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authorStephen Warren <swarren@nvidia.com>2012-11-08 11:51:58 -0700
committerStephen Warren <swarren@nvidia.com>2012-12-24 09:36:35 -0700
commit23c197b77f9553c30f9c8a5ab41279a35f135f37 (patch)
tree7da1f4b032ff24482afb1f289ab9c633de684d7a /arch/arm/mach-ep93xx
parentc8d5ba1891eda2aa63800f052cb5af128283d130 (diff)
downloadlinux-23c197b77f9553c30f9c8a5ab41279a35f135f37.tar.bz2
ARM: set arch_gettimeoffset directly
remove ARM's struct sys_timer .offset function pointer, and instead directly set the arch_gettimeoffset function pointer when the timer driver is initialized. This requires multiplying all function results by 1000, since the removed arm_gettimeoffset() did this. Also, s/unsigned long/u32/ just to make the function prototypes exactly match that of arch_gettimeoffset. Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Victor <linux@maxim.org.za> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Hartley Sweeten <hsweeten@visionengravers.com> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Stephen Warren <swarren@nvidia.com>
Diffstat (limited to 'arch/arm/mach-ep93xx')
-rw-r--r--arch/arm/mach-ep93xx/core.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
index e85bf17f2d2a..6f48b87a1ace 100644
--- a/arch/arm/mach-ep93xx/core.c
+++ b/arch/arm/mach-ep93xx/core.c
@@ -140,11 +140,29 @@ static struct irqaction ep93xx_timer_irq = {
.handler = ep93xx_timer_interrupt,
};
+static u32 ep93xx_gettimeoffset(void)
+{
+ int offset;
+
+ offset = __raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time;
+
+ /*
+ * Timer 4 is based on a 983.04 kHz reference clock,
+ * so dividing by 983040 gives the fraction of a second,
+ * so dividing by 0.983040 converts to uS.
+ * Refactor the calculation to avoid overflow.
+ * Finally, multiply by 1000 to give nS.
+ */
+ return (offset + (53 * offset / 3072)) * 1000;
+}
+
static void __init ep93xx_timer_init(void)
{
u32 tmode = EP93XX_TIMER123_CONTROL_MODE |
EP93XX_TIMER123_CONTROL_CLKSEL;
+ arch_gettimeoffset = ep93xx_gettimeoffset;
+
/* Enable periodic HZ timer. */
__raw_writel(tmode, EP93XX_TIMER1_CONTROL);
__raw_writel(TIMER1_RELOAD, EP93XX_TIMER1_LOAD);
@@ -158,19 +176,8 @@ static void __init ep93xx_timer_init(void)
setup_irq(IRQ_EP93XX_TIMER1, &ep93xx_timer_irq);
}
-static unsigned long ep93xx_gettimeoffset(void)
-{
- int offset;
-
- offset = __raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time;
-
- /* Calculate (1000000 / 983040) * offset. */
- return offset + (53 * offset / 3072);
-}
-
struct sys_timer ep93xx_timer = {
.init = ep93xx_timer_init,
- .offset = ep93xx_gettimeoffset,
};