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/system.h> 31 #include <asm/io.h> 32 #include <asm/pgtable.h> 33 #include <asm/machdep.h> 34 #include <asm/time.h> 35 36 #include "maple.h" 37 38 #ifdef DEBUG 39 #define DBG(x...) printk(x) 40 #else 41 #define DBG(x...) 42 #endif 43 44 extern void GregorianDay(struct rtc_time * tm); 45 46 static int maple_rtc_addr; 47 48 static int maple_clock_read(int addr) 49 { 50 outb_p(addr, maple_rtc_addr); 51 return inb_p(maple_rtc_addr+1); 52 } 53 54 static void maple_clock_write(unsigned long val, int addr) 55 { 56 outb_p(addr, maple_rtc_addr); 57 outb_p(val, maple_rtc_addr+1); 58 } 59 60 void maple_get_rtc_time(struct rtc_time *tm) 61 { 62 do { 63 tm->tm_sec = maple_clock_read(RTC_SECONDS); 64 tm->tm_min = maple_clock_read(RTC_MINUTES); 65 tm->tm_hour = maple_clock_read(RTC_HOURS); 66 tm->tm_mday = maple_clock_read(RTC_DAY_OF_MONTH); 67 tm->tm_mon = maple_clock_read(RTC_MONTH); 68 tm->tm_year = maple_clock_read(RTC_YEAR); 69 } while (tm->tm_sec != maple_clock_read(RTC_SECONDS)); 70 71 if (!(maple_clock_read(RTC_CONTROL) & RTC_DM_BINARY) 72 || RTC_ALWAYS_BCD) { 73 BCD_TO_BIN(tm->tm_sec); 74 BCD_TO_BIN(tm->tm_min); 75 BCD_TO_BIN(tm->tm_hour); 76 BCD_TO_BIN(tm->tm_mday); 77 BCD_TO_BIN(tm->tm_mon); 78 BCD_TO_BIN(tm->tm_year); 79 } 80 if ((tm->tm_year + 1900) < 1970) 81 tm->tm_year += 100; 82 83 GregorianDay(tm); 84 } 85 86 int maple_set_rtc_time(struct rtc_time *tm) 87 { 88 unsigned char save_control, save_freq_select; 89 int sec, min, hour, mon, mday, year; 90 91 spin_lock(&rtc_lock); 92 93 save_control = maple_clock_read(RTC_CONTROL); /* tell the clock it's being set */ 94 95 maple_clock_write((save_control|RTC_SET), RTC_CONTROL); 96 97 save_freq_select = maple_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */ 98 99 maple_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); 100 101 sec = tm->tm_sec; 102 min = tm->tm_min; 103 hour = tm->tm_hour; 104 mon = tm->tm_mon; 105 mday = tm->tm_mday; 106 year = tm->tm_year; 107 108 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { 109 BIN_TO_BCD(sec); 110 BIN_TO_BCD(min); 111 BIN_TO_BCD(hour); 112 BIN_TO_BCD(mon); 113 BIN_TO_BCD(mday); 114 BIN_TO_BCD(year); 115 } 116 maple_clock_write(sec, RTC_SECONDS); 117 maple_clock_write(min, RTC_MINUTES); 118 maple_clock_write(hour, RTC_HOURS); 119 maple_clock_write(mon, RTC_MONTH); 120 maple_clock_write(mday, RTC_DAY_OF_MONTH); 121 maple_clock_write(year, RTC_YEAR); 122 123 /* The following flags have to be released exactly in this order, 124 * otherwise the DS12887 (popular MC146818A clone with integrated 125 * battery and quartz) will not reset the oscillator and will not 126 * update precisely 500 ms later. You won't find this mentioned in 127 * the Dallas Semiconductor data sheets, but who believes data 128 * sheets anyway ... -- Markus Kuhn 129 */ 130 maple_clock_write(save_control, RTC_CONTROL); 131 maple_clock_write(save_freq_select, RTC_FREQ_SELECT); 132 133 spin_unlock(&rtc_lock); 134 135 return 0; 136 } 137 138 static struct resource rtc_iores = { 139 .name = "rtc", 140 .flags = IORESOURCE_BUSY, 141 }; 142 143 unsigned long __init maple_get_boot_time(void) 144 { 145 struct rtc_time tm; 146 struct device_node *rtcs; 147 148 rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00"); 149 if (rtcs) { 150 struct resource r; 151 if (of_address_to_resource(rtcs, 0, &r)) { 152 printk(KERN_EMERG "Maple: Unable to translate RTC" 153 " address\n"); 154 goto bail; 155 } 156 if (!(r.flags & IORESOURCE_IO)) { 157 printk(KERN_EMERG "Maple: RTC address isn't PIO!\n"); 158 goto bail; 159 } 160 maple_rtc_addr = r.start; 161 printk(KERN_INFO "Maple: Found RTC at IO 0x%x\n", 162 maple_rtc_addr); 163 } 164 bail: 165 if (maple_rtc_addr == 0) { 166 maple_rtc_addr = RTC_PORT(0); /* legacy address */ 167 printk(KERN_INFO "Maple: No device node for RTC, assuming " 168 "legacy address (0x%x)\n", maple_rtc_addr); 169 } 170 171 rtc_iores.start = maple_rtc_addr; 172 rtc_iores.end = maple_rtc_addr + 7; 173 request_resource(&ioport_resource, &rtc_iores); 174 175 maple_get_rtc_time(&tm); 176 return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, 177 tm.tm_hour, tm.tm_min, tm.tm_sec); 178 } 179 180