diff options
Diffstat (limited to 'drivers/regulator/devres.c')
-rw-r--r-- | drivers/regulator/devres.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/drivers/regulator/devres.c b/drivers/regulator/devres.c index 90bb0d178885..4f290b9b559b 100644 --- a/drivers/regulator/devres.c +++ b/drivers/regulator/devres.c @@ -145,6 +145,65 @@ struct regulator *devm_regulator_get_optional(struct device *dev, } EXPORT_SYMBOL_GPL(devm_regulator_get_optional); +/** + * devm_regulator_get_enable_read_voltage - Resource managed regulator get and + * enable that returns the voltage + * @dev: device to supply + * @id: supply name or regulator ID. + * + * Get and enable regulator for duration of the device life-time. + * regulator_disable() and regulator_put() are automatically called on driver + * detach. See regulator_get_optional(), regulator_enable(), and + * regulator_get_voltage() for more information. + * + * This is a convenience function for supplies that provide a reference voltage + * where the consumer driver just needs to know the voltage and keep the + * regulator enabled. + * + * In cases where the supply is not strictly required, callers can check for + * -ENODEV error and handle it accordingly. + * + * Returns: voltage in microvolts on success, or an error code on failure. + */ +int devm_regulator_get_enable_read_voltage(struct device *dev, const char *id) +{ + struct regulator *r; + int ret; + + /* + * Since we need a real voltage, we use devm_regulator_get_optional() + * rather than getting a dummy regulator with devm_regulator_get() and + * then letting regulator_get_voltage() fail with -EINVAL. This way, the + * caller can handle the -ENODEV error code if needed instead of the + * ambiguous -EINVAL. + */ + r = devm_regulator_get_optional(dev, id); + if (IS_ERR(r)) + return PTR_ERR(r); + + ret = regulator_enable(r); + if (ret) + goto err_regulator_put; + + ret = devm_add_action_or_reset(dev, regulator_action_disable, r); + if (ret) + goto err_regulator_put; + + ret = regulator_get_voltage(r); + if (ret < 0) + goto err_release_action; + + return 0; + +err_release_action: + devm_release_action(dev, regulator_action_disable, r); +err_regulator_put: + devm_regulator_put(r); + + return ret; +} +EXPORT_SYMBOL_GPL(devm_regulator_get_enable_read_voltage); + static int devm_regulator_match(struct device *dev, void *res, void *data) { struct regulator **r = res; |