ARM: pxa: add clk_set_rate()

Since there're mulitple clock rates in some device controllers, enable
clk_set_rate() for this usage.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>

arch/arm/mach-mmp/clock.c

@@ -88,3 +88,18 @@ unsigned long clk_get_rate(struct clk *clk)
 	return rate;
 }
 EXPORT_SYMBOL(clk_get_rate);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned long flags;
+	int ret = -EINVAL;
+
+	if (clk->ops->setrate) {
+		spin_lock_irqsave(&clocks_lock, flags);
+		ret = clk->ops->setrate(clk, rate);
+		spin_unlock_irqrestore(&clocks_lock, flags);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(clk_set_rate);

arch/arm/mach-mmp/clock.h

@@ -12,6 +12,7 @@ struct clkops {
 	void			(*enable)(struct clk *);
 	void			(*disable)(struct clk *);
 	unsigned long		(*getrate)(struct clk *);
+	int			(*setrate)(struct clk *, unsigned long);
 };
 
 struct clk {

arch/arm/mach-pxa/clock.c

@@ -53,6 +53,21 @@ unsigned long clk_get_rate(struct clk *clk)
 }
 EXPORT_SYMBOL(clk_get_rate);
 
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned long flags;
+	int ret = -EINVAL;
+
+	if (clk->ops->setrate) {
+		spin_lock_irqsave(&clocks_lock, flags);
+		ret = clk->ops->setrate(clk, rate);
+		spin_unlock_irqrestore(&clocks_lock, flags);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(clk_set_rate);
+
 void clk_dummy_enable(struct clk *clk)
 {
 }

arch/arm/mach-pxa/clock.h

@@ -5,6 +5,7 @@ struct clkops {
 	void			(*enable)(struct clk *);
 	void			(*disable)(struct clk *);
 	unsigned long		(*getrate)(struct clk *);
+	int			(*setrate)(struct clk *, unsigned long);
 };
 
 struct clk {