diff options
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/power/common.c | 43 | ||||
| -rw-r--r-- | drivers/base/power/domain.c | 134 |
2 files changed, 154 insertions, 23 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/drivers/base/power/domain.c b/drivers/base/power/domain.c index 6f403d6fccb2..4925af5c4cf0 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -2171,6 +2171,15 @@ struct generic_pm_domain *of_genpd_remove_last(struct device_node *np) } EXPORT_SYMBOL_GPL(of_genpd_remove_last); +static void genpd_release_dev(struct device *dev) +{ + kfree(dev); +} + +static struct bus_type genpd_bus_type = { + .name = "genpd", +}; + /** * genpd_dev_pm_detach - Detach a device from its PM domain. * @dev: Device to detach. @@ -2208,6 +2217,10 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off) /* Check if PM domain can be powered off after removing this device. */ genpd_queue_power_off_work(pd); + + /* Unregister the device if it was created by genpd. */ + if (dev->bus == &genpd_bus_type) + device_unregister(dev); } static void genpd_dev_pm_sync(struct device *dev) @@ -2221,32 +2234,17 @@ static void genpd_dev_pm_sync(struct device *dev) genpd_queue_power_off_work(pd); } -/** - * genpd_dev_pm_attach - Attach a device to its PM domain using DT. - * @dev: Device to attach. - * - * Parse device's OF node to find a PM domain specifier. If such is found, - * attaches the device to retrieved pm_domain ops. - * - * Returns 1 on successfully attached PM domain, 0 when the device don't need a - * PM domain or a negative error code in case of failures. Note that if a - * power-domain exists for the device, but it cannot be found or turned on, - * then return -EPROBE_DEFER to ensure that the device is not probed and to - * re-try again later. - */ -int genpd_dev_pm_attach(struct device *dev) +static int __genpd_dev_pm_attach(struct device *dev, struct device_node *np, + unsigned int index) { struct of_phandle_args pd_args; struct generic_pm_domain *pd; int ret; - if (!dev->of_node) - return 0; - - ret = of_parse_phandle_with_args(dev->of_node, "power-domains", - "#power-domain-cells", 0, &pd_args); + ret = of_parse_phandle_with_args(np, "power-domains", + "#power-domain-cells", index, &pd_args); if (ret < 0) - return 0; + return ret; mutex_lock(&gpd_list_lock); pd = genpd_get_from_provider(&pd_args); @@ -2282,8 +2280,98 @@ int genpd_dev_pm_attach(struct device *dev) return ret ? -EPROBE_DEFER : 1; } + +/** + * genpd_dev_pm_attach - Attach a device to its PM domain using DT. + * @dev: Device to attach. + * + * Parse device's OF node to find a PM domain specifier. If such is found, + * attaches the device to retrieved pm_domain ops. + * + * Returns 1 on successfully attached PM domain, 0 when the device don't need a + * PM domain or when multiple power-domains exists for it, else a negative error + * code. Note that if a power-domain exists for the device, but it cannot be + * found or turned on, then return -EPROBE_DEFER to ensure that the device is + * not probed and to re-try again later. + */ +int genpd_dev_pm_attach(struct device *dev) +{ + if (!dev->of_node) + return 0; + + /* + * Devices with multiple PM domains must be attached separately, as we + * can only attach one PM domain per device. + */ + if (of_count_phandle_with_args(dev->of_node, "power-domains", + "#power-domain-cells") != 1) + return 0; + + return __genpd_dev_pm_attach(dev, dev->of_node, 0); +} EXPORT_SYMBOL_GPL(genpd_dev_pm_attach); +/** + * genpd_dev_pm_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. + * + * Parse device's OF node to find a PM domain specifier at the provided @index. + * If such is found, creates a virtual device and attaches it to the retrieved + * pm_domain ops. To deal with detaching of the virtual device, the ->detach() + * callback in the struct dev_pm_domain are assigned to genpd_dev_pm_detach(). + * + * Returns the created virtual device if successfully attached PM domain, NULL + * when the device don't need a PM domain, else an ERR_PTR() in case of + * failures. If a power-domain exists for the device, but cannot be found or + * turned on, then ERR_PTR(-EPROBE_DEFER) is returned to ensure that the device + * is not probed and to re-try again later. + */ +struct device *genpd_dev_pm_attach_by_id(struct device *dev, + unsigned int index) +{ + struct device *genpd_dev; + int num_domains; + int ret; + + if (!dev->of_node) + return NULL; + + /* Deal only with devices using multiple PM domains. */ + num_domains = of_count_phandle_with_args(dev->of_node, "power-domains", + "#power-domain-cells"); + if (num_domains < 2 || index >= num_domains) + return NULL; + + /* Allocate and register device on the genpd bus. */ + genpd_dev = kzalloc(sizeof(*genpd_dev), GFP_KERNEL); + if (!genpd_dev) + return ERR_PTR(-ENOMEM); + + dev_set_name(genpd_dev, "genpd:%u:%s", index, dev_name(dev)); + genpd_dev->bus = &genpd_bus_type; + genpd_dev->release = genpd_release_dev; + + ret = device_register(genpd_dev); + if (ret) { + kfree(genpd_dev); + return ERR_PTR(ret); + } + + /* Try to attach the device to the PM domain at the specified index. */ + ret = __genpd_dev_pm_attach(genpd_dev, dev->of_node, index); + if (ret < 1) { + device_unregister(genpd_dev); + return ret ? ERR_PTR(ret) : NULL; + } + + pm_runtime_set_active(genpd_dev); + pm_runtime_enable(genpd_dev); + + return genpd_dev; +} +EXPORT_SYMBOL_GPL(genpd_dev_pm_attach_by_id); + static const struct of_device_id idle_state_match[] = { { .compatible = "domain-idle-state", }, { } @@ -2443,6 +2531,12 @@ unlock: } EXPORT_SYMBOL_GPL(of_genpd_opp_to_performance_state); +static int __init genpd_bus_init(void) +{ + return bus_register(&genpd_bus_type); +} +core_initcall(genpd_bus_init); + #endif /* CONFIG_PM_GENERIC_DOMAINS_OF */ |