@@ -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);
}