clocksource: mct: add support for mct clock setup

Add support for mct clock lookup and setup to ensure that the mct
clock is has been turned on.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index f817c5401269..203ac05e2b3d 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -479,7 +479,7 @@ static struct local_timer_ops exynos4_mct_tick_ops __cpuinitdata = {
 
 static void __init exynos4_timer_resources(struct device_node *np)
 {
-        struct clk *tick_clk;
+        struct clk *mct_clk, *tick_clk;
 
         tick_clk = np ? of_clk_get_by_name(np, "fin_pll") :
                                 clk_get(NULL, "fin_pll");
@@ -487,6 +487,11 @@ static void __init exynos4_timer_resources(struct device_node *np)
                 panic("%s: unable to determine tick clock rate\n", __func__);
         clk_rate = clk_get_rate(tick_clk);
 
+        mct_clk = np ? of_clk_get_by_name(np, "mct") : clk_get(NULL, "mct");
+        if (IS_ERR(mct_clk))
+                panic("%s: unable to retrieve mct clock instance\n", __func__);
+        clk_prepare_enable(mct_clk);
+
         reg_base = np ? of_iomap(np, 0) : S5P_VA_SYSTIMER;
         if (!reg_base)
                 panic("%s: unable to ioremap mct address space\n", __func__);