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
  32static int nvram_as1 = NVRAM_AS1;
  33static int nvram_as0 = NVRAM_AS0;
  34static int nvram_data = NVRAM_DATA;
  35
  36long __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
  61int 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
  69void 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 */
  81int 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
 125void 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