LXR linux/arch/powerpc/platforms/chrp/time.c

   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
  30extern spinlock_t rtc_lock;
  31
  32#define NVRAM_AS0  0x74
  33#define NVRAM_AS1  0x75
  34#define NVRAM_DATA 0x77
  35
  36static int nvram_as1 = NVRAM_AS1;
  37static int nvram_as0 = NVRAM_AS0;
  38static int nvram_data = NVRAM_DATA;
  39
  40long __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
  65int 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
  73void 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 */
  85int 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
 129void 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