clk: add helper functions clk_prepare_enable and clk_disable_unprepare

It's for migrating to generic clk framework API.

The helper functions  help cases clk_enable/clk_disable is used
in non-atomic context.
For example, Call clk_enable in probe and clk_disable in remove.

Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Marek Vasut <marek.vasut@gmail.com>

diff --git a/include/linux/clk.h b/include/linux/clk.h
index 7213b52b2c0e728275f6685b6d6a2840e751814b..b9d46fa154b40f065449b901ae5982503e1e4430 100644 (file)
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -107,6 +107,28 @@ static inline void clk_unprepare(struct clk *clk)
 }
 #endif
 
+/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
+static inline int clk_prepare_enable(struct clk *clk)
+{
+       int ret;
+
+       ret = clk_prepare(clk);
+       if (ret)
+               return ret;
+       ret = clk_enable(clk);
+       if (ret)
+               clk_unprepare(clk);
+
+       return ret;
+}
+
+/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
+static inline void clk_disable_unprepare(struct clk *clk)
+{
+       clk_disable(clk);
+       clk_unprepare(clk);
+}
+
 /**
  * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
  *               This is only valid once the clock source has been enabled.