arch/mips/sgi-ip27/ip27-timer.c

   1 /*
   2  * Copytight (C) 1999, 2000, 05 Ralf Baechle (ralf@linux-mips.org)
   3  * Copytight (C) 1999, 2000 Silicon Graphics, Inc.
   4  */
   5 #include <linux/bcd.h>
   6 #include <linux/init.h>
   7 #include <linux/kernel.h>
   8 #include <linux/sched.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/kernel_stat.h>
  11 #include <linux/param.h>
  12 #include <linux/time.h>
  13 #include <linux/timex.h>
  14 #include <linux/mm.h>
  15
  16 #include <asm/time.h>
  17 #include <asm/pgtable.h>
  18 #include <asm/sgialib.h>
  19 #include <asm/sn/ioc3.h>
  20 #include <asm/m48t35.h>
  21 #include <asm/sn/klconfig.h>
  22 #include <asm/sn/arch.h>
  23 #include <asm/sn/addrs.h>
  24 #include <asm/sn/sn_private.h>
  25 #include <asm/sn/sn0/ip27.h>
  26 #include <asm/sn/sn0/hub.h>
  27
  28 /*
  29  * This is a hack; we really need to figure these values out dynamically
  30  *
  31  * Since 800 ns works very well with various HUB frequencies, such as
  32  * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
  33  *
  34  * Ralf: which clock rate is used to feed the counter?
  35  */
  36 #define NSEC_PER_CYCLE          800
  37 #define CYCLES_PER_SEC          (NSEC_PER_SEC/NSEC_PER_CYCLE)
  38 #define CYCLES_PER_JIFFY        (CYCLES_PER_SEC/HZ)
  39
  40 #define TICK_SIZE (tick_nsec / 1000)
  41
  42 static unsigned long ct_cur[NR_CPUS];   /* What counter should be at next timer irq */
  43 static long last_rtc_update;            /* Last time the rtc clock got updated */
  44
  45 extern volatile unsigned long wall_jiffies;
  46
  47 #if 0
  48 static int set_rtc_mmss(unsigned long nowtime)
  49 {
  50         int retval = 0;
  51         int real_seconds, real_minutes, cmos_minutes;
  52         struct m48t35_rtc *rtc;
  53         nasid_t nid;
  54
  55         nid = get_nasid();
  56         rtc = (struct m48t35_rtc *)(KL_CONFIG_CH_CONS_INFO(nid)->memory_base +
  57                                                         IOC3_BYTEBUS_DEV0);
  58
  59         rtc->control |= M48T35_RTC_READ;
  60         cmos_minutes = BCD2BIN(rtc->min);
  61         rtc->control &= ~M48T35_RTC_READ;
  62
  63         /*
  64          * Since we're only adjusting minutes and seconds, don't interfere with
  65          * hour overflow. This avoids messing with unknown time zones but
  66          * requires your RTC not to be off by more than 15 minutes
  67          */
  68         real_seconds = nowtime % 60;
  69         real_minutes = nowtime / 60;
  70         if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
  71                 real_minutes += 30;     /* correct for half hour time zone */
  72         real_minutes %= 60;
  73
  74         if (abs(real_minutes - cmos_minutes) < 30) {
  75                 real_seconds = BIN2BCD(real_seconds);
  76                 real_minutes = BIN2BCD(real_minutes);
  77                 rtc->control |= M48T35_RTC_SET;
  78                 rtc->sec = real_seconds;
  79                 rtc->min = real_minutes;
  80                 rtc->control &= ~M48T35_RTC_SET;
  81         } else {
  82                 printk(KERN_WARNING
  83                        "set_rtc_mmss: can't update from %d to %d\n",
  84                        cmos_minutes, real_minutes);
  85                 retval = -1;
  86         }
  87
  88         return retval;
  89 }
  90 #endif
  91
  92 void ip27_rt_timer_interrupt(struct pt_regs *regs)
  93 {
  94         int cpu = smp_processor_id();
  95         int cpuA = cputoslice(cpu) == 0;
  96         int irq = 9;                            /* XXX Assign number */
  97
  98         irq_enter();
  99         write_seqlock(&xtime_lock);
 100
 101 again:
 102         LOCAL_HUB_S(cpuA ? PI_RT_PEND_A : PI_RT_PEND_B, 0);     /* Ack  */
 103         ct_cur[cpu] += CYCLES_PER_JIFFY;
 104         LOCAL_HUB_S(cpuA ? PI_RT_COMPARE_A : PI_RT_COMPARE_B, ct_cur[cpu]);
 105
 106         if (LOCAL_HUB_L(PI_RT_COUNT) >= ct_cur[cpu])
 107                 goto again;
 108
 109         kstat_this_cpu.irqs[irq]++;             /* kstat only for bootcpu? */
 110
 111         if (cpu == 0)
 112                 do_timer(regs);
 113
 114         update_process_times(user_mode(regs));
 115
 116         /*
 117          * If we have an externally synchronized Linux clock, then update
 118          * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
 119          * called as close as possible to when a second starts.
