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rtc.c revision 1.23
      1 /*	$NetBSD: rtc.c,v 1.23 2023/12/20 00:40:43 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988 University of Utah.
      5  * Copyright (c) 1982, 1990, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * This code is derived from software contributed to Berkeley by
      9  * the Systems Programming Group of the University of Utah Computer
     10  * Science Department.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  *
     36  * from: Utah $Hdr: clock.c 1.18 91/01/21$
     37  *
     38  *	@(#)clock.c	8.2 (Berkeley) 1/12/94
     39  */
     40 
     41 /*
     42  * attachment for HP300 real-time clock (RTC)
     43  */
     44 
     45 #include <sys/cdefs.h>
     46 __KERNEL_RCSID(0, "$NetBSD: rtc.c,v 1.23 2023/12/20 00:40:43 thorpej Exp $");
     47 
     48 #include <sys/param.h>
     49 #include <sys/systm.h>
     50 #include <sys/device.h>
     51 
     52 #include <hp300/dev/intiovar.h>
     53 #include <hp300/dev/rtcreg.h>
     54 
     55 #include <dev/clock_subr.h>
     56 
     57 struct rtc_softc {
     58 	device_t sc_dev;
     59 	bus_space_tag_t sc_bst;
     60 	bus_space_handle_t sc_bsh;
     61 	struct todr_chip_handle sc_handle;
     62 };
     63 
     64 static int	rtcmatch(device_t, cfdata_t, void *);
     65 static void	rtcattach(device_t, device_t, void *aux);
     66 
     67 CFATTACH_DECL_NEW(rtc, sizeof(struct rtc_softc),
     68     rtcmatch, rtcattach, NULL, NULL);
     69 
     70 static int	rtc_gettime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
     71 static int	rtc_settime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
     72 static uint8_t	rtc_readreg(struct rtc_softc *, int);
     73 static uint8_t	rtc_writereg(struct rtc_softc *, int, uint8_t);
     74 
     75 
     76 static int
     77 rtcmatch(device_t parent, cfdata_t cf, void *aux)
     78 {
     79 	struct intio_attach_args *ia = aux;
     80 
     81 	/* 425e doesn't have the traditional RTC at intio */
     82 	if (machineid == HP_425 && mmuid == MMUID_425_E)
     83 		return 0;
     84 
     85 	if (strcmp("rtc", ia->ia_modname) != 0)
     86 		return 0;
     87 
     88 	return 1;
     89 }
     90 
     91 static void
     92 rtcattach(device_t parent, device_t self, void *aux)
     93 {
     94 	struct rtc_softc *sc = device_private(self);
     95 	struct intio_attach_args *ia = aux;
     96 	struct todr_chip_handle *todr_handle;
     97 	bus_space_tag_t bst = ia->ia_bst;
     98 
     99 	sc->sc_dev = self;
    100 	if (bus_space_map(bst, ia->ia_iobase, INTIO_DEVSIZE, 0,
    101 	    &sc->sc_bsh)) {
    102 		aprint_error(": can't map registers\n");
    103 		return;
    104 	}
    105 
    106 	aprint_normal("\n");
    107 
    108 	sc->sc_bst = bst;
    109 
    110 	todr_handle = &sc->sc_handle;
    111 	todr_handle->cookie = sc;
    112 	todr_handle->todr_gettime = NULL;
    113 	todr_handle->todr_settime = NULL;
    114 	todr_handle->todr_gettime_ymdhms = rtc_gettime_ymdhms;
    115 	todr_handle->todr_settime_ymdhms = rtc_settime_ymdhms;
    116 	todr_handle->todr_setwen = NULL;
    117 
    118 	todr_attach(todr_handle);
    119 }
    120 
    121 static int
    122 rtc_gettime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt)
    123 {
