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Commit 0ff36b4f authored by Peter De Schrijver's avatar Peter De Schrijver Committed by Stephen Warren
Browse files

clocksource: tegra: Use us counter as delay timer 



All Tegra SoCs have a freerunning microsecond counter which can be used as a
delay timer.

Signed-off-by: default avatarPeter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
parent 5930c1a1

drivers/clocksource/tegra20_timer.c

+13 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <linux/of_address.h>

#include <linux/of_irq.h>

#include <linux/sched_clock.h>

#include <linux/delay.h>



#include <asm/mach/time.h>

#include <asm/smp_twd.h>
@@ -53,6 +54,8 @@ static void __iomem *rtc_base; 
static struct timespec persistent_ts;

static u64 persistent_ms, last_persistent_ms;



static struct delay_timer tegra_delay_timer;



#define timer_writel(value, reg) \

	__raw_writel(value, timer_reg_base + (reg))

#define timer_readl(reg) \
@@ -139,6 +142,11 @@ static void tegra_read_persistent_clock(struct timespec *ts) 
	*ts = *tsp;

}



static unsigned long tegra_delay_timer_read_counter_long(void)

{

	return readl(timer_reg_base + TIMERUS_CNTR_1US);

}



static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id)

{

	struct clock_event_device *evt = (struct clock_event_device *)dev_id;
@@ -206,6 +214,11 @@ static void __init tegra20_init_timer(struct device_node *np) 
		BUG();

	}



	tegra_delay_timer.read_current_timer =

			tegra_delay_timer_read_counter_long;

	tegra_delay_timer.freq = 1000000;

	register_current_timer_delay(&tegra_delay_timer);



	ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq);

	if (ret) {

		pr_err("Failed to register timer IRQ: %d\n", ret);