ARM: OMAP2+: Move dmtimer clock set function to dmtimer driver

OMAP1 uses an architecture specific function for setting the dmtimer clock
source, where as the OMAP2+ devices use the clock framework. Eventually OMAP1
device should also use the clock framework and hence we should not any
architecture specific functions.

For now move the OMAP2+ function for configuring the clock source into the
dmtimer driver. Therefore, we do no longer need to specify an architecture
specific function for setting the clock source for OMAP2+ devices. This will
simplify device tree migration of the dmtimers for OMAP2+ devices.

From now on, only OMAP1 devices should specify an architecture specific
function for setting the clock source via the platform data set_dmtimer_src()
function pointer.

Signed-off-by: Jon Hunter <jon-hunter@ti.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 6510e5e..6a70889 100644
--- a/arch/arm/plat-omap/dmtimer.c
+++ b/arch/arm/plat-omap/dmtimer.c
@@ -397,6 +397,8 @@
 int omap_dm_timer_set_source(struct omap_dm_timer *timer, int source)
 {
 	int ret;
+	char *parent_name = NULL;
+	struct clk *fclk, *parent;
 	struct dmtimer_platform_data *pdata;
 
 	if (unlikely(!timer))
@@ -407,7 +409,49 @@
 	if (source < 0 || source >= 3)
 		return -EINVAL;
 
-	ret = pdata->set_timer_src(timer->pdev, source);
+	/*
+	 * FIXME: Used for OMAP1 devices only because they do not currently
+	 * use the clock framework to set the parent clock. To be removed
+	 * once OMAP1 migrated to using clock framework for dmtimers
+	 */
+	if (pdata->set_timer_src)
+		return pdata->set_timer_src(timer->pdev, source);
+
+	fclk = clk_get(&timer->pdev->dev, "fck");
+	if (IS_ERR_OR_NULL(fclk)) {
+		pr_err("%s: fck not found\n", __func__);
+		return -EINVAL;
+	}
+
+	switch (source) {
+	case OMAP_TIMER_SRC_SYS_CLK:
+		parent_name = "sys_ck";
+		break;
+
+	case OMAP_TIMER_SRC_32_KHZ:
+		parent_name = "32k_ck";
+		break;
+
+	case OMAP_TIMER_SRC_EXT_CLK:
+		parent_name = "alt_ck";
+		break;
+	}
+
+	parent = clk_get(&timer->pdev->dev, parent_name);
+	if (IS_ERR_OR_NULL(parent)) {
+		pr_err("%s: %s not found\n", __func__, parent_name);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = clk_set_parent(fclk, parent);
+	if (IS_ERR_VALUE(ret))
+		pr_err("%s: failed to set %s as parent\n", __func__,
+			parent_name);
+
+	clk_put(parent);
+out:
+	clk_put(fclk);
 
 	return ret;
 }