78 {"microchip,mcp7941x", TYPE_MICROCHIP_MCP7941X},
79 {"epson,rx8035", TYPE_EPSON_RX8035},
80 { NULL, 0 }
81 };
82 #endif
83
84 static int
ds1307_read1(device_t dev,uint8_t reg,uint8_t * data)85 ds1307_read1(device_t dev, uint8_t reg, uint8_t *data)
86 {
87
88 return (iicdev_readfrom(dev, reg, data, 1, IIC_INTRWAIT));
89 }
90
91 static int
ds1307_write1(device_t dev,uint8_t reg,uint8_t data)92 ds1307_write1(device_t dev, uint8_t reg, uint8_t data)
93 {
94
95 return (iicdev_writeto(dev, reg, &data, 1, IIC_INTRWAIT));
96 }
97
98 static int
ds1307_ctrl_read(struct ds1307_softc * sc)99 ds1307_ctrl_read(struct ds1307_softc *sc)
100 {
101 int error;
102
103 sc->sc_ctrl = 0;
104 error = ds1307_read1(sc->sc_dev, DS1307_CONTROL, &sc->sc_ctrl);
105 if (error) {
106 device_printf(sc->sc_dev, "%s: cannot read from RTC: %d\n",
107 __func__, error);
108 return (error);
109 }
110
111 return (0);
112 }
113
114 static int
ds1307_ctrl_write(struct ds1307_softc * sc)115 ds1307_ctrl_write(struct ds1307_softc *sc)
116 {
117 int error;
118 uint8_t ctrl;
119
120 ctrl = sc->sc_ctrl & DS1307_CTRL_MASK;
121 error = ds1307_write1(sc->sc_dev, DS1307_CONTROL, ctrl);
122 if (error != 0)
123 device_printf(sc->sc_dev, "%s: cannot write to RTC: %d\n",
124 __func__, error);
125
126 return (error);
127 }
128
129 static int
ds1307_sqwe_sysctl(SYSCTL_HANDLER_ARGS)130 ds1307_sqwe_sysctl(SYSCTL_HANDLER_ARGS)
131 {
132 int sqwe, error, newv, sqwe_bit;
133 struct ds1307_softc *sc;
134
135 sc = (struct ds1307_softc *)arg1;
136 error = ds1307_ctrl_read(sc);
137 if (error != 0)
138 return (error);
139 if (sc->chiptype == TYPE_MICROCHIP_MCP7941X)
140 sqwe_bit = MCP7941X_CTRL_SQWE;
141 else
142 sqwe_bit = DS1307_CTRL_SQWE;
143 sqwe = newv = (sc->sc_ctrl & sqwe_bit) ? 1 : 0;
144 error = sysctl_handle_int(oidp, &newv, 0, req);
145 if (error != 0 || req->newptr == NULL)
146 return (error);
147 if (sqwe != newv) {
148 sc->sc_ctrl &= ~sqwe_bit;
149 if (newv)
150 sc->sc_ctrl |= sqwe_bit;
151 error = ds1307_ctrl_write(sc);
152 if (error != 0)
153 return (error);
154 }
155
156 return (error);
157 }
158
159 static int
ds1307_sqw_freq_sysctl(SYSCTL_HANDLER_ARGS)160 ds1307_sqw_freq_sysctl(SYSCTL_HANDLER_ARGS)
161 {
162 int ds1307_sqw_freq[] = { 1, 4096, 8192, 32768 };
163 int error, freq, i, newf, tmp;
164 struct ds1307_softc *sc;
165
166 sc = (struct ds1307_softc *)arg1;
167 error = ds1307_ctrl_read(sc);
168 if (error != 0)
169 return (error);
170 tmp = (sc->sc_ctrl & DS1307_CTRL_RS_MASK);
171 if (tmp >= nitems(ds1307_sqw_freq))
172 tmp = nitems(ds1307_sqw_freq) - 1;
173 freq = ds1307_sqw_freq[tmp];
174 error = sysctl_handle_int(oidp, &freq, 0, req);
175 if (error != 0 || req->newptr == NULL)
