1 files changed, 14 insertions, 5 deletions

diff --git a/arch/arm/plat-omap/common.c b/arch/arm/plat-omap/common.c
index 088c1a03b946..01cbb48442ac 100644
--- a/arch/arm/plat-omap/common.c
+++ b/arch/arm/plat-omap/common.c
@@ -100,10 +100,17 @@ EXPORT_SYMBOL(omap_get_var_config);
 
 #include <linux/clocksource.h>
 
+/*
+ * offset_32k holds the init time counter value. It is then subtracted
+ * from every counter read to achieve a counter that counts time from the
+ * kernel boot (needed for sched_clock()).
+ */
+static u32 offset_32k __read_mostly;
+
 #ifdef CONFIG_ARCH_OMAP16XX
 static cycle_t omap16xx_32k_read(struct clocksource *cs)
 {
-        return omap_readl(OMAP16XX_TIMER_32K_SYNCHRONIZED);
+        return omap_readl(OMAP16XX_TIMER_32K_SYNCHRONIZED) - offset_32k;
 }
 #else
 #define omap16xx_32k_read       NULL
@@ -112,7 +119,7 @@ static cycle_t omap16xx_32k_read(struct clocksource *cs)
 #ifdef CONFIG_ARCH_OMAP2420
 static cycle_t omap2420_32k_read(struct clocksource *cs)
 {
-        return omap_readl(OMAP2420_32KSYNCT_BASE + 0x10);
+        return omap_readl(OMAP2420_32KSYNCT_BASE + 0x10) - offset_32k;
 }
 #else
 #define omap2420_32k_read       NULL
@@ -121,7 +128,7 @@ static cycle_t omap2420_32k_read(struct clocksource *cs)
 #ifdef CONFIG_ARCH_OMAP2430
 static cycle_t omap2430_32k_read(struct clocksource *cs)
 {
-        return omap_readl(OMAP2430_32KSYNCT_BASE + 0x10);
+        return omap_readl(OMAP2430_32KSYNCT_BASE + 0x10) - offset_32k;
 }
 #else
 #define omap2430_32k_read       NULL
@@ -130,7 +137,7 @@ static cycle_t omap2430_32k_read(struct clocksource *cs)
 #ifdef CONFIG_ARCH_OMAP3
 static cycle_t omap34xx_32k_read(struct clocksource *cs)
 {
-        return omap_readl(OMAP3430_32KSYNCT_BASE + 0x10);
+        return omap_readl(OMAP3430_32KSYNCT_BASE + 0x10) - offset_32k;
 }
 #else
 #define omap34xx_32k_read       NULL
@@ -139,7 +146,7 @@ static cycle_t omap34xx_32k_read(struct clocksource *cs)
 #ifdef CONFIG_ARCH_OMAP4
 static cycle_t omap44xx_32k_read(struct clocksource *cs)
 {
-        return omap_readl(OMAP4430_32KSYNCT_BASE + 0x10);
+        return omap_readl(OMAP4430_32KSYNCT_BASE + 0x10) - offset_32k;
 }
 #else
 #define omap44xx_32k_read       NULL
@@ -227,6 +234,8 @@ static int __init omap_init_clocksource_32k(void)
                 clocksource_32k.mult = clocksource_hz2mult(32768,
                                             clocksource_32k.shift);
 
+                offset_32k = clocksource_32k.read(&clocksource_32k);
+
                 if (clocksource_register(&clocksource_32k))
                         printk(err, clocksource_32k.name);
         }