LXR linux-bk/arch/ppc64/kernel/pmac

   1/*
   2 * Support for periodic interrupts (100 per second) and for getting
   3 * the current time from the RTC on Power Macintoshes.
   4 *
   5 * We use the decrementer register for our periodic interrupts.
   6 *
   7 * Paul Mackerras       August 1996.
   8 * Copyright (C) 1996 Paul Mackerras.
   9 */
  10#include <linux/config.h>
  11#include <linux/errno.h>
  12#include <linux/sched.h>
  13#include <linux/kernel.h>
  14#include <linux/param.h>
  15#include <linux/string.h>
  16#include <linux/mm.h>
  17#include <linux/init.h>
  18#include <linux/time.h>
  19#include <linux/adb.h>
  20#include <linux/pmu.h>
  21
  22#include <asm/sections.h>
  23#include <asm/prom.h>
  24#include <asm/system.h>
  25#include <asm/io.h>
  26#include <asm/pgtable.h>
  27#include <asm/machdep.h>
  28#include <asm/hardirq.h>
  29#include <asm/time.h>
  30#include <asm/nvram.h>
  31
  32#undef DEBUG
  33
  34#ifdef DEBUG
  35#define DBG(x...) printk(x)
  36#else
  37#define DBG(x...)
  38#endif
  39
  40extern void setup_default_decr(void);
  41
  42extern unsigned long ppc_tb_freq;
  43extern unsigned long ppc_proc_freq;
  44
  45/* Apparently the RTC stores seconds since 1 Jan 1904 */
  46#define RTC_OFFSET      2082844800
  47
  48/*
  49 * Calibrate the decrementer frequency with the VIA timer 1.
  50 */
  51#define VIA_TIMER_FREQ_6        4700000 /* time 1 frequency * 6 */
  52
  53extern struct timezone sys_tz;
  54extern void to_tm(int tim, struct rtc_time * tm);
  55
  56void __pmac pmac_get_rtc_time(struct rtc_time *tm)
  57{
  58        struct adb_request req;
  59        unsigned int now;
  60
  61        /* Get the time from the RTC */
  62        if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
  63                return;
  64        while (!req.complete)
  65                pmu_poll();
  66        if (req.reply_len != 4)
  67                printk(KERN_ERR "pmac_get_rtc_time: got %d byte reply\n",
  68                       req.reply_len);
  69        now = (req.reply[0] << 24) + (req.reply[1] << 16)
  70                + (req.reply[2] << 8) + req.reply[3];
  71        DBG("get: %u -> %u\n", (int)now, (int)(now - RTC_OFFSET));
  72        now -= RTC_OFFSET;
  73
  74        to_tm(now, tm);
  75        tm->tm_year -= 1900;
  76        tm->tm_mon -= 1;
  77        
  78        DBG("-> tm_mday: %d, tm_mon: %d, tm_year: %d, %d:%02d:%02d\n",
  79               tm->tm_mday, tm->tm_mon, tm->tm_year,
  80               tm->tm_hour, tm->tm_min, tm->tm_sec);
  81}
  82
  83int __pmac pmac_set_rtc_time(struct rtc_time *tm)
  84{
  85        struct adb_request req;
  86        unsigned int nowtime;
  87
  88        DBG("set: tm_mday: %d, tm_mon: %d, tm_year: %d, %d:%02d:%02d\n",
  89               tm->tm_mday, tm->tm_mon, tm->tm_year,
  90               tm->tm_hour, tm->tm_min, tm->tm_sec);
  91
  92        nowtime = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
  93                         tm->tm_hour, tm->tm_min, tm->tm_sec);
  94        DBG("-> %u -> %u\n", (int)nowtime, (int)(nowtime + RTC_OFFSET));
  95        nowtime += RTC_OFFSET;
  96
  97        if (pmu_request(&req, NULL, 5, PMU_SET_RTC,
  98                        nowtime >> 24, nowtime >> 16, nowtime >> 8, nowtime) < 0)
  99                return 0;
 100        while (!req.complete)
 101                pmu_poll();
 102        if (req.reply_len != 0)
 103                printk(KERN_ERR "pmac_set_rtc_time: got %d byte reply\n",
 104                       req.reply_len);
 105        return 1;
 106}
 107
 108void __init pmac_get_boot_time(struct rtc_time *tm)
 109{
 110        pmac_get_rtc_time(tm);
 111
 112#ifdef disabled__CONFIG_NVRAM
 113        s32 delta = 0;
 114        int dst;
 115        
 116        delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
 117        delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
 118        delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
 119        if (delta & 0x00800000UL)
 120                delta |= 0xFF000000UL;
 121        dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
 122        printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
 123                dst ? "on" : "off");
 124#endif
 125}
 126
 127/*
 128 * Query the OF and get the decr frequency.
 129 * This was taken from the pmac time_init() when merging the prep/pmac
 130 * time functions.
 131 */
 132void __init pmac_calibrate_decr(void)
 133{
 134        struct device_node *cpu;
 135        unsigned int freq, *fp;
 136        struct div_result divres;
 137
 138        /*
 139         * The cpu node should have a timebase-frequency property
 140         * to tell us the rate at which the decrementer counts.
 141         */
 142        cpu = find_type_devices("cpu");
 143        if (cpu == 0)
 144                panic("can't find cpu node in time_init");
 145        fp = (unsigned int *) get_property(cpu, "timebase-frequency", NULL);
 146        if (fp == 0)
 147                panic("can't get cpu timebase frequency");
 148        freq = *fp;
 149        printk("time_init: decrementer frequency = %u.%.6u MHz\n",
 150               freq/1000000, freq%1000000);
 151        tb_ticks_per_jiffy = freq / HZ;
 152        tb_ticks_per_sec = tb_ticks_per_jiffy * HZ;
 153        tb_ticks_per_usec = freq / 1000000;
 154        tb_to_us = mulhwu_scale_factor(freq, 1000000);
 155        div128_by_32( 1024*1024, 0, tb_ticks_per_sec, &divres );
 156        tb_to_xs = divres.result_low;
 157        ppc_tb_freq = freq;
 158
 159        fp = (unsigned int *)get_property(cpu, "clock-frequency", NULL);
 160        if (fp == 0)
 161                panic("can't get cpu processor frequency");
 162        ppc_proc_freq = *fp;
 163
 164        setup_default_decr();
 165}
 166
 167