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Diffstat (limited to 'arch/arm/mach-versatile/core.c')
-rw-r--r--arch/arm/mach-versatile/core.c129
1 files changed, 85 insertions, 44 deletions
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c
index bf71507c76f..1275aa7d2eb 100644
--- a/arch/arm/mach-versatile/core.c
+++ b/arch/arm/mach-versatile/core.c
@@ -26,6 +26,8 @@
#include <linux/interrupt.h>
#include <linux/amba/bus.h>
#include <linux/amba/clcd.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
#include <asm/cnt32_to_63.h>
#include <asm/system.h>
@@ -828,59 +830,61 @@ void __init versatile_init(void)
#define TICKS2USECS(x) ((x) / TICKS_PER_uSEC)
#endif
-/*
- * Returns number of ms since last clock interrupt. Note that interrupts
- * will have been disabled by do_gettimeoffset()
- */
-static unsigned long versatile_gettimeoffset(void)
+static void timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *clk)
{
- unsigned long ticks1, ticks2, status;
+ unsigned long ctrl;
- /*
- * Get the current number of ticks. Note that there is a race
- * condition between us reading the timer and checking for
- * an interrupt. We get around this by ensuring that the
- * counter has not reloaded between our two reads.
- */
- ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;
- do {
- ticks1 = ticks2;
- status = __raw_readl(VA_IC_BASE + VIC_RAW_STATUS);
- ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;
- } while (ticks2 > ticks1);
+ switch(mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_LOAD);
- /*
- * Number of ticks since last interrupt.
- */
- ticks1 = TIMER_RELOAD - ticks2;
+ ctrl = TIMER_CTRL_PERIODIC;
+ ctrl |= TIMER_CTRL_32BIT | TIMER_CTRL_IE | TIMER_CTRL_ENABLE;
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ /* period set, and timer enabled in 'next_event' hook */
+ ctrl = TIMER_CTRL_ONESHOT;
+ ctrl |= TIMER_CTRL_32BIT | TIMER_CTRL_IE;
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ default:
+ ctrl = 0;
+ }
- /*
- * Interrupt pending? If so, we've reloaded once already.
- *
- * FIXME: Need to check this is effectively timer 0 that expires
- */
- if (status & IRQMASK_TIMERINT0_1)
- ticks1 += TIMER_RELOAD;
+ writel(ctrl, TIMER0_VA_BASE + TIMER_CTRL);
+}
- /*
- * Convert the ticks to usecs
- */
- return TICKS2USECS(ticks1);
+static int timer_set_next_event(unsigned long evt,
+ struct clock_event_device *unused)
+{
+ unsigned long ctrl = readl(TIMER0_VA_BASE + TIMER_CTRL);
+
+ writel(evt, TIMER0_VA_BASE + TIMER_LOAD);
+ writel(ctrl | TIMER_CTRL_ENABLE, TIMER0_VA_BASE + TIMER_CTRL);
+
+ return 0;
}
+static struct clock_event_device timer0_clockevent = {
+ .name = "timer0",
+ .shift = 32,
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .set_mode = timer_set_mode,
+ .set_next_event = timer_set_next_event,
+};
+
/*
* IRQ handler for the timer
*/
static irqreturn_t versatile_timer_interrupt(int irq, void *dev_id)
{
- write_seqlock(&xtime_lock);
+ struct clock_event_device *evt = &timer0_clockevent;
- // ...clear the interrupt
writel(1, TIMER0_VA_BASE + TIMER_INTCLR);
- timer_tick();
-
- write_sequnlock(&xtime_lock);
+ evt->event_handler(evt);
return IRQ_HANDLED;
}
@@ -891,6 +895,36 @@ static struct irqaction versatile_timer_irq = {
.handler = versatile_timer_interrupt,
};
+static cycle_t versatile_get_cycles(void)
+{
+ return ~readl(TIMER3_VA_BASE + TIMER_VALUE);
+}
+
+static struct clocksource clocksource_versatile = {
+ .name = "timer3",
+ .rating = 200,
+ .read = versatile_get_cycles,
+ .mask = CLOCKSOURCE_MASK(32),
+ .shift = 20,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init versatile_clocksource_init(void)
+{
+ /* setup timer3 as free-running clocksource */
+ writel(0, TIMER3_VA_BASE + TIMER_CTRL);
+ writel(0xffffffff, TIMER3_VA_BASE + TIMER_LOAD);
+ writel(0xffffffff, TIMER3_VA_BASE + TIMER_VALUE);
+ writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
+ TIMER3_VA_BASE + TIMER_CTRL);
+
+ clocksource_versatile.mult =
+ clocksource_khz2mult(1000, clocksource_versatile.shift);
+ clocksource_register(&clocksource_versatile);
+
+ return 0;
+}
+
/*
* Set up timer interrupt, and return the current time in seconds.
*/
@@ -918,18 +952,25 @@ static void __init versatile_timer_init(void)
writel(0, TIMER2_VA_BASE + TIMER_CTRL);
writel(0, TIMER3_VA_BASE + TIMER_CTRL);
- writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_LOAD);
- writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_VALUE);
- writel(TIMER_DIVISOR | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC |
- TIMER_CTRL_IE, TIMER0_VA_BASE + TIMER_CTRL);
-
/*
* Make irqs happen for the system timer
*/
setup_irq(IRQ_TIMERINT0_1, &versatile_timer_irq);
+
+ versatile_clocksource_init();
+
+ timer0_clockevent.mult =
+ div_sc(1000000, NSEC_PER_SEC, timer0_clockevent.shift);
+ timer0_clockevent.max_delta_ns =
+ clockevent_delta2ns(0xffffffff, &timer0_clockevent);
+ timer0_clockevent.min_delta_ns =
+ clockevent_delta2ns(0xf, &timer0_clockevent);
+
+ timer0_clockevent.cpumask = cpumask_of_cpu(0);
+ clockevents_register_device(&timer0_clockevent);
}
struct sys_timer versatile_timer = {
.init = versatile_timer_init,
- .offset = versatile_gettimeoffset,
};
+