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/sched_clock.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/kernel_stat.h>
  13 #include <linux/param.h>
  14 #include <linux/smp.h>
  15 #include <linux/time.h>
  16 #include <linux/timex.h>
  17 #include <linux/mm.h>
  18 #include <linux/platform_device.h>
  19
  20 #include <asm/time.h>
  21 #include <asm/pgtable.h>
  22 #include <asm/sgialib.h>
  23 #include <asm/sn/ioc3.h>
  24 #include <asm/sn/klconfig.h>
  25 #include <asm/sn/arch.h>
  26 #include <asm/sn/addrs.h>
  27 #include <asm/sn/sn_private.h>
  28 #include <asm/sn/sn0/ip27.h>
  29 #include <asm/sn/sn0/hub.h>
  30
  31 #define TICK_SIZE (tick_nsec / 1000)
  32
  33 /* Includes for ioc3_init().  */
  34 #include <asm/sn/types.h>
  35 #include <asm/sn/sn0/addrs.h>
  36 #include <asm/sn/sn0/hubni.h>
  37 #include <asm/sn/sn0/hubio.h>
  38 #include <asm/pci/bridge.h>
  39
  40 static void enable_rt_irq(struct irq_data *d)
  41 {
  42 }
  43
  44 static void disable_rt_irq(struct irq_data *d)
  45 {
  46 }
  47
  48 static struct irq_chip rt_irq_type = {
  49         .name           = "SN HUB RT timer",
  50         .irq_mask       = disable_rt_irq,
  51         .irq_unmask     = enable_rt_irq,
  52 };
  53
  54 static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
  55 {
  56         unsigned int cpu = smp_processor_id();
  57         int slice = cputoslice(cpu);
  58         unsigned long cnt;
  59
  60         cnt = LOCAL_HUB_L(PI_RT_COUNT);
  61         cnt += delta;
  62         LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
  63
  64         return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
  65 }
  66
  67 static void rt_set_mode(enum clock_event_mode mode,
  68                 struct clock_event_device *evt)
  69 {
  70         /* Nothing to do ...  */
  71 }
  72
  73 unsigned int rt_timer_irq;
  74
  75 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
  76 static DEFINE_PER_CPU(char [11], hub_rt_name);
  77
  78 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
  79 {
  80         unsigned int cpu = smp_processor_id();
  81         struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
  82         int slice = cputoslice(cpu);
  83
  84         /*
  85          * Ack
  86          */
  87         LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
  88         cd->event_handler(cd);
  89
  90         return IRQ_HANDLED;
  91 }
  92
  93 struct irqaction hub_rt_irqaction = {
  94         .handler        = hub_rt_counter_handler,
  95         .flags          = IRQF_PERCPU | IRQF_TIMER,
  96         .name           = "hub-rt",
  97 };
  98
  99 /*
 100  * This is a hack; we really need to figure these values out dynamically
 101  *
 102  * Since 800 ns works very well with various HUB frequencies, such as
 103  * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
 104  *
 105  * Ralf: which clock rate is used to feed the counter?
