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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 | /* * linux/arch/i386/kernel/time.c * * Copyright (C) 1991, 1992, 1995 Linus Torvalds * * Adapted for PowerPC (PreP) by Gary Thomas * Modified by Cort Dougan (cort@cs.nmt.edu) * copied and modified from intel version * */ #include <linux/errno.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/param.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/interrupt.h> #include <linux/timex.h> #include <linux/kernel_stat.h> #include <linux/init.h> #include <asm/init.h> #include <asm/segment.h> #include <asm/io.h> #include <asm/processor.h> #include <asm/machdep.h> #include <asm/prep_nvram.h> #include <asm/mk48t59.h> #include "time.h" /* * The motorola uses the m48t18 rtc (includes DS1643) whose registers * are at a higher end of nvram (1ff8-1fff) than the ibm mc146818 * rtc (ds1386) which has regs at addr 0-d). The intel gets * past this because the bios emulates the mc146818. * * Why in the world did they have to use different clocks? * * Right now things are hacked to check which machine we're on then * use the appropriate macro. This is very very ugly and I should * probably have a function that checks which machine we're on then * does things correctly transparently or a function pointer which * is setup at boot time to use the correct addresses. * -- Cort */ /* * Set the hardware clock. -- Cort */ __prep int mc146818_set_rtc_time(unsigned long nowtime) { unsigned char save_control, save_freq_select; struct rtc_time tm; to_tm(nowtime, &tm); /* tell the clock it's being set */ save_control = CMOS_READ(RTC_CONTROL); CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); /* stop and reset prescaler */ save_freq_select = CMOS_READ(RTC_FREQ_SELECT); CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); tm.tm_year = (tm.tm_year - 1900) % 100; if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { BIN_TO_BCD(tm.tm_sec); BIN_TO_BCD(tm.tm_min); BIN_TO_BCD(tm.tm_hour); BIN_TO_BCD(tm.tm_mon); BIN_TO_BCD(tm.tm_mday); BIN_TO_BCD(tm.tm_year); } CMOS_WRITE(tm.tm_sec, RTC_SECONDS); CMOS_WRITE(tm.tm_min, RTC_MINUTES); CMOS_WRITE(tm.tm_hour, RTC_HOURS); CMOS_WRITE(tm.tm_mon, RTC_MONTH); CMOS_WRITE(tm.tm_mday, RTC_DAY_OF_MONTH); CMOS_WRITE(tm.tm_year, RTC_YEAR); /* The following flags have to be released exactly in this order, * otherwise the DS12887 (popular MC146818A clone with integrated * battery and quartz) will not reset the oscillator and will not * update precisely 500 ms later. You won't find this mentioned in * the Dallas Semiconductor data sheets, but who believes data * sheets anyway ... -- Markus Kuhn */ CMOS_WRITE(save_control, RTC_CONTROL); CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); return 0; } __prep unsigned long mc146818_get_rtc_time(void) { unsigned int year, mon, day, hour, min, sec; int i; /* The Linux interpretation of the CMOS clock register contents: * When the Update-In-Progress (UIP) flag goes from 1 to 0, the * RTC registers show the second which has precisely just started. * Let's hope other operating systems interpret the RTC the same way. */ /* read RTC exactly on falling edge of update flag */ for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */ if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) break; for (i = 0 ; i < 1000000 ; i++) /* must try at least 2.228 ms */ if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)) break; do { /* Isn't this overkill ? UIP above should guarantee consistency */ sec = CMOS_READ(RTC_SECONDS); min = CMOS_READ(RTC_MINUTES); hour = CMOS_READ(RTC_HOURS); day = CMOS_READ(RTC_DAY_OF_MONTH); mon = CMOS_READ(RTC_MONTH); year = CMOS_READ(RTC_YEAR); } while (sec != CMOS_READ(RTC_SECONDS)); if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { BCD_TO_BIN(sec); BCD_TO_BIN(min); BCD_TO_BIN(hour); BCD_TO_BIN(day); BCD_TO_BIN(mon); BCD_TO_BIN(year); } if ((year += 1900) < 1970) year += 100; return mktime(year, mon, day, hour, min, sec); } __prep int mk48t59_set_rtc_time(unsigned long nowtime) { unsigned char save_control; struct rtc_time tm; to_tm(nowtime, &tm); /* tell the clock it's being written */ save_control = ppc_md.nvram_read_val(MK48T59_RTC_CONTROLA); ppc_md.nvram_write_val(MK48T59_RTC_CONTROLA, (save_control | MK48T59_RTC_CA_WRITE)); tm.tm_year = (tm.tm_year - 1900) % 100; BIN_TO_BCD(tm.tm_sec); BIN_TO_BCD(tm.tm_min); BIN_TO_BCD(tm.tm_hour); BIN_TO_BCD(tm.tm_mon); BIN_TO_BCD(tm.tm_mday); BIN_TO_BCD(tm.tm_year); ppc_md.nvram_write_val(MK48T59_RTC_SECONDS, tm.tm_sec); ppc_md.nvram_write_val(MK48T59_RTC_MINUTES, tm.tm_min); ppc_md.nvram_write_val(MK48T59_RTC_HOURS, tm.tm_hour); ppc_md.nvram_write_val(MK48T59_RTC_MONTH, tm.tm_mon); ppc_md.nvram_write_val(MK48T59_RTC_DAY_OF_MONTH, tm.tm_mday); ppc_md.nvram_write_val(MK48T59_RTC_YEAR, tm.tm_year); /* Turn off the write bit. */ ppc_md.nvram_write_val(MK48T59_RTC_CONTROLA, save_control); return 0; } __prep unsigned long mk48t59_get_rtc_time(void) { unsigned char save_control; unsigned int year, mon, day, hour, min, sec; int i; /* Make sure the time is not stopped. */ save_control = ppc_md.nvram_read_val(MK48T59_RTC_CONTROLB); ppc_md.nvram_write_val(MK48T59_RTC_CONTROLA, (save_control & (~MK48T59_RTC_CB_STOP))); /* Now make sure the read bit is off so the value will change. */ save_control = ppc_md.nvram_read_val(MK48T59_RTC_CONTROLA); save_control &= ~MK48T59_RTC_CA_READ; ppc_md.nvram_write_val(MK48T59_RTC_CONTROLA, save_control); /* Read the seconds value to see when it changes. */ sec = ppc_md.nvram_read_val(MK48T59_RTC_SECONDS); /* Wait until the seconds value changes, then read the value. */ for (i = 0 ; i < 1000000 ; i++) { /* may take up to 1 second... */ if (ppc_md.nvram_read_val(MK48T59_RTC_SECONDS) != sec) { break; } } /* Set the register to read the value. */ ppc_md.nvram_write_val(MK48T59_RTC_CONTROLA, (save_control | MK48T59_RTC_CA_READ)); sec = ppc_md.nvram_read_val(MK48T59_RTC_SECONDS); min = ppc_md.nvram_read_val(MK48T59_RTC_MINUTES); hour = ppc_md.nvram_read_val(MK48T59_RTC_HOURS); day = ppc_md.nvram_read_val(MK48T59_RTC_DAY_OF_MONTH); mon = ppc_md.nvram_read_val(MK48T59_RTC_MONTH); year = ppc_md.nvram_read_val(MK48T59_RTC_YEAR); /* Let the time values change again. */ ppc_md.nvram_write_val(MK48T59_RTC_CONTROLA, save_control); BCD_TO_BIN(sec); BCD_TO_BIN(min); BCD_TO_BIN(hour); BCD_TO_BIN(day); BCD_TO_BIN(mon); BCD_TO_BIN(year); year = year + 1900; if (year < 1970) { year += 100; } return mktime(year, mon, day, hour, min, sec); } |