xref: /src/sys/arch/sh3/dev/rtc.c

/*	$NetBSD: rtc.c,v 1.12 2025/09/07 21:45:14 thorpej Exp $ */

/*-
 * Copyright (c) 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rtc.c,v 1.12 2025/09/07 21:45:14 thorpej Exp $");

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/systm.h>
#ifdef GPROF
#include <sys/gmon.h>
#endif

#include <dev/clock_subr.h>

#include <sh3/rtcreg.h>

#if defined(DEBUG) && !defined(RTC_DEBUG)
#define RTC_DEBUG
#endif


struct rtc_softc {
	device_t sc_dev;

	int sc_valid;
	struct todr_chip_handle sc_todr;
	u_int sc_year0;
};

static int	rtc_match(device_t, cfdata_t, void *);
static void	rtc_attach(device_t, device_t, void *);

CFATTACH_DECL_NEW(rtc, sizeof(struct rtc_softc),
    rtc_match, rtc_attach, NULL, NULL);


/* todr(9) methods */
static int rtc_gettime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
static int rtc_settime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);

#ifndef SH3_RTC_BASEYEAR
#define SH3_RTC_BASEYEAR	1900
#endif
u_int sh3_rtc_baseyear = SH3_RTC_BASEYEAR;

static int
rtc_match(device_t parent, cfdata_t cfp, void *aux)
{

	return 1;
}


static void
rtc_attach(device_t parent, device_t self, void *aux)
{
	struct rtc_softc *sc;
	uint8_t r;
	prop_number_t prop_rtc_baseyear;
#ifdef RTC_DEBUG
	char bits[128];
#endif

	aprint_naive("\n");
	aprint_normal("\n");

	sc = device_private(self);
	sc->sc_dev = self;

	r = _reg_read_1(SH_(RCR2));

#ifdef RTC_DEBUG
	snprintb(bits, sizeof(bits), SH_RCR2_BITS, r);
	aprint_debug_dev(sc->sc_dev, "RCR2=%s\n", bits);
#endif

	/* Was the clock running? */
	if ((r & (SH_RCR2_ENABLE | SH_RCR2_START)) == (SH_RCR2_ENABLE
						       | SH_RCR2_START))
		sc->sc_valid = 1;
	else {
		sc->sc_valid = 0;
		aprint_error_dev(sc->sc_dev, "WARNING: clock was stopped\n");
	}

	/* Disable carry and alarm interrupts */
	_reg_write_1(SH_(RCR1), 0);

	/* Clock runs, no periodic interrupts, no 30-sec adjustment */
	_reg_write_1(SH_(RCR2), SH_RCR2_ENABLE | SH_RCR2_START);

	sc->sc_todr.todr_dev = self;
	sc->sc_todr.todr_gettime_ymdhms = rtc_gettime_ymdhms;
	sc->sc_todr.todr_settime_ymdhms = rtc_settime_ymdhms;

	prop_rtc_baseyear = prop_dictionary_get(device_properties(self),
	    "sh3_rtc_baseyear");
	if (prop_rtc_baseyear != NULL) {
		sh3_rtc_baseyear =
		    (u_int)prop_number_integer_value(prop_rtc_baseyear);
#ifdef RTC_DEBUG
		aprint_debug_dev(self,
		    "using baseyear %u passed via device property\n",
		    sh3_rtc_baseyear);
#endif
	}
	sc->sc_year0 = sh3_rtc_baseyear;

	todr_attach(&sc->sc_todr);

#ifdef RTC_DEBUG
	{
		struct clock_ymdhms dt;
		rtc_gettime_ymdhms(&sc->sc_todr, &dt);
	}
#endif

	if (!pmf_device_register(self, NULL, NULL))
		aprint_error_dev(self, "unable to establish power handler\n");
}


static int
rtc_gettime_ymdhms(todr_chip_handle_t h, struct clock_ymdhms *dt)
{
	struct rtc_softc *sc = device_private(h->todr_dev);
	unsigned int year;
	int retry = 8;

	if (!sc->sc_valid) {
#ifdef RTC_DEBUG
		aprint_debug_dev(sc->sc_dev, "gettime: not valid\n");
		/* but proceed and read/print it anyway */
#else
		return EIO;
#endif
	}

	/* disable carry interrupt */
	_reg_bclr_1(SH_(RCR1), SH_RCR1_CIE);

	do {
		uint8_t r = _reg_read_1(SH_(RCR1));
		r &= ~SH_RCR1_CF;
		r |= SH_RCR1_AF; /* don't clear alarm flag */
		_reg_write_1(SH_(RCR1), r);

		if (CPU_IS_SH3)
			year = _reg_read_1(SH3_RYRCNT);
		else
			year = _reg_read_2(SH4_RYRCNT) & 0x00ff;
		dt->dt_year = bcdtobin(year);

		/* read counter */
#define	RTCGET(x, y) \
		dt->dt_ ## x = bcdtobin(_reg_read_1(SH_(R ## y ## CNT)))

		RTCGET(mon, MON);
		RTCGET(wday, WK);
		RTCGET(day, DAY);
		RTCGET(hour, HR);
		RTCGET(min, MIN);
		RTCGET(sec, SEC);
#undef RTCGET
	} while ((_reg_read_1(SH_(RCR1)) & SH_RCR1_CF) && --retry > 0);

	if (retry == 0) {
#ifdef RTC_DEBUG
		aprint_debug_dev(sc->sc_dev, "gettime: retry failed\n");
#endif
		return EIO;
	}

	dt->dt_year += sc->sc_year0;
	if (dt->dt_year < POSIX_BASE_YEAR)
		dt->dt_year += 100;

#ifdef RTC_DEBUG
	aprint_debug_dev(sc->sc_dev,
			 "gettime: %04lu-%02d-%02d %02d:%02d:%02d\n",
			 (unsigned long)dt->dt_year, dt->dt_mon, dt->dt_day,
			 dt->dt_hour, dt->dt_min, dt->dt_sec);

	if (!sc->sc_valid)
		return EIO;
#endif

	return 0;
}


static int
rtc_settime_ymdhms(todr_chip_handle_t h, struct clock_ymdhms *dt)
{
	struct rtc_softc *sc = device_private(h->todr_dev);
	unsigned int year;
	uint8_t r;

	year = dt->dt_year - sc->sc_year0;
	if (year > 99)
		year -= 100;

	year = bintobcd(year);

	r = _reg_read_1(SH_(RCR2));

	/* stop clock */
	_reg_write_1(SH_(RCR2), (r & ~SH_RCR2_START) | SH_RCR2_RESET);

	/* set time */
	if (CPU_IS_SH3)
		_reg_write_1(SH3_RYRCNT, year);
	else
		_reg_write_2(SH4_RYRCNT, year);

#define	RTCSET(x, y) \
	_reg_write_1(SH_(R ## x ## CNT), bintobcd(dt->dt_ ## y))

	RTCSET(MON, mon);
	RTCSET(WK, wday);
	RTCSET(DAY, day);
	RTCSET(HR, hour);
	RTCSET(MIN, min);
	RTCSET(SEC, sec);

#undef RTCSET

	/* start clock */
	_reg_write_1(SH_(RCR2), r);
	sc->sc_valid = 1;

#ifdef RTC_DEBUG
	aprint_debug_dev(sc->sc_dev,
			 "settime: %04lu-%02d-%02d %02d:%02d:%02d\n",
			 (unsigned long)dt->dt_year, dt->dt_mon, dt->dt_day,
			 dt->dt_hour, dt->dt_min, dt->dt_sec);
#endif

	return 0;
}