diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index 5ee7aadf0abf..a8cc14fd8ae4 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -1362,6 +1362,73 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table) } EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulators); +/** + * dev_pm_opp_set_clkname() - Set clk name for the device + * @dev: Device for which clk name is being set. + * @name: Clk name. + * + * In order to support OPP switching, OPP layer needs to get pointer to the + * clock for the device. Simple cases work fine without using this routine (i.e. + * by passing connection-id as NULL), but for a device with multiple clocks + * available, the OPP core needs to know the exact name of the clk to use. + * + * This must be called before any OPPs are initialized for the device. + */ +struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const char *name) +{ + struct opp_table *opp_table; + int ret; + + opp_table = dev_pm_opp_get_opp_table(dev); + if (!opp_table) + return ERR_PTR(-ENOMEM); + + /* This should be called before OPPs are initialized */ + if (WARN_ON(!list_empty(&opp_table->opp_list))) { + ret = -EBUSY; + goto err; + } + + /* Already have default clk set, free it */ + if (!IS_ERR(opp_table->clk)) + clk_put(opp_table->clk); + + /* Find clk for the device */ + opp_table->clk = clk_get(dev, name); + if (IS_ERR(opp_table->clk)) { + ret = PTR_ERR(opp_table->clk); + if (ret != -EPROBE_DEFER) { + dev_err(dev, "%s: Couldn't find clock: %d\n", __func__, + ret); + } + goto err; + } + + return opp_table; + +err: + dev_pm_opp_put_opp_table(opp_table); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(dev_pm_opp_set_clkname); + +/** + * dev_pm_opp_put_clkname() - Releases resources blocked for clk. + * @opp_table: OPP table returned from dev_pm_opp_set_clkname(). + */ +void dev_pm_opp_put_clkname(struct opp_table *opp_table) +{ + /* Make sure there are no concurrent readers while updating opp_table */ + WARN_ON(!list_empty(&opp_table->opp_list)); + + clk_put(opp_table->clk); + opp_table->clk = ERR_PTR(-EINVAL); + + dev_pm_opp_put_opp_table(opp_table); +} +EXPORT_SYMBOL_GPL(dev_pm_opp_put_clkname); + /** * dev_pm_opp_register_set_opp_helper() - Register custom set OPP helper * @dev: Device for which the helper is getting registered. diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index a6685b3dde26..51ec727b4824 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -121,6 +121,8 @@ struct opp_table *dev_pm_opp_set_prop_name(struct device *dev, const char *name) void dev_pm_opp_put_prop_name(struct opp_table *opp_table); struct opp_table *dev_pm_opp_set_regulators(struct device *dev, const char * const names[], unsigned int count); void dev_pm_opp_put_regulators(struct opp_table *opp_table); +struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const char * name); +void dev_pm_opp_put_clkname(struct opp_table *opp_table); struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev, int (*set_opp)(struct dev_pm_set_opp_data *data)); void dev_pm_opp_register_put_opp_helper(struct opp_table *opp_table); int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq); @@ -257,6 +259,13 @@ static inline struct opp_table *dev_pm_opp_set_regulators(struct device *dev, co static inline void dev_pm_opp_put_regulators(struct opp_table *opp_table) {} +static inline struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const char * name) +{ + return ERR_PTR(-ENOTSUPP); +} + +static inline void dev_pm_opp_put_clkname(struct opp_table *opp_table) {} + static inline int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) { return -ENOTSUPP;