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      1 /*	$NetBSD: dsrtc.c,v 1.14 2025/09/07 21:45:11 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1998 Mark Brinicombe.
      5  * Copyright (c) 1998 Causality Limited.
      6  * All rights reserved.
      7  *
      8  * Written by Mark Brinicombe, Causality Limited
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by Mark Brinicombe
     21  *	for the NetBSD Project.
     22  * 4. The name of the company nor the name of the author may be used to
     23  *    endorse or promote products derived from this software without specific
     24  *    prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY CAUASLITY LIMITED ``AS IS'' AND ANY EXPRESS
     27  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     28  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     29  * DISCLAIMED. IN NO EVENT SHALL CAUSALITY LIMITED OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     32  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 __KERNEL_RCSID(0, "$NetBSD: dsrtc.c,v 1.14 2025/09/07 21:45:11 thorpej Exp $");
     41 
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/kernel.h>
     45 #include <sys/conf.h>
     46 #include <sys/device.h>
     47 
     48 #include <dev/clock_subr.h>
     49 #include <arm/footbridge/isa/ds1687reg.h>
     50 
     51 #include <dev/isa/isavar.h>
     52 
     53 #define NRTC_PORTS	2
     54 
     55 struct dsrtc_softc {
     56 	device_t sc_dev;
     57 	bus_space_tag_t	sc_iot;
     58 	bus_space_handle_t sc_ioh;
     59 	struct todr_chip_handle sc_todr;
     60 };
     61 
     62 void dsrtcattach(device_t parent, device_t self, void *aux);
     63 int dsrtcmatch(device_t parent, cfdata_t cf, void *aux);
     64 int ds1687_read(struct dsrtc_softc *sc, int addr);
     65 void ds1687_write(struct dsrtc_softc *sc, int addr, int data);
     66 #if 0
     67 int ds1687_ram_read(struct dsrtc_softc *sc, int addr);
     68 void ds1687_ram_write(struct dsrtc_softc *sc, int addr, int data);
     69 #endif
     70 static void ds1687_bank_select(struct dsrtc_softc *, int);
     71 static int dsrtc_write(todr_chip_handle_t, struct clock_ymdhms *);
     72 static int dsrtc_read(todr_chip_handle_t, struct clock_ymdhms *);
     73 
     74 int
     75 ds1687_read(struct dsrtc_softc *sc, int addr)
     76 {
     77 
     78 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, RTC_ADDR_REG, addr);
     79 	return(bus_space_read_1(sc->sc_iot, sc->sc_ioh, RTC_DATA_REG));
     80 }
     81 
     82 void
     83 ds1687_write(struct dsrtc_softc *sc, int addr, int data)
     84 {
     85 
     86 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, RTC_ADDR_REG, addr);
     87 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, RTC_DATA_REG, data);
     88 }
     89 
     90 static void
     91 ds1687_bank_select(struct dsrtc_softc *sc, int bank)
     92 {
     93 	int data;
     94 
     95 	data = ds1687_read(sc, RTC_REG_A);
     96 	data &= ~RTC_REG_A_BANK_MASK;
     97 	if (bank)
     98 		data |= RTC_REG_A_BANK1;
     99 	ds1687_write(sc, RTC_REG_A, data);
    100 }
    101 
    102 #if 0
    103 /* Nothing uses these yet */
    104 int
    105 ds1687_ram_read(struct dsrtc_softc *sc, int addr)
    106 {
    107 	if (addr < RTC_PC_RAM_SIZE)
    108 		return(ds1687_read(sc, RTC_PC_RAM_START + addr));
    109 
    110 	addr -= RTC_PC_RAM_SIZE;
    111 	if (addr < RTC_BANK0_RAM_SIZE)
    112 		return(ds1687_read(sc, RTC_BANK0_RAM_START + addr));
    113 
    114 	addr -= RTC_BANK0_RAM_SIZE;
    115 	if (addr < RTC_EXT_RAM_SIZE) {
    116 		int data;
    117 
    118 		ds1687_bank_select(sc, 1);
    119 		ds1687_write(sc, RTC_EXT_RAM_ADDRESS, addr);
    120 		data = ds1687_read(sc, RTC_EXT_RAM_DATA);
    121 		ds1687_bank_select(sc, 0);
    122 		return(data);
    123 	}
    124 	return(-1);
    125 }
