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

   1 /*
   2  * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org)
   3  * Copytight (C) 1999, 2000 Silicon Graphics, Inc.
   4  */
   5 #include <linux/bcd.h>
   6 #include <linux/clockchips.h>
   7 #include <linux/init.h>
   8 #include <linux/kernel.h>
   9 #include <linux/sched.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/kernel_stat.h>
  12 #include <linux/param.h>
  13 #include <linux/time.h>
  14 #include <linux/timex.h>
  15 #include <linux/mm.h>
  16
  17 #include <asm/time.h>
  18 #include <asm/pgtable.h>
  19 #include <asm/sgialib.h>
  20 #include <asm/sn/ioc3.h>
  21 #include <asm/m48t35.h>
  22 #include <asm/sn/klconfig.h>
  23 #include <asm/sn/arch.h>
  24 #include <asm/sn/addrs.h>
  25 #include <asm/sn/sn_private.h>
  26 #include <asm/sn/sn0/ip27.h>
  27 #include <asm/sn/sn0/hub.h>
  28
  29 #define TICK_SIZE (tick_nsec / 1000)
  30
  31 #if 0
  32 static int set_rtc_mmss(unsigned long nowtime)
  33 {
  34         int retval = 0;
  35         int real_seconds, real_minutes, cmos_minutes;
  36         struct m48t35_rtc *rtc;
  37         nasid_t nid;
  38
  39         nid = get_nasid();
  40         rtc = (struct m48t35_rtc *)(KL_CONFIG_CH_CONS_INFO(nid)->memory_base +
  41                                                         IOC3_BYTEBUS_DEV0);
  42
  43         rtc->control |= M48T35_RTC_READ;
  44         cmos_minutes = BCD2BIN(rtc->min);
  45         rtc->control &= ~M48T35_RTC_READ;
  46
  47         /*
  48          * Since we're only adjusting minutes and seconds, don't interfere with
  49          * hour overflow. This avoids messing with unknown time zones but
  50          * requires your RTC not to be off by more than 15 minutes
  51          */
  52         real_seconds = nowtime % 60;
  53         real_minutes = nowtime / 60;
  54         if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
  55                 real_minutes += 30;     /* correct for half hour time zone */
  56         real_minutes %= 60;
  57
  58         if (abs(real_minutes - cmos_minutes) < 30) {
  59                 real_seconds = BIN2BCD(real_seconds);
  60                 real_minutes = BIN2BCD(real_minutes);
  61                 rtc->control |= M48T35_RTC_SET;
  62                 rtc->sec = real_seconds;
  63                 rtc->min = real_minutes;
  64                 rtc->control &= ~M48T35_RTC_SET;
  65         } else {
  66                 printk(KERN_WARNING
  67                        "set_rtc_mmss: can't update from %d to %d\n",
  68                        cmos_minutes, real_minutes);
  69                 retval = -1;
  70         }
  71
  72         return retval;
  73 }
  74 #endif
  75
  76 /* Includes for ioc3_init().  */
  77 #include <asm/sn/types.h>
  78 #include <asm/sn/sn0/addrs.h>
  79 #include <asm/sn/sn0/hubni.h>
  80 #include <asm/sn/sn0/hubio.h>
  81 #include <asm/pci/bridge.h>
  82
  83 unsigned long read_persistent_clock(void)
  84 {
  85         unsigned int year, month, date, hour, min, sec;
  86         struct m48t35_rtc *rtc;
  87         nasid_t nid;
  88
  89         nid = get_nasid();
  90         rtc = (struct m48t35_rtc *)(KL_CONFIG_CH_CONS_INFO(nid)->memory_base +
  91                                                         IOC3_BYTEBUS_DEV0);
  92
  93         rtc->control |= M48T35_RTC_READ;
  94         sec = rtc->sec;
  95         min = rtc->min;
  96         hour = rtc->hour;
  97         date = rtc->date;
  98         month = rtc->month;
  99         year = rtc->year;
 100         rtc->control &= ~M48T35_RTC_READ;
 101
 102         sec = BCD2BIN(sec);
 103         min = BCD2BIN(min);
 104         hour = BCD2BIN(hour);
 105         date = BCD2BIN(date);
 106         month = BCD2BIN(month);
 107         year = BCD2BIN(year);
 108
 109         year += 1970;
 110
 111         return mktime(year, month, date, hour, min, sec);
 112 }
 113
 114 static void enable_rt_irq(unsigned int irq)
 115 {
 116 }
 117
 118 static void disable_rt_irq(unsigned int irq)
 119 {
 120 }
 121
 122 static struct irq_chip rt_irq_type = {
 123         .name           = "SN HUB RT timer",
 124         .ack            = disable_rt_irq,
 125         .mask           = disable_rt_irq,
 126         .mask_ack       = disable_rt_irq,
 127         .unmask         = enable_rt_irq,
 128         .eoi            = enable_rt_irq,
 129 };
 130
 131 static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
 132 {
 133         unsigned int cpu = smp_processor_id();
 134         int slice = cputoslice(cpu);
 135         unsigned long cnt;
 136
 137         cnt = LOCAL_HUB_L(PI_RT_COUNT);
 138         cnt += delta;
 139         LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
 140
 141         return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
 142 }
 143
 144 static void rt_set_mode(enum clock_event_mode mode,
 145                 struct clock_event_device *evt)
 146 {
 147         switch (mode) {
 148         case CLOCK_EVT_MODE_ONESHOT:
 149                 /* The only mode supported */
 150                 break;
 151
 152         case CLOCK_EVT_MODE_PERIODIC:
 153         case CLOCK_EVT_MODE_UNUSED:
 154         case CLOCK_EVT_MODE_SHUTDOWN:
 155         case CLOCK_EVT_MODE_RESUME:
 156                 /* Nothing to do  */
 157                 break;
 158         }
 159 }
 160
 161 unsigned int rt_timer_irq;
 162
 163 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
 164 {
 165         struct clock_event_device *cd = dev_id;
 166         unsigned int cpu = smp_processor_id();
 167         int slice = cputoslice(cpu);
 168
 169         /*
 170          * Ack
 171          */
 172         LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
 173         cd->event_handler(cd);
 174
 175         return IRQ_HANDLED;
 176 }
 177
 178 struct irqaction hub_rt_irqaction = {
 179         .handler        = hub_rt_counter_handler,
 180         .flags          = IRQF_DISABLED | IRQF_PERCPU,
 181         .name           = "hub-rt",
 182 };
 183
 184 /*
 185  * This is a hack; we really need to figure these values out dynamically
 186  *
 187  * Since 800 ns works very well with various HUB frequencies, such as
 188  * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
 189  *
 190  * Ralf: which clock rate is used to feed the counter?
