1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
30  * Driver for Dallas/Maxim DS13xx real-time clock/calendar chips:
32  * - DS1307 = Original/basic rtc + 56 bytes ram; 5v only.
33  * - DS1308 = Updated 1307, available in 1.8v-5v variations.
34  * - DS1337 = Like 1308, integrated xtal, 32khz output on at powerup.
35  * - DS1338 = Like 1308, integrated xtal.
36  * - DS1339 = Like 1337, integrated xtal, integrated trickle charger.
37  * - DS1340 = Like 1338, ST M41T00 compatible.
38  * - DS1341 = Like 1338, can slave-sync osc to external clock signal.
39  * - DS1342 = Like 1341 but requires different xtal.
40  * - DS1371 = 32-bit binary counter, watchdog timer.
41  * - DS1372 = 32-bit binary counter, 64-bit unique id in rom.
42  * - DS1374 = 32-bit binary counter, watchdog timer, trickle charger.
43  * - DS1375 = Like 1308 but only 16 bytes ram.
44  * - DS1388 = Rtc, watchdog timer, 512 bytes eeprom (not sram).
78  * Registers, bits within them, and masks for the various chip types.
116  * The chip types we support.
164 	u_int		chiptype;	/* Type of DS13xx chip */
169 	bool		is_binary_counter; /* Chip has 32-bit binary counter. */
173  * We use the compat_data table to look up hint strings in the non-FDT case, so
207 	return (iicdev_readfrom(sc->dev, reg, val, sizeof(*val), IIC_WAIT));  in read_reg()
214 	return (iicdev_writeto(sc->dev, reg, &val, sizeof(val), IIC_WAIT));  in write_reg()
222 	if ((err = iicdev_readfrom(sc->dev, sc->secaddr, tregs,  in read_timeregs()
233 	return (iicdev_writeto(sc->dev, sc->secaddr, tregs,  in write_timeregs()
243 	if ((err = iicdev_readfrom(sc->dev, sc->secaddr, buf, sizeof(buf),  in read_timeword()
256 	return (iicdev_writeto(sc->dev, sc->secaddr, buf, sizeof(buf),  in write_timeword()
269 	 * Every chip in this family can be usefully initialized by writing 0 to  in ds13rtc_start()
270 	 * the control register, except DS1375 which has an external oscillator  in ds13rtc_start()
273 	 * the oscillator, disables signals/outputs in battery-backed mode  in ds13rtc_start()
276 	switch (sc->chiptype) {  in ds13rtc_start()
301 		device_printf(sc->dev, "missing init code for this chiptype\n");  in ds13rtc_start()
310 	 * valid time to the chip (and must not be cleared before that).  in ds13rtc_start()
312 	if (read_reg(sc, sc->osfaddr, &statreg) != 0) {  in ds13rtc_start()
313 		device_printf(sc->dev, "cannot read RTC clock status bit\n");  in ds13rtc_start()
317 		device_printf(sc->dev,   in ds13rtc_start()
322 	 * Figure out whether the chip is configured for AM/PM mode.  On all  in ds13rtc_start()
326 	if ((sc->chiptype != TYPE_DS1340) && !sc->is_binary_counter) {  in ds13rtc_start()
327 		if (read_reg(sc, sc->secaddr + 2, &statreg) != 0) {  in ds13rtc_start()
328 			device_printf(sc->dev,  in ds13rtc_start()
333 			sc->use_ampm = true;  in ds13rtc_start()
338 	 * Schedule RTC updates to happen just after top-of-second.  in ds13rtc_start()
340 	clock_register_flags(sc->dev, 1000000, CLOCKF_SETTIME_NO_ADJ);  in ds13rtc_start()
341 	clock_schedule(sc->dev, 1);  in ds13rtc_start()
356 	if ((err = read_reg(sc, sc->osfaddr, &statreg)) != 0) {  in ds13rtc_gettime()
362 	/* If the chip counts time in binary, we just read and return it. */  in ds13rtc_gettime()
363 	if (sc->is_binary_counter) {  in ds13rtc_gettime()
364 		ts->tv_nsec = 0;  in ds13rtc_gettime()
