Index: linux-2.6/include/linux/pm_domain.h
===================================================================
--- /dev/null
+++ linux-2.6/include/linux/pm_domain.h
@@ -0,0 +1,75 @@
+/*
+ * 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_power_domain *domain);
+};
+
+struct generic_power_domain {
+	struct dev_power_domain domain;
+	struct list_head node;
+	struct generic_power_domain *master;
+	struct list_head subdomain_list;
+	struct list_head device_list;
+	struct mutex lock;
+	struct dev_power_governor *gov;
+	unsigned int in_progress;
+	bool power_is_off;
+	int (*power_off)(struct dev_power_domain *domain);
+	int (*power_on)(struct dev_power_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;
+};
+
+#ifdef CONFIG_PM
+extern int pm_genpd_add_device(struct generic_power_domain *genpd,
+			       struct device *dev);
+extern int pm_genpd_remove_device(struct generic_power_domain *genpd,
+				  struct device *dev);
+extern int pm_genpd_add_subdomain(struct generic_power_domain *genpd,
+				  struct generic_power_domain *new_subdomain);
+extern int pm_genpd_remove_subdomain(struct generic_power_domain *genpd,
+				     struct generic_power_domain *target);
+extern void pm_genpd_init(struct generic_power_domain *genpd,
+			  struct dev_power_governor *gov, bool is_off);
+#else
+static inline int pm_genpd_add_device(struct generic_power_domain *genpd,
+				      struct device *dev)
+{
+	return -ENOSYS;
+}
+static inline int pm_genpd_remove_device(struct generic_power_domain *genpd,
+					 struct device *dev)
+{
+	return -ENOSYS;
+}
+static inline int pm_genpd_add_subdomain(struct generic_power_domain *genpd,
+					 struct generic_power_domain *new_sd)
+{
+	return -ENOSYS;
+}
+static inline int pm_genpd_remove_subdomain(struct generic_power_domain *genpd,
+					    struct generic_power_domain *target)
+{
+	return -ENOSYS;
+}
+static inline void pm_genpd_init(struct generic_power_domain *genpd,
+				 struct dev_power_governor *gov, bool is_off) {}
+#endif
+
+#endif /* _LINUX_PM_DOMAIN_H */
Index: linux-2.6/include/linux/pm.h
===================================================================
--- linux-2.6.orig/include/linux/pm.h
+++ linux-2.6/include/linux/pm.h
@@ -472,7 +472,8 @@ extern void update_pm_runtime_accounting
  * subsystem-level and driver-level callbacks.
  */
 struct dev_power_domain {
-	struct dev_pm_ops	ops;
+	struct dev_pm_ops ops;
+	void *platform_data;
 };
 
 /*
Index: linux-2.6/drivers/base/power/Makefile
===================================================================
--- linux-2.6.orig/drivers/base/power/Makefile
+++ linux-2.6/drivers/base/power/Makefile
@@ -1,4 +1,4 @@
-obj-$(CONFIG_PM)	+= sysfs.o generic_ops.o
+obj-$(CONFIG_PM)	+= sysfs.o generic_ops.o domain.o
 obj-$(CONFIG_PM_SLEEP)	+= main.o wakeup.o
 obj-$(CONFIG_PM_RUNTIME)	+= runtime.o
 obj-$(CONFIG_PM_TRACE_RTC)	+= trace.o
Index: linux-2.6/drivers/base/power/domain.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/base/power/domain.c
@@ -0,0 +1,444 @@
+/*
+ * 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
+
+/**
+ * __pm_genpd_restore_device - Restore a pre-suspend state of a device.
+ * @dev: Device to restore the state of.
+ * @genpd: Power domain the device belongs to.
+ */
+static void __pm_genpd_restore_device(struct device *dev,
+				      struct generic_power_domain *genpd)
+{
+	struct device_driver *drv = dev->driver;
+
+	if (genpd->start_device)
+		genpd->start_device(dev);
+
+	if (drv && drv->pm && drv->pm->runtime_resume)
+		drv->pm->runtime_resume(dev);
+
+	if (genpd->stop_device)
+		genpd->stop_device(dev);
+}
+
+/**
+ * __pm_genpd_poweroff - Remove power from a given power domain.
