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/smp.h>
  14 #include <linux/time.h>
  15 #include <linux/timex.h>
  16 #include <linux/mm.h>
  17 #include <linux/platform_device.h>
  18
  19 #include <asm/time.h>
  20 #include <asm/pgtable.h>
  21 #include <asm/sgialib.h>
  22 #include <asm/sn/ioc3.h>
  23 #include <asm/sn/klconfig.h>
  24 #include <asm/sn/arch.h>
  25 #include <asm/sn/addrs.h>
  26 #include <asm/sn/sn_private.h>
  27 #include <asm/sn/sn0/ip27.h>
  28 #include <asm/sn/sn0/hub.h>
  29
  30 #define TICK_SIZE (tick_nsec / 1000)
  31
  32 /* Includes for ioc3_init().  */
  33 #include <asm/sn/types.h>
  34 #include <asm/sn/sn0/addrs.h>
  35 #include <asm/sn/sn0/hubni.h>
  36 #include <asm/sn/sn0/hubio.h>
  37 #include <asm/pci/bridge.h>
  38
  39 static void enable_rt_irq(struct irq_data *d)
  40 {
  41 }
  42
  43 static void disable_rt_irq(struct irq_data *d)
  44 {
  45 }
  46
  47 static struct irq_chip rt_irq_type = {
  48         .name           = "SN HUB RT timer",
  49         .irq_mask       = disable_rt_irq,
  50         .irq_unmask     = enable_rt_irq,
  51 };
  52
  53 static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
  54 {
  55         unsigned int cpu = smp_processor_id();
  56         int slice = cputoslice(cpu);
  57         unsigned long cnt;
  58
  59         cnt = LOCAL_HUB_L(PI_RT_COUNT);
  60         cnt += delta;
  61         LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
  62
  63         return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
  64 }
  65
  66 static void rt_set_mode(enum clock_event_mode mode,
  67                 struct clock_event_device *evt)
  68 {
  69         /* Nothing to do ...  */
  70 }
  71
  72 unsigned int rt_timer_irq;
  73
  74 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
  75 static DEFINE_PER_CPU(char [11], hub_rt_name);
  76
  77 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
  78 {
  79         unsigned int cpu = smp_processor_id();
  80         struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
  81         int slice = cputoslice(cpu);
  82
  83         /*
  84          * Ack
  85          */
  86         LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
  87         cd->event_handler(cd);
  88
  89         return IRQ_HANDLED;
  90 }
  91
  92 struct irqaction hub_rt_irqaction = {
  93         .handler        = hub_rt_counter_handler,
  94         .flags          = IRQF_PERCPU | IRQF_TIMER,
  95         .name           = "hub-rt",
  96 };
  97
  98 /*
  99  * This is a hack; we really need to figure these values out dynamically
 100  *
 101  * Since 800 ns works very well with various HUB frequencies, such as
 102  * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
 103  *
 104  * Ralf: which clock rate is used to feed the counter?
 105  */
 106 #define NSEC_PER_CYCLE          800
 107 #define CYCLES_PER_SEC          (NSEC_PER_SEC / NSEC_PER_CYCLE)
 108
 109 void __cpuinit hub_rt_clock_event_init(void)
 110 {
 111         unsigned int cpu = smp_processor_id();
 112         struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
 113         unsigned char *name = per_cpu(hub_rt_name, cpu);
 114         int irq = rt_timer_irq;
 115
 116         sprintf(name, "hub-rt %d", cpu);
 117         cd->name                = name;
 118         cd->features            = CLOCK_EVT_FEAT_ONESHOT;
 119         clockevent_set_clock(cd, CYCLES_PER_SEC);
 120         cd->max_delta_ns        = clockevent_delta2ns(0xfffffffffffff, cd);
 121         cd->min_delta_ns        = clockevent_delta2ns(0x300, cd);
 122         cd->rating              = 200;
 123         cd->irq                 = irq;
 124         cd->cpumask             = cpumask_of(cpu);
 125         cd->set_next_event      = rt_next_event;
 126         cd->set_mode            = rt_set_mode;
 127         clockevents_register_device(cd);
 128 }
 129
 130 static void __init hub_rt_clock_event_global_init(void)
 131 {
 132         int irq;
 133
 134         do {
 135                 smp_wmb();
 136                 irq = rt_timer_irq;
 137                 if (irq)
 138                         break;
 139
 140                 irq = allocate_irqno();
 141                 if (irq < 0)
 142                         panic("Allocation of irq number for timer failed");
 143         } while (xchg(&rt_timer_irq, irq));
 144
 145         irq_set_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
 146         setup_irq(irq, &hub_rt_irqaction);
 147 }
 148
 149 static cycle_t hub_rt_read(struct clocksource *cs)
 150 {
 151         return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
 152 }
 153
 154 struct clocksource hub_rt_clocksource = {
 155         .name   = "HUB-RT",
 156         .rating = 200,
 157         .read   = hub_rt_read,
 158         .mask   = CLOCKSOURCE_MASK(52),
 159         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 160 };
 161
 162 static void __init hub_rt_clocksource_init(void)
 163 {
 164         struct clocksource *cs = &hub_rt_clocksource;
 165
 166         clocksource_register_hz(cs, CYCLES_PER_SEC);
 167 }
 168
 169 void __init plat_time_init(void)
 170 {
 171         hub_rt_clocksource_init();
 172         hub_rt_clock_event_global_init();
 173         hub_rt_clock_event_init();
 174 }
 175
 176 void __cpuinit cpu_time_init(void)
 177 {
 178         lboard_t *board;
 179         klcpu_t *cpu;
 180         int cpuid;
 181
 182         /* Don't use ARCS.  ARCS is fragile.  Klconfig is simple and sane.  */
 183         board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
 184         if (!board)
 185                 panic("Can't find board info for myself.");
 186
 187         cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
 188         cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
 189         if (!cpu)
 190                 panic("No information about myself?");
 191
 192         printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
 193
 194         set_c0_status(SRB_TIMOCLK);
 195 }
 196
 197 void __cpuinit hub_rtc_init(cnodeid_t cnode)
 198 {
 199
 200         /*
 201          * We only need to initialize the current node.
 202          * If this is not the current node then it is a cpuless
 203          * node and timeouts will not happen there.
 204          */
 205         if (get_compact_nodeid() == cnode) {
 206                 LOCAL_HUB_S(PI_RT_EN_A, 1);
 207                 LOCAL_HUB_S(PI_RT_EN_B, 1);
 208                 LOCAL_HUB_S(PI_PROF_EN_A, 0);
 209                 LOCAL_HUB_S(PI_PROF_EN_B, 0);
 210                 LOCAL_HUB_S(PI_RT_COUNT, 0);
 211                 LOCAL_HUB_S(PI_RT_PEND_A, 0);
 212                 LOCAL_HUB_S(PI_RT_PEND_B, 0);
 213         }
 214 }
 215
 216 static int __init sgi_ip27_rtc_devinit(void)
 217 {
 218         struct resource res;
 219
 220         memset(&res, 0, sizeof(res));
 221         res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base +
 222                               IOC3_BYTEBUS_DEV0);
 223         res.end = res.start + 32767;
 224         res.flags = IORESOURCE_MEM;
 225
 226         return IS_ERR(platform_device_register_simple("rtc-m48t35", -1,
 227                                                       &res, 1));
 228 }
 229
 230 /*
 231  * kludge make this a device_initcall after ioc3 resource conflicts
 232  * are resolved
 233  */
 234 late_initcall(sgi_ip27_rtc_devinit);