176 return (error);
177 if (freq != ds1307_sqw_freq[tmp]) {
178 newf = 0;
179 for (i = 0; i < nitems(ds1307_sqw_freq); i++)
180 if (freq >= ds1307_sqw_freq[i])
181 newf = i;
182 sc->sc_ctrl &= ~DS1307_CTRL_RS_MASK;
183 sc->sc_ctrl |= newf;
184 error = ds1307_ctrl_write(sc);
185 if (error != 0)
186 return (error);
187 }
188
189 return (error);
190 }
191
192 static int
ds1307_sqw_out_sysctl(SYSCTL_HANDLER_ARGS)193 ds1307_sqw_out_sysctl(SYSCTL_HANDLER_ARGS)
194 {
195 int sqwe, error, newv;
196 struct ds1307_softc *sc;
197
198 sc = (struct ds1307_softc *)arg1;
199 error = ds1307_ctrl_read(sc);
200 if (error != 0)
201 return (error);
202 sqwe = newv = (sc->sc_ctrl & DS1307_CTRL_OUT) ? 1 : 0;
203 error = sysctl_handle_int(oidp, &newv, 0, req);
204 if (error != 0 || req->newptr == NULL)
205 return (error);
206 if (sqwe != newv) {
207 sc->sc_ctrl &= ~DS1307_CTRL_OUT;
208 if (newv)
209 sc->sc_ctrl |= DS1307_CTRL_OUT;
210 error = ds1307_ctrl_write(sc);
211 if (error != 0)
212 return (error);
213 }
214
215 return (error);
216 }
217
218 static int
ds1307_probe(device_t dev)219 ds1307_probe(device_t dev)
220 {
221 #ifdef FDT
222 const struct ofw_compat_data *compat;
223
224 if (!ofw_bus_status_okay(dev))
225 return (ENXIO);
226
227 compat = ofw_bus_search_compatible(dev, ds1307_compat_data);
228 if (compat->ocd_str != NULL) {
229 switch(compat->ocd_data) {
230 case TYPE_DS1307:
231 device_set_desc(dev, "Dallas DS1307");
232 break;
233 case TYPE_MAXIM1307:
234 device_set_desc(dev, "Maxim DS1307");
235 break;
236 case TYPE_MICROCHIP_MCP7941X:
237 device_set_desc(dev, "Microchip MCP7941X");
238 break;
239 case TYPE_EPSON_RX8035:
240 device_set_desc(dev, "Epson RX-8035");
241 break;
242 default:
243 device_set_desc(dev, "Unknown DS1307-like device");
244 break;
245 }
246 return (BUS_PROBE_DEFAULT);
247 }
248 #endif
249
250 device_set_desc(dev, "Maxim DS1307");
251 return (BUS_PROBE_NOWILDCARD);
252 }
253
254 static int
ds1307_attach(device_t dev)255 ds1307_attach(device_t dev)
256 {
257 #ifdef FDT
258 const struct ofw_compat_data *compat;
259 #endif
260 struct ds1307_softc *sc;
261
262 sc = device_get_softc(dev);
263 sc->sc_dev = dev;
264 sc->enum_hook.ich_func = ds1307_start;
265 sc->enum_hook.ich_arg = dev;
266 #ifdef FDT
267 compat = ofw_bus_search_compatible(dev, ds1307_compat_data);
268 sc->chiptype = compat->ocd_data;
269 /* Unify the chiptypes to DS1307 where possible. */
270 if (sc->chiptype == TYPE_MAXIM1307)
271 sc->chiptype = TYPE_DS1307;
272 #else
273 sc->chiptype = TYPE_DS1307;
274 #endif
275
276 /*
277 * We have to wait until interrupts are enabled. Usually I2C read
278 * and write only works when the interrupts are available.
