1/* $NetBSD: s390.c,v 1.7 2021/01/30 17:38:57 thorpej Exp $ */ 2 3/*- 4 * Copyright (c) 2011 Frank Wille. 5 * All rights reserved. 6 * 7 * Written by Frank Wille for The NetBSD Project. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <sys/cdefs.h> 32__KERNEL_RCSID(0, "$NetBSD: s390.c,v 1.7 2021/01/30 17:38:57 thorpej Exp $"); 33 34#include <sys/param.h> 35#include <sys/systm.h> 36#include <sys/device.h> 37#include <sys/conf.h> 38 39#include <dev/clock_subr.h> 40 41#include <dev/i2c/i2cvar.h> 42#include <dev/i2c/s390reg.h> 43 44struct s390rtc_softc { 45 device_t sc_dev; 46 i2c_tag_t sc_tag; 47 i2c_addr_t sc_addr; 48 struct todr_chip_handle sc_todr; 49}; 50 51static int s390rtc_match(device_t, cfdata_t, void *); 52static void s390rtc_attach(device_t, device_t, void *); 53 54CFATTACH_DECL_NEW(s390rtc, sizeof(struct s390rtc_softc), 55 s390rtc_match, s390rtc_attach, NULL, NULL); 56 57static int s390rtc_gettime_ymdhms(struct todr_chip_handle *, 58 struct clock_ymdhms *); 59static int s390rtc_settime_ymdhms(struct todr_chip_handle *, 60 struct clock_ymdhms *); 61static int s390rtc_read(struct s390rtc_softc *, int, uint8_t *, size_t); 62static int s390rtc_write(struct s390rtc_softc *, int, uint8_t *, size_t); 63static uint8_t bitreverse(uint8_t); 64 65static const struct device_compatible_entry compat_data[] = { 66 { .compat = "sii,s35390a" }, 67 DEVICE_COMPAT_EOL 68}; 69 70static int 71s390rtc_match(device_t parent, cfdata_t cf, void *arg) 72{ 73 struct i2c_attach_args *ia = arg; 74 int match_result; 75 76 if (iic_use_direct_match(ia, cf, compat_data, &match_result)) 77 return match_result; 78 79 /* indirect config - check typical address */ 80 if (ia->ia_addr == S390_ADDR) 81 return I2C_MATCH_ADDRESS_ONLY; 82 83 return 0; 84} 85 86static void 87s390rtc_attach(device_t parent, device_t self, void *arg) 88{ 89 struct s390rtc_softc *sc = device_private(self); 90 struct i2c_attach_args *ia = arg; 91 uint8_t reg[1]; 92 93 aprint_naive(": Real-time Clock\n"); 94 aprint_normal(": Seiko Instruments 35390A Real-time Clock\n"); 95 96 sc->sc_tag = ia->ia_tag; 97 sc->sc_addr = ia->ia_addr; 98 sc->sc_dev = self; 99 100 /* Reset the chip and turn on 24h mode, after power-off or battery. */ 101 if (s390rtc_read(sc, S390_STATUS1, reg, sizeof(reg))) 102 return; 103 if (reg[0] & (S390_ST1_POC | S390_ST1_BLD)) { 104 reg[0] |= S390_ST1_24H | S390_ST1_RESET; 105 if (s390rtc_write(sc, S390_STATUS1, reg, sizeof(reg))) 106 return; 107 } 108 109 /* Disable the test mode, when enabled. */ 110 if (s390rtc_read(sc, S390_STATUS2, reg, sizeof(reg))) 111 return; 112 if ((reg[0] & S390_ST2_TEST)) { 113 reg[0] &= ~S390_ST2_TEST; 114 if (s390rtc_write(sc, S390_STATUS2, reg, sizeof(reg))) 115 return; 116 } 117 118 sc->sc_todr.cookie = sc; 119 sc->sc_todr.todr_gettime = NULL; 120 sc->sc_todr.todr_settime = NULL; 121 sc->sc_todr.todr_gettime_ymdhms = s390rtc_gettime_ymdhms; 122 sc->sc_todr.todr_settime_ymdhms = s390rtc_settime_ymdhms; 123 sc->sc_todr.todr_setwen = NULL; 124 todr_attach(&sc->sc_todr); 125} 126 127static int 128s390rtc_gettime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt) 129{ 130 struct s390rtc_softc *sc = ch->cookie; 131 uint8_t bcd[S390_RT1_NBYTES]; 132 int error; 133 134 if ((error = s390rtc_read(sc, S390_REALTIME1, bcd, 135 S390_RT1_NBYTES)) != 0) 136 return error; 137 138 /* 139 * Convert the register values into something useable. 