#include <linux/init.h>
#include <linux/timex.h>
#include <linux/io.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/mach/time.h>
#include <mach/time.h>
+/*
+ * IOP clocksource (free-running timer 1).
+ */
+static cycle_t iop_clocksource_read(struct clocksource *unused)
+{
+ return 0xffffffffu - read_tcr1();
+}
+
+static struct clocksource iop_clocksource = {
+ .name = "iop_timer1",
+ .rating = 300,
+ .read = iop_clocksource_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void __init iop_clocksource_set_hz(struct clocksource *cs, unsigned int hz)
+{
+ u64 temp;
+ u32 shift;
+
+ /* Find shift and mult values for hz. */
+ shift = 32;
+ do {
+ temp = (u64) NSEC_PER_SEC << shift;
+ do_div(temp, hz);
+ if ((temp >> 32) == 0)
+ break;
+ } while (--shift != 0);
+
+ cs->shift = shift;
+ cs->mult = (u32) temp;
+
+ printk(KERN_INFO "clocksource: %s uses shift %u mult %#x\n",
+ cs->name, cs->shift, cs->mult);
+}
+
+/*
+ * IOP sched_clock() implementation via its clocksource.
+ */
+unsigned long long sched_clock(void)
+{
+ cycle_t cyc = iop_clocksource_read(NULL);
+ struct clocksource *cs = &iop_clocksource;
+
+ return clocksource_cyc2ns(cyc, cs->mult, cs->shift);
+}
+
+/*
+ * IOP clockevents (interrupting timer 0).
+ */
+static int iop_set_next_event(unsigned long delta,
+ struct clock_event_device *unused)
+{
+ u32 tmr = IOP_TMR_PRIVILEGED | IOP_TMR_RATIO_1_1;
+
+ BUG_ON(delta == 0);
+ write_tmr0(tmr & ~(IOP_TMR_EN | IOP_TMR_RELOAD));
+ write_tcr0(delta);
+ write_tmr0((tmr & ~IOP_TMR_RELOAD) | IOP_TMR_EN);
+
+ return 0;
+}
+
static unsigned long ticks_per_jiffy;
-static unsigned long ticks_per_usec;
-static unsigned long next_jiffy_time;
-unsigned long iop_gettimeoffset(void)
+static void iop_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *unused)
{
- unsigned long offset, temp;
+ u32 tmr = read_tmr0();
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ write_tmr0(tmr & ~IOP_TMR_EN);
+ write_tcr0(ticks_per_jiffy - 1);
+ tmr |= (IOP_TMR_RELOAD | IOP_TMR_EN);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ /* ->set_next_event sets period and enables timer */
+ tmr &= ~(IOP_TMR_RELOAD | IOP_TMR_EN);
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ tmr |= IOP_TMR_EN;
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ default:
+ tmr &= ~IOP_TMR_EN;
+ break;
+ }
- /* enable cp6, if necessary, to avoid taking the overhead of an
- * undefined instruction trap
- */
- asm volatile (
- "mrc p15, 0, %0, c15, c1, 0\n\t"
- "tst %0, #(1 << 6)\n\t"
- "orreq %0, %0, #(1 << 6)\n\t"
- "mcreq p15, 0, %0, c15, c1, 0\n\t"
-#ifdef CONFIG_CPU_XSCALE
- "mrceq p15, 0, %0, c15, c1, 0\n\t"
- "moveq %0, %0\n\t"
- "subeq pc, pc, #4\n\t"
-#endif
- : "=r"(temp) : : "cc");
-
- offset = next_jiffy_time - read_tcr1();
-
- return offset / ticks_per_usec;
+ write_tmr0(tmr);
+}
+
+static struct clock_event_device iop_clockevent = {
+ .name = "iop_timer0",
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 300,
+ .set_next_event = iop_set_next_event,
+ .set_mode = iop_set_mode,
+};
+
+static void __init iop_clockevent_set_hz(struct clock_event_device *ce, unsigned int hz)
+{
+ u64 temp;
+ u32 shift;
+
+ /* Find shift and mult values for hz. */
+ shift = 32;
+ do {
+ temp = (u64) hz << shift;
+ do_div(temp, NSEC_PER_SEC);
+ if ((temp >> 32) == 0)
+ break;
+ } while (--shift != 0);
+
+ ce->shift = shift;
+ ce->mult = (u32) temp;
+
+ printk(KERN_INFO "clockevent: %s uses shift %u mult %#lx\n",
+ ce->name, ce->shift, ce->mult);
}
static irqreturn_t
iop_timer_interrupt(int irq, void *dev_id)
{
- write_tisr(1);
-
- while ((signed long)(next_jiffy_time - read_tcr1())
- >= ticks_per_jiffy) {
- timer_tick();
- next_jiffy_time -= ticks_per_jiffy;
- }
+ struct clock_event_device *evt = dev_id;
+ write_tisr(1);
+ evt->event_handler(evt);
return IRQ_HANDLED;
}
.name = "IOP Timer Tick",
.handler = iop_timer_interrupt,
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+ .dev_id = &iop_clockevent,
};
static unsigned long iop_tick_rate;
u32 timer_ctl;
ticks_per_jiffy = DIV_ROUND_CLOSEST(tick_rate, HZ);
- ticks_per_usec = tick_rate / 1000000;
- next_jiffy_time = 0xffffffff;
iop_tick_rate = tick_rate;
timer_ctl = IOP_TMR_EN | IOP_TMR_PRIVILEGED |
IOP_TMR_RELOAD | IOP_TMR_RATIO_1_1;
/*
- * We use timer 0 for our timer interrupt, and timer 1 as
- * monotonic counter for tracking missed jiffies.
+ * Set up interrupting clockevent timer 0.
*/
+ write_tmr0(timer_ctl & ~IOP_TMR_EN);
+ setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq);
+ iop_clockevent_set_hz(&iop_clockevent, tick_rate);
+ iop_clockevent.max_delta_ns =
+ clockevent_delta2ns(0xfffffffe, &iop_clockevent);
+ iop_clockevent.min_delta_ns =
+ clockevent_delta2ns(0xf, &iop_clockevent);
+ iop_clockevent.cpumask = cpumask_of(0);
+ clockevents_register_device(&iop_clockevent);
write_trr0(ticks_per_jiffy - 1);
+ write_tcr0(ticks_per_jiffy - 1);
write_tmr0(timer_ctl);
+
+ /*
+ * Set up free-running clocksource timer 1.
+ */
write_trr1(0xffffffff);
+ write_tcr1(0xffffffff);
write_tmr1(timer_ctl);
-
- setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq);
+ iop_clocksource_set_hz(&iop_clocksource, tick_rate);
+ clocksource_register(&iop_clocksource);
}
git.samba.org / sfrench / cifs-2.6.git / blobdiff