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authorRussell King <rmk+kernel@armlinux.org.uk>2017-03-11 17:42:34 +0000
committerDaniel Lezcano <daniel.lezcano@linaro.org>2017-04-07 16:23:03 +0200
commit9a4914ce0dff47b53df9ffbf9f48120b86ccb4a3 (patch)
tree5629c50430e4ae90e435dc19f7a7701f8054c4d1 /drivers/clocksource
parent0d9298ea37b5f590f3d10ccc2d8d34d26af3fa84 (diff)
downloadlinux-9a4914ce0dff47b53df9ffbf9f48120b86ccb4a3.tar.bz2
clocksource/drivers/orion: Add delay_timer implementation
Add an implementation for the ARM delay timer, which is used for udelay(). This provides less CPU dependent and more accurate delays - the CPU loop on Marvell Dove appears to calibrate to around 6% too short. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/time-orion.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/clocksource/time-orion.c b/drivers/clocksource/time-orion.c
index c4818a5dc8e5..7eb2ab0bd114 100644
--- a/drivers/clocksource/time-orion.c
+++ b/drivers/clocksource/time-orion.c
@@ -15,6 +15,7 @@
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
+#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
@@ -36,6 +37,21 @@
static void __iomem *timer_base;
+static unsigned long notrace orion_read_timer(void)
+{
+ return ~readl(timer_base + TIMER0_VAL);
+}
+
+static struct delay_timer orion_delay_timer = {
+ .read_current_timer = orion_read_timer,
+};
+
+static void orion_delay_timer_init(unsigned long rate)
+{
+ orion_delay_timer.freq = rate;
+ register_current_timer_delay(&orion_delay_timer);
+}
+
/*
* Free-running clocksource handling.
*/
@@ -168,6 +184,9 @@ static int __init orion_timer_init(struct device_node *np)
clockevents_config_and_register(&orion_clkevt, rate,
ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
+
+ orion_delay_timer_init(rate);
+
return 0;
}
CLOCKSOURCE_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);