--- /dev/null
+/*
+ * 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;
+}
--- /dev/null
+/*
+ * pm_domain.h - Definitions and headers related to device power domains.
+ *
+ * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#ifndef _LINUX_PM_DOMAIN_H
+#define _LINUX_PM_DOMAIN_H
+
+#include <linux/device.h>
+
+struct dev_power_governor {
+ bool (*power_down_ok)(struct dev_pm_domain *domain);
+};
+
+struct generic_pm_domain {
+ struct dev_pm_domain domain; /* PM domain operations */
+ struct list_head sd_node; /* Node in the parent's subdomain list */
+ struct generic_pm_domain *parent; /* Parent PM domain */
+ struct list_head sd_list; /* List of dubdomains */
+ struct list_head dev_list; /* List of devices */
+ struct mutex lock;
+ struct dev_power_governor *gov;
+ struct work_struct power_off_work;
+ unsigned int in_progress; /* Number of devices being suspended now */
+ unsigned int sd_count; /* Number of subdomains with power "on" */
+ bool power_is_off; /* Whether or not power has been removed */
+ int (*power_off)(struct generic_pm_domain *domain);
+ int (*power_on)(struct generic_pm_domain *domain);
+ int (*start_device)(struct device *dev);
+ int (*stop_device)(struct device *dev);
+};
+
+struct dev_list_entry {
+ struct list_head node;
+ struct device *dev;
+ bool need_restore;
+};
+
+#ifdef CONFIG_PM_GENERIC_DOMAINS
+extern int pm_genpd_add_device(struct generic_pm_domain *genpd,
+ struct device *dev);
+extern int pm_genpd_remove_device(struct generic_pm_domain *genpd,
+ struct device *dev);
+extern int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
+ struct generic_pm_domain *new_subdomain);
+extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
+ struct generic_pm_domain *target);
+extern void pm_genpd_init(struct generic_pm_domain *genpd,
+ struct dev_power_governor *gov, bool is_off);
+#else
+static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
+ struct device *dev)
+{
+ return -ENOSYS;
+}
+static inline int pm_genpd_remove_device(struct generic_pm_domain *genpd,
+ struct device *dev)
+{
+ return -ENOSYS;
+}
+static inline int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
+ struct generic_pm_domain *new_sd)
+{
+ return -ENOSYS;
+}
+static inline int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
+ struct generic_pm_domain *target)
+{
+ return -ENOSYS;
+}
+static inline void pm_genpd_init(struct generic_pm_domain *genpd,
+ struct dev_power_governor *gov, bool is_off) {}
+#endif
+
+#endif /* _LINUX_PM_DOMAIN_H */