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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>
This commit is contained in:
Rick Chen 2017-12-12 13:12:21 +08:00 committed by Greentime Hu
parent 35dbb74aa7
commit ea4625c386
1 changed files with 18 additions and 0 deletions
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18
drivers/clocksource/timer-atcpit100.c
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@ -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;
}