ARM: S3C2443: handle unset armdiv values gracefully

The armdiv array may contain unset divider values.
Check the relevant value to prevent division by zero
errors. Also check for set nr_armdiv and armdivmask
before meddling with clkdiv0.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

1 files changed, 20 insertions, 7 deletions

diff --git a/arch/arm/plat-s3c24xx/s3c2443-clock.c b/arch/arm/plat-s3c24xx/s3c2443-clock.c
index fea3d5c0252..31f97f1bb36 100644
--- a/arch/arm/plat-s3c24xx/s3c2443-clock.c
+++ b/arch/arm/plat-s3c24xx/s3c2443-clock.c
@@ -179,11 +179,16 @@ static unsigned long s3c2443_armclk_roundrate(struct clk *clk,
         unsigned div;
         int ptr;
 
+        if (!nr_armdiv)
+                return -EINVAL;
+
         for (ptr = 0; ptr < nr_armdiv; ptr++) {
                 div = armdiv[ptr];
-                calc = parent / div;
-                if (calc <= rate && div < best)
-                        best = div;
+                if (div) {
+                        calc = parent / div;
+                        if (calc <= rate && div < best)
+                                best = div;
+                }
         }
 
         return parent / best;
@@ -195,6 +200,9 @@ static unsigned long s3c2443_armclk_getrate(struct clk *clk)
         unsigned long clkcon0;
         int val;
 
+        if (!nr_armdiv || !armdivmask)
+                return -EINVAL;
+
         clkcon0 = __raw_readl(S3C2443_CLKDIV0);
         clkcon0 &= armdivmask;
         val = clkcon0 >> S3C2443_CLKDIV0_ARMDIV_SHIFT;
@@ -211,12 +219,17 @@ static int s3c2443_armclk_setrate(struct clk *clk, unsigned long rate)
         int ptr;
         int val = -1;
 
+        if (!nr_armdiv || !armdivmask)
+                return -EINVAL;
+
         for (ptr = 0; ptr < nr_armdiv; ptr++) {
                 div = armdiv[ptr];
-                calc = parent / div;
-                if (calc <= rate && div < best) {
-                        best = div;
-                        val = ptr;
+                if (div) {
+                        calc = parent / div;
+                        if (calc <= rate && div < best) {
+                                best = div;
+                                val = ptr;
+                        }
                 }
         }