1 /* 2 * Copyright (C) 1991, 1992, 1995 Linus Torvalds 3 * 4 * Adapted for PowerPC (PReP) by Gary Thomas 5 * Modified by Cort Dougan (cort@cs.nmt.edu). 6 * Copied and modified from arch/i386/kernel/time.c 7 * 8 */ 9 #include <linux/errno.h> 10 #include <linux/sched.h> 11 #include <linux/kernel.h> 12 #include <linux/param.h> 13 #include <linux/string.h> 14 #include <linux/mm.h> 15 #include <linux/interrupt.h> 16 #include <linux/time.h> 17 #include <linux/timex.h> 18 #include <linux/kernel_stat.h> 19 #include <linux/mc146818rtc.h> 20 #include <linux/init.h> 21 #include <linux/bcd.h> 22 #include <linux/ioport.h> 23 24 #include <asm/io.h> 25 #include <asm/nvram.h> 26 #include <asm/prom.h> 27 #include <asm/sections.h> 28 #include <asm/time.h> 29 30 extern spinlock_t rtc_lock; 31 32 static int nvram_as1 = NVRAM_AS1; 33 static int nvram_as0 = NVRAM_AS0; 34 static int nvram_data = NVRAM_DATA; 35 36 long __init chrp_time_init(void) 37 { 38 struct device_node *rtcs; 39 struct resource r; 40 int base; 41 42 rtcs = find_compatible_devices("rtc", "pnpPNP,b00"); 43 if (rtcs == NULL) 44 rtcs = find_compatible_devices("rtc", "ds1385-rtc"); 45 if (rtcs == NULL || of_address_to_resource(rtcs, 0, &r)) 46 return 0; 47 48 base = r.start; 49 nvram_as1 = 0; 50 nvram_as0 = base; 51 nvram_data = base + 1; 52 53 return 0; 54 } 55 56 int chrp_cmos_clock_read(int addr) 57 { 58 if (nvram_as1 != 0) 59 outb(addr>>8, nvram_as1); 60 outb(addr, nvram_as0); 61 return (inb(nvram_data)); 62 } 63 64 void chrp_cmos_clock_write(unsigned long val, int addr) 65 { 66 if (nvram_as1 != 0) 67 outb(addr>>8, nvram_as1); 68 outb(addr, nvram_as0); 69 outb(val, nvram_data); 70 return; 71 } 72 73 /* 74 * Set the hardware clock. -- Cort 75 */ 76 int chrp_set_rtc_time(struct rtc_time *tmarg) 77 { 78 unsigned char save_control, save_freq_select; 79 struct rtc_time tm = *tmarg; 80 81 spin_lock(&rtc_lock); 82 83 save_control = chrp_cmos_clock_read(RTC_CONTROL); /* tell the clock it's being set */ 84 85 chrp_cmos_clock_write((save_control|RTC_SET), RTC_CONTROL); 86 87 save_freq_select = chrp_cmos_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */ 88 89 chrp_cmos_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); 90 91 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { 92 BIN_TO_BCD(tm.tm_sec); 93 BIN_TO_BCD(tm.tm_min); 94 BIN_TO_BCD(tm.tm_hour); 95 BIN_TO_BCD(tm.tm_mon); 96 BIN_TO_BCD(tm.tm_mday); 97 BIN_TO_BCD(tm.tm_year); 98 } 99 chrp_cmos_clock_write(tm.tm_sec,RTC_SECONDS); 100 chrp_cmos_clock_write(tm.tm_min,RTC_MINUTES); 101 chrp_cmos_clock_write(tm.tm_hour,RTC_HOURS); 102 chrp_cmos_clock_write(tm.tm_mon,RTC_MONTH); 103 chrp_cmos_clock_write(tm.tm_mday,RTC_DAY_OF_MONTH); 104 chrp_cmos_clock_write(tm.tm_year,RTC_YEAR); 105 106 /* The following flags have to be released exactly in this order, 107 * otherwise the DS12887 (popular MC146818A clone with integrated 108 * battery and quartz) will not reset the oscillator and will not 109 * update precisely 500 ms later. You won't find this mentioned in 110 * the Dallas Semiconductor data sheets, but who believes data 111 * sheets anyway ... -- Markus Kuhn 112 */ 113 chrp_cmos_clock_write(save_control, RTC_CONTROL); 114 chrp_cmos_clock_write(save_freq_select, RTC_FREQ_SELECT); 115 116 spin_unlock(&rtc_lock); 117 return 0; 118 } 119 120 void chrp_get_rtc_time(struct rtc_time *tm) 121 { 122 unsigned int year, mon, day, hour, min, sec; 123 124 do { 125 sec = chrp_cmos_clock_read(RTC_SECONDS); 126 min = chrp_cmos_clock_read(RTC_MINUTES); 127 hour = chrp_cmos_clock_read(RTC_HOURS); 128 day = chrp_cmos_clock_read(RTC_DAY_OF_MONTH); 129 mon = chrp_cmos_clock_read(RTC_MONTH); 130 year = chrp_cmos_clock_read(RTC_YEAR); 131 } while (sec != chrp_cmos_clock_read(RTC_SECONDS)); 132 133 if (!(chrp_cmos_clock_read(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { 134 BCD_TO_BIN(sec); 135 BCD_TO_BIN(min); 136 BCD_TO_BIN(hour); 137 BCD_TO_BIN(day); 138 BCD_TO_BIN(mon); 139 BCD_TO_BIN(year); 140 } 141 if (year < 70) 142 year += 100; 143 tm->tm_sec = sec; 144 tm->tm_min = min; 145 tm->tm_hour = hour; 146 tm->tm_mday = day; 147 tm->tm_mon = mon; 148 tm->tm_year = year; 149 } 150