Subject: [PATCH v3 1/2] clk: Add consumer APIs for discovering possible parent clocks

From: Scott Wood <[email-masked]>
Date: Thu, 16 Jun 2016 01:21:24 -0500

From: Scott Wood <[email-masked]>

Commit fc4a05d4b0eb ("clk: Remove unused provider APIs") removed
__clk_get_num_parents() and clk_hw_get_parent_by_index(), leaving only
true provider API versions that operate on struct clk_hw.

qoriq-cpufreq needs these functions in order to determine the options
it has for calling clk_set_parent() and thus populate the cpufreq
table, so revive them as legitimate consumer APIs.

Signed-off-by: Scott Wood <[email-masked]>
---
v2: Add missing 'static inline' to stub functions.

v3: no changes

 drivers/clk/clk.c   | 19 +++++++++++++++++++
 include/linux/clk.h | 31 +++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index d584004..d61a3fe 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -290,6 +290,12 @@ struct clk_hw *__clk_get_hw(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(__clk_get_hw);
 
+unsigned int clk_get_num_parents(struct clk *clk)
+{
+	return !clk ? 0 : clk->core->num_parents;
+}
+EXPORT_SYMBOL_GPL(clk_get_num_parents);
+
 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
 {
 	return hw->core->num_parents;
@@ -358,6 +364,19 @@ static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
 	return core->parents[index];
 }
 
+struct clk *clk_get_parent_by_index(struct clk *clk, unsigned int index)
+{
+	struct clk_core *parent;
+
+	if (!clk)
+		return NULL;
+
+	parent = clk_core_get_parent_by_index(clk->core, index);
+
+	return !parent ? NULL : parent->hw->clk;
+}
+EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
+
 struct clk_hw *
 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
 {
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 0df4a51..acd115f 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -392,6 +392,26 @@ int clk_set_parent(struct clk *clk, struct clk *parent);
 struct clk *clk_get_parent(struct clk *clk);
 
 /**
+ * clk_get_parent_by_index - get a possible parent clock by index
+ * @clk: clock source
+ * @index: index into the array of possible parents of this clock
+ *
+ * Returns struct clk corresponding to the requested possible
+ * parent clock source, or NULL.
+ */
+struct clk *clk_get_parent_by_index(struct clk *clk,
+				    unsigned int index);
+
+/**
+ * clk_get_num_parents - get number of possible parents
+ * @clk: clock source
+ *
+ * Returns the number of possible parents of this clock,
+ * which can then be enumerated using clk_get_parent_by_index().
+ */
+unsigned int clk_get_num_parents(struct clk *clk);
+
+/**
  * clk_get_sys - get a clock based upon the device name
  * @dev_id: device name
  * @con_id: connection ID
@@ -461,6 +481,17 @@ static inline struct clk *clk_get_parent(struct clk *clk)
 	return NULL;
 }
 
+static inline struct clk *clk_get_parent_by_index(struct clk *clk,
+						  unsigned int index)
+{
+	return NULL;
+}
+
+static inline unsigned int clk_get_num_parents(struct clk *clk)
+{
+	return 0;
+}
+
 #endif
 
 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
-- 
2.5.0