    126 
    127 void
    128 ds1687_ram_write(struct dsrtc_softc *sc, int addr, int val)
    129 {
    130 	if (addr < RTC_PC_RAM_SIZE)
    131 		return(ds1687_write(sc, RTC_PC_RAM_START + addr, val));
    132 
    133 	addr -= RTC_PC_RAM_SIZE;
    134 	if (addr < RTC_BANK0_RAM_SIZE)
    135 		return(ds1687_write(sc, RTC_BANK0_RAM_START + addr, val));
    136 
    137 	addr -= RTC_BANK0_RAM_SIZE;
    138 	if (addr < RTC_EXT_RAM_SIZE) {
    139 		ds1687_bank_select(sc, 1);
    140 		ds1687_write(sc, RTC_EXT_RAM_ADDRESS, addr);
    141 		ds1687_write(sc, RTC_EXT_RAM_DATA, val);
    142 		ds1687_bank_select(sc, 0);
    143 	}
    144 }
    145 #endif
    146 
    147 static int
    148 dsrtc_write(todr_chip_handle_t tc, struct clock_ymdhms *dt)
    149 {
    150 	struct dsrtc_softc *sc = device_private(tc->todr_dev);
    151 
    152 	ds1687_write(sc, RTC_SECONDS, dt->dt_sec);
    153 	ds1687_write(sc, RTC_MINUTES, dt->dt_min);
    154 	ds1687_write(sc, RTC_HOURS, dt->dt_hour);
    155 	ds1687_write(sc, RTC_DAYOFMONTH, dt->dt_day);
    156 	ds1687_write(sc, RTC_MONTH, dt->dt_mon);
    157 	ds1687_write(sc, RTC_YEAR, dt->dt_year % 100);
    158 	ds1687_bank_select(sc, 1);
    159 	ds1687_write(sc, RTC_CENTURY, dt->dt_year / 100);
    160 	ds1687_bank_select(sc, 0);
    161 	return(0);
    162 }
    163 
    164 static int
    165 dsrtc_read(todr_chip_handle_t tc, struct clock_ymdhms *dt)
    166 {
    167 	struct dsrtc_softc *sc = device_private(tc->todr_dev);
    168 
    169 	dt->dt_sec   = ds1687_read(sc, RTC_SECONDS);
    170 	dt->dt_min   = ds1687_read(sc, RTC_MINUTES);
    171 	dt->dt_hour  = ds1687_read(sc, RTC_HOURS);
    172 	dt->dt_day   = ds1687_read(sc, RTC_DAYOFMONTH);
    173 	dt->dt_mon   = ds1687_read(sc, RTC_MONTH);
    174 	dt->dt_year  = ds1687_read(sc, RTC_YEAR);
    175 	ds1687_bank_select(sc, 1);
    176 	dt->dt_year  += ds1687_read(sc, RTC_CENTURY) * 100;
    177 	ds1687_bank_select(sc, 0);
    178 
    179 	return(0);
    180 }
    181 
    182 /* device and attach structures */
    183 CFATTACH_DECL_NEW(ds1687rtc, sizeof(struct dsrtc_softc),
    184     dsrtcmatch, dsrtcattach, NULL, NULL);
    185 
    186 /*
    187  * dsrtcmatch()
    188  *
    189  * Validate the IIC address to make sure its an RTC we understand
    190  */
    191 
    192 int
    193 dsrtcmatch(device_t parent, cfdata_t cf, void *aux)
    194 {
    195 	struct isa_attach_args *ia = aux;
    196 
    197 	if (ia->ia_nio < 1 ||
    198 	    ia->ia_io[0].ir_addr == ISA_UNKNOWN_PORT)
    199 		return (0);
    200 
    201 	ia->ia_nio = 1;
    202 	ia->ia_io[0].ir_size = NRTC_PORTS;
    203 
    204 	ia->ia_niomem = 0;
    205 	ia->ia_nirq = 0;
    206 	ia->ia_ndrq = 0;
    207 
    208 	return(1);
    209 }
    210 
    211 /*
    212  * dsrtcattach()
    213  *
    214  * Attach the rtc device
    215  */
    216 
    217 void
    218 dsrtcattach(device_t parent, device_t self, void *aux)
    219 {
    220 	struct dsrtc_softc *sc = device_private(self);
    221 	struct isa_attach_args *ia = aux;
    222 
    223 	sc->sc_dev = self;
    224 	sc->sc_iot = ia->ia_iot;
    225 	if (bus_space_map(sc->sc_iot, ia->ia_io[0].ir_addr,
    226 	    ia->ia_io[0].ir_size, 0, &sc->sc_ioh)) {
    227 		aprint_error(": cannot map I/O space\n");
    228 		return;
    229 	}
    230 
    231 	ds1687_write(sc, RTC_REG_A, RTC_REG_A_DV1);
    232 	ds1687_write(sc, RTC_REG_B, RTC_REG_B_BINARY | RTC_REG_B_24_HOUR);
    233 
    234 	if (!(ds1687_read(sc, RTC_REG_D) & RTC_REG_D_VRT))
    235 		aprint_error(": lithium cell is dead, RTC unreliable");
    236 	aprint_normal("\n");
    237 
    238 	sc->sc_todr.todr_gettime_ymdhms = dsrtc_read;
    239 	sc->sc_todr.todr_settime_ymdhms = dsrtc_write;
    240 	sc->sc_todr.todr_dev = self;
    241 	todr_attach(&sc->sc_todr);
    242 }
    243 
    244 /* End of dsrtc.c */
    245