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authorRick Chen <rickchen36@gmail.com>2017-12-12 08:12:21 +0300
committerGreentime Hu <greentime@andestech.com>2018-02-22 05:44:36 +0300
commitea4625c3860ba002c83b1dffc528e1a4f0a89cf5 (patch)
tree9d3ffbbbb47f114d1b53af9e238658013a86e1bd /drivers/clocksource/timer-atcpit100.c
parent35dbb74aa752cff90e8dac1a24ed2a452aed0251 (diff)
downloadlinux-ea4625c3860ba002c83b1dffc528e1a4f0a89cf5.tar.xz
clocksource/drivers/atcpit100: VDSO support
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>
Diffstat (limited to 'drivers/clocksource/timer-atcpit100.c')
-rw-r--r--drivers/clocksource/timer-atcpit100.c18
1 files changed, 18 insertions, 0 deletions
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;
}