 191  */
 192 #define NSEC_PER_CYCLE          800
 193 #define CYCLES_PER_SEC          (NSEC_PER_SEC / NSEC_PER_CYCLE)
 194
 195 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
 196 static DEFINE_PER_CPU(char [11], hub_rt_name);
 197
 198 static void __cpuinit hub_rt_clock_event_init(void)
 199 {
 200         unsigned int cpu = smp_processor_id();
 201         struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
 202         unsigned char *name = per_cpu(hub_rt_name, cpu);
 203         int irq = rt_timer_irq;
 204
 205         sprintf(name, "hub-rt %d", cpu);
 206         cd->name                = "HUB-RT",
 207         cd->features            = CLOCK_EVT_FEAT_ONESHOT,
 208         clockevent_set_clock(cd, CYCLES_PER_SEC);
 209         cd->max_delta_ns        = clockevent_delta2ns(0xfffffffffffff, cd);
 210         cd->min_delta_ns        = clockevent_delta2ns(0x300, cd);
 211         cd->rating              = 200,
 212         cd->irq                 = irq,
 213         cd->cpumask             = cpumask_of_cpu(cpu),
 214         cd->rating              = 300,
 215         cd->set_next_event      = rt_next_event,
 216         cd->set_mode            = rt_set_mode,
 217         clockevents_register_device(cd);
 218 }
 219
 220 static void __init hub_rt_clock_event_global_init(void)
 221 {
 222         unsigned int irq;
 223
 224         do {
 225                 smp_wmb();
 226                 irq = rt_timer_irq;
 227                 if (irq)
 228                         break;
 229
 230                 irq = allocate_irqno();
 231                 if (irq < 0)
 232                         panic("Allocation of irq number for timer failed");
 233         } while (xchg(&rt_timer_irq, irq));
 234
 235         set_irq_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
 236         setup_irq(irq, &hub_rt_irqaction);
 237 }
 238
 239 static cycle_t hub_rt_read(void)
 240 {
 241         return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
 242 }
 243
 244 struct clocksource hub_rt_clocksource = {
 245         .name   = "HUB-RT",
 246         .rating = 200,
 247         .read   = hub_rt_read,
 248         .mask   = CLOCKSOURCE_MASK(52),
 249         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 250 };
 251
 252 static void __init hub_rt_clocksource_init(void)
 253 {
 254         struct clocksource *cs = &hub_rt_clocksource;
 255
 256         clocksource_set_clock(cs, CYCLES_PER_SEC);
 257         clocksource_register(cs);
 258 }
 259
 260 void __init plat_time_init(void)
 261 {
 262         hub_rt_clocksource_init();
 263         hub_rt_clock_event_global_init();
 264 }
 265
 266 void __cpuinit cpu_time_init(void)
 267 {
 268         lboard_t *board;
 269         klcpu_t *cpu;
 270         int cpuid;
 271
 272         /* Don't use ARCS.  ARCS is fragile.  Klconfig is simple and sane.  */
 273         board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
 274         if (!board)
 275                 panic("Can't find board info for myself.");
 276
 277         cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
 278         cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
 279         if (!cpu)
 280                 panic("No information about myself?");
 281
 282         printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
 283
 284         hub_rt_clock_event_init();
 285         set_c0_status(SRB_TIMOCLK);
 286 }
 287
 288 void __init hub_rtc_init(cnodeid_t cnode)
 289 {
 290         /*
 291          * We only need to initialize the current node.
 292          * If this is not the current node then it is a cpuless
 293          * node and timeouts will not happen there.
 294          */
 295         if (get_compact_nodeid() == cnode) {
 296                 LOCAL_HUB_S(PI_RT_EN_A, 1);
 297                 LOCAL_HUB_S(PI_RT_EN_B, 1);
 298                 LOCAL_HUB_S(PI_PROF_EN_A, 0);
 299                 LOCAL_HUB_S(PI_PROF_EN_B, 0);
 300                 LOCAL_HUB_S(PI_RT_COUNT, 0);
 301                 LOCAL_HUB_S(PI_RT_PEND_A, 0);
 302                 LOCAL_HUB_S(PI_RT_PEND_B, 0);
 303         }
 304 }