[ARM] 3856/1: Add clocksource for Intel IXP4xx platforms
Enables the ixp4xx platforms to use Generic time-of-day.
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index 7c25dbd..35dd8b3 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -26,6 +26,7 @@
#include <linux/bitops.h>
#include <linux/time.h>
#include <linux/timex.h>
+#include <linux/clocksource.h>
#include <asm/hardware.h>
#include <asm/uaccess.h>
@@ -255,16 +256,6 @@
#define CLOCK_TICKS_PER_USEC ((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC)
-/* IRQs are disabled before entering here from do_gettimeofday() */
-static unsigned long ixp4xx_gettimeoffset(void)
-{
- u32 elapsed;
-
- elapsed = *IXP4XX_OSTS - last_jiffy_time;
-
- return elapsed / CLOCK_TICKS_PER_USEC;
-}
-
static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
write_seqlock(&xtime_lock);
@@ -309,7 +300,6 @@
struct sys_timer ixp4xx_timer = {
.init = ixp4xx_timer_init,
- .offset = ixp4xx_gettimeoffset,
};
static struct resource ixp46x_i2c_resources[] = {
@@ -365,3 +355,29 @@
ixp4xx_exp_bus_size >> 20);
}
+cycle_t ixp4xx_get_cycles(void)
+{
+ return *IXP4XX_OSTS;
+}
+
+static struct clocksource clocksource_ixp4xx = {
+ .name = "OSTS",
+ .rating = 200,
+ .read = ixp4xx_get_cycles,
+ .mask = CLOCKSOURCE_MASK(32),
+ .shift = 20,
+ .is_continuous = 1,
+};
+
+unsigned long ixp4xx_timer_freq = FREQ;
+static int __init ixp4xx_clocksource_init(void)
+{
+ clocksource_ixp4xx.mult =
+ clocksource_hz2mult(ixp4xx_timer_freq,
+ clocksource_ixp4xx.shift);
+ clocksource_register(&clocksource_ixp4xx);
+
+ return 0;
+}
+
+device_initcall(ixp4xx_clocksource_init);