drivers: clk: Add a managed API to get clocks from the device-tree

Add devm_clk_get(), devm_clk_get_optional() to get clocks from the
device-tree. The clocks is automatically released and the data structure
freed when the device is unbound.
Also add devm_clk_put() to release the clock and free the data structure
manually.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/include/clk.h b/include/clk.h
index 6568865d40..9be3264113 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -155,6 +155,37 @@ int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk);
 int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk);
 
 /**
+ * devm_clk_get - lookup and obtain a managed reference to a clock producer.
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Returns a struct clk corresponding to the clock producer, or
+ * valid IS_ERR() condition containing errno.  The implementation
+ * uses @dev and @id to determine the clock consumer, and thereby
+ * the clock producer.  (IOW, @id may be identical strings, but
+ * clk_get may return different clock producers depending on @dev.)
+ *
+ * Drivers must assume that the clock source is not enabled.
+ *
+ * devm_clk_get should not be called from within interrupt context.
+ *
+ * The clock will automatically be freed when the device is unbound
+ * from the bus.
+ */
+struct clk *devm_clk_get(struct udevice *dev, const char *id);
+
+/**
+ * devm_clk_get_optional - lookup and obtain a managed reference to an optional
+ *			   clock producer.
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Behaves the same as devm_clk_get() except where there is no clock producer.
+ * In this case, instead of returning -ENOENT, the function returns NULL.
+ */
+struct clk *devm_clk_get_optional(struct udevice *dev, const char *id);
+
+/**
  * clk_release_all() - Disable (turn off)/Free an array of previously
  * requested clocks.
  *
@@ -168,6 +199,19 @@ int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk);
  */
 int clk_release_all(struct clk *clk, int count);
 
+/**
+ * devm_clk_put	- "free" a managed clock source
+ * @dev: device used to acquire the clock
+ * @clk: clock source acquired with devm_clk_get()
+ *
+ * Note: drivers must ensure that all clk_enable calls made on this
+ * clock source are balanced by clk_disable calls prior to calling
+ * this function.
+ *
+ * clk_put should not be called from within interrupt context.
+ */
+void devm_clk_put(struct udevice *dev, struct clk *clk);
+
 #else
 static inline int clk_get_by_index(struct udevice *dev, int index,
 				   struct clk *clk)
@@ -379,3 +423,6 @@ int clk_get_by_id(ulong id, struct clk **clkp);
  */
 bool clk_dev_binded(struct clk *clk);
 #endif
+
+#define clk_prepare_enable(clk) clk_enable(clk)
+#define clk_disable_unprepare(clk) clk_disable(clk)