From: Russell King <rmk+ker...@armlinux.org.uk>
Add an implementation for the ARM delay timer, which is used for
udelay(). This provides less CPU dependent and more accurate delays -
the CPU loop on Marvell Dove appears to calibrate to around 6% too
short.
Signed-off-by: Russell King <rmk+ker...@armlinux.org.uk>
Signed-off-by: Daniel Lezcano <daniel.lezc...@linaro.org>
---
drivers/clocksource/time-orion.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/drivers/clocksource/time-orion.c b/drivers/clocksource/time-orion.c
index c4818a5..7eb2ab0 100644
--- a/drivers/clocksource/time-orion.c
+++ b/drivers/clocksource/time-orion.c
@@ -15,6 +15,7 @@
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
+#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
@@ -36,6 +37,21 @@
static void __iomem *timer_base;
+static unsigned long notrace orion_read_timer(void)
+{
+ return ~readl(timer_base + TIMER0_VAL);
+}
+
+static struct delay_timer orion_delay_timer = {
+ .read_current_timer = orion_read_timer,
+};
+
+static void orion_delay_timer_init(unsigned long rate)
+{
+ orion_delay_timer.freq = rate;
+ register_current_timer_delay(&orion_delay_timer);
+}
+
/*
* Free-running clocksource handling.
*/
@@ -168,6 +184,9 @@ static int __init orion_timer_init(struct device_node *np)
clockevents_config_and_register(&orion_clkevt, rate,
ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
+
+ orion_delay_timer_init(rate);
+
return 0;
}
CLOCKSOURCE_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);
--
2.7.4
