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 --- include/linux/clk.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'include/linux') 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 v1.2.3 From 3eee6c7d119cd8563ad25898f94d6c1b514da548 Mon Sep 17 00:00:00 2001 From: Matti Vaittinen Date: Fri, 7 Dec 2018 13:09:39 +0200 Subject: clkdev: add managed clkdev lookup registration Clkdev registration lacks of managed registration functions and it seems few drivers do not drop clkdev lookups at exit. Add devm_clk_hw_register_clkdev and devm_clk_release_clkdev to ease lookup releasing at exit. Signed-off-by: Matti Vaittinen Signed-off-by: Stephen Boyd --- Documentation/driver-model/devres.txt | 1 + drivers/clk/clkdev.c | 111 +++++++++++++++++++++++++++------- include/linux/clkdev.h | 4 ++ 3 files changed, 93 insertions(+), 23 deletions(-) (limited to 'include/linux') diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index b277cafce71e..805b7bf5d98f 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -245,6 +245,7 @@ CLOCK devm_clk_put() devm_clk_hw_register() devm_of_clk_add_hw_provider() + devm_clk_hw_register_clkdev() DMA dmaenginem_async_device_register() diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 9ab3db8b3988..4621f8a91fc0 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -401,6 +401,23 @@ static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw, return cl; } +static int do_clk_register_clkdev(struct clk_hw *hw, + struct clk_lookup **cl, const char *con_id, const char *dev_id) +{ + if (IS_ERR(hw)) + return PTR_ERR(hw); + /* + * Since dev_id can be NULL, and NULL is handled specially, we must + * pass it as either a NULL format string, or with "%s". + */ + if (dev_id) + *cl = __clk_register_clkdev(hw, con_id, "%s", dev_id); + else + *cl = __clk_register_clkdev(hw, con_id, NULL); + + return *cl ? 0 : -ENOMEM; +} + /** * clk_register_clkdev - register one clock lookup for a struct clk * @clk: struct clk to associate with all clk_lookups @@ -423,17 +440,8 @@ int clk_register_clkdev(struct clk *clk, const char *con_id, if (IS_ERR(clk)) return PTR_ERR(clk); - /* - * Since dev_id can be NULL, and NULL is handled specially, we must - * pass it as either a NULL format string, or with "%s". - */ - if (dev_id) - cl = __clk_register_clkdev(__clk_get_hw(clk), con_id, "%s", - dev_id); - else - cl = __clk_register_clkdev(__clk_get_hw(clk), con_id, NULL); - - return cl ? 0 : -ENOMEM; + return do_clk_register_clkdev(__clk_get_hw(clk), &cl, con_id, + dev_id); } EXPORT_SYMBOL(clk_register_clkdev); @@ -456,18 +464,75 @@ int clk_hw_register_clkdev(struct clk_hw *hw, const char *con_id, { struct clk_lookup *cl; - if (IS_ERR(hw)) - return PTR_ERR(hw); + return do_clk_register_clkdev(hw, &cl, con_id, dev_id); +} +EXPORT_SYMBOL(clk_hw_register_clkdev); - /* - * Since dev_id can be NULL, and NULL is handled specially, we must - * pass it as either a NULL format string, or with "%s". - */ - if (dev_id) - cl = __clk_register_clkdev(hw, con_id, "%s", dev_id); - else - cl = __clk_register_clkdev(hw, con_id, NULL); +static void devm_clkdev_release(struct device *dev, void *res) +{ + clkdev_drop(*(struct clk_lookup **)res); +} - return cl ? 0 : -ENOMEM; +static int devm_clk_match_clkdev(struct device *dev, void *res, void *data) +{ + struct clk_lookup **l = res; + + return *l == data; } -EXPORT_SYMBOL(clk_hw_register_clkdev); + +/** + * devm_clk_release_clkdev - Resource managed clkdev lookup release + * @dev: device this lookup is bound + * @con_id: connection ID string on device + * @dev_id: format string describing device name + * + * Drop the clkdev lookup created with devm_clk_hw_register_clkdev. + * Normally this function will not need to be called and the resource + * management code will ensure that the resource is freed. + */ +void devm_clk_release_clkdev(struct device *dev, const char *con_id, + const char *dev_id) +{ + struct clk_lookup *cl; + int rval; + + cl = clk_find(dev_id, con_id); + WARN_ON(!cl); + rval = devres_release(dev, devm_clkdev_release, + devm_clk_match_clkdev, cl); + WARN_ON(rval); +} +EXPORT_SYMBOL(devm_clk_release_clkdev); + +/** + * devm_clk_hw_register_clkdev - managed clk lookup registration for clk_hw + * @dev: device this lookup is bound + * @hw: struct clk_hw to associate with all clk_lookups + * @con_id: connection ID string on device + * @dev_id: format string describing device name + * + * con_id or dev_id may be NULL as a wildcard, just as in the rest of + * clkdev. + * + * To make things easier for mass registration, we detect error clk_hws + * from a previous clk_hw_register_*() call, and return the error code for + * those. This is to permit this function to be called immediately + * after clk_hw_register_*(). + */ +int devm_clk_hw_register_clkdev(struct device *dev, struct clk_hw *hw, + const char *con_id, const char *dev_id) +{ + int rval = -ENOMEM; + struct clk_lookup **cl; + + cl = devres_alloc(devm_clkdev_release, sizeof(*cl), GFP_KERNEL); + if (cl) { + rval = do_clk_register_clkdev(hw, cl, con_id, dev_id); + if (!rval) + devres_add(dev, cl); + else + devres_free(cl); + } + return rval; +} +EXPORT_SYMBOL(devm_clk_hw_register_clkdev); diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h index 4890ff033220..ccb32af5848b 100644 --- a/include/linux/clkdev.h +++ b/include/linux/clkdev.h @@ -52,4 +52,8 @@ int clk_add_alias(const char *, const char *, const char *, struct device *); int clk_register_clkdev(struct clk *, const char *, const char *); int clk_hw_register_clkdev(struct clk_hw *, const char *, const char *); +int devm_clk_hw_register_clkdev(struct device *dev, struct clk_hw *hw, + const char *con_id, const char *dev_id); +void devm_clk_release_clkdev(struct device *dev, const char *con_id, + const char *dev_id); #endif -- cgit v1.2.3