    124 	struct rtc_softc *sc;
    125 	int i, year;
    126 	bool read_okay;
    127 	uint8_t rtc_registers[NUM_RTC_REGS];
    128 
    129 	sc = handle->cookie;
    130 
    131 	/* read rtc registers */
    132 	read_okay = false;
    133 	while (!read_okay) {
    134 		read_okay = true;
    135 		for (i = 0; i < NUM_RTC_REGS; i++)
    136 			rtc_registers[i] = rtc_readreg(sc, i);
    137 		for (i = 0; i < NUM_RTC_REGS; i++)
    138 			if (rtc_registers[i] != rtc_readreg(sc, i))
    139 				read_okay = false;
    140 	}
    141 
    142 #define	rtc_to_decimal(a,b)	(rtc_registers[a] * 10 + rtc_registers[b])
    143 
    144 	dt->dt_sec  = rtc_to_decimal(1, 0);
    145 	dt->dt_min  = rtc_to_decimal(3, 2);
    146 	dt->dt_hour = (rtc_registers[5] & RTC_REG5_HOUR) * 10 +
    147 	    rtc_registers[4];
    148 	dt->dt_day  = rtc_to_decimal(8, 7);
    149 	dt->dt_mon  = rtc_to_decimal(10, 9);
    150 
    151 	year = rtc_to_decimal(12, 11) + RTC_BASE_YEAR;
    152 	if (year < POSIX_BASE_YEAR)
    153 		year += 100;
    154 	dt->dt_year = year;
    155 
    156 #undef	rtc_to_decimal
    157 
    158 	return 0;
    159 }
    160 
    161 static int
    162 rtc_settime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt)
    163 {
    164 	struct rtc_softc *sc;
    165 	int i, year;
    166 	uint8_t rtc_registers[NUM_RTC_REGS];
    167 
    168 	sc = handle->cookie;
    169 	year = dt->dt_year - RTC_BASE_YEAR;
    170 	if (year > 99)
    171 		year -= 100;
    172 
    173 #define	decimal_to_rtc(a,b,n)		\
    174 	rtc_registers[a] = (n) % 10;	\
    175 	rtc_registers[b] = (n) / 10;
    176 
    177 	decimal_to_rtc(0, 1, dt->dt_sec);
    178 	decimal_to_rtc(2, 3, dt->dt_min);
    179 	decimal_to_rtc(7, 8, dt->dt_day);
    180 	decimal_to_rtc(9, 10, dt->dt_mon);
    181 	decimal_to_rtc(11, 12, year);
    182 
    183 	rtc_registers[4] = dt->dt_hour % 10;
    184 	rtc_registers[5] = ((dt->dt_hour / 10) & RTC_REG5_HOUR) | RTC_REG5_24HR;
    185 
    186 	rtc_registers[6] = 0;
    187 
    188 #undef	decimal_to_rtc
    189 
    190 	/* write rtc registers */
    191 	rtc_writereg(sc, 15, 13);	/* reset prescalar */
    192 	for (i = 0; i < NUM_RTC_REGS; i++)
    193 		if (rtc_registers[i] !=
    194 		    rtc_writereg(sc, i, rtc_registers[i]))
    195 			return 1;
    196 	return 0;
    197 }
    198 
    199 static uint8_t
    200 rtc_readreg(struct rtc_softc *sc, int reg)
    201 {
    202 	bus_space_tag_t bst = sc->sc_bst;
    203 	bus_space_handle_t bsh = sc->sc_bsh;
    204 	uint8_t data;
    205 	int s = splvm();
    206 
    207 	data = reg;
    208 	intio_device_writecmd(bst, bsh, RTC_SET_REG, &data, 1);
    209 	intio_device_readcmd(bst, bsh, RTC_READ_REG, &data);
    210 
    211 	splx(s);
    212 	return data;
    213 }
    214 
    215 static uint8_t
    216 rtc_writereg(struct rtc_softc *sc, int reg, uint8_t data)
    217 {
    218 	bus_space_tag_t bst = sc->sc_bst;
    219 	bus_space_handle_t bsh = sc->sc_bsh;
    220 	uint8_t tmp;
    221 	int s = splvm();
    222 
    223 	tmp = (data << 4) | reg;
    224 	intio_device_writecmd(bst, bsh, RTC_SET_REG, &tmp, 1);
    225 	intio_device_writecmd(bst, bsh, RTC_WRITE_REG, NULL, 0);
    226 	intio_device_readcmd(bst, bsh, RTC_READ_REG, &tmp);
    227 
    228 	splx(s);
    229 	return tmp;
    230 }
    231