[PATCH] clocksource: arm_global_timer: register delay timer

From: Rabin Vincent
Date: Wed Aug 19 2015 - 09:49:44 EST


Provide a delay timer using the lower 32-bits of the global timer so
that we can use that instead of having to calibrating delays.

Signed-off-by: Rabin Vincent <rabin.vincent@xxxxxxxx>
---
drivers/clocksource/arm_global_timer.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
index e683377..f92a77d 100644
--- a/drivers/clocksource/arm_global_timer.c
+++ b/drivers/clocksource/arm_global_timer.c
@@ -16,6 +16,7 @@
#include <linux/clockchips.h>
#include <linux/cpu.h>
#include <linux/clk.h>
+#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
@@ -208,6 +209,21 @@ static u64 notrace gt_sched_clock_read(void)
}
#endif

+static unsigned long gt_read_long(void)
+{
+ return readl_relaxed(gt_base + GT_COUNTER0);
+}
+
+static struct delay_timer gt_delay_timer = {
+ .read_current_timer = gt_read_long,
+};
+
+static void __init gt_delay_timer_init(void)
+{
+ gt_delay_timer.freq = gt_clk_rate;
+ register_current_timer_delay(&gt_delay_timer);
+}
+
static void __init gt_clocksource_init(void)
{
writel(0, gt_base + GT_CONTROL);
@@ -304,6 +320,7 @@ static void __init global_timer_of_register(struct device_node *np)
/* Immediately configure the timer on the boot CPU */
gt_clocksource_init();
gt_clockevents_init(this_cpu_ptr(gt_evt));
+ gt_delay_timer_init();

return;

--
1.7.10.4

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