[PATCH v3 1/2] clk: Provide managed helper to get and enable bulk clocks

[Shradha Todi]

Provide a managed devm_clk_bulk* wrapper to get and enable all
bulk clocks in order to simplify drivers that keeps all clocks
enabled for the time of driver operation.

Suggested-by: Marek Szyprowski <m.szyprowski at samsung.com>
Signed-off-by: Shradha Todi <shradha.t at samsung.com>
---
 drivers/clk/clk-devres.c | 41 ++++++++++++++++++++++++++++++++++++++++
 include/linux/clk.h      | 25 ++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index 4fb4fd4b06bd..05b0ff4bc1d4 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -102,6 +102,7 @@ EXPORT_SYMBOL_GPL(devm_clk_get_optional_enabled);
 struct clk_bulk_devres {
 	struct clk_bulk_data *clks;
 	int num_clks;
+	void (*exit)(int num_clks, const struct clk_bulk_data *clks);
 };
 
 static void devm_clk_bulk_release(struct device *dev, void *res)
@@ -182,6 +183,46 @@ int __must_check devm_clk_bulk_get_all(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all);
 
+static void devm_clk_bulk_release_all_enabled(struct device *dev, void *res)
+{
+	struct clk_bulk_devres *devres = res;
+
+	if (devres->exit)
+		devres->exit(devres->num_clks, devres->clks);
+
+	clk_bulk_put_all(devres->num_clks, devres->clks);
+}
+
+int __must_check devm_clk_bulk_get_all_enabled(struct device *dev,
+				  struct clk_bulk_data **clks, int *num_clks)
+{
+	struct clk_bulk_devres *devres;
+	int ret;
+
+	devres = devres_alloc(devm_clk_bulk_release_all_enabled,
+			      sizeof(*devres), GFP_KERNEL);
+	if (!devres)
+		return -ENOMEM;
+
+	ret = clk_bulk_get_all(dev, &devres->clks);
+	if (ret > 0) {
+		*clks = devres->clks;
+		devres->num_clks = ret;
+		*num_clks = ret;
+		devres_add(dev, devres);
+	} else {
+		devres_free(devres);
+		return ret;
+	}
+
+	ret = clk_bulk_prepare_enable(devres->num_clks, *clks);
+	if (!ret)
+		devres->exit = clk_bulk_disable_unprepare;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all_enabled);
+
 static int devm_clk_match(struct device *dev, void *res, void *data)
 {
 	struct clk **c = res;
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 1ef013324237..bf3e9bee5754 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -438,6 +438,24 @@ int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
 int __must_check devm_clk_bulk_get_all(struct device *dev,
 				       struct clk_bulk_data **clks);
 
+/**
+ * devm_clk_bulk_get_all_enabled - managed get multiple clk consumers and
+ *					enable all clk
+ * @dev: device for clock "consumer"
+ * @clks: pointer to the clk_bulk_data table of consumer
+ * @num_clks: out parameter to store the number of clk_bulk_data
+ *
+ * Returns success (0) or negative errno.
+ *
+ * This helper function allows drivers to get several clk
+ * consumers and enable all of them in one operation with management.
+ * The clks will automatically be disabled and freed when the device
+ * is unbound.
+ */
+
+int __must_check devm_clk_bulk_get_all_enabled(struct device *dev,
+				struct clk_bulk_data **clks, int *num_clks);
+
 /**
  * devm_clk_get - lookup and obtain a managed reference to a clock producer.
  * @dev: device for clock "consumer"
@@ -960,6 +978,13 @@ static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
 	return 0;
 }
 
+static inline int __must_check devm_clk_bulk_get_all_enabled(struct device *dev,
+				struct clk_bulk_data **clks, int *num_clks)
+{
+
+	return 0;
+}
+
 static inline struct clk *devm_get_clk_from_child(struct device *dev,
 				struct device_node *np, const char *con_id)
 {
-- 
2.17.1