1 /* 2 * (c) Copyright 2004 Benjamin Herrenschmidt (benh@kernel.crashing.org), 3 * IBM Corp. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License 7 * as published by the Free Software Foundation; either version 8 * 2 of the License, or (at your option) any later version. 9 * 10 */ 11 12 #undef DEBUG 13 14 #include <linux/errno.h> 15 #include <linux/sched.h> 16 #include <linux/kernel.h> 17 #include <linux/param.h> 18 #include <linux/string.h> 19 #include <linux/mm.h> 20 #include <linux/init.h> 21 #include <linux/time.h> 22 #include <linux/adb.h> 23 #include <linux/pmu.h> 24 #include <linux/interrupt.h> 25 #include <linux/mc146818rtc.h> 26 #include <linux/bcd.h> 27 28 #include <asm/sections.h> 29 #include <asm/prom.h> 30 #include <asm/io.h> 31 #include <asm/pgtable.h> 32 #include <asm/machdep.h> 33 #include <asm/time.h> 34 35 #include "maple.h" 36 37 #ifdef DEBUG 38 #define DBG(x...) printk(x) 39 #else 40 #define DBG(x...) 41 #endif 42 43 static int maple_rtc_addr; 44 45 static int maple_clock_read(int addr) 46 { 47 outb_p(addr, maple_rtc_addr); 48 return inb_p(maple_rtc_addr+1); 49 } 50 51 static void maple_clock_write(unsigned long val, int addr) 52 { 53 outb_p(addr, maple_rtc_addr); 54 outb_p(val, maple_rtc_addr+1); 55 } 56 57 void maple_get_rtc_time(struct rtc_time *tm) 58 { 59 do { 60 tm->tm_sec = maple_clock_read(RTC_SECONDS); 61 tm->tm_min = maple_clock_read(RTC_MINUTES); 62 tm->tm_hour = maple_clock_read(RTC_HOURS); 63 tm->tm_mday = maple_clock_read(RTC_DAY_OF_MONTH); 64 tm->tm_mon = maple_clock_read(RTC_MONTH); 65 tm->tm_year = maple_clock_read(RTC_YEAR); 66 } while (tm->tm_sec != maple_clock_read(RTC_SECONDS)); 67 68 if (!(maple_clock_read(RTC_CONTROL) & RTC_DM_BINARY) 69 || RTC_ALWAYS_BCD) { 70 tm->tm_sec = bcd2bin(tm->tm_sec); 71 tm->tm_min = bcd2bin(tm->tm_min); 72 tm->tm_hour = bcd2bin(tm->tm_hour); 73 tm->tm_mday = bcd2bin(tm->tm_mday); 74 tm->tm_mon = bcd2bin(tm->tm_mon); 75 tm->tm_year = bcd2bin(tm->tm_year); 76 } 77 if ((tm->tm_year + 1900) < 1970) 78 tm->tm_year += 100; 79 80 GregorianDay(tm); 81 } 82 83 int maple_set_rtc_time(struct rtc_time *tm) 84 { 85 unsigned char save_control, save_freq_select; 86 int sec, min, hour, mon, mday, year; 87 88 spin_lock(&rtc_lock); 89 90 save_control = maple_clock_read(RTC_CONTROL); /* tell the clock it's being set */ 91 92 maple_clock_write((save_control|RTC_SET), RTC_CONTROL); 93 94 save_freq_select = maple_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */ 95 96 maple_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); 97 98 sec = tm->tm_sec; 99 min = tm->tm_min; 100 hour = tm->tm_hour; 101 mon = tm->tm_mon; 102 mday = tm->tm_mday; 103 year = tm->tm_year; 104 105 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { 106 sec = bin2bcd(sec); 107 min = bin2bcd(min); 108 hour = bin2bcd(hour); 109 mon = bin2bcd(mon); 110 mday = bin2bcd(mday); 111 year = bin2bcd(year); 112 } 113 maple_clock_write(sec, RTC_SECONDS); 114 maple_clock_write(min, RTC_MINUTES); 115 maple_clock_write(hour, RTC_HOURS); 116 maple_clock_write(mon, RTC_MONTH); 117 maple_clock_write(mday, RTC_DAY_OF_MONTH); 118 maple_clock_write(year, RTC_YEAR); 119 120 /* The following flags have to be released exactly in this order, 121 * otherwise the DS12887 (popular MC146818A clone with integrated 122 * battery and quartz) will not reset the oscillator and will not 123 * update precisely 500 ms later. You won't find this mentioned in 124 * the Dallas Semiconductor data sheets, but who believes data 125 * sheets anyway ... -- Markus Kuhn 126 */ 127 maple_clock_write(save_control, RTC_CONTROL); 128 maple_clock_write(save_freq_select, RTC_FREQ_SELECT); 129 130 spin_unlock(&rtc_lock); 131 132 return 0; 133 } 134 135 static struct resource rtc_iores = { 136 .name = "rtc", 137 .flags = IORESOURCE_BUSY, 138 }; 139 140 unsigned long __init maple_get_boot_time(void) 141 { 142 struct rtc_time tm; 143 struct device_node *rtcs; 144 145 rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00"); 146 if (rtcs) { 147 struct resource r; 148 if (of_address_to_resource(rtcs, 0, &r)) { 149 printk(KERN_EMERG "Maple: Unable to translate RTC" 150 " address\n"); 151 goto bail; 152 } 153 if (!(r.flags & IORESOURCE_IO)) { 154 printk(KERN_EMERG "Maple: RTC address isn't PIO!\n"); 155 goto bail; 156 } 157 maple_rtc_addr = r.start; 158 printk(KERN_INFO "Maple: Found RTC at IO 0x%x\n", 159 maple_rtc_addr); 160 } 161 bail: 162 if (maple_rtc_addr == 0) { 163 maple_rtc_addr = RTC_PORT(0); /* legacy address */ 164 printk(KERN_INFO "Maple: No device node for RTC, assuming " 165 "legacy address (0x%x)\n", maple_rtc_addr); 166 } 167 168 rtc_iores.start = maple_rtc_addr; 169 rtc_iores.end = maple_rtc_addr + 7; 170 request_resource(&ioport_resource, &rtc_iores); 171 172 maple_get_rtc_time(&tm); 173 return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, 174 tm.tm_hour, tm.tm_min, tm.tm_sec); 175 } 176 177