s390.c revision 1.6
1 /* $NetBSD: s390.c,v 1.6 2020/01/02 19:00:34 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 1.6 2020/01/02 19:00:34 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 int 66 s390rtc_match(device_t parent, cfdata_t cf, void *arg) 67 { 68 struct i2c_attach_args *ia = arg; 69 int match_result; 70 71 if (iic_use_direct_match(ia, cf, NULL, &match_result)) 72 return match_result; 73 74 /* indirect config - check typical address */ 75 if (ia->ia_addr == S390_ADDR) 76 return I2C_MATCH_ADDRESS_ONLY; 77 78 return 0; 79 } 80 81 static void 82 s390rtc_attach(device_t parent, device_t self, void *arg) 83 { 84 struct s390rtc_softc *sc = device_private(self); 85 struct i2c_attach_args *ia = arg; 86 uint8_t reg[1]; 87 88 aprint_naive(": Real-time Clock\n"); 89 aprint_normal(": Seiko Instruments 35390A Real-time Clock\n"); 90 91 sc->sc_tag = ia->ia_tag; 92 sc->sc_addr = ia->ia_addr; 93 sc->sc_dev = self; 94 95 /* Reset the chip and turn on 24h mode, after power-off or battery. */ 96 if (s390rtc_read(sc, S390_STATUS1, reg, sizeof(reg))) 97 return; 98 if (reg[0] & (S390_ST1_POC | S390_ST1_BLD)) { 99 reg[0] |= S390_ST1_24H | S390_ST1_RESET; 100 if (s390rtc_write(sc, S390_STATUS1, reg, sizeof(reg))) 101 return; 102 } 103 104 /* Disable the test mode, when enabled. */ 105 if (s390rtc_read(sc, S390_STATUS2, reg, sizeof(reg))) 106 return; 107 if ((reg[0] & S390_ST2_TEST)) { 108 reg[0] &= ~S390_ST2_TEST; 109 if (s390rtc_write(sc, S390_STATUS2, reg, sizeof(reg))) 110 return; 111 } 112 113 sc->sc_todr.cookie = sc; 114 sc->sc_todr.todr_gettime = NULL; 115 sc->sc_todr.todr_settime = NULL; 116 sc->sc_todr.todr_gettime_ymdhms = s390rtc_gettime_ymdhms; 117 sc->sc_todr.todr_settime_ymdhms = s390rtc_settime_ymdhms; 118 sc->sc_todr.todr_setwen = NULL; 119 todr_attach(&sc->sc_todr); 120 } 121 122 static int 123 s390rtc_gettime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt) 124 { 125 struct s390rtc_softc *sc = ch->cookie; 126 uint8_t bcd[S390_RT1_NBYTES]; 127 int error; 128 129 if ((error = s390rtc_read(sc, S390_REALTIME1, bcd, 130 S390_RT1_NBYTES)) != 0) 131 return error; 132 133 /* 134 * Convert the register values into something useable. 135 */ 136 dt->dt_sec = bcdtobin(bcd[S390_RT1_SECOND]); 137 dt->dt_min = bcdtobin(bcd[S390_RT1_MINUTE]); 138 dt->dt_hour = bcdtobin(bcd[S390_RT1_HOUR] & 0x3f); 139 dt->dt_day = bcdtobin(bcd[S390_RT1_DAY]); 140 dt->dt_mon = bcdtobin(bcd[S390_RT1_MONTH]); 141 dt->dt_year = bcdtobin(bcd[S390_RT1_YEAR]) + 2000; 142 143 return 0; 144 } 145 146 static int 147 s390rtc_settime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt) 148 { 149 struct s390rtc_softc *sc = ch->cookie; 150 uint8_t bcd[S390_RT1_NBYTES]; 151 152 /* 153 * Convert our time representation into something the S-xx390 154 * can understand. 155 */ 156 bcd[S390_RT1_SECOND] = bintobcd(dt->dt_sec); 157 bcd[S390_RT1_MINUTE] = bintobcd(dt->dt_min); 158 bcd[S390_RT1_HOUR] = bintobcd(dt->dt_hour); 159 bcd[S390_RT1_DAY] = bintobcd(dt->dt_day); 160 bcd[S390_RT1_WDAY] = bintobcd(dt->dt_wday); 161 bcd[S390_RT1_MONTH] = bintobcd(dt->dt_mon); 162 bcd[S390_RT1_YEAR] = bintobcd(dt->dt_year % 100); 163 164 return s390rtc_write(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES); 165 } 166 167 static int 168 s390rtc_read(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 169 { 170 int i, error; 171 172 if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) { 173 aprint_error_dev(sc->sc_dev, 174 "%s: failed to acquire I2C bus\n", __func__); 175 return error; 176 } 177 178 if ((error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, 179 sc->sc_addr + reg, NULL, 0, buf, len, 0)) != 0) { 180 iic_release_bus(sc->sc_tag, 0); 181 aprint_error_dev(sc->sc_dev, 182 "%s: failed to read reg%d\n", __func__, reg); 183 return error; 184 } 185 186 iic_release_bus(sc->sc_tag, 0); 187 188 /* this chip returns each byte in reverse order */ 189 for (i = 0; i < len; i++) 190 buf[i] = bitreverse(buf[i]); 191 192 return 0; 193 } 194 195 static int 196 s390rtc_write(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 197 { 198 int i, error; 199 200 if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) { 201 aprint_error_dev(sc->sc_dev, 202 "%s: failed to acquire I2C bus\n", __func__); 203 return error; 204 } 205 206 /* this chip expects each byte in reverse order */ 207 for (i = 0; i < len; i++) 208 buf[i] = bitreverse(buf[i]); 209 210 if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, 211 sc->sc_addr + reg, NULL, 0, buf, len, 0)) != 0) { 212 iic_release_bus(sc->sc_tag, 0); 213 aprint_error_dev(sc->sc_dev, 214 "%s: failed to write reg%d\n", __func__, reg); 215 return error; 216 } 217 218 iic_release_bus(sc->sc_tag, 0); 219 return 0; 220 } 221 222 static uint8_t 223 bitreverse(uint8_t x) 224 { 225 static unsigned char nibbletab[16] = { 226 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 227 }; 228 229 return (nibbletab[x & 15] << 4) | nibbletab[x >> 4]; 230 } 231
Indexes created Wed Sep 24 02:09:48 GMT 2025