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