ARM: OMAP: More NULL clock checks

NULL pointer checks were not added to all functions as pointed
out by Richards Woodruff.

arch/arm/plat-omap/clock.c

@@ -81,7 +81,7 @@ int clk_enable(struct clk *clk)
 	int ret = 0;
 
 	if (clk == NULL || IS_ERR(clk))
-		return -ENODEV;
+		return -EINVAL;
 
 	spin_lock_irqsave(&clockfw_lock, flags);
 	if (arch_clock->clk_enable)
@@ -154,6 +154,9 @@ long clk_round_rate(struct clk *clk, unsigned long rate)
 	unsigned long flags;
 	long ret = 0;
 
+	if (clk == NULL || IS_ERR(clk))
+		return ret;
+
 	spin_lock_irqsave(&clockfw_lock, flags);
 	if (arch_clock->clk_round_rate)
 		ret = arch_clock->clk_round_rate(clk, rate);
@@ -166,7 +169,10 @@ EXPORT_SYMBOL(clk_round_rate);
 int clk_set_rate(struct clk *clk, unsigned long rate)
 {
 	unsigned long flags;
-	int ret = 0;
+	int ret = -EINVAL;
+
+	if (clk == NULL || IS_ERR(clk))
+		return ret;
 
 	spin_lock_irqsave(&clockfw_lock, flags);
 	if (arch_clock->clk_set_rate)
@@ -180,7 +186,10 @@ EXPORT_SYMBOL(clk_set_rate);
 int clk_set_parent(struct clk *clk, struct clk *parent)
 {
 	unsigned long flags;
-	int ret = 0;
+	int ret = -EINVAL;
+
+	if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
+		return ret;
 
 	spin_lock_irqsave(&clockfw_lock, flags);
 	if (arch_clock->clk_set_parent)
@@ -196,6 +205,9 @@ struct clk *clk_get_parent(struct clk *clk)
 	unsigned long flags;
 	struct clk * ret = NULL;
 
+	if (clk == NULL || IS_ERR(clk))
+		return ret;
+
 	spin_lock_irqsave(&clockfw_lock, flags);
 	if (arch_clock->clk_get_parent)
 		ret = arch_clock->clk_get_parent(clk);
@@ -232,6 +244,9 @@ __setup("mpurate=", omap_clk_setup);
 /* Used for clocks that always have same value as the parent clock */
 void followparent_recalc(struct clk *clk)
 {
+	if (clk == NULL || IS_ERR(clk))
+		return;
+
 	clk->rate = clk->parent->rate;
 }
 
@@ -240,6 +255,9 @@ void propagate_rate(struct clk * tclk)
 {
 	struct clk *clkp;
 
+	if (tclk == NULL || IS_ERR(tclk))
+		return;
+
 	list_for_each_entry(clkp, &clocks, node) {
 		if (likely(clkp->parent != tclk))
 			continue;
@@ -250,6 +268,9 @@ void propagate_rate(struct clk * tclk)
 
 int clk_register(struct clk *clk)
 {
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
 	mutex_lock(&clocks_mutex);
 	list_add(&clk->node, &clocks);
 	if (clk->init)
@@ -262,6 +283,9 @@ EXPORT_SYMBOL(clk_register);
 
 void clk_unregister(struct clk *clk)
 {
+	if (clk == NULL || IS_ERR(clk))
+		return;
+
 	mutex_lock(&clocks_mutex);
 	list_del(&clk->node);
 	mutex_unlock(&clocks_mutex);
@@ -272,6 +296,9 @@ void clk_deny_idle(struct clk *clk)
 {
 	unsigned long flags;
 
+	if (clk == NULL || IS_ERR(clk))
+		return;
+
 	spin_lock_irqsave(&clockfw_lock, flags);
 	if (arch_clock->clk_deny_idle)
 		arch_clock->clk_deny_idle(clk);
@@ -283,6 +310,9 @@ void clk_allow_idle(struct clk *clk)
 {
 	unsigned long flags;
 
+	if (clk == NULL || IS_ERR(clk))
+		return;
+
 	spin_lock_irqsave(&clockfw_lock, flags);
 	if (arch_clock->clk_allow_idle)
 		arch_clock->clk_allow_idle(clk);