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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org)
   4  * Copytight (C) 1999, 2000 Silicon Graphics, Inc.
   5  */
   6 #include <linux/bcd.h>
   7 #include <linux/clockchips.h>
   8 #include <linux/init.h>
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/sched_clock.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/kernel_stat.h>
  14 #include <linux/param.h>
  15 #include <linux/smp.h>
  16 #include <linux/time.h>
  17 #include <linux/timex.h>
  18 #include <linux/mm.h>
  19 #include <linux/platform_device.h>
  20
  21 #include <asm/time.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/sgialib.h>
  24 #include <asm/sn/ioc3.h>
  25 #include <asm/sn/klconfig.h>
  26 #include <asm/sn/arch.h>
  27 #include <asm/sn/addrs.h>
  28 #include <asm/sn/sn_private.h>
  29 #include <asm/sn/sn0/ip27.h>
  30 #include <asm/sn/sn0/hub.h>
  31
  32 #define TICK_SIZE (tick_nsec / 1000)
  33
  34 /* Includes for ioc3_init().  */
  35 #include <asm/sn/types.h>
  36 #include <asm/sn/sn0/addrs.h>
  37 #include <asm/sn/sn0/hubni.h>
  38 #include <asm/sn/sn0/hubio.h>
  39 #include <asm/pci/bridge.h>
  40
  41 static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
  42 {
  43         unsigned int cpu = smp_processor_id();
  44         int slice = cputoslice(cpu);
  45         unsigned long cnt;
  46
  47         cnt = LOCAL_HUB_L(PI_RT_COUNT);
  48         cnt += delta;
  49         LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
  50
  51         return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
  52 }
  53
  54 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
  55 static DEFINE_PER_CPU(char [11], hub_rt_name);
  56
  57 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
  58 {
  59         unsigned int cpu = smp_processor_id();
  60         struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
  61         int slice = cputoslice(cpu);
  62
  63         /*
  64          * Ack
  65          */
  66         LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
  67         cd->event_handler(cd);
  68
  69         return IRQ_HANDLED;
  70 }
  71
  72 struct irqaction hub_rt_irqaction = {
  73         .handler        = hub_rt_counter_handler,
  74         .percpu_dev_id  = &hub_rt_clockevent,
  75         .flags          = IRQF_PERCPU | IRQF_TIMER,
  76         .name           = "hub-rt",
  77 };
  78
  79 /*
  80  * This is a hack; we really need to figure these values out dynamically
  81  *
  82  * Since 800 ns works very well with various HUB frequencies, such as
  83  * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
  84  *
  85  * Ralf: which clock rate is used to feed the counter?
  86  */
  87 #define NSEC_PER_CYCLE          800
  88 #define CYCLES_PER_SEC          (NSEC_PER_SEC / NSEC_PER_CYCLE)
  89
  90 void hub_rt_clock_event_init(void)
  91 {
  92         unsigned int cpu = smp_processor_id();
  93         struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
  94         unsigned char *name = per_cpu(hub_rt_name, cpu);
  95
  96         sprintf(name, "hub-rt %d", cpu);
  97         cd->name                = name;
  98         cd->features            = CLOCK_EVT_FEAT_ONESHOT;
  99         clockevent_set_clock(cd, CYCLES_PER_SEC);
 100         cd->max_delta_ns        = clockevent_delta2ns(0xfffffffffffff, cd);
 101         cd->max_delta_ticks     = 0xfffffffffffff;
 102         cd->min_delta_ns        = clockevent_delta2ns(0x300, cd);
 103         cd->min_delta_ticks     = 0x300;
 104         cd->rating              = 200;
 105         cd->irq                 = IP27_RT_TIMER_IRQ;
 106         cd->cpumask             = cpumask_of(cpu);
 107         cd->set_next_event      = rt_next_event;
 108         clockevents_register_device(cd);
 109
 110         enable_percpu_irq(IP27_RT_TIMER_IRQ, IRQ_TYPE_NONE);
 111 }
 112
 113 static void __init hub_rt_clock_event_global_init(void)
 114 {
 115         irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq);
 116         irq_set_percpu_devid(IP27_RT_TIMER_IRQ);
 117         setup_percpu_irq(IP27_RT_TIMER_IRQ, &hub_rt_irqaction);
 118 }
 119
 120 static u64 hub_rt_read(struct clocksource *cs)
 121 {
 122         return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
 123 }
 124
 125 struct clocksource hub_rt_clocksource = {
 126         .name   = "HUB-RT",
 127         .rating = 200,
 128         .read   = hub_rt_read,
 129         .mask   = CLOCKSOURCE_MASK(52),
 130         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 131 };
 132
 133 static u64 notrace hub_rt_read_sched_clock(void)
 134 {
 135         return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
 136 }
 137
 138 static void __init hub_rt_clocksource_init(void)
 139 {
 140         struct clocksource *cs = &hub_rt_clocksource;
 141
 142         clocksource_register_hz(cs, CYCLES_PER_SEC);
 143
 144         sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC);
 145 }
 146
 147 void __init plat_time_init(void)
 148 {
 149         hub_rt_clocksource_init();
 150         hub_rt_clock_event_global_init();
 151         hub_rt_clock_event_init();
 152 }
 153
 154 void cpu_time_init(void)
 155 {
 156         lboard_t *board;
 157         klcpu_t *cpu;
 158         int cpuid;
 159
 160         /* Don't use ARCS.  ARCS is fragile.  Klconfig is simple and sane.  */
 161         board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
 162         if (!board)
 163                 panic("Can't find board info for myself.");
 164
 165         cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
 166         cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
 167         if (!cpu)
 168                 panic("No information about myself?");
 169
 170         printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
 171 }
 172
 173 void hub_rtc_init(cnodeid_t cnode)
 174 {
 175
 176         /*
 177          * We only need to initialize the current node.
 178          * If this is not the current node then it is a cpuless
 179          * node and timeouts will not happen there.
 180          */
 181         if (get_compact_nodeid() == cnode) {
 182                 LOCAL_HUB_S(PI_RT_EN_A, 1);
 183                 LOCAL_HUB_S(PI_RT_EN_B, 1);
 184                 LOCAL_HUB_S(PI_PROF_EN_A, 0);
 185                 LOCAL_HUB_S(PI_PROF_EN_B, 0);
 186                 LOCAL_HUB_S(PI_RT_COUNT, 0);
 187                 LOCAL_HUB_S(PI_RT_PEND_A, 0);
 188                 LOCAL_HUB_S(PI_RT_PEND_B, 0);
 189         }
 190 }
 191
 192 static int __init sgi_ip27_rtc_devinit(void)
 193 {
 194         struct resource res;
 195
 196         memset(&res, 0, sizeof(res));
 197         res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base +
 198                               IOC3_BYTEBUS_DEV0);
 199         res.end = res.start + 32767;
 200         res.flags = IORESOURCE_MEM;
 201
 202         return IS_ERR(platform_device_register_simple("rtc-m48t35", -1,
 203                                                       &res, 1));
 204 }
 205
 206 /*
 207  * kludge make this a device_initcall after ioc3 resource conflicts
 208  * are resolved
 209  */
 210 late_initcall(sgi_ip27_rtc_devinit);