365 		return (read_timeword(sc, &ts->tv_sec));  in ds13rtc_gettime()
369 	 * Chip counts in BCD, read and decode it...  in ds13rtc_gettime()
376 	if (sc->use_ampm)  in ds13rtc_gettime()
391 	 * If this chip has a century bit, honor it.  Otherwise let  in ds13rtc_gettime()
392 	 * clock_ct_to_ts() infer the century from the 2-digit year.  in ds13rtc_gettime()
394 	if (sc->use_century)  in ds13rtc_gettime()
397 	clock_dbgprint_bcd(sc->dev, CLOCK_DBG_READ, &bct);   in ds13rtc_gettime()
398 	err = clock_bcd_to_ts(&bct, ts, sc->use_ampm);  in ds13rtc_gettime()
415 	 * We request a timespec with no resolution-adjustment.  That also  in ds13rtc_settime()
418 	ts->tv_sec -= utc_offset();  in ds13rtc_settime()
420 	/* If the chip counts time in binary, store tv_sec and we're done. */  in ds13rtc_settime()
421 	if (sc->is_binary_counter)  in ds13rtc_settime()
422 		return (write_timeword(sc, ts->tv_sec));  in ds13rtc_settime()
424 	clock_ts_to_bcd(ts, &bct, sc->use_ampm);  in ds13rtc_settime()
425 	clock_dbgprint_bcd(sc->dev, CLOCK_DBG_WRITE, &bct);   in ds13rtc_settime()
427 	/* If the chip is in AMPM mode deal with the PM flag. */  in ds13rtc_settime()
429 	if (sc->use_ampm) {  in ds13rtc_settime()
435 	/* If the chip has a century bit, set it as needed. */  in ds13rtc_settime()
437 	if (sc->use_century) {  in ds13rtc_settime()
456 	if (sc->osfaddr != sc->secaddr) {  in ds13rtc_settime()
457 		if ((err = read_reg(sc, sc->osfaddr, &statreg)) != 0)  in ds13rtc_settime()
461 			err = write_reg(sc, sc->osfaddr, statreg);  in ds13rtc_settime()
478 	return (ofw_bus_search_compatible(dev, compat_data)->ocd_data);  in ds13rtc_get_chiptype()
491 	 * Loop through the ofw compat data comparing the hinted chip type to  in ds13rtc_get_chiptype()
494 	for (cdata = compat_data; cdata->ocd_str != NULL; ++cdata) {  in ds13rtc_get_chiptype()
495 		if (strcmp(htype, cdata->ocd_str) == 0)  in ds13rtc_get_chiptype()
498 	return (cdata->ocd_data);  in ds13rtc_get_chiptype()
529 	sc->dev = dev;  in ds13rtc_attach()
530 	sc->busdev = device_get_parent(dev);  in ds13rtc_attach()
533 	 * We need to know what kind of chip we're driving.  in ds13rtc_attach()
535 	if ((sc->chiptype = ds13rtc_get_chiptype(dev)) == TYPE_NONE) {  in ds13rtc_attach()
536 		device_printf(dev, "impossible: cannot determine chip type\n");  in ds13rtc_attach()
541 	if (sc->chiptype == TYPE_DS1388)   in ds13rtc_attach()
542 		sc->secaddr = DS1388_R_SECOND;  in ds13rtc_attach()
544 		sc->secaddr = DS13xx_R_SECOND;  in ds13rtc_attach()
547 	 * The OSF/CH (osc failed/clock-halted) bit appears in different  in ds13rtc_attach()
548 	 * registers for different chip types.  The DS1375 has no OSF indicator  in ds13rtc_attach()
549 	 * because it has no internal oscillator; we just point to an always-  in ds13rtc_attach()
550 	 * zero bit in the status register for that chip.  in ds13rtc_attach()
552 	switch (sc->chiptype) {  in ds13rtc_attach()
556 		sc->osfaddr = DS13xx_R_SECOND;  in ds13rtc_attach()
563 		sc->osfaddr = DS133x_R_STATUS;  in ds13rtc_attach()
564 		sc->use_century = true;  in ds13rtc_attach()
567 		sc->osfaddr = DS1340_R_STATUS;  in ds13rtc_attach()
572 		sc->osfaddr = DS137x_R_STATUS;  in ds13rtc_attach()
573 		sc->is_binary_counter = true;  in ds13rtc_attach()
576 		sc->osfaddr = DS1388_R_STATUS;  in ds13rtc_attach()