[PATCH v5 2/9] clk: of_clk - add managed provider registrations

[Matti Vaittinen]

With MFD devices the clk properties may be contained in MFD (parent) DT
node. Current devm_of_clk_add_hw_provider assumes the clk is bound to MFD
subdevice not to MFD device (parent). Add
devm_of_clk_add_hw_provider_parent to tackle this issue.

Signed-off-by: Matti Vaittinen <matti.vaittinen@xxxxxxxxxxxxxxxxx>
---
 Documentation/driver-model/devres.txt |  1 +
 drivers/clk/clk.c                     | 65 ++++++++++++++++++++++++++++++-----
 include/linux/clk-provider.h          | 11 ++++++
 3 files changed, 68 insertions(+), 9 deletions(-)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index dbf14326243b..97c9c575b2af 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -238,6 +238,7 @@ CLOCK
   devm_clk_put()
   devm_clk_hw_register()
   devm_of_clk_add_hw_provider()
+  devm_of_clk_add_parent_hw_provider()
   devm_clk_hw_register_clkdev()
 
 DMA
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index af011974d4ec..30beb60bd8f9 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3893,12 +3893,12 @@ static void devm_of_clk_release_provider(struct device *dev, void *res)
 	of_clk_del_provider(*(struct device_node **)res);
 }
 
-int devm_of_clk_add_hw_provider(struct device *dev,
+static int __devm_of_clk_add_hw_provider(struct device *dev,
 			struct clk_hw *(*get)(struct of_phandle_args *clkspec,
 					      void *data),
-			void *data)
+			struct device_node *of_node, void *data)
 {
-	struct device_node **ptr, *np;
+	struct device_node **ptr;
 	int ret;
 
 	ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
@@ -3906,19 +3906,62 @@ int devm_of_clk_add_hw_provider(struct device *dev,
 	if (!ptr)
 		return -ENOMEM;
 
-	np = dev->of_node;
-	ret = of_clk_add_hw_provider(np, get, data);
-	if (!ret) {
-		*ptr = np;
+	*ptr = of_node;
+	ret = of_clk_add_hw_provider(of_node, get, data);
+	if (!ret)
 		devres_add(dev, ptr);
-	} else {
+	else
 		devres_free(ptr);
-	}
 
 	return ret;
 }
+
+/**
+ * devm_of_clk_add_hw_provider() - Managed clk provider node registration
+ * @dev: Device acting as the clock provider. Used for DT node and lifetime.
+ * @get: callback for decoding clk_hw
+ * @data: context pointer for @get callback.
+ *
+ * Returns 0 on success or an errno on failure.
+ *
+ * Registers clock provider for given device's node. Provider is automatically
+ * released at device exit.
+ */
+int devm_of_clk_add_hw_provider(struct device *dev,
+			struct clk_hw *(*get)(struct of_phandle_args *clkspec,
+					      void *data),
+			void *data)
+{
+	return __devm_of_clk_add_hw_provider(dev, get, dev->of_node, data);
+}
 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
 
+/**
+ * devm_of_clk_add_parent_hw_provider() - Managed clk provider node registration
+ * @dev: Device acting as the clock provider. Provider's DT node is parent node.
+ * @get: callback for decoding clk_hw
+ * @data: context pointer for @get callback.
+ *
+ * Returns 0 on success or an errno on failure.
+ *
+ * Registers clock provider for given device's parent node. Usable in cases
+ * where it really is the parent node that contains the provider information.
+ * Typical use-cases are MFD devices where the MFD sub-device is handling
+ * actual clock HW but the MFD node (parent) is containing the clock
+ * information.
+ *
+ * Provider is automatically released at device exit.
+ */
+int devm_of_clk_add_parent_hw_provider(struct device *dev,
+			struct clk_hw *(*get)(struct of_phandle_args *clkspec,
+					      void *data),
+			void *data)
+{
+	return __devm_of_clk_add_hw_provider(dev, get, dev->parent->of_node,
+					     data);
+}
+EXPORT_SYMBOL_GPL(devm_of_clk_add_parent_hw_provider);
+
 /**
  * of_clk_del_provider() - Remove a previously registered clock provider
  * @np: Device node pointer associated with clock provider
@@ -3950,6 +3993,10 @@ static int devm_clk_provider_match(struct device *dev, void *res, void *data)
 	return *np == data;
 }
 
+/**
+ * devm_of_clk_del_provider() - Remove clock provider registered using devm
+ * @dev: Device to whose lifetime the clock provider was bound
+ */
 void devm_of_clk_del_provider(struct device *dev)
 {
 	int ret;
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 60c51871b04b..a6663f084cf1 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -916,6 +916,10 @@ int devm_of_clk_add_hw_provider(struct device *dev,
 			   struct clk_hw *(*get)(struct of_phandle_args *clkspec,
 						 void *data),
 			   void *data);
+int devm_of_clk_add_parent_hw_provider(struct device *dev,
+			   struct clk_hw *(*get)(struct of_phandle_args *clkspec,
+						 void *data),
+			   void *data);
 void of_clk_del_provider(struct device_node *np);
 void devm_of_clk_del_provider(struct device *dev);
 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
@@ -953,6 +957,13 @@ static inline int devm_of_clk_add_hw_provider(struct device *dev,
 {
 	return 0;
 }
+static inline int devm_of_clk_add_parent_hw_provider(struct device *dev,
+			   struct clk_hw *(*get)(struct of_phandle_args *clkspec,
+						 void *data),
+			   void *data)
+{
+	return 0;
+}
 static inline void of_clk_del_provider(struct device_node *np) {}
 static inline void devm_of_clk_del_provider(struct device *dev) {}
 static inline struct clk *of_clk_src_simple_get(
-- 
2.14.3


-- 
Matti Vaittinen
ROHM Semiconductors

~~~ "I don't think so," said Rene Descartes.  Just then, he vanished ~~~