Messages in this thread Patch in this message | | | From | Paul Osmialowski <> | Subject | [PATCH v2] clk: add devm_of_clk_get() and devm_of_clk_get_by_name() functions | Date | Wed, 30 Sep 2015 09:46:52 +0200 |
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From: Paul Osmialowski <pawelo@king.net.pl>
These two functions are added to ease management of clocks obtained from OF device nodes.
They are particulary useful while iterating over DT subnodes using e.g. for_each_child_of_node(dev->of_node, child) in order do get resources (i.e. clocks) for subdevices defined by these DT subnodes.
For example:
some_device { compatible = "something" #address-cells = <1>; #size-cells = <1>; ranges;
subdevice1: some_subdevice@some_address1 { reg = <0xsome_address1 0xsome_size> clocks = <&some_clock1> }
subdevice2: some_subdevice@some_address2 { reg = <0xsome_address2 0xsome_size> clocks = <&some_clock2> } }
Normally, I'd have to use of_clk_get() on each subdevice node and then worry about proper resource release myself.
IMHO using devres infrastructure for this is far better. This patch adds missing functions needed to do it a better way.
Signed-off-by: Paul Osmialowski <pawelo@king.net.pl> --- Documentation/driver-model/devres.txt | 2 ++ drivers/clk/clk-devres.c | 46 +++++++++++++++++++++++++++++++++++ include/linux/clk.h | 46 +++++++++++++++++++++++++++++++++++ 3 files changed, 94 insertions(+)
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 831a536..f3ad67a 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -235,6 +235,8 @@ certainly invest a bit more effort into libata core layer). CLOCK devm_clk_get() + devm_of_clk_get() + devm_of_clk_get_by_name() devm_clk_put() DMA diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c index 8f57154..197075a 100644 --- a/drivers/clk/clk-devres.c +++ b/drivers/clk/clk-devres.c @@ -34,6 +34,52 @@ struct clk *devm_clk_get(struct device *dev, const char *id) } EXPORT_SYMBOL(devm_clk_get); +#ifdef CONFIG_OF + +struct clk *devm_of_clk_get(struct device *dev, struct device_node *np, + int index) +{ + struct clk **ptr, *clk; + + ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + clk = of_clk_get(np, index); + if (!IS_ERR(clk)) { + *ptr = clk; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return clk; +} +EXPORT_SYMBOL(devm_of_clk_get); + +struct clk *devm_of_clk_get_by_name(struct device *dev, struct device_node *np, + const char *name) +{ + struct clk **ptr, *clk; + + ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + clk = of_clk_get_by_name(np, name); + if (!IS_ERR(clk)) { + *ptr = clk; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return clk; +} +EXPORT_SYMBOL(devm_of_clk_get_by_name); + +#endif /* CONFIG_OF */ + 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 0df4a51..8f31f9a 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -504,4 +504,50 @@ static inline struct clk *of_clk_get_by_name(struct device_node *np, } #endif +#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) +/** + * devm_of_clk_get - obtain a managed reference to a clock producer + * from device tree node (by index). + * @dev: device for clock "consumer" + * @np: device tree node + * @index: clock consumer index (within the node) + * + * devm_of_clk_get should not be called from within interrupt context. + * + * The clock will automatically be freed when the device is unbound + * from the bus. + */ +struct clk *devm_of_clk_get(struct device *dev, struct device_node *np, + int index); + +/** + * devm_of_clk_get_by_name - obtain a managed reference to a clock producer + * from device tree node (by name). + * @dev: device for clock "consumer" + * @np: device tree node + * @name: clock consumer name (within the node) + * + * devm_of_clk_get_by_name should not be called from within interrupt context. + * + * The clock will automatically be freed when the device is unbound + * from the bus. + */ +struct clk *devm_of_clk_get_by_name(struct device *dev, struct device_node *np, + const char *name); + +#else +static inline struct clk *devm_of_clk_get(struct device *dev, + struct device_node *np, + int index) +{ + return ERR_PTR(-ENOENT); +} +static inline struct clk *devm_of_clk_get_by_name(struct device *dev, + struct device_node *np, + const char *name) +{ + return ERR_PTR(-ENOENT); +} +#endif + #endif -- 2.4.9
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