clk: Add clk_bulk_get_optional() function

clk_bulk_get_optional() allows to get a group of clocks where one
or more is optional.  For a not available clock, e.g. not specifed
in the clock consumer node in DT, its respective struct clk pointer
will be NULL.  This allows for operating on a group of returned
clocks (struct clk_bulk_data array) with existing clk_bulk* APIs.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/linux/clk.h b/include/linux/clk.h
index f689fc58d7be..1b50e7d1675c 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -332,6 +332,19 @@ int __must_check clk_bulk_get(struct device *dev, int num_clks,
  */
 int __must_check clk_bulk_get_all(struct device *dev,
                                   struct clk_bulk_data **clks);
+
+/**
+ * clk_bulk_get_optional - lookup and obtain a number of references to clock producer
+ * @dev: device for clock "consumer"
+ * @num_clks: the number of clk_bulk_data
+ * @clks: the clk_bulk_data table of consumer
+ *
+ * Behaves the same as clk_bulk_get() except where there is no clock producer.
+ * In this case, instead of returning -ENOENT, the function returns 0 and
+ * NULL for a clk for which a clock producer could not be determined.
+ */
+int __must_check clk_bulk_get_optional(struct device *dev, int num_clks,
+                                       struct clk_bulk_data *clks);
 /**
  * devm_clk_bulk_get - managed get multiple clk consumers
  * @dev: device for clock "consumer"
@@ -718,6 +731,12 @@ static inline int __must_check clk_bulk_get(struct device *dev, int num_clks,
         return 0;
 }
 
+static inline int __must_check clk_bulk_get_optional(struct device *dev,
+                                int num_clks, struct clk_bulk_data *clks)
+{
+        return 0;
+}
+
 static inline int __must_check clk_bulk_get_all(struct device *dev,
                                          struct clk_bulk_data **clks)
 {