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Subject[PATCH v7 2/3] clocksource/drivers/atcpit100: VDSO support
Date
From: Rick Chen <rickchen36@gmail.com>

VDSO needs real-time cycle count to ensure the time accuracy.
Unlike others, nds32 architecture does not define clock source,
hence VDSO needs atcpit100 offering real-time cycle count
to derive the correct time.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Rick Chen <rickchen36@gmail.com>
Signed-off-by: Greentime Hu <green.hu@gmail.com>
---
drivers/clocksource/timer-atcpit100.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/drivers/clocksource/timer-atcpit100.c b/drivers/clocksource/timer-atcpit100.c
index 2190096cffa3..5e23d7b4a722 100644
--- a/drivers/clocksource/timer-atcpit100.c
+++ b/drivers/clocksource/timer-atcpit100.c
@@ -18,6 +18,9 @@
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include "timer-of.h"
+#ifdef CONFIG_NDS32
+#include <asm/vdso_timer_info.h>
+#endif

/*
* Definition of register offsets
@@ -204,6 +207,17 @@ static u64 notrace atcpit100_timer_sched_read(void)
return ~readl(timer_of_base(&to) + CH1_CNT);
}

+#ifdef CONFIG_NDS32
+static void fill_vdso_need_info(struct device_node *node)
+{
+ struct resource timer_res;
+ of_address_to_resource(node, 0, &timer_res);
+ timer_info.mapping_base = (unsigned long)timer_res.start;
+ timer_info.cycle_count_down = true;
+ timer_info.cycle_count_reg_offset = CH1_CNT;
+}
+#endif
+
static int __init atcpit100_timer_init(struct device_node *node)
{
int ret;
@@ -242,6 +256,10 @@ static int __init atcpit100_timer_init(struct device_node *node)
val = readl(base + INT_EN);
writel(val | CH0INT0EN, base + INT_EN);

+#ifdef CONFIG_NDS32
+ fill_vdso_need_info(node);
+#endif
+
return ret;
}

--
2.16.1
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