1 files changed, 39 insertions, 1 deletions

diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index f0575610b17e..a9783947c086 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 |