diff options
| -rw-r--r-- | drivers/base/power/common.c | 43 | ||||
| -rw-r--r-- | include/linux/pm_domain.h | 7 |
2 files changed, 47 insertions, 3 deletions
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c index 7ae62b6355b8..df41b4780b3b 100644 --- a/drivers/base/power/common.c +++ b/drivers/base/power/common.c @@ -117,13 +117,50 @@ int dev_pm_domain_attach(struct device *dev, bool power_on) EXPORT_SYMBOL_GPL(dev_pm_domain_attach); /** + * dev_pm_domain_attach_by_id - Associate a device with one of its PM domains. + * @dev: The device used to lookup the PM domain. + * @index: The index of the PM domain. + * + * As @dev may only be attached to a single PM domain, the backend PM domain + * provider creates a virtual device to attach instead. If attachment succeeds, + * the ->detach() callback in the struct dev_pm_domain are assigned by the + * corresponding backend attach function, as to deal with detaching of the + * created virtual device. + * + * This function should typically be invoked by a driver during the probe phase, + * in case its device requires power management through multiple PM domains. The + * driver may benefit from using the received device, to configure device-links + * towards its original device. Depending on the use-case and if needed, the + * links may be dynamically changed by the driver, which allows it to control + * the power to the PM domains independently from each other. + * + * Callers must ensure proper synchronization of this function with power + * management callbacks. + * + * Returns the virtual created device when successfully attached to its PM + * domain, NULL in case @dev don't need a PM domain, else an ERR_PTR(). + * Note that, to detach the returned virtual device, the driver shall call + * dev_pm_domain_detach() on it, typically during the remove phase. + */ +struct device *dev_pm_domain_attach_by_id(struct device *dev, + unsigned int index) +{ + if (dev->pm_domain) + return ERR_PTR(-EEXIST); + + return genpd_dev_pm_attach_by_id(dev, index); +} +EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_id); + +/** * dev_pm_domain_detach - Detach a device from its PM domain. * @dev: Device to detach. * @power_off: Used to indicate whether we should power off the device. * - * This functions will reverse the actions from dev_pm_domain_attach() and thus - * try to detach the @dev from its PM domain. Typically it should be invoked - * from subsystem level code during the remove phase. + * This functions will reverse the actions from dev_pm_domain_attach() and + * dev_pm_domain_attach_by_id(), thus it detaches @dev from its PM domain. + * Typically it should be invoked during the remove phase, either from + * subsystem level code or from drivers. * * Callers must ensure proper synchronization of this function with power * management callbacks. diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 82458e8e2e01..9206a4fef9ac 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -299,6 +299,8 @@ struct generic_pm_domain *of_genpd_remove_last(struct device_node *np) #ifdef CONFIG_PM int dev_pm_domain_attach(struct device *dev, bool power_on); +struct device *dev_pm_domain_attach_by_id(struct device *dev, + unsigned int index); void dev_pm_domain_detach(struct device *dev, bool power_off); void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd); #else @@ -306,6 +308,11 @@ static inline int dev_pm_domain_attach(struct device *dev, bool power_on) { return 0; } +static inline struct device *dev_pm_domain_attach_by_id(struct device *dev, + unsigned int index) +{ + return NULL; +} static inline void dev_pm_domain_detach(struct device *dev, bool power_off) {} static inline void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd) {} |