/* * drivers/base/power/domain.c - Common code related to device power domains. * * Copyright (C) 2011 Rafael J. Wysocki , Renesas Electronics Corp. * * This file is released under the GPLv2. */ #include #include #include #include #include #include #include #ifdef CONFIG_PM_RUNTIME static void genpd_sd_counter_dec(struct generic_pm_domain *genpd) { if (!WARN_ON(genpd->sd_count == 0)) genpd->sd_count--; } /** * __pm_genpd_save_device - Save the pre-suspend state of a device. * @dle: Device list entry of the device to save the state of. * @genpd: PM domain the device belongs to. */ static int __pm_genpd_save_device(struct dev_list_entry *dle, struct generic_pm_domain *genpd) { struct device *dev = dle->dev; struct device_driver *drv = dev->driver; int ret = 0; if (dle->need_restore) return 0; if (drv && drv->pm && drv->pm->runtime_suspend) { if (genpd->start_device) genpd->start_device(dev); ret = drv->pm->runtime_suspend(dev); if (genpd->stop_device) genpd->stop_device(dev); } if (!ret) dle->need_restore = true; return ret; } /** * __pm_genpd_restore_device - Restore the pre-suspend state of a device. * @dle: Device list entry of the device to restore the state of. * @genpd: PM domain the device belongs to. */ static void __pm_genpd_restore_device(struct dev_list_entry *dle, struct generic_pm_domain *genpd) { struct device *dev = dle->dev; struct device_driver *drv = dev->driver; if (!dle->need_restore) return; if (drv && drv->pm && drv->pm->runtime_resume) { if (genpd->start_device) genpd->start_device(dev); drv->pm->runtime_resume(dev); if (genpd->stop_device) genpd->stop_device(dev); } dle->need_restore = false; } /** * pm_genpd_poweroff - Remove power from a given PM domain. * @genpd: PM domain to power down. * * If all of the @genpd's devices have been suspended and all of its subdomains * have been powered down, run the runtime suspend callbacks provided by all of * the @genpd's devices' drivers and remove power from @genpd. */ static int pm_genpd_poweroff(struct generic_pm_domain *genpd) { struct generic_pm_domain *parent; struct dev_list_entry *dle; unsigned int not_suspended; int ret; if (genpd->power_is_off) return 0; if (genpd->sd_count > 0) return -EBUSY; not_suspended = 0; list_for_each_entry(dle, &genpd->dev_list, node) if (dle->dev->driver && !pm_runtime_suspended(dle->dev)) not_suspended++; if (not_suspended > genpd->in_progress) return -EBUSY; if (genpd->gov && genpd->gov->power_down_ok) { if (!genpd->gov->power_down_ok(&genpd->domain)) return -EAGAIN; } list_for_each_entry_reverse(dle, &genpd->dev_list, node) { ret = __pm_genpd_save_device(dle, genpd); if (ret) goto err_dev; } if (genpd->power_off) genpd->power_off(genpd); genpd->power_is_off = true; parent = genpd->parent; if (parent) { genpd_sd_counter_dec(parent); if (parent->sd_count == 0) queue_work(pm_wq, &parent->power_off_work); } return 0; err_dev: list_for_each_entry_continue(dle, &genpd->dev_list, node) __pm_genpd_restore_device(dle, genpd); return ret; } /** * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0. * @work: Work structure used for scheduling the execution of this function. */ static void genpd_power_off_work_fn(struct work_struct *work) { struct generic_pm_domain *genpd; genpd = container_of(work, struct generic_pm_domain, power_off_work); if (genpd->parent) mutex_lock(&genpd->parent->lock); mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); pm_genpd_poweroff(genpd); mutex_unlock(&genpd->lock); if (genpd->parent) mutex_unlock(&genpd->parent->lock); } /** * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain. * @dev: Device to suspend. * * Carry out a runtime suspend of a device under the assumption that its * pm_domain field points to the domain member of an object of type * struct generic_pm_domain representing a PM domain consisting of I/O devices. */ static int pm_genpd_runtime_suspend(struct device *dev) { struct generic_pm_domain *genpd; dev_dbg(dev, "%s()\n", __func__); if (IS_ERR_OR_NULL(dev->pm_domain)) return -EINVAL; genpd = container_of(dev->pm_domain, struct generic_pm_domain, domain); if (genpd->parent) mutex_lock(&genpd->parent->lock); mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); if (genpd->stop_device) { int ret = genpd->stop_device(dev); if (ret) goto out; } genpd->in_progress++; pm_genpd_poweroff(genpd); genpd->in_progress--; out: mutex_unlock(&genpd->lock); if (genpd->parent) mutex_unlock(&genpd->parent->lock); return 0; } /** * pm_genpd_poweron - Restore power to a given PM domain and its parents. * @genpd: PM domain to power up. * * Restore power to @genpd and all of its parents so that it is possible to * resume a device belonging to it. */ static int pm_genpd_poweron(struct generic_pm_domain *genpd) { int ret = 0; start: if (genpd->parent) mutex_lock(&genpd->parent->lock); mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); if (!genpd->power_is_off) goto out; if (genpd->parent && genpd->parent->power_is_off) { mutex_unlock(&genpd->lock); mutex_unlock(&genpd->parent->lock); ret = pm_genpd_poweron(genpd->parent); if (ret) return ret; goto start; } if (genpd->power_on) { int ret = genpd->power_on(genpd); if (ret) goto out; } genpd->power_is_off = false; if (genpd->parent) genpd->parent->sd_count++; out: