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authorPhil Edworthy <phil.edworthy@renesas.com>2018-12-03 11:13:09 +0000
committerStephen Boyd <sboyd@kernel.org>2019-02-06 10:33:10 -0800
commit60b8f0ddf1a927ef02141a6610fd52575134f821 (patch)
tree60ea4fd636e291ff196d984885d2690571c9021b
parent5c56dfe63b6e7da3d9fd84a6c553ff4d2753dd1c (diff)
clk: Add (devm_)clk_get_optional() functions
This adds clk_get_optional() and devm_clk_get_optional() functions to get optional clocks. They behave the same as (devm_)clk_get() except where there is no clock producer. In this case, instead of returning -ENOENT, the function returns NULL. This makes error checking simpler and allows clk_prepare_enable, etc to be called on the returned reference without additional checks. Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Russell King <linux@armlinux.org.uk> [sboyd@kernel.org: Document in devres.txt] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
-rw-r--r--Documentation/driver-model/devres.txt1
-rw-r--r--drivers/clk/clk-devres.c11
-rw-r--r--include/linux/clk.h36
3 files changed, 48 insertions, 0 deletions
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index b277cafce71e..83f38c0439cd 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -242,6 +242,7 @@ certainly invest a bit more effort into libata core layer).
CLOCK
devm_clk_get()
+ devm_clk_get_optional()
devm_clk_put()
devm_clk_hw_register()
devm_of_clk_add_hw_provider()
diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index c9a86156ced8..daa1fc8fba53 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -29,6 +29,17 @@ struct clk *devm_clk_get(struct device *dev, const char *id)
}
EXPORT_SYMBOL(devm_clk_get);
+struct clk *devm_clk_get_optional(struct device *dev, const char *id)
+{
+ struct clk *clk = devm_clk_get(dev, id);
+
+ if (clk == ERR_PTR(-ENOENT))
+ return NULL;
+
+ return clk;
+}
+EXPORT_SYMBOL(devm_clk_get_optional);
+
struct clk_bulk_devres {
struct clk_bulk_data *clks;
int num_clks;
diff --git a/include/linux/clk.h b/include/linux/clk.h
index a7773b5c0b9f..d8bc1a856b39 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -384,6 +384,17 @@ int __must_check devm_clk_bulk_get_all(struct device *dev,
struct clk *devm_clk_get(struct device *dev, const char *id);
/**
+ * devm_clk_get_optional - lookup and obtain a managed reference to an optional
+ * clock producer.
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Behaves the same as devm_clk_get() except where there is no clock producer.
+ * In this case, instead of returning -ENOENT, the function returns NULL.
+ */
+struct clk *devm_clk_get_optional(struct device *dev, const char *id);
+
+/**
* devm_get_clk_from_child - lookup and obtain a managed reference to a
* clock producer from child node.
* @dev: device for clock "consumer"
@@ -718,6 +729,12 @@ static inline struct clk *devm_clk_get(struct device *dev, const char *id)
return NULL;
}
+static inline struct clk *devm_clk_get_optional(struct device *dev,
+ const char *id)
+{
+ return NULL;
+}
+
static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
struct clk_bulk_data *clks)
{
@@ -862,6 +879,25 @@ static inline void clk_bulk_disable_unprepare(int num_clks,
clk_bulk_unprepare(num_clks, clks);
}
+/**
+ * clk_get_optional - lookup and obtain a reference to an optional clock
+ * producer.
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Behaves the same as clk_get() except where there is no clock producer. In
+ * this case, instead of returning -ENOENT, the function returns NULL.
+ */
+static inline struct clk *clk_get_optional(struct device *dev, const char *id)
+{
+ struct clk *clk = clk_get(dev, id);
+
+ if (clk == ERR_PTR(-ENOENT))
+ return NULL;
+
+ return clk;
+}
+
#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
struct clk *of_clk_get(struct device_node *np, int index);
struct clk *of_clk_get_by_name(struct device_node *np, const char *name);