279 */
280 if (config_intrhook_establish(&sc->enum_hook) != 0)
281 return (ENOMEM);
282
283 return (0);
284 }
285
286 static int
ds1307_detach(device_t dev)287 ds1307_detach(device_t dev)
288 {
289
290 clock_unregister(dev);
291 return (0);
292 }
293
294 static bool
is_epson_time_valid(struct ds1307_softc * sc)295 is_epson_time_valid(struct ds1307_softc *sc)
296 {
297 device_t dev;
298 int error;
299 uint8_t ctrl2;
300
301 dev = sc->sc_dev;
302
303 /*
304 * The RX-8035 single register read is non-standard
305 * Refer to section 8.9.5 of the RX-8035 application manual:
306 * "I2C bus basic transfer format", under "Standard Read Method".
307 * Basically, register to read goes into the top 4 bits.
308 */
309 error = ds1307_read1(dev, (RX8035_CTRL_2 << 4), &ctrl2);
310 if (error) {
311 device_printf(dev, "%s cannot read Control 2 register: %d\n",
312 __func__, error);
313 return (false);
314 }
315
316 if (ctrl2 & RX8035_CTRL_2_XSTP) {
317 device_printf(dev, "Oscillation stop detected (ctrl2=%#02x)\n",
318 ctrl2);
319 return (false);
320 }
321
322 /*
323 * Power on reset (PON) generally implies oscillation stop,
324 * but catch it as well to be sure.
325 */
326 if (ctrl2 & RX8035_CTRL_2_PON) {
327 device_printf(dev, "Power-on reset detected (ctrl2=%#02x)\n",
328 ctrl2);
329 return (false);
330 }
331
332 return (true);
333 }
334
335 static int
mark_epson_time_valid(struct ds1307_softc * sc)336 mark_epson_time_valid(struct ds1307_softc *sc)
337 {
338 device_t dev;
339 int error;
340 uint8_t ctrl2;
341 uint8_t control_mask;
342
343 dev = sc->sc_dev;
344
345 error = ds1307_read1(dev, (RX8035_CTRL_2 << 4), &ctrl2);
346 if (error) {
347 device_printf(dev, "%s cannot read Control 2 register: %d\n",
348 __func__, error);
349 return (error);
350 }
351
352 control_mask = (RX8035_CTRL_2_PON | RX8035_CTRL_2_XSTP | RX8035_CTRL_2_VDET);
353 ctrl2 = ctrl2 & ~(control_mask);
354
355 error = ds1307_write1(dev, (RX8035_CTRL_2 << 4), ctrl2);
356 if (error) {
357 device_printf(dev, "%s cannot write to Control 2 register: %d\n",
358 __func__, error);
359 return (error);
360 }
361 return (0);
362 }
363
is_dev_time_valid(struct ds1307_softc * sc)364 static bool is_dev_time_valid(struct ds1307_softc *sc)
365 {
366 device_t dev;
367 int error;
368 uint8_t osc_en;
369 uint8_t secs;
370
371 /* Epson RTCs have different control/status registers. */
372 if (sc->chiptype == TYPE_EPSON_RX8035)
373 return (is_epson_time_valid(sc));
374
375 dev = sc->sc_dev;
376 /* Check if the oscillator is disabled. */
377 error = ds1307_read1(dev, DS1307_SECS, &secs);
378 if (error) {
379 device_printf(dev, "%s: cannot read from RTC: %d\n",
380 __func__, error);
381 return (false);
382 }
383
384 switch (sc->chiptype) {
385 case TYPE_MICROCHIP_MCP7941X:
386 osc_en = 0x80;
387 break;
388 default:
389 osc_en = 0x00;
390 break;
391 }
392 if (((secs & DS1307_SECS_CH) ^ osc_en) != 0)
393 return (false);
394
395 return (true);
396 }
397
398 static void
ds1307_start(void * xdev)399 ds1307_start(void *xdev)
400 {
401 device_t dev;
402 struct ds1307_softc *sc;
403 struct sysctl_ctx_list *ctx;
404 struct sysctl_oid *tree_node;
405 struct sysctl_oid_list *tree;
406
407 dev = (device_t)xdev;
408 sc = device_get_softc(dev);
409
410 config_intrhook_disestablish(&sc->enum_hook);
411
412 if (!is_dev_time_valid(sc))
413 device_printf(dev,
414 "WARNING: RTC clock stopped, check the battery.\n");
415
416 /*
417 * Configuration parameters:
418 * square wave output cannot be changed or inhibited on the RX-8035,
419 * so don't present the sysctls there.