mutex_unlock(&genpd->lock); if (genpd->parent) mutex_unlock(&genpd->parent->lock); return ret; } /** * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain. * @dev: Device to resume. * * Carry out a runtime resume of a device under the assumption that its * pm_domain field points to the domain member of an object of type * struct generic_pm_domain representing a PM domain consisting of I/O devices. */ static int pm_genpd_runtime_resume(struct device *dev) { struct generic_pm_domain *genpd; struct dev_list_entry *dle; int ret; dev_dbg(dev, "%s()\n", __func__); if (IS_ERR_OR_NULL(dev->pm_domain)) return -EINVAL; genpd = container_of(dev->pm_domain, struct generic_pm_domain, domain); ret = pm_genpd_poweron(genpd); if (ret) return ret; mutex_lock(&genpd->lock); list_for_each_entry(dle, &genpd->dev_list, node) { if (dle->dev == dev) { __pm_genpd_restore_device(dle, genpd); break; } } if (genpd->start_device) genpd->start_device(dev); mutex_unlock(&genpd->lock); return 0; } #else static inline void genpd_power_off_work_fn(struct work_struct *work) {} #define pm_genpd_runtime_suspend NULL #define pm_genpd_runtime_resume NULL #endif /* CONFIG_PM_RUNTIME */ /** * pm_genpd_add_device - Add a device to an I/O PM domain. * @genpd: PM domain to add the device to. * @dev: Device to be added. */ int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev) { struct dev_list_entry *dle; int ret = 0; dev_dbg(dev, "%s()\n", __func__); if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) return -EINVAL; mutex_lock(&genpd->lock); if (genpd->power_is_off) { ret = -EINVAL; goto out; } list_for_each_entry(dle, &genpd->dev_list, node) if (dle->dev == dev) { ret = -EINVAL; goto out; } dle = kzalloc(sizeof(*dle), GFP_KERNEL); if (!dle) { ret = -ENOMEM; goto out; } dle->dev = dev; dle->need_restore = false; list_add_tail(&dle->node, &genpd->dev_list); spin_lock_irq(&dev->power.lock); dev->pm_domain = &genpd->domain; spin_unlock_irq(&dev->power.lock); out: mutex_unlock(&genpd->lock); return ret; } /** * pm_genpd_remove_device - Remove a device from an I/O PM domain. * @genpd: PM domain to remove the device from. * @dev: Device to be removed. */ int pm_genpd_remove_device(struct generic_pm_domain *genpd, struct device *dev) { struct dev_list_entry *dle; int ret = -EINVAL; dev_dbg(dev, "%s()\n", __func__); if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) return -EINVAL; mutex_lock(&genpd->lock); list_for_each_entry(dle, &genpd->dev_list, node) { if (dle->dev != dev) continue; spin_lock_irq(&dev->power.lock); dev->pm_domain = NULL; spin_unlock_irq(&dev->power.lock); list_del(&dle->node); kfree(dle); ret = 0; break; } mutex_unlock(&genpd->lock); return ret; } /** * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain. * @genpd: Master PM domain to add the subdomain to. * @new_subdomain: Subdomain to be added. */ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd, struct generic_pm_domain *new_subdomain) { struct generic_pm_domain *subdomain; int ret = 0; if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(new_subdomain)) return -EINVAL; mutex_lock(&genpd->lock); if (genpd->power_is_off && !new_subdomain->power_is_off) { ret = -EINVAL; goto out; } list_for_each_entry(subdomain, &genpd->sd_list, sd_node) { if (subdomain == new_subdomain) { ret = -EINVAL; goto out; } } mutex_lock_nested(&new_subdomain->lock, SINGLE_DEPTH_NESTING); list_add_tail(&new_subdomain->sd_node, &genpd->sd_list); new_subdomain->parent = genpd; if (!subdomain->power_is_off) genpd->sd_count++; mutex_unlock(&new_subdomain->lock); out: mutex_unlock(&genpd->lock); return ret; } /** * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain. * @genpd: Master PM domain to remove the subdomain from. * @target: Subdomain to be removed. */ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, struct generic_pm_domain *target) { struct generic_pm_domain *subdomain; int ret = -EINVAL; if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(target)) return -EINVAL; mutex_lock(&genpd->lock); list_for_each_entry(subdomain, &genpd->sd_list, sd_node) { if (subdomain != target) continue; mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING); list_del(&subdomain->sd_node); subdomain->parent = NULL; if (!subdomain->power_is_off) genpd_sd_counter_dec(genpd); mutex_unlock(&subdomain->lock); ret = 0; break; } mutex_unlock(&genpd->lock); return ret; } /** * pm_genpd_init - Initialize a generic I/O PM domain object. * @genpd: PM domain object to initialize. * @gov: PM domain governor to associate with the domain (may be NULL). * @is_off: Initial value of the domain's power_is_off field. */ void pm_genpd_init(struct generic_pm_domain *genpd, struct dev_power_governor *gov, bool is_off) { if (IS_ERR_OR_NULL(genpd)) return; INIT_LIST_HEAD(&genpd->sd_node); genpd->parent = NULL; INIT_LIST_HEAD(&genpd->dev_list); INIT_LIST_HEAD(&genpd->sd_list); mutex_init(&genpd->lock); genpd->gov = gov; INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn); genpd->in_progress = 0; genpd->sd_count = 0; genpd->power_is_off = is_off; genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend; genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume; genpd->domain.ops.runtime_idle = pm_generic_runtime_idle; }