140 */ 141 dt->dt_sec = bcdtobin(bcd[S390_RT1_SECOND]); 142 dt->dt_min = bcdtobin(bcd[S390_RT1_MINUTE]); 143 dt->dt_hour = bcdtobin(bcd[S390_RT1_HOUR] & 0x3f); 144 dt->dt_day = bcdtobin(bcd[S390_RT1_DAY]); 145 dt->dt_mon = bcdtobin(bcd[S390_RT1_MONTH]); 146 dt->dt_year = bcdtobin(bcd[S390_RT1_YEAR]) + 2000; 147 148 return 0; 149} 150 151static int 152s390rtc_settime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt) 153{ 154 struct s390rtc_softc *sc = ch->cookie; 155 uint8_t bcd[S390_RT1_NBYTES]; 156 157 /* 158 * Convert our time representation into something the S-xx390 159 * can understand. 160 */ 161 bcd[S390_RT1_SECOND] = bintobcd(dt->dt_sec); 162 bcd[S390_RT1_MINUTE] = bintobcd(dt->dt_min); 163 bcd[S390_RT1_HOUR] = bintobcd(dt->dt_hour); 164 bcd[S390_RT1_DAY] = bintobcd(dt->dt_day); 165 bcd[S390_RT1_WDAY] = bintobcd(dt->dt_wday); 166 bcd[S390_RT1_MONTH] = bintobcd(dt->dt_mon); 167 bcd[S390_RT1_YEAR] = bintobcd(dt->dt_year % 100); 168 169 return s390rtc_write(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES); 170} 171 172static int 173s390rtc_read(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 174{ 175 int i, error; 176 177 if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) { 178 aprint_error_dev(sc->sc_dev, 179 "%s: failed to acquire I2C bus\n", __func__); 180 return error; 181 } 182 183 if ((error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, 184 sc->sc_addr + reg, NULL, 0, buf, len, 0)) != 0) { 185 iic_release_bus(sc->sc_tag, 0); 186 aprint_error_dev(sc->sc_dev, 187 "%s: failed to read reg%d\n", __func__, reg); 188 return error; 189 } 190 191 iic_release_bus(sc->sc_tag, 0); 192 193 /* this chip returns each byte in reverse order */ 194 for (i = 0; i < len; i++) 195 buf[i] = bitreverse(buf[i]); 196 197 return 0; 198} 199 200static int 201s390rtc_write(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 202{ 203 int i, error; 204 205 if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) { 206 aprint_error_dev(sc->sc_dev, 207 "%s: failed to acquire I2C bus\n", __func__); 208 return error; 209 } 210 211 /* this chip expects each byte in reverse order */ 212 for (i = 0; i < len; i++) 213 buf[i] = bitreverse(buf[i]); 214 215 if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, 216 sc->sc_addr + reg, NULL, 0, buf, len, 0)) != 0) { 217 iic_release_bus(sc->sc_tag, 0); 218 aprint_error_dev(sc->sc_dev, 219 "%s: failed to write reg%d\n", __func__, reg); 220 return error; 221 } 222 223 iic_release_bus(sc->sc_tag, 0); 224 return 0; 225} 226 227static uint8_t 228bitreverse(uint8_t x) 229{ 230 static unsigned char nibbletab[16] = { 231 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 232 }; 233 234 return (nibbletab[x & 15] << 4) | nibbletab[x >> 4]; 235} 236