[PATCH 1/2] clk: Add clk_bulk_get_optional() function

[PATCH 1/2] clk: Add clk_bulk_get_optional() function

[Sylwester Nawrocki]

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>
---
 drivers/clk/clk-bulk.c | 23 ++++++++++++++++++++---
 include/linux/clk.h    | 19 +++++++++++++++++++
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk-bulk.c b/drivers/clk/clk-bulk.c
index 06499568cf076..524bf9a530985 100644
--- a/drivers/clk/clk-bulk.c
+++ b/drivers/clk/clk-bulk.c
@@ -75,8 +75,8 @@ void clk_bulk_put(int num_clks, struct clk_bulk_data *clks)
 }
 EXPORT_SYMBOL_GPL(clk_bulk_put);
 
-int __must_check clk_bulk_get(struct device *dev, int num_clks,
-			      struct clk_bulk_data *clks)
+static int __clk_bulk_get(struct device *dev, int num_clks,
+			  struct clk_bulk_data *clks, bool optional)
 {
 	int ret;
 	int i;
@@ -88,10 +88,14 @@ int __must_check clk_bulk_get(struct device *dev, int num_clks,
 		clks[i].clk = clk_get(dev, clks[i].id);
 		if (IS_ERR(clks[i].clk)) {
 			ret = PTR_ERR(clks[i].clk);
+			clks[i].clk = NULL;
+
+			if (ret == -ENOENT && optional)
+				continue;
+
 			if (ret != -EPROBE_DEFER)
 				dev_err(dev, "Failed to get clk '%s': %d\n",
 					clks[i].id, ret);
-			clks[i].clk = NULL;
 			goto err;
 		}
 	}
@@ -103,8 +107,21 @@ int __must_check clk_bulk_get(struct device *dev, int num_clks,
 
 	return ret;
 }
+
+int __must_check clk_bulk_get(struct device *dev, int num_clks,
+			      struct clk_bulk_data *clks)
+{
+	return __clk_bulk_get(dev, num_clks, clks, false);
+}
 EXPORT_SYMBOL(clk_bulk_get);
 
+int __must_check clk_bulk_get_optional(struct device *dev, int num_clks,
+				       struct clk_bulk_data *clks)
+{
+	return __clk_bulk_get(dev, num_clks, clks, true);
+}
+EXPORT_SYMBOL_GPL(clk_bulk_get_optional);
+
 void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks)
 {
 	if (IS_ERR_OR_NULL(clks))
diff --git a/include/linux/clk.h b/include/linux/clk.h
index f689fc58d7be3..98ea3e29f34b1 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)
 {
-- 
2.17.1

[PATCH 2/2] clk: Add devm_clk_bulk_get_optional() function

[Sylwester Nawrocki]

Add managed version of the clk_bulk_get_optional() helper function.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---
 drivers/clk/clk-devres.c | 22 +++++++++++++++++++---
 include/linux/clk.h      | 28 ++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index daa1fc8fba537..f5f310ef001ac 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -52,8 +52,8 @@ static void devm_clk_bulk_release(struct device *dev, void *res)
 	clk_bulk_put(devres->num_clks, devres->clks);
 }
 
-int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
-		      struct clk_bulk_data *clks)
+int __devm_clk_bulk_get(struct device *dev, int num_clks,
+			struct clk_bulk_data *clks, bool optional)
 {
 	struct clk_bulk_devres *devres;
 	int ret;
@@ -63,7 +63,10 @@ int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
 	if (!devres)
 		return -ENOMEM;
 
-	ret = clk_bulk_get(dev, num_clks, clks);
+	if (optional)
+		ret = clk_bulk_get_optional(dev, num_clks, clks);
+	else
+		ret = clk_bulk_get(dev, num_clks, clks);
 	if (!ret) {
 		devres->clks = clks;
 		devres->num_clks = num_clks;
@@ -74,8 +77,21 @@ int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
 
 	return ret;
 }
+
+int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
+		      struct clk_bulk_data *clks)
+{
+	return __devm_clk_bulk_get(dev, num_clks, clks, false);
+}
 EXPORT_SYMBOL_GPL(devm_clk_bulk_get);
 
+int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
+		      struct clk_bulk_data *clks)
+{
+	return __devm_clk_bulk_get(dev, num_clks, clks, true);
+}
+EXPORT_SYMBOL_GPL(devm_clk_bulk_get_optional);
+
 int __must_check devm_clk_bulk_get_all(struct device *dev,
 				       struct clk_bulk_data **clks)
 {
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 98ea3e29f34b1..d943ee204d68b 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -359,6 +359,28 @@ int __must_check clk_bulk_get_optional(struct device *dev, int num_clks,
  */
 int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
 				   struct clk_bulk_data *clks);
+/**
+ * devm_clk_bulk_get_optional - managed get multiple optional consumer clocks
+ * @dev: device for clock "consumer"
+ * @clks: pointer to the clk_bulk_data table of consumer
+ *
+ * Behaves the same as devm_clk_bulk_get() except where there is no clock
+ * producer.  In this case, instead of returning -ENOENT, the function returns
+ * NULL for given clk. It is assumed all clocks in clk_bulk_data are optional.
+ *
+ * Returns 0 if all clocks specified in clk_bulk_data table are obtained
+ * successfully or for any clk there was no clk provider available, otherwise
+ * returns valid IS_ERR() condition containing errno.
+ * The implementation uses @dev and @clk_bulk_data.id to determine the
+ * clock consumer, and thereby the clock producer.
+ * The clock returned is stored in each @clk_bulk_data.clk field.
+ *
+ * Drivers must assume that the clock source is not enabled.
+ *
+ * clk_bulk_get should not be called from within interrupt context.
+ */
+int __must_check devm_clk_bulk_get_optional(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"
@@ -760,6 +782,12 @@ static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clk
 	return 0;
 }
 
+static inline int __must_check devm_clk_bulk_get_optional(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)
 {
-- 
2.17.1

Re: [PATCH 2/2] clk: Add devm_clk_bulk_get_optional() function

[Stephen Boyd]

Quoting Sylwester Nawrocki (2019-06-19 02:39:26)
> Add managed version of the clk_bulk_get_optional() helper function.
> 
> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
> ---

Applied to clk-next

Re: [PATCH 1/2] clk: Add clk_bulk_get_optional() function

[Stephen Boyd]

Quoting Sylwester Nawrocki (2019-06-19 02:39:25)
> 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>
> ---

Applied to clk-next