s390.c revision 1.9
1 /* $NetBSD: s390.c,v 1.9 2025/09/07 21:45:16 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 1.9 2025/09/07 21:45:16 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 44 struct 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 51 static int s390rtc_match(device_t, cfdata_t, void *); 52 static void s390rtc_attach(device_t, device_t, void *); 53 54 CFATTACH_DECL_NEW(s390rtc, sizeof(struct s390rtc_softc), 55 s390rtc_match, s390rtc_attach, NULL, NULL); 56 57 static int s390rtc_gettime_ymdhms(struct todr_chip_handle *, 58 struct clock_ymdhms *); 59 static int s390rtc_settime_ymdhms(struct todr_chip_handle *, 60 struct clock_ymdhms *); 61 static int s390rtc_read(struct s390rtc_softc *, int, uint8_t *, size_t); 62 static int s390rtc_write(struct s390rtc_softc *, int, uint8_t *, size_t); 63 static uint8_t bitreverse(uint8_t); 64 65 static const struct device_compatible_entry compat_data[] = { 66 { .compat = "sii,s35390a" }, 67 DEVICE_COMPAT_EOL 68 }; 69 70 static int 71 s390rtc_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 86 static void 87 s390rtc_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.todr_dev = self; 119 sc->sc_todr.todr_gettime_ymdhms = s390rtc_gettime_ymdhms; 120 sc->sc_todr.todr_settime_ymdhms = s390rtc_settime_ymdhms; 121 todr_attach(&sc->sc_todr); 122 } 123 124 static int 125 s390rtc_gettime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt) 126 { 127 struct s390rtc_softc *sc = device_private(ch->todr_dev); 128 uint8_t bcd[S390_RT1_NBYTES]; 129 int error; 130 131 if ((error = s390rtc_read(sc, S390_REALTIME1, bcd, 132 S390_RT1_NBYTES)) != 0) 133 return error; 134 135 /* 136 * Convert the register values into something useable. 137 */ 138 dt->dt_sec = bcdtobin(bcd[S390_RT1_SECOND]); 139 dt->dt_min = bcdtobin(bcd[S390_RT1_MINUTE]); 140 dt->dt_hour = bcdtobin(bcd[S390_RT1_HOUR] & 0x3f); 141 dt->dt_day = bcdtobin(bcd[S390_RT1_DAY]); 142 dt->dt_mon = bcdtobin(bcd[S390_RT1_MONTH]); 143 dt->dt_year = bcdtobin(bcd[S390_RT1_YEAR]) + 2000; 144 145 return 0; 146 } 147 148 static int 149 s390rtc_settime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt) 150 { 151 struct s390rtc_softc *sc = device_private(ch->todr_dev); 152 uint8_t bcd[S390_RT1_NBYTES]; 153 154 /* 155 * Convert our time representation into something the S-xx390 156 * can understand. 157 */ 158 bcd[S390_RT1_SECOND] = bintobcd(dt->dt_sec); 159 bcd[S390_RT1_MINUTE] = bintobcd(dt->dt_min); 160 bcd[S390_RT1_HOUR] = bintobcd(dt->dt_hour); 161 bcd[S390_RT1_DAY] = bintobcd(dt->dt_day); 162 bcd[S390_RT1_WDAY] = bintobcd(dt->dt_wday); 163 bcd[S390_RT1_MONTH] = bintobcd(dt->dt_mon); 164 bcd[S390_RT1_YEAR] = bintobcd(dt->dt_year % 100); 165 166 return s390rtc_write(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES); 167 } 168 169 static int 170 s390rtc_read(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 171 { 172 int i, error; 173 174 if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) { 175 aprint_error_dev(sc->sc_dev, 176 "%s: failed to acquire I2C bus\n", __func__); 177 return error; 178 } 179 180 if ((error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, 181 sc->sc_addr + reg, NULL, 0, buf, len, 0)) != 0) { 182 iic_release_bus(sc->sc_tag, 0); 183 aprint_error_dev(sc->sc_dev, 184 "%s: failed to read reg%d\n", __func__, reg); 185 return error; 186 } 187 188 iic_release_bus(sc->sc_tag, 0); 189 190 /* this chip returns each byte in reverse order */ 191 for (i = 0; i < len; i++) 192 buf[i] = bitreverse(buf[i]); 193 194 return 0; 195 } 196 197 static int 198 s390rtc_write(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 199 { 200 int i, error; 201 202 if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) { 203 aprint_error_dev(sc->sc_dev, 204 "%s: failed to acquire I2C bus\n", __func__); 205 return error; 206 } 207 208 /* this chip expects each byte in reverse order */ 209 for (i = 0; i < len; i++) 210 buf[i] = bitreverse(buf[i]); 211 212 if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, 213 sc->sc_addr + reg, NULL, 0, buf, len, 0)) != 0) { 214 iic_release_bus(sc->sc_tag, 0); 215 aprint_error_dev(sc->sc_dev, 216 "%s: failed to write reg%d\n", __func__, reg); 217 return error; 218 } 219 220 iic_release_bus(sc->sc_tag, 0); 221 return 0; 222 } 223 224 static uint8_t 225 bitreverse(uint8_t x) 226 { 227 static unsigned char nibbletab[16] = { 228 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 229 }; 230 231 return (nibbletab[x & 15] << 4) | nibbletab[x >> 4]; 232 } 233
Indexes created Mon Sep 22 21:09:42 GMT 2025