Convert omap to use the new sched_clock() infrastructure for extending
32bit counters to full 64-bit nanoseconds.
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
---
arch/arm/Kconfig | 1 +
arch/arm/plat-omap/counter_32k.c | 24 ++++++++++++++++++++++--
2 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 58e2fe3..726279f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -839,6 +839,7 @@ config ARCH_OMAP
select ARCH_REQUIRE_GPIOLIB
select ARCH_HAS_CPUFREQ
select GENERIC_CLOCKEVENTS
+ select HAVE_SCHED_CLOCK
select ARCH_HAS_HOLES_MEMORYMODEL
help
Support for TI's OMAP platform (OMAP1/2/3/4).
diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c
index aed301b..1b558ef 100644
--- a/arch/arm/plat-omap/counter_32k.c
+++ b/arch/arm/plat-omap/counter_32k.c
@@ -18,6 +18,8 @@
#include <linux/io.h>
#include <linux/sched.h>
+#include <asm/sched_clock.h>
+
#include <plat/common.h>
#include <plat/board.h>
@@ -110,10 +112,25 @@ static struct clocksource clocksource_32k = {
* Returns current time from boot in nsecs. It's OK for this to wrap
* around for now, as it's just a relative time stamp.
*/
+static DEFINE_CLOCK_DATA(cd);
+
+/*
+ * Constants generated by clocks_calc_mult_shift(m, s, 32768, NSEC_PER_SEC, 60).
+ * This gives a resolution of about 30us and a wrap period of about 36hrs.
+ */
+#define SC_MULT 4000000000u
+#define SC_SHIFT 17
+
unsigned long long notrace sched_clock(void)
{
- return clocksource_cyc2ns(clocksource_32k.read(&clocksource_32k),
- clocksource_32k.mult, clocksource_32k.shift);
+ u32 cyc = clocksource_32k.read(&clocksource_32k);
+ return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0, SC_MULT, SC_SHIFT);
+}
+
+static void notrace omap_update_sched_clock(void)
+{
+ u32 cyc = clocksource_32k.read(&clocksource_32k);
+ update_sched_clock(&cd, cyc, (u32)~0);
}
/**
@@ -171,6 +188,9 @@ static int __init omap_init_clocksource_32k(void)
if (clocksource_register_hz(&clocksource_32k, 32768))
printk(err, clocksource_32k.name);
+
+ init_fixed_sched_clock(&cd, omap_update_sched_clock, 32,
+ 32768, SC_MULT, SC_SHIFT);
}
return 0;
}
--
1.6.2.5
--
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