[PATCH V3 1/2] clk: Add devm_clk_bulk_get_optional_enable() helper

[Suraj Gupta <suraj.gupta2@amd.com>]

Add a new managed clock framework helper function that combines getting
optional bulk clocks and enabling them in a single operation.

The devm_clk_bulk_get_optional_enable() function simplifies the common
pattern where drivers need to get optional bulk clocks, prepare and enable
them, and have them automatically disabled/unprepared and freed when the
device is unbound.

This new API follows the established pattern of
devm_clk_bulk_get_all_enabled() and reduces boilerplate code in drivers
that manage multiple optional clocks.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Suraj Gupta <suraj.gupta2@amd.com>
Reviewed-by: Brian Masney <bmasney@redhat.com>
---
 drivers/clk/clk-devres.c | 50 ++++++++++++++++++++++++++++++++++++++++
 include/linux/clk.h      | 23 ++++++++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index 5368d92d9b39..994d5bc5168b 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -179,6 +179,56 @@ int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
 }
 EXPORT_SYMBOL_GPL(devm_clk_bulk_get_optional);
 
+static void devm_clk_bulk_release_enable(struct device *dev, void *res)
+{
+	struct clk_bulk_devres *devres = res;
+
+	clk_bulk_disable_unprepare(devres->num_clks, devres->clks);
+	clk_bulk_put(devres->num_clks, devres->clks);
+}
+
+static int __devm_clk_bulk_get_enable(struct device *dev, int num_clks,
+				      struct clk_bulk_data *clks, bool optional)
+{
+	struct clk_bulk_devres *devres;
+	int ret;
+
+	devres = devres_alloc(devm_clk_bulk_release_enable,
+			      sizeof(*devres), GFP_KERNEL);
+	if (!devres)
+		return -ENOMEM;
+
+	if (optional)
+		ret = clk_bulk_get_optional(dev, num_clks, clks);
+	else
+		ret = clk_bulk_get(dev, num_clks, clks);
+	if (ret)
+		goto err_clk_get;
+
+	ret = clk_bulk_prepare_enable(num_clks, clks);
+	if (ret)
+		goto err_clk_prepare;
+
+	devres->clks = clks;
+	devres->num_clks = num_clks;
+	devres_add(dev, devres);
+
+	return 0;
+
+err_clk_prepare:
+	clk_bulk_put(num_clks, clks);
+err_clk_get:
+	devres_free(devres);
+	return ret;
+}
+
+int __must_check devm_clk_bulk_get_optional_enable(struct device *dev, int num_clks,
+						   struct clk_bulk_data *clks)
+{
+	return __devm_clk_bulk_get_enable(dev, num_clks, clks, true);
+}
+EXPORT_SYMBOL_GPL(devm_clk_bulk_get_optional_enable);
+
 static void devm_clk_bulk_release_all(struct device *dev, void *res)
 {
 	struct clk_bulk_devres *devres = res;
diff --git a/include/linux/clk.h b/include/linux/clk.h
index b607482ca77e..ac0affa16c8a 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -478,6 +478,22 @@ int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
  */
 int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
 					    struct clk_bulk_data *clks);
+/**
+ * devm_clk_bulk_get_optional_enable - Get and enable optional bulk clocks (managed)
+ * @dev: device for clock "consumer"
+ * @num_clks: the number of clk_bulk_data
+ * @clks: pointer to the clk_bulk_data table of consumer
+ *
+ * Behaves the same as devm_clk_bulk_get_optional() but also prepares and enables
+ * the clocks in one operation with management. The clks will automatically be
+ * disabled, unprepared and freed when the device is unbound.
+ *
+ * Return: 0 if all clocks specified in clk_bulk_data table are obtained
+ * and enabled successfully, or for any clk there was no clk provider available.
+ * Otherwise returns valid IS_ERR() condition containing errno.
+ */
+int __must_check devm_clk_bulk_get_optional_enable(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"
@@ -1029,6 +1045,13 @@ static inline int __must_check devm_clk_bulk_get_optional(struct device *dev,
 	return 0;
 }
 
+static inline int __must_check devm_clk_bulk_get_optional_enable(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)
 {
-- 
2.25.1