clocksource: timer-ti-dm: Consolidate set source

Reorder omap_dm_timer_set_source internals to get
source verification more straightforward.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c
index 935350176c016ead964e3d2a6844eee5dba2b320..6abe5ab553ce206391a51618f4fd4e0992a52c28 100644 (file)
--- a/drivers/clocksource/timer-ti-dm.c
+++ b/drivers/clocksource/timer-ti-dm.c
@@ -166,17 +166,28 @@ static int omap_dm_timer_of_set_source(struct omap_dm_timer *timer)
 static int omap_dm_timer_set_source(struct omap_dm_timer *timer, int source)
 {
        int ret;
-       char *parent_name = NULL;
+       const char *parent_name;
        struct clk *parent;
        struct dmtimer_platform_data *pdata;
 
-       if (unlikely(!timer))
+       if (unlikely(!timer) || IS_ERR(timer->fclk))
                return -EINVAL;
 
-       pdata = timer->pdev->dev.platform_data;
-
-       if (source < 0 || source >= 3)
+       switch (source) {
+       case OMAP_TIMER_SRC_SYS_CLK:
+               parent_name = "timer_sys_ck";
+               break;
+       case OMAP_TIMER_SRC_32_KHZ:
+               parent_name = "timer_32k_ck";
+               break;
+       case OMAP_TIMER_SRC_EXT_CLK:
+               parent_name = "timer_ext_ck";
+               break;
+       default:
                return -EINVAL;
+       }
+
+       pdata = timer->pdev->dev.platform_data;
 
        /*
         * FIXME: Used for OMAP1 devices only because they do not currently
@@ -186,29 +197,12 @@ static int omap_dm_timer_set_source(struct omap_dm_timer *timer, int source)
        if (pdata && pdata->set_timer_src)
                return pdata->set_timer_src(timer->pdev, source);
 
-       if (IS_ERR(timer->fclk))
-               return -EINVAL;
-
 #if defined(CONFIG_COMMON_CLK)
        /* Check if the clock has configurable parents */
        if (clk_hw_get_num_parents(__clk_get_hw(timer->fclk)) < 2)
                return 0;
 #endif
 
-       switch (source) {
-       case OMAP_TIMER_SRC_SYS_CLK:
-               parent_name = "timer_sys_ck";
-               break;
-
-       case OMAP_TIMER_SRC_32_KHZ:
-               parent_name = "timer_32k_ck";
-               break;
-
-       case OMAP_TIMER_SRC_EXT_CLK:
-               parent_name = "timer_ext_ck";
-               break;
-       }
-
        parent = clk_get(&timer->pdev->dev, parent_name);
        if (IS_ERR(parent)) {
                pr_err("%s: %s not found\n", __func__, parent_name);