 106  */
 107 #define NSEC_PER_CYCLE          800
 108 #define CYCLES_PER_SEC          (NSEC_PER_SEC / NSEC_PER_CYCLE)
 109
 110 void hub_rt_clock_event_init(void)
 111 {
 112         unsigned int cpu = smp_processor_id();
 113         struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
 114         unsigned char *name = per_cpu(hub_rt_name, cpu);
 115         int irq = rt_timer_irq;
 116
 117         sprintf(name, "hub-rt %d", cpu);
 118         cd->name                = name;
 119         cd->features            = CLOCK_EVT_FEAT_ONESHOT;
 120         clockevent_set_clock(cd, CYCLES_PER_SEC);
 121         cd->max_delta_ns        = clockevent_delta2ns(0xfffffffffffff, cd);
 122         cd->min_delta_ns        = clockevent_delta2ns(0x300, cd);
 123         cd->rating              = 200;
 124         cd->irq                 = irq;
 125         cd->cpumask             = cpumask_of(cpu);
 126         cd->set_next_event      = rt_next_event;
 127         cd->set_mode            = rt_set_mode;
 128         clockevents_register_device(cd);
 129 }
 130
 131 static void __init hub_rt_clock_event_global_init(void)
 132 {
 133         int irq;
 134
 135         do {
 136                 smp_wmb();
 137                 irq = rt_timer_irq;
 138                 if (irq)
 139                         break;
 140
 141                 irq = allocate_irqno();
 142                 if (irq < 0)
 143                         panic("Allocation of irq number for timer failed");
 144         } while (xchg(&rt_timer_irq, irq));
 145
 146         irq_set_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
 147         setup_irq(irq, &hub_rt_irqaction);
 148 }
 149
 150 static cycle_t hub_rt_read(struct clocksource *cs)
 151 {
 152         return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
 153 }
 154
 155 struct clocksource hub_rt_clocksource = {
 156         .name   = "HUB-RT",
 157         .rating = 200,
 158         .read   = hub_rt_read,
 159         .mask   = CLOCKSOURCE_MASK(52),
 160         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 161 };
 162
 163 static u64 notrace hub_rt_read_sched_clock(void)
 164 {
 165         return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
 166 }
 167
 168 static void __init hub_rt_clocksource_init(void)
 169 {
 170         struct clocksource *cs = &hub_rt_clocksource;
 171
 172         clocksource_register_hz(cs, CYCLES_PER_SEC);
 173
 174         sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC);
 175 }
 176
 177 void __init plat_time_init(void)
 178 {
 179         hub_rt_clocksource_init();
 180         hub_rt_clock_event_global_init();
 181         hub_rt_clock_event_init();
 182 }
 183
 184 void cpu_time_init(void)
 185 {
 186         lboard_t *board;
 187         klcpu_t *cpu;
 188         int cpuid;
 189
 190         /* Don't use ARCS.  ARCS is fragile.  Klconfig is simple and sane.  */
 191         board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
 192         if (!board)
 193                 panic("Can't find board info for myself.");
 194
 195         cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
 196         cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
 197         if (!cpu)
 198                 panic("No information about myself?");
 199
 200         printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
 201
 202         set_c0_status(SRB_TIMOCLK);
 203 }
 204
 205 void hub_rtc_init(cnodeid_t cnode)
 206 {
 207
 208         /*
 209          * We only need to initialize the current node.
 210          * If this is not the current node then it is a cpuless
 211          * node and timeouts will not happen there.
 212          */
 213         if (get_compact_nodeid() == cnode) {
 214                 LOCAL_HUB_S(PI_RT_EN_A, 1);
 215                 LOCAL_HUB_S(PI_RT_EN_B, 1);
 216                 LOCAL_HUB_S(PI_PROF_EN_A, 0);
 217                 LOCAL_HUB_S(PI_PROF_EN_B, 0);
 218                 LOCAL_HUB_S(PI_RT_COUNT, 0);
 219                 LOCAL_HUB_S(PI_RT_PEND_A, 0);
 220                 LOCAL_HUB_S(PI_RT_PEND_B, 0);
 221         }
 222 }
 223
 224 static int __init sgi_ip27_rtc_devinit(void)
 225 {
 226         struct resource res;
 227
 228         memset(&res, 0, sizeof(res));
 229         res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base +
 230                               IOC3_BYTEBUS_DEV0);
 231         res.end = res.start + 32767;
 232         res.flags = IORESOURCE_MEM;
 233
 234         return IS_ERR(platform_device_register_simple("rtc-m48t35", -1,
 235                                                       &res, 1));
 236 }
 237
 238 /*
 239  * kludge make this a device_initcall after ioc3 resource conflicts
 240  * are resolved
 241  */
 242 late_initcall(sgi_ip27_rtc_devinit);