ARM: OMAP: dmtimer: Add clock source from DT

Add a function which sets the timer source from the clocks
binding on dm_timer_prepare call.

In case the clocks property is not valid, it falls back to
the set_source() with 32_KHZ clock as default.

Suggested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
index 8ca94d3..7c7f260 100644 (file)
--- a/arch/arm/plat-omap/dmtimer.c
+++ b/arch/arm/plat-omap/dmtimer.c
@@ -137,6 +137,31 @@ static int omap_dm_timer_reset(struct omap_dm_timer *timer)
        return 0;
 }
 
+static int omap_dm_timer_of_set_source(struct omap_dm_timer *timer)
+{
+       int ret;
+       struct clk *parent;
+
+       /*
+        * FIXME: OMAP1 devices do not use the clock framework for dmtimers so
+        * do not call clk_get() for these devices.
+        */
+       if (!timer->fclk)
+               return -ENODEV;
+
+       parent = clk_get(&timer->pdev->dev, NULL);
+       if (IS_ERR(parent))
+               return -ENODEV;
+
+       ret = clk_set_parent(timer->fclk, parent);
+       if (ret < 0)
+               pr_err("%s: failed to set parent\n", __func__);
+
+       clk_put(parent);
+
+       return ret;
+}
+
 static int omap_dm_timer_prepare(struct omap_dm_timer *timer)
 {
        int rc;
@@ -166,7 +191,11 @@ static int omap_dm_timer_prepare(struct omap_dm_timer *timer)
        __omap_dm_timer_enable_posted(timer);
        omap_dm_timer_disable(timer);
 
-       return omap_dm_timer_set_source(timer, OMAP_TIMER_SRC_32_KHZ);
+       rc = omap_dm_timer_of_set_source(timer);
+       if (rc == -ENODEV)
+               return omap_dm_timer_set_source(timer, OMAP_TIMER_SRC_32_KHZ);
+
+       return rc;
 }
 
 static inline u32 omap_dm_timer_reserved_systimer(int id)