1 /* $NetBSD: mm58167.c,v 1.14 2009/12/12 16:12:05 tsutsui Exp $ */ 2 3 /* 4 * Copyright (c) 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matthew Fredette. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * National Semiconductor MM58167 time-of-day chip subroutines. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: mm58167.c,v 1.14 2009/12/12 16:12:05 tsutsui Exp $"); 38 39 #include <sys/param.h> 40 #include <sys/malloc.h> 41 #include <sys/systm.h> 42 #include <sys/errno.h> 43 #include <sys/device.h> 44 45 #include <sys/bus.h> 46 #include <dev/clock_subr.h> 47 #include <dev/ic/mm58167var.h> 48 49 static int mm58167_gettime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *); 50 static int mm58167_settime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *); 51 52 /* 53 * To quote SunOS's todreg.h: 54 * "This brain damaged chip insists on keeping the time in 55 * MM/DD HH:MM:SS format, even though it doesn't know about 56 * leap years and Feb. 29, thus making it nearly worthless." 57 */ 58 #define mm58167_read(sc, r) \ 59 bus_space_read_1(sc->mm58167_regt, sc->mm58167_regh, sc-> r) 60 #define mm58167_write(sc, r, v) \ 61 bus_space_write_1(sc->mm58167_regt, sc->mm58167_regh, sc-> r, v) 62 63 todr_chip_handle_t 64 mm58167_attach(struct mm58167_softc *sc) 65 { 66 struct todr_chip_handle *handle; 67 68 aprint_normal(": mm58167"); 69 70 handle = &sc->_mm58167_todr_handle; 71 memset(handle, 0, sizeof(handle)); 72 handle->cookie = sc; 73 handle->todr_gettime_ymdhms = mm58167_gettime_ymdhms; 74 handle->todr_settime_ymdhms = mm58167_settime_ymdhms; 75 return handle; 76 } 77 78 /* 79 * Set up the system's time, given a `reasonable' time value. 80 */ 81 int 82 mm58167_gettime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt) 83 { 84 struct mm58167_softc *sc = handle->cookie; 85 struct clock_ymdhms dt_reasonable; 86 struct timeval now; 87 int s; 88 uint8_t byte_value; 89 int leap_year, had_leap_day; 90 91 /* First, read the date out of the chip. */ 92 93 /* No interrupts while we're in the chip. */ 94 s = splhigh(); 95 96 /* Reset the status bit: */ 97 byte_value = mm58167_read(sc, mm58167_status); 98 99 /* 100 * Read the date values until we get a coherent read (one 101 * where the status stays zero, indicating no increment was 102 * rippling through while we were reading). 103 */ 104 do { 105 #define _MM58167_GET(dt_f, mm_f) \ 106 byte_value = mm58167_read(sc, mm_f); \ 107 dt->dt_f = FROMBCD(byte_value) 108 109 _MM58167_GET(dt_mon, mm58167_mon); 110 _MM58167_GET(dt_day, mm58167_day); 111 _MM58167_GET(dt_hour, mm58167_hour); 112 _MM58167_GET(dt_min, mm58167_min); 113 _MM58167_GET(dt_sec, mm58167_sec); 114 #undef _MM58167_GET 115 } while ((mm58167_read(sc, mm58167_status) & 1) == 0); 116 117 splx(s); 118 119 /* Convert the reasonable time into a date: */ 120 getmicrotime(&now); 121 clock_secs_to_ymdhms(now.tv_sec, &dt_reasonable); 122 if (dt_reasonable.dt_year == POSIX_BASE_YEAR) { 123 /* 124 * Not a reasonable year. 125 * Assume called from inittodr(9) on boot and 126 * use file system time set in inittodr(9). 