[ARM] 4777/1: S3C24XX: Ensure clk_set_rate() checks the set_rate method for the clk

Add checks for clk_set_rate() and ensure that we do not allow set_rate
to be called for a clock that does not have it defined. Add default
methods for fclk, hclk, pclk and mpll.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 19 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c24xx/clock.c b/arch/arm/plat-s3c24xx/clock.c
index 79cda0faec86..99a44746f8f2 100644
--- a/arch/arm/plat-s3c24xx/clock.c
+++ b/arch/arm/plat-s3c24xx/clock.c
@@ -172,6 +172,15 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
         if (IS_ERR(clk))
                 return -EINVAL;
 
+        /* We do not default just do a clk->rate = rate as
+         * the clock may have been made this way by choice.
+         */
+
+        WARN_ON(clk->set_rate == NULL);
+
+        if (clk->set_rate == NULL)
+                return -EINVAL;
+
         mutex_lock(&clocks_mutex);
         ret = (clk->set_rate)(clk, rate);
         mutex_unlock(&clocks_mutex);
@@ -213,6 +222,12 @@ EXPORT_SYMBOL(clk_set_parent);
 
 /* base clocks */
 
+static int clk_default_setrate(struct clk *clk, unsigned long rate)
+{
+        clk->rate = rate;
+        return 0;
+}
+
 struct clk clk_xtal = {
         .name           = "xtal",
         .id             = -1,
@@ -224,6 +239,7 @@ struct clk clk_xtal = {
 struct clk clk_mpll = {
         .name           = "mpll",
         .id             = -1,
+        .set_rate       = clk_default_setrate,
 };
 
 struct clk clk_upll = {
@@ -239,6 +255,7 @@ struct clk clk_f = {
         .rate           = 0,
         .parent         = &clk_mpll,
         .ctrlbit        = 0,
+        .set_rate       = clk_default_setrate,
 };
 
 struct clk clk_h = {
@@ -247,6 +264,7 @@ struct clk clk_h = {
         .rate           = 0,
         .parent         = NULL,
         .ctrlbit        = 0,
+        .set_rate       = clk_default_setrate,
 };
 
 struct clk clk_p = {
@@ -255,6 +273,7 @@ struct clk clk_p = {
         .rate           = 0,
         .parent         = NULL,
         .ctrlbit        = 0,
+        .set_rate       = clk_default_setrate,
 };
 
 struct clk clk_usb_bus = {