420 */
421 if (sc->chiptype == TYPE_EPSON_RX8035)
422 goto skip_sysctl;
423
424 ctx = device_get_sysctl_ctx(dev);
425 tree_node = device_get_sysctl_tree(dev);
426 tree = SYSCTL_CHILDREN(tree_node);
427
428 SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "sqwe",
429 CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0,
430 ds1307_sqwe_sysctl, "IU", "DS1307 square-wave enable");
431 SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "sqw_freq",
432 CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0,
433 ds1307_sqw_freq_sysctl, "IU",
434 "DS1307 square-wave output frequency");
435 SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "sqw_out",
436 CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0,
437 ds1307_sqw_out_sysctl, "IU", "DS1307 square-wave output state");
438 skip_sysctl:
439
440 /*
441 * Register as a clock with 1 second resolution. Schedule the
442 * clock_settime() method to be called just after top-of-second;
443 * resetting the time resets top-of-second in the hardware.
444 */
445 clock_register_flags(dev, 1000000, CLOCKF_SETTIME_NO_ADJ);
446 clock_schedule(dev, 1);
447 }
448
449 static int
ds1307_gettime(device_t dev,struct timespec * ts)450 ds1307_gettime(device_t dev, struct timespec *ts)
451 {
452 struct bcd_clocktime bct;
453 struct ds1307_softc *sc;
454 int error;
455 uint8_t data[7], hourmask, ampm_mode;
456
457 sc = device_get_softc(dev);
458 error = iicdev_readfrom(sc->sc_dev, DS1307_SECS, data, sizeof(data),
459 IIC_INTRWAIT);
460 if (error != 0) {
461 device_printf(dev, "%s: cannot read from RTC: %d\n",
462 __func__, error);
463 return (error);
464 }
465
466 if (!is_dev_time_valid(sc)) {
467 device_printf(dev, "Device time not valid.\n");
468 return (EINVAL);
469 }
470
471 /*
472 * If the chip is in AM/PM mode remember that.
473 * The EPSON uses a 1 to signify 24 hour mode, while the DS uses a 0,
474 * in slightly different positions.
475 */
476 if (sc->chiptype == TYPE_EPSON_RX8035)
477 ampm_mode = !(data[DS1307_HOUR] & RX8035_HOUR_USE_24);
478 else
479 ampm_mode = data[DS1307_HOUR] & DS1307_HOUR_USE_AMPM;
480
481 if (ampm_mode) {
482 sc->sc_use_ampm = true;
483 hourmask = DS1307_HOUR_MASK_12HR;
484 } else
485 hourmask = DS1307_HOUR_MASK_24HR;
486
487 bct.nsec = 0;
488 bct.ispm = (data[DS1307_HOUR] & DS1307_HOUR_IS_PM) != 0;
489 bct.sec = data[DS1307_SECS] & DS1307_SECS_MASK;
490 bct.min = data[DS1307_MINS] & DS1307_MINS_MASK;
491 bct.hour = data[DS1307_HOUR] & hourmask;
492 bct.day = data[DS1307_DATE] & DS1307_DATE_MASK;
493 bct.mon = data[DS1307_MONTH] & DS1307_MONTH_MASK;
494 bct.year = data[DS1307_YEAR] & DS1307_YEAR_MASK;
495
496 clock_dbgprint_bcd(sc->sc_dev, CLOCK_DBG_READ, &bct);
497 return (clock_bcd_to_ts(&bct, ts, sc->sc_use_ampm));
498 }
499
500 static int
ds1307_settime(device_t dev,struct timespec * ts)501 ds1307_settime(device_t dev, struct timespec *ts)
502 {
503 struct bcd_clocktime bct;
504 struct ds1307_softc *sc;
505 int error, year;
506 uint8_t data[7];
507 uint8_t pmflags;
508
509 sc = device_get_softc(dev);
510
511 /*
512 * We request a timespec with no resolution-adjustment. That also
513 * disables utc adjustment, so apply that ourselves.
