mm58167.c revision 1.3
1 /* $NetBSD: mm58167.c,v 1.3 2001/11/13 13:14:41 lukem 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * National Semiconductor MM58167 time-of-day chip subroutines. 41 */ 42 43 #include <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: mm58167.c,v 1.3 2001/11/13 13:14:41 lukem Exp $"); 45 46 #include <sys/param.h> 47 #include <sys/malloc.h> 48 #include <sys/systm.h> 49 #include <sys/errno.h> 50 #include <sys/device.h> 51 52 #include <machine/bus.h> 53 #include <dev/clock_subr.h> 54 #include <dev/ic/mm58167var.h> 55 56 int mm58167_gettime __P((todr_chip_handle_t, struct timeval *)); 57 int mm58167_settime __P((todr_chip_handle_t, struct timeval *)); 58 int mm58167_getcal __P((todr_chip_handle_t, int *)); 59 int mm58167_setcal __P((todr_chip_handle_t, int)); 60 61 /* 62 * To quote SunOS's todreg.h: 63 * "This brain damaged chip insists on keeping the time in 64 * MM/DD HH:MM:SS format, even though it doesn't know about 65 * leap years and Feb. 29, thus making it nearly worthless." 66 */ 67 #define mm58167_read(sc, r) bus_space_read_1(sc->mm58167_regt, sc->mm58167_regh, sc-> r) 68 #define mm58167_write(sc, r, v) bus_space_write_1(sc->mm58167_regt, sc->mm58167_regh, sc-> r, v) 69 70 todr_chip_handle_t 71 mm58167_attach(sc) 72 struct mm58167_softc *sc; 73 { 74 struct todr_chip_handle *handle; 75 76 printf(": mm58167"); 77 78 handle = &sc->_mm58167_todr_handle; 79 memset(handle, 0, sizeof(handle)); 80 handle->cookie = sc; 81 handle->todr_gettime = mm58167_gettime; 82 handle->todr_settime = mm58167_settime; 83 handle->todr_getcal = mm58167_getcal; 84 handle->todr_setcal = mm58167_setcal; 85 return (handle); 86 } 87 88 /* 89 * Set up the system's time, given a `reasonable' time value. 90 */ 91 int 92 mm58167_gettime(handle, tv) 93 todr_chip_handle_t handle; 94 struct timeval *tv; 95 { 96 struct mm58167_softc *sc = handle->cookie; 97 struct clock_ymdhms dt_hardware; 98 struct clock_ymdhms dt_reasonable; 99 int s; 100 u_int8_t byte_value; 101 int leap_year, had_leap_day; 102 103 /* First, read the date out of the chip. */ 104 105 /* No interrupts while we're in the chip. */ 106 s = splhigh(); 107 108 /* Reset the status bit: */ 109 byte_value = mm58167_read(sc, mm58167_status); 110 111 /* 112 * Read the date values until we get a coherent read (one 113 * where the status stays zero, indicating no increment was 114 * rippling through while we were reading). 115 */ 116 do { 117 #define _MM58167_GET(dt_f, mm_f) byte_value = mm58167_read(sc, mm_f); dt_hardware.dt_f = FROMBCD(byte_value) 118 _MM58167_GET(dt_mon, mm58167_mon); 119 _MM58167_GET(dt_day, mm58167_day); 120 _MM58167_GET(dt_hour, mm58167_hour); 121 _MM58167_GET(dt_min, mm58167_min); 122 _MM58167_GET(dt_sec, mm58167_sec); 123 #undef _MM58167_GET 124 } while ((mm58167_read(sc, mm58167_status) & 1) == 0); 125 126 splx(s); 127 128 /* Convert the reasonable time into a date: */ 129 clock_secs_to_ymdhms(tv->tv_sec, &dt_reasonable); 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_hardware.dt_mon < dt_reasonable.dt_mon || 138 (dt_hardware.dt_mon == dt_reasonable.dt_mon && 139 (dt_hardware.dt_day < dt_reasonable.dt_day || 140 (dt_hardware.dt_day == dt_reasonable.dt_day && 141 (dt_hardware.dt_hour < dt_reasonable.dt_hour || 142 (dt_hardware.dt_hour == dt_reasonable.dt_hour && 143 (dt_hardware.dt_min < dt_reasonable.dt_min || 144 (dt_hardware.dt_min == dt_reasonable.dt_min && 145 (dt_hardware.dt_sec < dt_reasonable.dt_sec))))))))) { 146 dt_hardware.dt_year = dt_reasonable.dt_year + 1; 147 } else { 148 dt_hardware.dt_year = dt_reasonable.dt_year; 149 } 150 151 /* convert the hardware date into a