127 */ 128 clock_secs_to_ymdhms(handle->base_time, &dt_reasonable); 129 } 130 131 /* 132 * We need to fake a hardware year. if the hardware MM/DD 133 * HH:MM:SS date is less than the reasonable MM/DD 134 * HH:MM:SS, call it the reasonable year plus one, else call 135 * it the reasonable year. 136 */ 137 if (dt->dt_mon < dt_reasonable.dt_mon || 138 (dt->dt_mon == dt_reasonable.dt_mon && 139 (dt->dt_day < dt_reasonable.dt_day || 140 (dt->dt_day == dt_reasonable.dt_day && 141 (dt->dt_hour < dt_reasonable.dt_hour || 142 (dt->dt_hour == dt_reasonable.dt_hour && 143 (dt->dt_min < dt_reasonable.dt_min || 144 (dt->dt_min == dt_reasonable.dt_min && 145 (dt->dt_sec < dt_reasonable.dt_sec))))))))) { 146 dt->dt_year = dt_reasonable.dt_year + 1; 147 } else { 148 dt->dt_year = dt_reasonable.dt_year; 149 } 150 151 /* 152 * Make a reasonable effort to see if a leap day has passed 153 * that we need to account for. This does the right thing 154 * only when the system was shut down before a leap day, and 155 * it is now after that leap day. It doesn't do the right 156 * thing when a leap day happened while the machine was last 157 * up. When that happens, the hardware clock becomes 158 * instantly wrong forever, until it gets fixed for some 159 * reason. Use NTP to deal. 160 */ 161 162 /* 163 * This may have happened if the hardware says we're into 164 * March in the following year. Check that following year for 165 * a leap day. 166 */ 167 if (dt->dt_year > dt_reasonable.dt_year && 168 dt->dt_mon >= 3) { 169 leap_year = dt->dt_year; 170 } 171 172 /* 173 * This may have happened if the hardware says we're in the 174 * following year, and the system was shut down before March 175 * the previous year. check that previous year for a leap 176 * day. 177 */ 178 else if (dt->dt_year > dt_reasonable.dt_year && 179 dt_reasonable.dt_mon < 3) { 180 leap_year = dt_reasonable.dt_year; 181 } 182 183 /* 184 * This may have happened if the hardware says we're in the 185 * same year, but we weren't to March before, and we're in or 186 * past March now. Check this year for a leap day. 187 */ 188 else if (dt->dt_year == dt_reasonable.dt_year 189 && dt_reasonable.dt_mon < 3 190 && dt->dt_mon >= 3) { 191 leap_year = dt_reasonable.dt_year; 192 } 193 194 /* 195 * Otherwise, no leap year to check. 196 */ 197 else { 198 leap_year = 0; 199 } 200 201 /* Do the real leap day check. */ 202 had_leap_day = 0; 203 if (leap_year > 0) { 204 if ((leap_year & 3) == 0) { 205 had_leap_day = 1; 206 if ((leap_year % 100) == 0) { 207 had_leap_day = 0; 208 if ((leap_year % 400) == 0) 209 had_leap_day = 1; 210 } 211 } 212 } 213 214 /* 215 * If we had a leap day, adjust the value we will return, and 216 * also update the hardware clock. 217 */ 218 /* 219 * XXX - Since this update just writes back a corrected 220 * version of what we read out above, we lose whatever 221 * amount of time the clock has advanced since that read. 222 * Use NTP to deal. 223 */ 224 if (had_leap_day) { 225 mm58167_settime_ymdhms(handle, dt); 226 } 227 228 return 0; 229 } 230 231 int 232 mm58167_settime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt) 233 { 234 struct mm58167_softc *sc = handle->cookie; 235 int s; 236 uint8_t byte_value; 237 238 /* No interrupts while we're in the chip. */ 239 s = splhigh(); 240 241 /* 242 * Issue a GO command to reset everything less significant 243 * than the minutes to zero. 244 */ 245 mm58167_write(sc, mm58167_go, 0xFF); 246 247 /* Load everything. */ 248 #define _MM58167_PUT(dt_f, mm_f) \ 249 byte_value = TOBCD(dt->dt_f); \ 250 mm58167_write(sc, mm_f, byte_value) 251 252 _MM58167_PUT(dt_mon, mm58167_mon); 253 _MM58167_PUT(dt_day, mm58167_day); 254 _MM58167_PUT(dt_hour, mm58167_hour); 255 _MM58167_PUT(dt_min, mm58167_min); 256 _MM58167_PUT(dt_sec, mm58167_sec); 257 #undef _MM58167_PUT 258 259 splx(s); 260 return 0; 261 } 262