[ARM] 4592/1: ns9xxx: clocksource driver
Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-ns9xxx/time.c b/arch/arm/mach-ns9xxx/time.c
index 3327d30..d293455 100644
--- a/arch/arm/mach-ns9xxx/time.c
+++ b/arch/arm/mach-ns9xxx/time.c
@@ -11,6 +11,9 @@
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
+#include <linux/stringify.h>
+#include <linux/clocksource.h>
+
#include <asm/arch-ns9xxx/regs-sys.h>
#include <asm/arch-ns9xxx/clock.h>
#include <asm/arch-ns9xxx/irqs.h>
@@ -18,8 +21,7 @@
#include "generic.h"
#define TIMERCLOCKSELECT 64
-
-static u32 usecs_per_tick;
+#define TIMER_CLOCKSOURCE 1
static irqreturn_t
ns9xxx_timer_interrupt(int irq, void *dev_id)
@@ -45,39 +47,30 @@
return IRQ_HANDLED;
}
-static unsigned long ns9xxx_timer_gettimeoffset(void)
-{
- /* return the microseconds which have passed since the last interrupt
- * was _serviced_. That is, if an interrupt is pending or the counter
- * reloads, return one period more. */
-
- u32 counter1 = SYS_TR(0);
- int pending = SYS_ISR & (1 << IRQ_TIMER0);
- u32 counter2 = SYS_TR(0);
- u32 elapsed;
-
- if (pending || counter2 > counter1)
- elapsed = 2 * SYS_TRC(0) - counter2;
- else
- elapsed = SYS_TRC(0) - counter1;
-
- return (elapsed * usecs_per_tick) >> 16;
-
-}
-
static struct irqaction ns9xxx_timer_irq = {
.name = "NS9xxx Timer Tick",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = ns9xxx_timer_interrupt,
};
+static cycle_t ns9xxx_clocksource_read(void)
+{
+ return SYS_TR(TIMER_CLOCKSOURCE);
+}
+
+static struct clocksource ns9xxx_clocksource = {
+ .name = "ns9xxx-timer" __stringify(TIMER_CLOCKSOURCE),
+ .rating = 300,
+ .read = ns9xxx_clocksource_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .shift = 20,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
static void __init ns9xxx_timer_init(void)
{
int tc;
- usecs_per_tick =
- SH_DIV(1000000 * TIMERCLOCKSELECT, ns9xxx_cpuclock(), 16);
-
/* disable timer */
if ((tc = SYS_TC(0)) & SYS_TCx_TEN)
SYS_TC(0) = tc & ~SYS_TCx_TEN;
@@ -94,9 +87,32 @@
SYS_TC(0) = tc;
setup_irq(IRQ_TIMER0, &ns9xxx_timer_irq);
+
+ tc = SYS_TC(TIMER_CLOCKSOURCE);
+ if (REGGET(tc, SYS_TCx, TEN)) {
+ REGSET(tc, SYS_TCx, TEN, DIS);
+ SYS_TC(TIMER_CLOCKSOURCE) = tc;
+ }
+
+ SYS_TRC(TIMER_CLOCKSOURCE) = 0;
+
+ REGSET(tc, SYS_TCx, TEN, EN);
+ REGSET(tc, SYS_TCx, TDBG, STOP);
+ REGSET(tc, SYS_TCx, TLCS, CPU);
+ REGSET(tc, SYS_TCx, TM, IEE);
+ REGSET(tc, SYS_TCx, INTS, DIS);
+ REGSET(tc, SYS_TCx, UDS, UP);
+ REGSET(tc, SYS_TCx, TSZ, 32);
+ REGSET(tc, SYS_TCx, REN, EN);
+
+ SYS_TC(TIMER_CLOCKSOURCE) = tc;
+
+ ns9xxx_clocksource.mult = clocksource_hz2mult(ns9xxx_cpuclock(),
+ ns9xxx_clocksource.shift);
+
+ clocksource_register(&ns9xxx_clocksource);
}
struct sys_timer ns9xxx_timer = {
.init = ns9xxx_timer_init,
- .offset = ns9xxx_timer_gettimeoffset,
};