* Copytight (C) 1999, 2000 Silicon Graphics, Inc.
*/
#include <linux/bcd.h>
+#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <asm/sn/sn0/ip27.h>
#include <asm/sn/sn0/hub.h>
-/*
- * This is a hack; we really need to figure these values out dynamically
- *
- * Since 800 ns works very well with various HUB frequencies, such as
- * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
- *
- * Ralf: which clock rate is used to feed the counter?
- */
-#define NSEC_PER_CYCLE 800
-#define CYCLES_PER_SEC (NSEC_PER_SEC/NSEC_PER_CYCLE)
-#define CYCLES_PER_JIFFY (CYCLES_PER_SEC/HZ)
-
#define TICK_SIZE (tick_nsec / 1000)
-static unsigned long ct_cur[NR_CPUS]; /* What counter should be at next timer irq */
-static long last_rtc_update; /* Last time the rtc clock got updated */
-
#if 0
static int set_rtc_mmss(unsigned long nowtime)
{
}
#endif
-static unsigned int rt_timer_irq;
-
-void ip27_rt_timer_interrupt(void)
-{
- int cpu = smp_processor_id();
- int cpuA = cputoslice(cpu) == 0;
- unsigned int irq = rt_timer_irq;
-
- irq_enter();
- write_seqlock(&xtime_lock);
-
-again:
- LOCAL_HUB_S(cpuA ? PI_RT_PEND_A : PI_RT_PEND_B, 0); /* Ack */
- ct_cur[cpu] += CYCLES_PER_JIFFY;
- LOCAL_HUB_S(cpuA ? PI_RT_COMPARE_A : PI_RT_COMPARE_B, ct_cur[cpu]);
-
- if (LOCAL_HUB_L(PI_RT_COUNT) >= ct_cur[cpu])
- goto again;
-
- kstat_this_cpu.irqs[irq]++; /* kstat only for bootcpu? */
-
- if (cpu == 0)
- do_timer(1);
-
- update_process_times(user_mode(get_irq_regs()));
-
- /*
- * If we have an externally synchronized Linux clock, then update
- * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
- * called as close as possible to when a second starts.
- */
- if (ntp_synced() &&
- xtime.tv_sec > last_rtc_update + 660 &&
- (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
- (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
- if (rtc_mips_set_time(xtime.tv_sec) == 0) {
- last_rtc_update = xtime.tv_sec;
- } else {
- last_rtc_update = xtime.tv_sec - 600;
- /* do it again in 60 s */
- }
- }
-
- write_sequnlock(&xtime_lock);
- irq_exit();
-}
-
/* Includes for ioc3_init(). */
#include <asm/sn/types.h>
#include <asm/sn/sn0/addrs.h>
#include <asm/sn/sn0/hubio.h>
#include <asm/pci/bridge.h>
-static __init unsigned long get_m48t35_time(void)
+unsigned long read_persistent_clock(void)
{
unsigned int year, month, date, hour, min, sec;
struct m48t35_rtc *rtc;
return mktime(year, month, date, hour, min, sec);
}
+static int rt_set_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ unsigned int cpu = smp_processor_id();
+ int slice = cputoslice(cpu) == 0;
+ unsigned long cnt;
+
+ cnt = LOCAL_HUB_L(PI_RT_COUNT);
+ cnt += delta;
+ LOCAL_HUB_S(slice ? PI_RT_COMPARE_A : PI_RT_COMPARE_B, cnt);
+
+ return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
+}
+
+static void rt_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ /* The only mode supported */
+ break;
+
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_ONESHOT:
+ case CLOCK_EVT_MODE_RESUME:
+ /* Nothing to do */
+ break;
+ }
+}
+
+struct clock_event_device rt_clock_event_device = {
+ .name = "HUB-RT",
+ .features = CLOCK_EVT_FEAT_ONESHOT,
+
+ .rating = 300,
+ .set_next_event = rt_set_next_event,
+ .set_mode = rt_set_mode,
+};
+
static void enable_rt_irq(unsigned int irq)
{
}
.eoi = enable_rt_irq,
};
+unsigned int rt_timer_irq;
+
+static irqreturn_t ip27_rt_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *cd = &rt_clock_event_device;
+ unsigned int cpu = smp_processor_id();
+ int slice = cputoslice(cpu) == 0;
+
+ LOCAL_HUB_S(slice ? PI_RT_PEND_A : PI_RT_PEND_B, 0); /* Ack */
+ cd->event_handler(cd);
+
+ return IRQ_HANDLED;
+}
+
static struct irqaction rt_irqaction = {
.handler = (irq_handler_t) ip27_rt_timer_interrupt,
.flags = IRQF_DISABLED,
.name = "timer"
};
-void __init plat_timer_setup(struct irqaction *irq)
+/*
+ * This is a hack; we really need to figure these values out dynamically
+ *
+ * Since 800 ns works very well with various HUB frequencies, such as
+ * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
+ *
+ * Ralf: which clock rate is used to feed the counter?
