Messages in this thread Patch in this message | | | From | Uwe Kleine-König <> | Subject | [PATCH 1/2] clk: provide new devm helpers for prepared and enabled clocks | Date | Tue, 13 Oct 2020 10:21:31 +0200 |
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When a driver keeps a clock prepared (or enabled) during the whole lifetime of the driver, these helpers allow to simplify the drivers.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- drivers/clk/clk-devres.c | 85 ++++++++++++++++++++++++++++++++------- include/linux/clk.h | 87 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 157 insertions(+), 15 deletions(-)
diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c index be160764911b..a56289c04921 100644 --- a/drivers/clk/clk-devres.c +++ b/drivers/clk/clk-devres.c @@ -4,42 +4,99 @@ #include <linux/export.h> #include <linux/gfp.h> +struct devm_clk_state { + struct clk *clk; + void (*exit)(struct clk *clk); +}; + static void devm_clk_release(struct device *dev, void *res) { - clk_put(*(struct clk **)res); + struct devm_clk_state *state = *(struct devm_clk_state **)res; + + if (state->exit) + state->exit(state->clk); + clk_put(state->clk); } -struct clk *devm_clk_get(struct device *dev, const char *id) +static struct clk *__devm_clk_get(struct device *dev, const char *id, + struct clk *(*get)(struct device *dev, const char *id), + int (*init)(struct clk *clk), + void (*exit)(struct clk *clk)) { - struct clk **ptr, *clk; + struct devm_clk_state **ptr, *state; + struct clk *clk; + int ret; ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL); if (!ptr) return ERR_PTR(-ENOMEM); - clk = clk_get(dev, id); - if (!IS_ERR(clk)) { - *ptr = clk; - devres_add(dev, ptr); - } else { - devres_free(ptr); + clk = get(dev, id); + if (IS_ERR(clk)) + goto err_clk_get; + + state->clk = clk; + + ret = init ? init(clk) : 0; + if (ret) { + clk = ERR_PTR(ret); + goto err_init; } + state->exit = exit; + *ptr = state; + devres_add(dev, ptr); + + return clk; + +err_init: + + clk_put(state->clk); +err_clk_get: + return clk; } + +struct clk *devm_clk_get(struct device *dev, const char *id) +{ + return __devm_clk_get(dev, id, clk_get, NULL, NULL); +} EXPORT_SYMBOL(devm_clk_get); -struct clk *devm_clk_get_optional(struct device *dev, const char *id) +struct clk *devm_clk_get_prepared(struct device *dev, const char *id) { - struct clk *clk = devm_clk_get(dev, id); + return __devm_clk_get(dev, id, clk_get, + clk_prepare, clk_disable); +} +EXPORT_SYMBOL(devm_clk_get_prepared); - if (clk == ERR_PTR(-ENOENT)) - return NULL; +struct clk *devm_clk_get_enabled(struct device *dev, const char *id) +{ + return __devm_clk_get(dev, id, clk_get, + clk_prepare_enable, clk_disable_unprepare); +} +EXPORT_SYMBOL(devm_clk_get_enabled); - return clk; +struct clk *devm_clk_get_optional(struct device *dev, const char *id) +{ + return __devm_clk_get(dev, id, clk_get_optional, NULL, NULL); } EXPORT_SYMBOL(devm_clk_get_optional); +struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id) +{ + return __devm_clk_get(dev, id, clk_get_optional, + clk_prepare, clk_unprepare); +} +EXPORT_SYMBOL(devm_clk_get_optional_prepared); + +struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id) +{ + return __devm_clk_get(dev, id, clk_get_optional, + clk_prepare_enable, clk_disable_unprepare); +} +EXPORT_SYMBOL(devm_clk_get_optional_enabled); + 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 7fd6a1febcf4..14050d9b5b38 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -409,7 +409,7 @@ int __must_check devm_clk_bulk_get_all(struct device *dev, * the clock producer. (IOW, @id may be identical strings, but * clk_get may return different clock producers depending on @dev.) * - * Drivers must assume that the clock source is not enabled. + * Drivers must assume that the clock source is neither prepared nor enabled. * * devm_clk_get should not be called from within interrupt context. * @@ -418,6 +418,47 @@ 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_prepared - devm_clk_get() + clk_prepare() + * @dev: device for clock "consumer" + * @id: clock consumer ID + * + * Returns a struct clk corresponding to the clock producer, or + * valid IS_ERR() condition containing errno. The implementation + * uses @dev and @id to determine the clock consumer, and thereby + * the clock producer. (IOW, @id may be identical strings, but + * clk_get may return different clock producers depending on @dev.) + * + * The returned clk (if valid) is prepared. Drivers must however assume that the + * clock is not enabled. + * + * devm_clk_get_prepared should not be called from within interrupt context. + * + * The clock will automatically be unprepared and freed when the + * device is unbound from the bus. + */ +struct clk *devm_clk_get_prepared(struct device *dev, const char *id); + +/** + * devm_clk_get_enabled - devm_clk_get() + clk_prepare_enable() + * @dev: device for clock "consumer" + * @id: clock consumer ID + * + * Returns a struct clk corresponding to the clock producer, or + * valid IS_ERR() condition containing errno. The implementation + * uses @dev and @id to determine the clock consumer, and thereby + * the clock producer. (IOW, @id may be identical strings, but + * clk_get may return different clock producers depending on @dev.) + * + * The returned clk (if valid) is prepared and enabled. + * + * devm_clk_get_prepared should not be called from within interrupt context. + * + * The clock will automatically be disabled, unprepared and freed when the + * device is unbound from the bus. + */ +struct clk *devm_clk_get_enabled(struct device *dev, const char *id); + /** * devm_clk_get_optional - lookup and obtain a managed reference to an optional * clock producer. @@ -429,6 +470,26 @@ struct clk *devm_clk_get(struct device *dev, const char *id); */ struct clk *devm_clk_get_optional(struct device *dev, const char *id); +/** + * devm_clk_get_optional_prepared - devm_clk_get_optional() + clk_prepare() + * @dev: device for clock "consumer" + * @id: clock consumer ID + * + * Behaves the same as devm_clk_get_prepared() except where there is no clock producer. + * In this case, instead of returning -ENOENT, the function returns NULL. + */ +struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id); + +/** + * devm_clk_get_optional_enabled - devm_clk_get_optional() + clk_prepare_enable() + * @dev: device for clock "consumer" + * @id: clock consumer ID + * + * Behaves the same as devm_clk_get_enabled() except where there is no clock producer. + * In this case, instead of returning -ENOENT, the function returns NULL. + */ +struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id); + /** * devm_get_clk_from_child - lookup and obtain a managed reference to a * clock producer from child node. @@ -773,12 +834,36 @@ static inline struct clk *devm_clk_get(struct device *dev, const char *id) return NULL; } +static inline struct clk *devm_clk_get_prepared(struct device *dev, + const char *id) +{ + return NULL; +} + +static inline struct clk *devm_clk_get_enabled(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 struct clk *devm_clk_get_optional_prepared(struct device *dev, + const char *id) +{ + return NULL; +} + +static inline struct clk *devm_clk_get_optional_enabled(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) { -- 2.28.0
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