diff options
Diffstat (limited to 'drivers/base/power/domain.c')
| -rw-r--r-- | drivers/base/power/domain.c | 494 |
1 files changed, 494 insertions, 0 deletions
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c new file mode 100644 index 000000000000..fd31be3be404 --- /dev/null +++ b/drivers/base/power/domain.c @@ -0,0 +1,494 @@ +/* + * drivers/base/power/domain.c - Common code related to device power domains. + * + * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp. + * + * This file is released under the GPLv2. + */ + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/pm_runtime.h> +#include <linux/pm_domain.h> +#include <linux/slab.h> +#include <linux/err.h> + +#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; +} |