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Diffstat (limited to 'arch/arm/kernel/smp_twd.c')
-rw-r--r--arch/arm/kernel/smp_twd.c40
1 files changed, 39 insertions, 1 deletions
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index f0575610b17..a9783947c08 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -10,8 +10,10 @@
*/
#include <linux/init.h>
#include <linux/kernel.h>
+#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
+#include <linux/err.h>
#include <linux/smp.h>
#include <linux/jiffies.h>
#include <linux/clockchips.h>
@@ -25,6 +27,7 @@
/* set up by the platform code */
void __iomem *twd_base;
+static struct clk *twd_clk;
static unsigned long twd_timer_rate;
static struct clock_event_device __percpu **twd_evt;
@@ -140,6 +143,35 @@ static irqreturn_t twd_handler(int irq, void *dev_id)
return IRQ_NONE;
}
+static struct clk *twd_get_clock(void)
+{
+ struct clk *clk;
+ int err;
+
+ clk = clk_get_sys("smp_twd", NULL);
+ if (IS_ERR(clk)) {
+ pr_err("smp_twd: clock not found: %d\n", (int)PTR_ERR(clk));
+ return clk;
+ }
+
+ err = clk_prepare(clk);
+ if (err) {
+ pr_err("smp_twd: clock failed to prepare: %d\n", err);
+ clk_put(clk);
+ return ERR_PTR(err);
+ }
+
+ err = clk_enable(clk);
+ if (err) {
+ pr_err("smp_twd: clock failed to enable: %d\n", err);
+ clk_unprepare(clk);
+ clk_put(clk);
+ return ERR_PTR(err);
+ }
+
+ return clk;
+}
+
/*
* Setup the local clock events for a CPU.
*/
@@ -165,7 +197,13 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk)
}
}
- twd_calibrate_rate();
+ if (!twd_clk)
+ twd_clk = twd_get_clock();
+
+ if (!IS_ERR_OR_NULL(twd_clk))
+ twd_timer_rate = clk_get_rate(twd_clk);
+ else
+ twd_calibrate_rate();
clk->name = "local_timer";
clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |