s390.c revision 1.3
1 /* $NetBSD: s390.c,v 1.3 2014/11/20 16:34:26 christos 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 1.3 2014/11/20 16:34:26 christos 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 70 if (ia->ia_name) { 71 /* direct config - check name */ 72 if (strcmp(ia->ia_name, "s390rtc") == 0) 73 return 1; 74 } else { 75 /* indirect config - check typical address */ 76 if (ia->ia_addr == S390_ADDR) 77 return 1; 78 } 79 return 0; 80 } 81 82 static void 83 s390rtc_attach(device_t parent, device_t self, void *arg) 84 { 85 struct s390rtc_softc *sc = device_private(self); 86 struct i2c_attach_args *ia = arg; 87 uint8_t reg[1]; 88 89 aprint_naive(": Real-time Clock\n"); 90 aprint_normal(": Seiko Instruments 35390A Real-time Clock\n"); 91 92 sc->sc_tag = ia->ia_tag; 93 sc->sc_addr = ia->ia_addr; 94 sc->sc_dev = self; 95 96 /* Reset the chip and turn on 24h mode, after power-off or battery. */ 97 if (!s390rtc_read(sc, S390_STATUS1, reg, sizeof(reg))) 98 return; 99 if (reg[0] & (S390_ST1_POC | S390_ST1_BLD)) { 100 reg[0] |= S390_ST1_24H | S390_ST1_RESET; 101 if (!s390rtc_write(sc, S390_STATUS1, reg, sizeof(reg))) 102 return; 103 } 104 105 /* Disable the test mode, when enabled. */ 106 if (!s390rtc_read(sc, S390_STATUS2, reg, sizeof(reg))) 107 return; 108 if ((reg[0] & S390_ST2_TEST)) { 109 reg[0] &= ~S390_ST2_TEST; 110 if (!s390rtc_write(sc, S390_STATUS2, reg, sizeof(reg))) 111 return; 112 } 113 114 sc->sc_todr.cookie = sc; 115 sc->sc_todr.todr_gettime = s390rtc_gettime; 116 sc->sc_todr.todr_settime = s390rtc_settime; 117 sc->sc_todr.todr_setwen = NULL; 118 todr_attach(&sc->sc_todr); 119 } 120 121 static int 122 s390rtc_gettime(struct todr_chip_handle *ch, struct timeval *tv) 123 { 124 struct s390rtc_softc *sc = ch->cookie; 125 struct clock_ymdhms dt; 126 127 memset(&dt, 0, sizeof(dt)); 128 129 if (!s390rtc_clock_read(sc, &dt)) 130 return -1; 131 132 tv->tv_sec = clock_ymdhms_to_secs(&dt); 133 tv->tv_usec = 0; 134 135 return 0; 136 } 137 138 static int 139 s390rtc_settime(struct todr_chip_handle *ch, struct timeval *tv) 140 { 141 struct s390rtc_softc *sc = ch->cookie; 142 struct clock_ymdhms dt; 143 144 clock_secs_to_ymdhms(tv->tv_sec, &dt); 145 146 if (!s390rtc_clock_write(sc, &dt)) 147 return -1; 148 149 return 0; 150 } 151 152 static int 153 s390rtc_clock_read(struct s390rtc_softc *sc, struct clock_ymdhms *dt) 154 { 155 uint8_t bcd[S390_RT1_NBYTES]; 156 157 if (!s390rtc_read(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES)) 158 return 0; 159 160 /* 161 * Convert the register values into something useable. 162 */ 163 dt->dt_sec = bcdtobin(bcd[S390_RT1_SECOND]); 164 dt->dt_min = bcdtobin(bcd[S390_RT1_MINUTE]); 165 dt->dt_hour = bcdtobin(bcd[S390_RT1_HOUR] & 0x3f); 166 dt->dt_day = bcdtobin(bcd[S390_RT1_DAY]); 167 dt->dt_mon = bcdtobin(bcd[S390_RT1_MONTH]); 168 dt->dt_year = bcdtobin(bcd[S390_RT1_YEAR]) + 2000; 169 170 return 1; 171 } 172 173 static int 174 s390rtc_clock_write(struct s390rtc_softc *sc, struct clock_ymdhms *dt) 175 { 176 uint8_t bcd[S390_RT1_NBYTES]; 177 178 /* 179 * Convert our time representation into something the S-xx390 180 * can understand. 181 */ 182 bcd[S390_RT1_SECOND] = bintobcd(dt->dt_sec); 183 bcd[S390_RT1_MINUTE] = bintobcd(dt->dt_min); 184 bcd[S390_RT1_HOUR] = bintobcd(dt->dt_hour); 185 bcd[S390_RT1_DAY] = bintobcd(dt->dt_day); 186 bcd[S390_RT1_WDAY] = bintobcd(dt->dt_wday); 187 bcd[S390_RT1_MONTH] = bintobcd(dt->dt_mon); 188 bcd[S390_RT1_YEAR] = bintobcd(dt->dt_year % 100); 189 190 return s390rtc_write(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES); 191 } 192 193 static int 194 s390rtc_read(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 195 { 196 int i; 197 198 if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) { 199 aprint_error_dev(sc->sc_dev, 200 "%s: failed to acquire I2C bus\n", __func__); 201 return 0; 202 } 203 204 if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr + reg, 205 NULL, 0, buf, len, I2C_F_POLL)) { 206 iic_release_bus(sc->sc_tag, I2C_F_POLL); 207 aprint_error_dev(sc->sc_dev, 208 "%s: failed to read reg%d\n", __func__, reg); 209 return 0; 210 } 211 212 iic_release_bus(sc->sc_tag, I2C_F_POLL); 213 214 /* this chip returns each byte in reverse order */ 215 for (i = 0; i < len; i++) 216 buf[i] = bitreverse(buf[i]); 217 218 return 1; 219 } 220 221 static int 222 s390rtc_write(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 223 { 224 int i; 225 226 if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) { 227 aprint_error_dev(sc->sc_dev, 228 "%s: failed to acquire I2C bus\n", __func__); 229 return 0; 230 } 231 232 /* this chip expects each byte in reverse order */ 233 for (i = 0; i < len; i++) 234 buf[i] = bitreverse(buf[i]); 235 236 if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr + reg, 237 NULL, 0, buf, len, I2C_F_POLL)) { 238 iic_release_bus(sc->sc_tag, I2C_F_POLL); 239 aprint_error_dev(sc->sc_dev, 240 "%s: failed to write reg%d\n", __func__, reg); 241 return 0; 242 } 243 244 iic_release_bus(sc->sc_tag, I2C_F_POLL); 245 return 1; 246 } 247 248 static uint8_t 249 bitreverse(uint8_t x) 250 { 251 static unsigned char nibbletab[16] = { 252 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 253 }; 254 255 return (nibbletab[x & 15] << 4) | nibbletab[x >> 4]; 256 } 257
Indexes created Mon Sep 22 05:09:51 GMT 2025