From 60b8f0ddf1a927ef02141a6610fd52575134f821 Mon Sep 17 00:00:00 2001 From: Phil Edworthy Date: Mon, 3 Dec 2018 11:13:09 +0000 Subject: 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 Reviewed-by: Andy Shevchenko Cc: Russell King [sboyd@kernel.org: Document in devres.txt] Signed-off-by: Stephen Boyd --- 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 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 @@ -383,6 +383,17 @@ 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. @@ -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); -- cgit