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authorOlof Johansson <olof@lixom.net>2014-07-07 04:47:28 +0400
committerOlof Johansson <olof@lixom.net>2014-07-07 04:47:28 +0400
commitb040614c5bf6af6657574299fdf0572d47b53366 (patch)
tree0c969ce83d8a76cfaf3ff7b58d963b668eab23d4 /drivers/clocksource
parent21760aedabc795a6758bf15fafcd59fe0799cd9f (diff)
parent0ff36b4f479ec8e0cd9b7a919ab877f2d553cd30 (diff)
downloadlinux-b040614c5bf6af6657574299fdf0572d47b53366.tar.xz
Merge tag 'tegra-for-3.17-delay-timer' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into next/soc
Merge "ARM: tegra: use us counter as delay timer" from Stephen Warren: Tegra has a micro-second counter whose rate doesn't vary with cpufreq changes. Register it so it can be used as the delay timer, so delays aren't influenced by cpufreq. * tag 'tegra-for-3.17-delay-timer' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux: clocksource: tegra: Use us counter as delay timer ARM: choose highest resolution delay timer kernel: add calibration_delay_done() Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/tegra20_timer.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/clocksource/tegra20_timer.c b/drivers/clocksource/tegra20_timer.c
index d1869f02051c..d2616ef16770 100644
--- a/drivers/clocksource/tegra20_timer.c
+++ b/drivers/clocksource/tegra20_timer.c
@@ -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);