clk: Add devm_clk_bulk_get_optional() function

Add managed version of the clk_bulk_get_optional() helper function.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
[sboyd@kernel.org: Mark __devm_clk_bulk_get() static]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/clk-devres.c

@@ -52,8 +52,8 @@ static void devm_clk_bulk_release(struct device *dev, void *res)
 	clk_bulk_put(devres->num_clks, devres->clks);
 }
 
-int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
-		      struct clk_bulk_data *clks)
+static int __devm_clk_bulk_get(struct device *dev, int num_clks,
+			       struct clk_bulk_data *clks, bool optional)
 {
 	struct clk_bulk_devres *devres;
 	int ret;
@@ -63,7 +63,10 @@ int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
 	if (!devres)
 		return -ENOMEM;
 
-	ret = clk_bulk_get(dev, num_clks, clks);
+	if (optional)
+		ret = clk_bulk_get_optional(dev, num_clks, clks);
+	else
+		ret = clk_bulk_get(dev, num_clks, clks);
 	if (!ret) {
 		devres->clks = clks;
 		devres->num_clks = num_clks;
@@ -74,8 +77,21 @@ int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
 
 	return ret;
 }
+
+int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
+		      struct clk_bulk_data *clks)
+{
+	return __devm_clk_bulk_get(dev, num_clks, clks, false);
+}
 EXPORT_SYMBOL_GPL(devm_clk_bulk_get);
 
+int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
+		      struct clk_bulk_data *clks)
+{
+	return __devm_clk_bulk_get(dev, num_clks, clks, true);
+}
+EXPORT_SYMBOL_GPL(devm_clk_bulk_get_optional);
+
 int __must_check devm_clk_bulk_get_all(struct device *dev,
 				       struct clk_bulk_data **clks)
 {

include/linux/clk.h

@@ -359,6 +359,28 @@ int __must_check clk_bulk_get_optional(struct device *dev, int num_clks,
  */
 int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
 				   struct clk_bulk_data *clks);
+/**
+ * devm_clk_bulk_get_optional - managed get multiple optional consumer clocks
+ * @dev: device for clock "consumer"
+ * @clks: pointer to the clk_bulk_data table of consumer
+ *
+ * Behaves the same as devm_clk_bulk_get() except where there is no clock
+ * producer.  In this case, instead of returning -ENOENT, the function returns
+ * NULL for given clk. It is assumed all clocks in clk_bulk_data are optional.
+ *
+ * Returns 0 if all clocks specified in clk_bulk_data table are obtained
+ * successfully or for any clk there was no clk provider available, otherwise
+ * returns valid IS_ERR() condition containing errno.
+ * The implementation uses @dev and @clk_bulk_data.id to determine the
+ * clock consumer, and thereby the clock producer.
+ * The clock returned is stored in each @clk_bulk_data.clk field.
+ *
+ * Drivers must assume that the clock source is not enabled.
+ *
+ * clk_bulk_get should not be called from within interrupt context.
+ */
+int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
+					    struct clk_bulk_data *clks);
 /**
  * devm_clk_bulk_get_all - managed get multiple clk consumers
  * @dev: device for clock "consumer"
@@ -760,6 +782,12 @@ static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clk
 	return 0;
 }
 
+static inline int __must_check devm_clk_bulk_get_optional(struct device *dev,
+				int num_clks, struct clk_bulk_data *clks)
+{
+	return 0;
+}
+
 static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
 						     struct clk_bulk_data **clks)
 {