s390.c revision 1.4
1 /* $NetBSD: s390.c,v 1.4 2018/06/16 21:22:13 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 1.4 2018/06/16 21:22:13 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(struct todr_chip_handle *, struct timeval *); 58 static int s390rtc_settime(struct todr_chip_handle *, struct timeval *); 59 static int s390rtc_clock_read(struct s390rtc_softc *, struct clock_ymdhms *); 60 static int s390rtc_clock_write(struct s390rtc_softc *, 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 = s390rtc_gettime; 115 sc->sc_todr.todr_settime = s390rtc_settime; 116 sc->sc_todr.todr_setwen = NULL; 117 todr_attach(&sc->sc_todr); 118 } 119 120 static int 121 s390rtc_gettime(struct todr_chip_handle *ch, struct timeval *tv) 122 { 123 struct s390rtc_softc *sc = ch->cookie; 124 struct clock_ymdhms dt; 125 126 memset(&dt, 0, sizeof(dt)); 127 128 if (!s390rtc_clock_read(sc, &dt)) 129 return -1; 130 131 tv->tv_sec = clock_ymdhms_to_secs(&dt); 132 tv->tv_usec = 0; 133 134 return 0; 135 } 136 137 static int 138 s390rtc_settime(struct todr_chip_handle *ch, struct timeval *tv) 139 { 140 struct s390rtc_softc *sc = ch->cookie; 141 struct clock_ymdhms dt; 142 143 clock_secs_to_ymdhms(tv->tv_sec, &dt); 144 145 if (!s390rtc_clock_write(sc, &dt)) 146 return -1; 147 148 return 0; 149 } 150 151 static int 152 s390rtc_clock_read(struct s390rtc_softc *sc, struct clock_ymdhms *dt) 153 { 154 uint8_t bcd[S390_RT1_NBYTES]; 155 156 if (!s390rtc_read(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES)) 157 return 0; 158 159 /* 160 * Convert the register values into something useable. 161 */ 162 dt->dt_sec = bcdtobin(bcd[S390_RT1_SECOND]); 163 dt->dt_min = bcdtobin(bcd[S390_RT1_MINUTE]); 164 dt->dt_hour = bcdtobin(bcd[S390_RT1_HOUR] & 0x3f); 165 dt->dt_day = bcdtobin(bcd[S390_RT1_DAY]); 166 dt->dt_mon = bcdtobin(bcd[S390_RT1_MONTH]); 167 dt->dt_year = bcdtobin(bcd[S390_RT1_YEAR]) + 2000; 168 169 return 1; 170 } 171 172 static int 173 s390rtc_clock_write(struct s390rtc_softc *sc, struct clock_ymdhms *dt) 174 { 175 uint8_t bcd[S390_RT1_NBYTES]; 176 177 /* 178 * Convert our time representation into something the S-xx390 179 * can understand. 180 */ 181 bcd[S390_RT1_SECOND] = bintobcd(dt->dt_sec); 182 bcd[S390_RT1_MINUTE] = bintobcd(dt->dt_min); 183 bcd[S390_RT1_HOUR] = bintobcd(dt->dt_hour); 184 bcd[S390_RT1_DAY] = bintobcd(dt->dt_day); 185 bcd[S390_RT1_WDAY] = bintobcd(dt->dt_wday); 186 bcd[S390_RT1_MONTH] = bintobcd(dt->dt_mon); 187 bcd[S390_RT1_YEAR] = bintobcd(dt->dt_year % 100); 188 189 return s390rtc_write(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES); 190 } 191 192 static int 193 s390rtc_read(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 194 { 195 int i; 196 197 if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) { 198 aprint_error_dev(sc->sc_dev, 199 "%s: failed to acquire I2C bus\n", __func__); 200 return 0; 201 } 202 203 if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr + reg, 204 NULL, 0, buf, len, I2C_F_POLL)) { 205 iic_release_bus(sc->sc_tag, I2C_F_POLL); 206 aprint_error_dev(sc->sc_dev, 207 "%s: failed to read reg%d\n", __func__, reg); 208 return 0; 209 } 210 211 iic_release_bus(sc->sc_tag, I2C_F_POLL); 212 213 /* this chip returns each byte in reverse order */ 214 for (i = 0; i < len; i++) 215 buf[i] = bitreverse(buf[i]); 216 217 return 1; 218 } 219 220 static int 221 s390rtc_write(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 222 { 223 int i; 224 225 if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) { 226 aprint_error_dev(sc->sc_dev, 227 "%s: failed to acquire I2C bus\n", __func__); 228 return 0; 229 } 230 231 /* this chip expects each byte in reverse order */ 232 for (i = 0; i < len; i++) 233 buf[i] = bitreverse(buf[i]); 234 235 if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr + reg, 236 NULL, 0, buf, len, I2C_F_POLL)) { 237 iic_release_bus(sc->sc_tag, I2C_F_POLL); 238 aprint_error_dev(sc->sc_dev, 239 "%s: failed to write reg%d\n", __func__, reg); 240 return 0; 241 } 242 243 iic_release_bus(sc->sc_tag, I2C_F_POLL); 244 return 1; 245 } 246 247 static uint8_t 248 bitreverse(uint8_t x) 249 { 250 static unsigned char nibbletab[16] = { 251 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 252 }; 253 254 return (nibbletab[x & 15] << 4) | nibbletab[x >> 4]; 255 } 256
Indexes created Mon Sep 22 21:09:42 GMT 2025