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 #define NVRAM_AS0 0x74 33 #define NVRAM_AS1 0x75 34 #define NVRAM_DATA 0x77 35 36 static int nvram_as1 = NVRAM_AS1; 37 static int nvram_as0 = NVRAM_AS0; 38 static int nvram_data = NVRAM_DATA; 39 40 long __init chrp_time_init(void) 41 { 42 struct device_node *rtcs; 43 struct resource r; 44 int base; 45 46 rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00"); 47 if (rtcs == NULL) 48 rtcs = of_find_compatible_node(NULL, "rtc", "ds1385-rtc"); 49 if (rtcs == NULL) 50 return 0; 51 if (of_address_to_resource(rtcs, 0, &r)) { 52 of_node_put(rtcs); 53 return 0; 54 } 55 of_node_put(rtcs); 56 57 base = r.start; 58 nvram_as1 = 0; 59 nvram_as0 = base; 60 nvram_data = base + 1; 61 62 return 0; 63 } 64 65 int chrp_cmos_clock_read(int addr) 66 { 67 if (nvram_as1 != 0) 68 outb(addr>>8, nvram_as1); 69 outb(addr, nvram_as0); 70 return (inb(nvram_data)); 71 } 72 73 void chrp_cmos_clock_write(unsigned long val, int addr) 74 { 75 if (nvram_as1 != 0) 76 outb(addr>>8, nvram_as1); 77 outb(addr, nvram_as0); 78 outb(val, nvram_data); 79 return; 80 } 81 82 /* 83 * Set the hardware clock. -- Cort 84 */ 85 int chrp_set_rtc_time(struct rtc_time *tmarg) 86 { 87 unsigned char save_control, save_freq_select; 88 struct rtc_time tm = *tmarg; 89 90 spin_lock(&rtc_lock); 91 92 save_control = chrp_cmos_clock_read(RTC_CONTROL); /* tell the clock it's being set */ 93 94 chrp_cmos_clock_write((save_control|RTC_SET), RTC_CONTROL); 95 96 save_freq_select = chrp_cmos_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */ 97 98 chrp_cmos_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); 99 100 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { 101 tm.tm_sec = bin2bcd(tm.tm_sec); 102 tm.tm_min = bin2bcd(tm.tm_min); 103 tm.tm_hour = bin2bcd(tm.tm_hour); 104 tm.tm_mon = bin2bcd(tm.tm_mon); 105 tm.tm_mday = bin2bcd(tm.tm_mday); 106 tm.tm_year = bin2bcd(tm.tm_year); 107 } 108 chrp_cmos_clock_write(tm.tm_sec,RTC_SECONDS); 109 chrp_cmos_clock_write(tm.tm_min,RTC_MINUTES); 110 chrp_cmos_clock_write(tm.tm_hour,RTC_HOURS); 111 chrp_cmos_clock_write(tm.tm_mon,RTC_MONTH); 112 chrp_cmos_clock_write(tm.tm_mday,RTC_DAY_OF_MONTH); 113 chrp_cmos_clock_write(tm.tm_year,RTC_YEAR); 114 115 /* The following flags have to be released exactly in this order, 116 * otherwise the DS12887 (popular MC146818A clone with integrated 117 * battery and quartz) will not reset the oscillator and will not 118 * update precisely 500 ms later. You won't find this mentioned in 119 * the Dallas Semiconductor data sheets, but who believes data 120 * sheets anyway ... -- Markus Kuhn 121 */ 122 chrp_cmos_clock_write(save_control, RTC_CONTROL); 123 chrp_cmos_clock_write(save_freq_select, RTC_FREQ_SELECT); 124 125 spin_unlock(&rtc_lock); 126 return 0; 127 } 128 129 void chrp_get_rtc_time(struct rtc_time *tm) 130 { 131 unsigned int year, mon, day, hour, min, sec; 132 133 do { 134 sec = chrp_cmos_clock_read(RTC_SECONDS); 135 min = chrp_cmos_clock_read(RTC_MINUTES); 136 hour = chrp_cmos_clock_read(RTC_HOURS); 137 day = chrp_cmos_clock_read(RTC_DAY_OF_MONTH); 138 mon = chrp_cmos_clock_read(RTC_MONTH); 139 year = chrp_cmos_clock_read(RTC_YEAR); 140 } while (sec != chrp_cmos_clock_read(RTC_SECONDS)); 141 142 if (!(chrp_cmos_clock_read(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { 143 sec = bcd2bin(sec); 144 min = bcd2bin(min); 145 hour = bcd2bin(hour); 146 day = bcd2bin(day); 147 mon = bcd2bin(mon); 148 year = bcd2bin(year); 149 } 150 if (year < 70) 151 year += 100; 152 tm->tm_sec = sec; 153 tm->tm_min = min; 154 tm->tm_hour = hour; 155 tm->tm_mday = day; 156 tm->tm_mon = mon; 157 tm->tm_year = year; 158 } 159