arch/ppc64/kernel/pmac_time.c

   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  * Copyright (C) 2003-2005 Benjamin Herrenschmidt.
  10  *
  11  */
  12 #include <linux/config.h>
  13 #include <linux/errno.h>
  14 #include <linux/sched.h>
  15 #include <linux/kernel.h>
  16 #include <linux/param.h>
  17 #include <linux/string.h>
  18 #include <linux/mm.h>
  19 #include <linux/init.h>
  20 #include <linux/time.h>
  21 #include <linux/adb.h>
  22 #include <linux/pmu.h>
  23 #include <linux/interrupt.h>
  24
  25 #include <asm/sections.h>
  26 #include <asm/prom.h>
  27 #include <asm/system.h>
  28 #include <asm/io.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/machdep.h>
  31 #include <asm/time.h>
  32 #include <asm/nvram.h>
  33 #include <asm/smu.h>
  34
  35 #undef DEBUG
  36
  37 #ifdef DEBUG
  38 #define DBG(x...) printk(x)
  39 #else
  40 #define DBG(x...)
  41 #endif
  42
  43 /* Apparently the RTC stores seconds since 1 Jan 1904 */
  44 #define RTC_OFFSET      2082844800
  45
  46 /*
  47  * Calibrate the decrementer frequency with the VIA timer 1.
  48  */
  49 #define VIA_TIMER_FREQ_6        4700000 /* time 1 frequency * 6 */
  50
  51 extern struct timezone sys_tz;
  52 extern void to_tm(int tim, struct rtc_time * tm);
  53
  54 void __pmac pmac_get_rtc_time(struct rtc_time *tm)
  55 {
  56         switch(sys_ctrler) {
  57 #ifdef CONFIG_ADB_PMU
  58         case SYS_CTRLER_PMU: {
  59                 /* TODO: Move that to a function in the PMU driver */
  60                 struct adb_request req;
  61                 unsigned int now;
  62
  63                 if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
  64                         return;
  65                 pmu_wait_complete(&req);
  66                 if (req.reply_len != 4)
  67                         printk(KERN_ERR "pmac_get_rtc_time: PMU returned a %d"
  68                                " bytes reply\n", 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                 break;
  82         }
  83 #endif /* CONFIG_ADB_PMU */
  84
  85 #ifdef CONFIG_PMAC_SMU
  86         case SYS_CTRLER_SMU:
  87                 smu_get_rtc_time(tm);
  88                 break;
  89 #endif /* CONFIG_PMAC_SMU */
  90         default:
  91                 ;
  92         }
  93 }
  94
  95 int __pmac pmac_set_rtc_time(struct rtc_time *tm)
  96 {
  97         switch(sys_ctrler) {
  98 #ifdef CONFIG_ADB_PMU
  99         case SYS_CTRLER_PMU: {
 100                 /* TODO: Move that to a function in the PMU driver */
 101                 struct adb_request req;
 102                 unsigned int nowtime;
 103
 104                 DBG("set: tm_mday: %d, tm_mon: %d, tm_year: %d,"
 105                     " %d:%02d:%02d\n",
 106                     tm->tm_mday, tm->tm_mon, tm->tm_year,
 107                     tm->tm_hour, tm->tm_min, tm->tm_sec);
 108
 109                 nowtime = mktime(tm->tm_year + 1900, tm->tm_mon + 1,
 110                                  tm->tm_mday, tm->tm_hour, tm->tm_min,
 111                                  tm->tm_sec);
 112
 113                 DBG("-> %u -> %u\n", (int)nowtime,
 114                     (int)(nowtime + RTC_OFFSET));
 115                 nowtime += RTC_OFFSET;
 116
 117                 if (pmu_request(&req, NULL, 5, PMU_SET_RTC,
 118                                 nowtime >> 24, nowtime >> 16,
 119                                 nowtime >> 8, nowtime) < 0)
 120                         return -ENXIO;
 121                 pmu_wait_complete(&req);
 122                 if (req.reply_len != 0)
 123                         printk(KERN_ERR "pmac_set_rtc_time: PMU returned a %d"
 124                                " bytes reply\n", req.reply_len);
 125                 return 0;
 126         }
 127 #endif /* CONFIG_ADB_PMU */
 128
 129 #ifdef CONFIG_PMAC_SMU
 130         case SYS_CTRLER_SMU:
 131                 return smu_set_rtc_time(tm);
 132 #endif /* CONFIG_PMAC_SMU */
 133         default:
 134                 return -ENODEV;
 135         }
 136 }
 137
 138 void __init pmac_get_boot_time(struct rtc_time *tm)
 139 {
 140         pmac_get_rtc_time(tm);
 141
 142 #ifdef disabled__CONFIG_NVRAM
 143         s32 delta = 0;
 144         int dst;
 145
 146         delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
 147         delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
 148         delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
 149         if (delta & 0x00800000UL)
 150                 delta |= 0xFF000000UL;
 151         dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
 152         printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
 153                 dst ? "on" : "off");
 154 #endif
 155 }
 156
 157 /*
 158  * Query the OF and get the decr frequency.
 159  * FIXME: merge this with generic_calibrate_decr
 160  */
 161 void __init pmac_calibrate_decr(void)
 162 {
 163         struct device_node *cpu;
 164         unsigned int freq, *fp;
 165         struct div_result divres;
 166
 167         /*
 168          * The cpu node should have a timebase-frequency property
 169          * to tell us the rate at which the decrementer counts.
 170          */
 171         cpu = find_type_devices("cpu");
 172         if (cpu == 0)
 173                 panic("can't find cpu node in time_init");
 174         fp = (unsigned int *) get_property(cpu, "timebase-frequency", NULL);
 175         if (fp == 0)
 176                 panic("can't get cpu timebase frequency");
 177         freq = *fp;
 178         printk("time_init: decrementer frequency = %u.%.6u MHz\n",
 179                freq/1000000, freq%1000000);
 180         tb_ticks_per_jiffy = freq / HZ;
 181         tb_ticks_per_sec = tb_ticks_per_jiffy * HZ;
 182         tb_ticks_per_usec = freq / 1000000;
 183         tb_to_us = mulhwu_scale_factor(freq, 1000000);
 184         div128_by_32( 1024*1024, 0, tb_ticks_per_sec, &divres );
 185         tb_to_xs = divres.result_low;
 186         ppc_tb_freq = freq;
 187
 188         fp = (unsigned int *)get_property(cpu, "clock-frequency", NULL);
 189         if (fp == 0)
 190                 panic("can't get cpu processor frequency");
 191         ppc_proc_freq = *fp;
 192
 193         setup_default_decr();
 194 }
 195