 120          */
 121         if ((time_status & STA_UNSYNC) == 0 &&
 122             xtime.tv_sec > last_rtc_update + 660 &&
 123             (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
 124             (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
 125                 if (rtc_set_time(xtime.tv_sec) == 0) {
 126                         last_rtc_update = xtime.tv_sec;
 127                 } else {
 128                         last_rtc_update = xtime.tv_sec - 600;
 129                         /* do it again in 60 s */
 130                 }
 131         }
 132
 133         write_sequnlock(&xtime_lock);
 134         irq_exit();
 135 }
 136
 137 unsigned long ip27_do_gettimeoffset(void)
 138 {
 139         unsigned long ct_cur1;
 140         ct_cur1 = REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT) + CYCLES_PER_JIFFY;
 141         return (ct_cur1 - ct_cur[0]) * NSEC_PER_CYCLE / 1000;
 142 }
 143
 144 /* Includes for ioc3_init().  */
 145 #include <asm/sn/types.h>
 146 #include <asm/sn/sn0/addrs.h>
 147 #include <asm/sn/sn0/hubni.h>
 148 #include <asm/sn/sn0/hubio.h>
 149 #include <asm/pci/bridge.h>
 150
 151 static __init unsigned long get_m48t35_time(void)
 152 {
 153         unsigned int year, month, date, hour, min, sec;
 154         struct m48t35_rtc *rtc;
 155         nasid_t nid;
 156
 157         nid = get_nasid();
 158         rtc = (struct m48t35_rtc *)(KL_CONFIG_CH_CONS_INFO(nid)->memory_base +
 159                                                         IOC3_BYTEBUS_DEV0);
 160
 161         rtc->control |= M48T35_RTC_READ;
 162         sec = rtc->sec;
 163         min = rtc->min;
 164         hour = rtc->hour;
 165         date = rtc->date;
 166         month = rtc->month;
 167         year = rtc->year;
 168         rtc->control &= ~M48T35_RTC_READ;
 169
 170         sec = BCD2BIN(sec);
 171         min = BCD2BIN(min);
 172         hour = BCD2BIN(hour);
 173         date = BCD2BIN(date);
 174         month = BCD2BIN(month);
 175         year = BCD2BIN(year);
 176
 177         year += 1970;
 178
 179         return mktime(year, month, date, hour, min, sec);
 180 }
 181
 182 static void ip27_timer_setup(struct irqaction *irq)
 183 {
 184         /* over-write the handler, we use our own way */
 185         irq->handler = no_action;
 186
 187         /* setup irqaction */
 188 //      setup_irq(IP27_TIMER_IRQ, irq);         /* XXX Can't do this yet.  */
 189 }
 190
 191 void __init ip27_time_init(void)
 192 {
 193         xtime.tv_sec = get_m48t35_time();
 194         xtime.tv_nsec = 0;
 195
 196         do_gettimeoffset = ip27_do_gettimeoffset;
 197
 198         board_timer_setup = ip27_timer_setup;
 199 }
 200
 201 void __init cpu_time_init(void)
 202 {
 203         lboard_t *board;
 204         klcpu_t *cpu;
 205         int cpuid;
 206
 207         /* Don't use ARCS.  ARCS is fragile.  Klconfig is simple and sane.  */
 208         board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
 209         if (!board)
 210                 panic("Can't find board info for myself.");
 211
 212         cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
 213         cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
 214         if (!cpu)
 215                 panic("No information about myself?");
 216
 217         printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
 218
 219         set_c0_status(SRB_TIMOCLK);
 220 }
 221
 222 void __init hub_rtc_init(cnodeid_t cnode)
 223 {
 224         /*
 225          * We only need to initialize the current node.
 226          * If this is not the current node then it is a cpuless
 227          * node and timeouts will not happen there.
 228          */
 229         if (get_compact_nodeid() == cnode) {
 230                 int cpu = smp_processor_id();
 231                 LOCAL_HUB_S(PI_RT_EN_A, 1);
 232                 LOCAL_HUB_S(PI_RT_EN_B, 1);
 233                 LOCAL_HUB_S(PI_PROF_EN_A, 0);
 234                 LOCAL_HUB_S(PI_PROF_EN_B, 0);
 235                 ct_cur[cpu] = CYCLES_PER_JIFFY;
 236                 LOCAL_HUB_S(PI_RT_COMPARE_A, ct_cur[cpu]);
 237                 LOCAL_HUB_S(PI_RT_COUNT, 0);
 238                 LOCAL_HUB_S(PI_RT_PEND_A, 0);
 239                 LOCAL_HUB_S(PI_RT_COMPARE_B, ct_cur[cpu]);
 240                 LOCAL_HUB_S(PI_RT_COUNT, 0);
 241                 LOCAL_HUB_S(PI_RT_PEND_B, 0);
 242         }
 243 }