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 extern void setup_default_decr(void);
  44
  45 extern unsigned long ppc_tb_freq;
  46 extern unsigned long ppc_proc_freq;
  47
  48 /* Apparently the RTC stores seconds since 1 Jan 1904 */
  49 #define RTC_OFFSET      2082844800
  50
  51 /*
  52  * Calibrate the decrementer frequency with the VIA timer 1.
  53  */
  54 #define VIA_TIMER_FREQ_6        4700000 /* time 1 frequency * 6 */
  55
  56 extern struct timezone sys_tz;
  57 extern void to_tm(int tim, struct rtc_time * tm);
  58
  59 void __pmac pmac_get_rtc_time(struct rtc_time *tm)
  60 {
  61         switch(sys_ctrler) {
  62 #ifdef CONFIG_ADB_PMU
  63         case SYS_CTRLER_PMU: {
  64                 /* TODO: Move that to a function in the PMU driver */
  65                 struct adb_request req;
  66                 unsigned int now;
  67
  68                 if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
  69                         return;
  70                 pmu_wait_complete(&req);
  71                 if (req.reply_len != 4)
  72                         printk(KERN_ERR "pmac_get_rtc_time: PMU returned a %d"
  73                                " bytes reply\n", req.reply_len);
  74                 now = (req.reply[0] << 24) + (req.reply[1] << 16)
  75                         + (req.reply[2] << 8) + req.reply[3];
  76                 DBG("get: %u -> %u\n", (int)now, (int)(now - RTC_OFFSET));
  77                 now -= RTC_OFFSET;
  78
  79                 to_tm(now, tm);
  80                 tm->tm_year -= 1900;
  81                 tm->tm_mon -= 1;
  82
  83                 DBG("-> tm_mday: %d, tm_mon: %d, tm_year: %d, %d:%02d:%02d\n",
  84                     tm->tm_mday, tm->tm_mon, tm->tm_year,
  85                     tm->tm_hour, tm->tm_min, tm->tm_sec);
  86                 break;
  87         }
  88 #endif /* CONFIG_ADB_PMU */
  89
  90 #ifdef CONFIG_PMAC_SMU
  91         case SYS_CTRLER_SMU:
  92                 smu_get_rtc_time(tm);
  93                 break;
  94 #endif /* CONFIG_PMAC_SMU */
  95         default:
  96                 ;
  97         }
  98 }
  99
 100 int __pmac pmac_set_rtc_time(struct rtc_time *tm)
 101 {
 102         switch(sys_ctrler) {
 103 #ifdef CONFIG_ADB_PMU
 104         case SYS_CTRLER_PMU: {
 105                 /* TODO: Move that to a function in the PMU driver */
 106                 struct adb_request req;
 107                 unsigned int nowtime;
 108
 109                 DBG("set: tm_mday: %d, tm_mon: %d, tm_year: %d,"
 110                     " %d:%02d:%02d\n",
 111                     tm->tm_mday, tm->tm_mon, tm->tm_year,
 112                     tm->tm_hour, tm->tm_min, tm->tm_sec);
 113
 114                 nowtime = mktime(tm->tm_year + 1900, tm->tm_mon + 1,
 115                                  tm->tm_mday, tm->tm_hour, tm->tm_min,
 116                                  tm->tm_sec);
 117
 118                 DBG("-> %u -> %u\n", (int)nowtime,
 119                     (int)(nowtime + RTC_OFFSET));
 120                 nowtime += RTC_OFFSET;
 121
 122                 if (pmu_request(&req, NULL, 5, PMU_SET_RTC,
 123                                 nowtime >> 24, nowtime >> 16,
 124                                 nowtime >> 8, nowtime) < 0)
 125                         return -ENXIO;
 126                 pmu_wait_complete(&req);
 127                 if (req.reply_len != 0)
 128                         printk(KERN_ERR "pmac_set_rtc_time: PMU returned a %d"
 129                                " bytes reply\n", req.reply_len);
 130                 return 0;
 131         }
 132 #endif /* CONFIG_ADB_PMU */
 133
 134 #ifdef CONFIG_PMAC_SMU
 135         case SYS_CTRLER_SMU:
 136                 return smu_set_rtc_time(tm);
 137 #endif /* CONFIG_PMAC_SMU */
 138         default:
 139                 return -ENODEV;
 140         }
 141 }
 142
 143 void __init pmac_get_boot_time(struct rtc_time *tm)
 144 {
 145         pmac_get_rtc_time(tm);
 146
 147 #ifdef disabled__CONFIG_NVRAM
 148         s32 delta = 0;
 149         int dst;
 150
 151         delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
 152         delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
 153         delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
 154         if (delta & 0x00800000UL)
 155                 delta |= 0xFF000000UL;
 156         dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
 157         printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
 158                 dst ? "on" : "off");
 159 #endif
 160 }
 161
 162 /*
 163  * Query the OF and get the decr frequency.
 164  * This was taken from the pmac time_init() when merging the prep/pmac
 165  * time functions.
 166  */
 167 void __init pmac_calibrate_decr(void)
 168 {
 169         struct device_node *cpu;
 170         unsigned int freq, *fp;
 171         struct div_result divres;
 172
 173         /*
 174          * The cpu node should have a timebase-frequency property
 175          * to tell us the rate at which the decrementer counts.
 176          */
 177         cpu = find_type_devices("cpu");
 178         if (cpu == 0)
 179                 panic("can't find cpu node in time_init");
 180         fp = (unsigned int *) get_property(cpu, "timebase-frequency", NULL);
 181         if (fp == 0)
 182                 panic("can't get cpu timebase frequency");
 183         freq = *fp;
 184         printk("time_init: decrementer frequency = %u.%.6u MHz\n",
 185                freq/1000000, freq%1000000);
 186         tb_ticks_per_jiffy = freq / HZ;
 187         tb_ticks_per_sec = tb_ticks_per_jiffy * HZ;
 188         tb_ticks_per_usec = freq / 1000000;
 189         tb_to_us = mulhwu_scale_factor(freq, 1000000);
 190         div128_by_32( 1024*1024, 0, tb_ticks_per_sec, &divres );
 191         tb_to_xs = divres.result_low;
 192         ppc_tb_freq = freq;
 193
 194         fp = (unsigned int *)get_property(cpu, "clock-frequency", NULL);
 195         if (fp == 0)
 196                 panic("can't get cpu processor frequency");
 197         ppc_proc_freq = *fp;
 198
 199         setup_default_decr();
 200 }
 201