4.19-stable review patch. If anyone has any objections, please let me know.
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From: Phil Edworthy phil.edworthy@renesas.com
[ Upstream commit 60b8f0ddf1a927ef02141a6610fd52575134f821 ]
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 Stable-dep-of: a6191a3d1811 ("gpio: aspeed: Use devm_clk api to manage clock source") Signed-off-by: Sasha Levin sashal@kernel.org --- Documentation/driver-model/devres.txt | 1 + drivers/clk/clk-devres.c | 11 ++++++++ include/linux/clk.h | 36 +++++++++++++++++++++++++++ 3 files changed, 48 insertions(+)
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 43681ca0837f8..5a2d8c7ce2474 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -235,6 +235,7 @@ 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 d854e26a8ddbc..a062389ccd3d5 100644 --- a/drivers/clk/clk-devres.c +++ b/drivers/clk/clk-devres.c @@ -34,6 +34,17 @@ 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 0a2382d3f68c8..55b08adaaa3c1 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -388,6 +388,17 @@ int __must_check devm_clk_bulk_get(struct device *dev, int num_clks, */ 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. @@ -655,6 +666,12 @@ 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) { @@ -774,6 +791,25 @@ 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);