514 */
515 ts->tv_sec -= utc_offset();
516 clock_ts_to_bcd(ts, &bct, sc->sc_use_ampm);
517 clock_dbgprint_bcd(sc->sc_dev, CLOCK_DBG_WRITE, &bct);
518
519 /*
520 * If the chip is in AM/PM mode, adjust hour and set flags as needed.
521 * The AM/PM bit polarity and position is different on the EPSON.
522 */
523 if (sc->sc_use_ampm) {
524 pmflags = (sc->chiptype != TYPE_EPSON_RX8035) ?
525 DS1307_HOUR_USE_AMPM : 0;
526 if (bct.ispm)
527 pmflags |= DS1307_HOUR_IS_PM;
528
529 } else if (sc->chiptype == TYPE_EPSON_RX8035)
530 pmflags = RX8035_HOUR_USE_24;
531 else
532 pmflags = 0;
533
534 data[DS1307_SECS] = bct.sec;
535 data[DS1307_MINS] = bct.min;
536 data[DS1307_HOUR] = bct.hour | pmflags;
537 data[DS1307_DATE] = bct.day;
538 data[DS1307_WEEKDAY] = bct.dow;
539 data[DS1307_MONTH] = bct.mon;
540 data[DS1307_YEAR] = bct.year & 0xff;
541 if (sc->chiptype == TYPE_MICROCHIP_MCP7941X) {
542 data[DS1307_SECS] |= MCP7941X_SECS_ST;
543 data[DS1307_WEEKDAY] |= MCP7941X_WEEKDAY_VBATEN;
544 year = bcd2bin(bct.year >> 8) * 100 + bcd2bin(bct.year & 0xff);
545 if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
546 data[DS1307_MONTH] |= MCP7941X_MONTH_LPYR;
547 }
548
549 /* Write the time back to RTC. */
550 error = iicdev_writeto(sc->sc_dev, DS1307_SECS, data, sizeof(data),
551 IIC_INTRWAIT);
552 if (error != 0)
553 device_printf(dev, "%s: cannot write to RTC: %d\n",
554 __func__, error);
555
556 if (sc->chiptype == TYPE_EPSON_RX8035)
557 error = mark_epson_time_valid(sc);
558
559 return (error);
560 }
561
562 static device_method_t ds1307_methods[] = {
563 DEVMETHOD(device_probe, ds1307_probe),
564 DEVMETHOD(device_attach, ds1307_attach),
565 DEVMETHOD(device_detach, ds1307_detach),
566
567 DEVMETHOD(clock_gettime, ds1307_gettime),
568 DEVMETHOD(clock_settime, ds1307_settime),
569
570 DEVMETHOD_END
571 };
572
573 static driver_t ds1307_driver = {
574 "ds1307",
575 ds1307_methods,
576 sizeof(struct ds1307_softc),
577 };
578
579 DRIVER_MODULE(ds1307, iicbus, ds1307_driver, NULL, NULL);
580 MODULE_VERSION(ds1307, 1);
581 MODULE_DEPEND(ds1307, iicbus, 1, 1, 1);
582 IICBUS_FDT_PNP_INFO(ds1307_compat_data);
583