[POWERPC] clk.h interface for platforms

This provides an implementation of the <linux/clk.h> interface for
arch/powerpc using a set of function pointers in clk_functions.
Platforms that want to support this interface should fill
clk_functions and select CONFIG_PPC_CLOCK in Kconfig.

Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/clk_interface.h b/include/asm-powerpc/clk_interface.h
new file mode 100644
index 0000000..ab1882c
--- /dev/null
+++ b/include/asm-powerpc/clk_interface.h
@@ -0,0 +1,20 @@
+#ifndef __ASM_POWERPC_CLK_INTERFACE_H
+#define __ASM_POWERPC_CLK_INTERFACE_H
+
+#include <linux/clk.h>
+
+struct clk_interface {
+	struct clk*	(*clk_get)	(struct device *dev, const char *id);
+	int		(*clk_enable)	(struct clk *clk);
+	void		(*clk_disable)	(struct clk *clk);
+	unsigned long	(*clk_get_rate)	(struct clk *clk);
+	void		(*clk_put)	(struct clk *clk);
+	long		(*clk_round_rate) (struct clk *clk, unsigned long rate);
+	int 		(*clk_set_rate)	(struct clk *clk, unsigned long rate);
+	int		(*clk_set_parent) (struct clk *clk, struct clk *parent);
+	struct clk*	(*clk_get_parent) (struct clk *clk);
+};
+
+extern struct clk_interface clk_functions;
+
+#endif /* __ASM_POWERPC_CLK_INTERFACE_H */