clk: Extract OF clock helpers in <linux/of_clk.h>

The use of of_clk_get_parent_{count,name}() and of_clk_init() is not
limited to clock providers.

Hence move these helpers into their own header file, so callers that are
not clock providers no longer have to include <linux/clk-provider.h>.

Suggested-by: Stephen Boyd <[e-mail]>
Signed-off-by: Geert Uytterhoeven <[e-mail]>
Reviewed-by: Heiko Stuebner <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

MAINTAINERS

···
 X:	drivers/clk/clkdev.c
 F:	include/linux/clk-pr*
 F:	include/linux/clk/
+F:	include/linux/of_clk.h
 
 COMMON INTERNET FILE SYSTEM (CIFS)
 M:	Steve French <[e-mail]>

include/linux/clk-provider.h

···
 
 #include <linux/io.h>
 #include <linux/of.h>
+#include <linux/of_clk.h>
 
 #ifdef CONFIG_COMMON_CLK
 
···
 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data);
 struct clk_hw *of_clk_hw_onecell_get(struct of_phandle_args *clkspec,
 				     void *data);
-unsigned int of_clk_get_parent_count(struct device_node *np);
 int of_clk_parent_fill(struct device_node *np, const char **parents,
 		       unsigned int size);
-const char *of_clk_get_parent_name(struct device_node *np, int index);
 int of_clk_detect_critical(struct device_node *np, int index,
 			    unsigned long *flags);
-void of_clk_init(const struct of_device_id *matches);
 
 #else /* !CONFIG_OF */
 
···
 {
 	return ERR_PTR(-ENOENT);
 }
-static inline unsigned int of_clk_get_parent_count(struct device_node *np)
-{
-	return 0;
-}
 static inline int of_clk_parent_fill(struct device_node *np,
 				     const char **parents, unsigned int size)
 {
 	return 0;
-}
-static inline const char *of_clk_get_parent_name(struct device_node *np,
-						 int index)
-{
-	return NULL;
 }
 static inline int of_clk_detect_critical(struct device_node *np, int index,
 					  unsigned long *flags)
 {
 	return 0;
 }
-static inline void of_clk_init(const struct of_device_id *matches) {}
 #endif /* CONFIG_OF */
 
 /*

include/linux/of_clk.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * OF clock helpers
+ */
+
+#ifndef __LINUX_OF_CLK_H
+#define __LINUX_OF_CLK_H
+
+#if defined(CONFIG_COMMON_CLK) && defined(CONFIG_OF)
+
+unsigned int of_clk_get_parent_count(struct device_node *np);
+const char *of_clk_get_parent_name(struct device_node *np, int index);
+void of_clk_init(const struct of_device_id *matches);
+
+#else /* !CONFIG_COMMON_CLK || !CONFIG_OF */
+
+static inline unsigned int of_clk_get_parent_count(struct device_node *np)
+{
+	return 0;
+}
+static inline const char *of_clk_get_parent_name(struct device_node *np,
+						 int index)
+{
+	return NULL;
+}
+static inline void of_clk_init(const struct of_device_id *matches) {}
+
+#endif /* !CONFIG_COMMON_CLK || !CONFIG_OF */
+
+#endif /* __LINUX_OF_CLK_H */