diff options
| -rw-r--r-- | Documentation/driver-model/devres.txt | 4 | ||||
| -rw-r--r-- | drivers/clk/clkdev.c | 45 | ||||
| -rw-r--r-- | include/linux/clk.h | 32 |
3 files changed, 81 insertions, 0 deletions
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 10c64c8a13d4..6346042c3b54 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -267,3 +267,7 @@ IOMAP pcim_iounmap() pcim_iomap_table() : array of mapped addresses indexed by BAR pcim_iomap_regions() : do request_region() and iomap() on multiple BARs + +CLOCK + devm_clk_get() + devm_clk_put() diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 6db161f64ae0..a9a113782821 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -89,6 +89,51 @@ void clk_put(struct clk *clk) } EXPORT_SYMBOL(clk_put); +static void devm_clk_release(struct device *dev, void *res) +{ + clk_put(*(struct clk **)res); +} + +struct clk *devm_clk_get(struct device *dev, const char *id) +{ + struct clk **ptr, *clk; + + 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); + } + + return clk; +} +EXPORT_SYMBOL(devm_clk_get); + +static int devm_clk_match(struct device *dev, void *res, void *data) +{ + struct clk **c = res; + if (!c || !*c) { + WARN_ON(!c || !*c); + return 0; + } + return *c == data; +} + +void devm_clk_put(struct device *dev, struct clk *clk) +{ + int ret; + + ret = devres_destroy(dev, devm_clk_release, devm_clk_match, clk); + + WARN_ON(ret); +} +EXPORT_SYMBOL(devm_clk_put); + void clkdev_add(struct clk_lookup *cl) { mutex_lock(&clocks_mutex); diff --git a/include/linux/clk.h b/include/linux/clk.h index 1d37f42ac294..59b428e5fbc5 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -41,6 +41,26 @@ struct clk; struct clk *clk_get(struct device *dev, const char *id); /** + * devm_clk_get - lookup and obtain a managed reference to a clock producer. + * @dev: device for clock "consumer" + * @id: clock comsumer 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.) + * + * Drivers must assume that the clock source is not enabled. + * + * devm_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_clk_get(struct device *dev, const char *id); + +/** * clk_enable - inform the system when the clock source should be running. * @clk: clock source * @@ -83,6 +103,18 @@ unsigned long clk_get_rate(struct clk *clk); */ void clk_put(struct clk *clk); +/** + * devm_clk_put - "free" a managed clock source + * @dev: device used to acuqire the clock + * @clk: clock source acquired with devm_clk_get() + * + * Note: drivers must ensure that all clk_enable calls made on this + * clock source are balanced by clk_disable calls prior to calling + * this function. + * + * clk_put should not be called from within interrupt context. + */ +void devm_clk_put(struct device *dev, struct clk *clk); /* * The remaining APIs are optional for machine class support. |