+ */
+#define NSEC_PER_CYCLE 800
+#define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE)
+
+static void __init ip27_rt_clock_event_init(void)
{
- int irqno = allocate_irqno();
+ struct clock_event_device *cd = &rt_clock_event_device;
+ unsigned int cpu = smp_processor_id();
+ int irq = allocate_irqno();
- if (irqno < 0)
+ if (irq < 0)
panic("Can't allocate interrupt number for timer interrupt");
- set_irq_chip_and_handler(irqno, &rt_irq_type, handle_percpu_irq);
+ rt_timer_irq = irq;
- /* over-write the handler, we use our own way */
- irq->handler = no_action;
+ cd->irq = irq,
+ cd->cpumask = cpumask_of_cpu(cpu),
- /* setup irqaction */
- irq_desc[irqno].status |= IRQ_PER_CPU;
-
- rt_timer_irq = irqno;
/*
- * Only needed to get /proc/interrupt to display timer irq stats
+ * Calculate the min / max delta
*/
- setup_irq(irqno, &rt_irqaction);
+ cd->mult =
+ div_sc((unsigned long) CYCLES_PER_SEC, NSEC_PER_SEC, 32);
+ cd->shift = 32;
+ cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
+ cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
+ clockevents_register_device(cd);
+
+ set_irq_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
+ setup_irq(irq, &rt_irqaction);
}
-static cycle_t ip27_hpt_read(void)
+static cycle_t hub_rt_read(void)
{
return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
}
-void __init ip27_time_init(void)
+struct clocksource ht_rt_clocksource = {
+ .name = "HUB-RT",
+ .rating = 200,
+ .read = hub_rt_read,
+ .mask = CLOCKSOURCE_MASK(52),
+ .shift = 32,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void __init ip27_rt_clocksource_init(void)
{
- clocksource_mips.read = ip27_hpt_read;
- mips_hpt_frequency = CYCLES_PER_SEC;
- xtime.tv_sec = get_m48t35_time();
- xtime.tv_nsec = 0;
+ clocksource_register(&ht_rt_clocksource);
+}
+
+void __init plat_time_init(void)
+{
+ ip27_rt_clock_event_init();
+ ip27_rt_clocksource_init();
}
void __init cpu_time_init(void)
* node and timeouts will not happen there.
*/
if (get_compact_nodeid() == cnode) {
- int cpu = smp_processor_id();
LOCAL_HUB_S(PI_RT_EN_A, 1);
LOCAL_HUB_S(PI_RT_EN_B, 1);
LOCAL_HUB_S(PI_PROF_EN_A, 0);
LOCAL_HUB_S(PI_PROF_EN_B, 0);
- ct_cur[cpu] = CYCLES_PER_JIFFY;
- LOCAL_HUB_S(PI_RT_COMPARE_A, ct_cur[cpu]);
LOCAL_HUB_S(PI_RT_COUNT, 0);
LOCAL_HUB_S(PI_RT_PEND_A, 0);
- LOCAL_HUB_S(PI_RT_COMPARE_B, ct_cur[cpu]);
- LOCAL_HUB_S(PI_RT_COUNT, 0);
LOCAL_HUB_S(PI_RT_PEND_B, 0);
}
}
git.openpandora.org / pandora-kernel.git / blobdiff