s390.c revision 1.1
1 /* $NetBSD: s390.c,v 1.1 2011/04/04 17:58:40 phx 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 1.1 2011/04/04 17:58:40 phx 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_addr == S390_ADDR) 71 return 1; 72 return 0; 73 } 74 75 static void 76 s390rtc_attach(device_t parent, device_t self, void *arg) 77 { 78 struct s390rtc_softc *sc = device_private(self); 79 struct i2c_attach_args *ia = arg; 80 uint8_t reg[1]; 81 82 aprint_naive(": Real-time Clock\n"); 83 aprint_normal(": Seiko Instruments 35390A Real-time Clock\n"); 84 85 sc->sc_tag = ia->ia_tag; 86 sc->sc_addr = ia->ia_addr; 87 sc->sc_dev = self; 88 89 /* Reset the chip and turn on 24h mode, after power-off or battery. */ 90 if (!s390rtc_read(sc, S390_STATUS1, reg, sizeof(reg))) 91 return; 92 if (reg[0] & (S390_ST1_POC | S390_ST1_BLD)) { 93 reg[0] |= S390_ST1_24H | S390_ST1_RESET; 94 if (!s390rtc_write(sc, S390_STATUS1, reg, sizeof(reg))) 95 return; 96 } 97 98 /* Disable the test mode, when enabled. */ 99 if (!s390rtc_read(sc, S390_STATUS2, reg, sizeof(reg))) 100 return; 101 if ((reg[0] & S390_ST2_TEST)) { 102 reg[0] &= ~S390_ST2_TEST; 103 if (!s390rtc_write(sc, S390_STATUS2, reg, sizeof(reg))) 104 return; 105 } 106 107 sc->sc_todr.cookie = sc; 108 sc->sc_todr.todr_gettime = s390rtc_gettime; 109 sc->sc_todr.todr_settime = s390rtc_settime; 110 sc->sc_todr.todr_setwen = NULL; 111 todr_attach(&sc->sc_todr); 112 } 113 114 static int 115 s390rtc_gettime(struct todr_chip_handle *ch, struct timeval *tv) 116 { 117 struct s390rtc_softc *sc = ch->cookie; 118 struct clock_ymdhms dt; 119 120 memset(&dt, 0, sizeof(dt)); 121 122 if (!s390rtc_clock_read(sc, &dt)) 123 return -1; 124 125 tv->tv_sec = clock_ymdhms_to_secs(&dt); 126 tv->tv_usec = 0; 127 128 return 0; 129 } 130 131 static int 132 s390rtc_settime(struct todr_chip_handle *ch, struct timeval *tv) 133 { 134 struct s390rtc_softc *sc = ch->cookie; 135 struct clock_ymdhms dt; 136 137 clock_secs_to_ymdhms(tv->tv_sec, &dt); 138 139 if (!s390rtc_clock_write(sc, &dt)) 140 return -1; 141 142 return 0; 143 } 144 145 static int 146 s390rtc_clock_read(struct s390rtc_softc *sc, struct clock_ymdhms *dt) 147 { 148 uint8_t bcd[S390_RT1_NBYTES]; 149 150 if (!s390rtc_read(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES)) 151 return 0; 152 153 /* 154 * Convert the register values into something useable. 155 */ 156 dt->dt_sec = FROMBCD(bcd[S390_RT1_SECOND]); 157 dt->dt_min = FROMBCD(bcd[S390_RT1_MINUTE]); 158 dt->dt_hour = FROMBCD(bcd[S390_RT1_HOUR] & 0x3f); 159 dt->dt_day = FROMBCD(bcd[S390_RT1_DAY]); 160 dt->dt_mon = FROMBCD(bcd[S390_RT1_MONTH]); 161 dt->dt_year = FROMBCD(bcd[S390_RT1_YEAR]) + 2000; 162 163 return 1; 164 } 165 166 static int 167 s390rtc_clock_write(struct s390rtc_softc *sc, struct clock_ymdhms *dt) 168 { 169 uint8_t bcd[S390_RT1_NBYTES]; 170 171 /* 172 * Convert our time representation into something the S-xx390 173 * can understand. 174 */ 175 bcd[S390_RT1_SECOND] = TOBCD(dt->dt_sec); 176 bcd[S390_RT1_MINUTE] = TOBCD(dt->dt_min); 177 bcd[S390_RT1_HOUR] = TOBCD(dt->dt_hour); 178 bcd[S390_RT1_DAY] = TOBCD(dt->dt_day); 179 bcd[S390_RT1_WDAY] = TOBCD(dt->dt_wday); 180 bcd[S390_RT1_MONTH] = TOBCD(dt->dt_mon); 181 bcd[S390_RT1_YEAR] = TOBCD(dt->dt_year % 100); 182 183 return s390rtc_write(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES); 184 } 185 186 static int 187 s390rtc_read(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 188 { 189 int i; 190 191 if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) { 192 aprint_error_dev(sc->sc_dev, 193 "%s: failed to acquire I2C bus\n", __func__); 194 return 0; 195 } 196 197 if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr + reg, 198 NULL, 0, buf, len, I2C_F_POLL)) { 199 iic_release_bus(sc->sc_tag, I2C_F_POLL); 200 aprint_error_dev(sc->sc_dev, 201 "%s: failed to read reg%d\n", __func__, reg); 202 return 0; 203 } 204 205 iic_release_bus(sc->sc_tag, I2C_F_POLL); 206 207 /* this chip returns each byte in reverse order */ 208 for (i = 0; i < len; i++) 209 buf[i] = bitreverse(buf[i]); 210 211 return 1; 212 } 213 214 static int 215 s390rtc_write(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len) 216 { 217 int i; 218 219 if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) { 220 aprint_error_dev(sc->sc_dev, 221 "%s: failed to acquire I2C bus\n", __func__); 222 return 0; 223 } 224 225 /* this chip expects each byte in reverse order */ 226 for (i = 0; i < len; i++) 227 buf[i] = bitreverse(buf[i]); 228 229 if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr + reg, 230 NULL, 0, buf, len, I2C_F_POLL)) { 231 iic_release_bus(sc->sc_tag, I2C_F_POLL); 232 aprint_error_dev(sc->sc_dev, 233 "%s: failed to write reg%d\n", __func__, reg); 234 return 0; 235 } 236 237 iic_release_bus(sc->sc_tag, I2C_F_POLL); 238 return 1; 239 } 240 241 static uint8_t 242 bitreverse(uint8_t x) 243 { 244 static unsigned char nibbletab[16] = { 245 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 246 }; 247 248 return (nibbletab[x & 15] << 4) | nibbletab[x >> 4]; 249 } 250
Indexes created Tue Sep 23 07:09:52 GMT 2025