time: */ 152 tv->tv_sec = clock_ymdhms_to_secs(&dt_hardware); 153 tv->tv_usec = 0; 154 155 /* 156 * Make a reasonable effort to see if a leap day has passed 157 * that we need to account for. This does the right thing 158 * only when the system was shut down before a leap day, and 159 * it is now after that leap day. It doesn't do the right 160 * thing when a leap day happened while the machine was last 161 * up. When that happens, the hardware clock becomes 162 * instantly wrong forever, until it gets fixed for some 163 * reason. Use NTP to deal. 164 */ 165 166 /* 167 * This may have happened if the hardware says we're into 168 * March in the following year. Check that following year for 169 * a leap day. 170 */ 171 if (dt_hardware.dt_year > dt_reasonable.dt_year && 172 dt_hardware.dt_mon >= 3) { 173 leap_year = dt_hardware.dt_year; 174 } 175 176 /* 177 * This may have happened if the hardware says we're in the 178 * following year, and the system was shut down before March 179 * the previous year. check that previous year for a leap 180 * day. 181 */ 182 else if (dt_hardware.dt_year > dt_reasonable.dt_year && 183 dt_reasonable.dt_mon < 3) { 184 leap_year = dt_reasonable.dt_year; 185 } 186 187 /* 188 * This may have happened if the hardware says we're in the 189 * same year, but we weren't to March before, and we're in or 190 * past March now. Check this year for a leap day. 191 */ 192 else if (dt_hardware.dt_year == dt_reasonable.dt_year 193 && dt_reasonable.dt_mon < 3 194 && dt_hardware.dt_mon >= 3) { 195 leap_year = dt_reasonable.dt_year; 196 } 197 198 /* 199 * Otherwise, no leap year to check. 200 */ 201 else { 202 leap_year = 0; 203 } 204 205 /* Do the real leap day check. */ 206 had_leap_day = 0; 207 if (leap_year > 0) { 208 if ((leap_year & 3) == 0) { 209 had_leap_day = 1; 210 if ((leap_year % 100) == 0) { 211 had_leap_day = 0; 212 if ((leap_year % 400) == 0) 213 had_leap_day = 1; 214 } 215 } 216 } 217 218 /* 219 * If we had a leap day, adjust the value we will return, and 220 * also update the hardware clock. 221 */ 222 /* 223 * XXX - Since this update just writes back a corrected 224 * version of what we read out above, we lose whatever 225 * amount of time the clock has advanced since that read. 226 * Use NTP to deal. 227 */ 228 if (had_leap_day) { 229 tv->tv_sec += SECDAY; 230 todr_settime(handle, tv); 231 } 232 233 return (0); 234 } 235 236 int 237 mm58167_settime(handle, tv) 238 todr_chip_handle_t handle; 239 struct timeval *tv; 240 { 241 struct mm58167_softc *sc = handle->cookie; 242 struct clock_ymdhms dt_hardware; 243 int s; 244 u_int8_t byte_value; 245 246 /* Convert the seconds into ymdhms. */ 247 clock_secs_to_ymdhms(tv->tv_sec, &dt_hardware); 248 249 /* No interrupts while we're in the chip. */ 250 s = splhigh(); 251 252 /* 253 * Issue a GO command to reset everything less significant 254 * than the minutes to zero. 255 */ 256 mm58167_write(sc, mm58167_go, 0xFF); 257 258 /* Load everything. */ 259 #define _MM58167_PUT(dt_f, mm_f) byte_value = TOBCD(dt_hardware.dt_f); mm58167_write(sc, mm_f, byte_value) 260 _MM58167_PUT(dt_mon, mm58167_mon); 261 _MM58167_PUT(dt_day, mm58167_day); 262 _MM58167_PUT(dt_hour, mm58167_hour); 263 _MM58167_PUT(dt_min, mm58167_min); 264 _MM58167_PUT(dt_sec, mm58167_sec); 265 #undef _MM58167_PUT 266 267 splx(s); 268 return (0); 269 } 270 271 int 272 mm58167_getcal(handle, vp) 273 todr_chip_handle_t handle; 274 int *vp; 275 { 276 return (EOPNOTSUPP); 277 } 278 279 int 280 mm58167_setcal(handle, v) 281 todr_chip_handle_t handle; 282 int v; 283 { 284 return (EOPNOTSUPP); 285 } 286
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