+ * @genpd: Power 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_power_domain *genpd)
+{
+	struct generic_power_domain *subdomain;
+	struct dev_list_entry *dle;
+	unsigned int not_suspended;
+	int ret;
+
+	if (genpd->power_is_off)
+		return 0;
+
+	not_suspended = 0;
+	list_for_each_entry(dle, &genpd->device_list, node)
+		if (!pm_runtime_suspended(dle->dev))
+			not_suspended++;
+
+	if (not_suspended > genpd->in_progress)
+		return -EBUSY;
+
+	list_for_each_entry_reverse(subdomain, &genpd->subdomain_list, node) {
+		mutex_lock(&subdomain->lock);
+		ret = __pm_genpd_poweroff(subdomain);
+		mutex_unlock(&subdomain->lock);
+		if (ret)
+			return ret;
+	}
+
+	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->device_list, node) {
+		struct device *dev = dle->dev;
+		struct device_driver *drv = dev->driver;
+
+		if (genpd->start_device)
+			genpd->start_device(dev);
+
+		if (drv && drv->pm && drv->pm->runtime_suspend)
+			ret = drv->pm->runtime_suspend(dev);
+
+		if (genpd->stop_device)
+			genpd->stop_device(dev);
+
+		if (ret)
+			goto err_dev;
+	}
+
+	if (genpd->power_off)
+		genpd->power_off(&genpd->domain);
+
+	genpd->power_is_off = true;
+
+	return 0;
+
+ err_dev:
+	list_for_each_entry_continue(dle, &genpd->device_list, node)
+		__pm_genpd_restore_device(dle->dev, genpd);
+
+	return ret;
+}
+
+/**
+ * pm_genpd_poweroff - Remove power from a given power domain and its masters.
+ * @genpd: Power domain to power down.
+ *
+ * Try to remove power from @genpd and all of its masters in order to save as
+ * much power as possible.
+ */
+static void pm_genpd_poweroff(struct generic_power_domain *genpd)
+{
+	struct generic_power_domain *master;
+
+	mutex_lock(&genpd->lock);
+	master = genpd->master;
+	if (master) {
+		mutex_unlock(&genpd->lock);
+		pm_genpd_poweroff(master);
+		return;
+	}
+	__pm_genpd_poweroff(genpd);
+	mutex_unlock(&genpd->lock);
+}
+
+/**
+ * pm_genpd_runtime_suspend - Suspend a device belonging to I/O power domain.
+ * @dev: Device to suspend.
+ *
+ * Carry out a runtime suspend of a device under the assumption that its
+ * pwr_domain field points to the domain member of an object of type
+ * struct generic_power_domain representing a power domain consisting of I/O
+ * devices.
+ */
+static int pm_genpd_runtime_suspend(struct device *dev)
+{
+	struct generic_power_domain *genpd, *master;
+
+	dev_dbg(dev, "%s()\n", __func__);
+
+	if (IS_ERR_OR_NULL(dev->pwr_domain))
+		return -EINVAL;
+
+	genpd = container_of(dev->pwr_domain,
+			     struct generic_power_domain, domain);
+
+	mutex_lock(&genpd->lock);
+
+	if (genpd->stop_device) {
+		int ret = genpd->stop_device(dev);
+		if (ret)
+			goto out;
+	}
+	genpd->in_progress++;
+
+	master = genpd->master;
+	if (master) {
+		mutex_unlock(&genpd->lock);
+
+		pm_genpd_poweroff(master);
+
+		mutex_lock(&genpd->lock);
+	} else {
+		__pm_genpd_poweroff(genpd);
+	}
+
+	genpd->in_progress--;
+
+ out:
+	mutex_unlock(&genpd->lock);
+
+	return 0;
+}
+
+/**
+ * __pm_genpd_poweron - Restore power for a given power domain.
+ * @genpd: Power domain to power up.
+ *
+ * Restore power for @genpd and run runtime resume callbacks provided by all of
+ * its devices' drivers.
+ */
+static int __pm_genpd_poweron(struct generic_power_domain *genpd)
+{
+	struct dev_list_entry *dle;
+
+	if (!genpd->power_is_off)
+		return 0;
+
+	if (genpd->power_on) {
+		int ret = genpd->power_on(&genpd->domain);
+		if (ret)
+			return ret;
+	}
+
+	genpd->power_is_off = false;
+
+	list_for_each_entry(dle, &genpd->device_list, node)
+		__pm_genpd_restore_device(dle->dev, genpd);
+
+	return 0;
+}
+
+/**
+ * pm_genpd_poweron - Restore power for a given power domain and its masters.
+ * @genpd: Power domain to power up.
+ *
+ * Restore power for @genpd and all of its masters so that it is possible to
+ * resume a device belonging to it.
+ */
+static int pm_genpd_poweron(struct generic_power_domain *genpd)
+{
+	struct generic_power_domain *master;
+	int ret;
+
+	mutex_lock(&genpd->lock);
+	master = genpd->master;
+	if (master) {
+		mutex_unlock(&genpd->lock);
+
+		ret = pm_genpd_poweron(master);
+		if (ret)
+			return ret;
+
+		mutex_lock(&genpd->lock);
+	}
+	ret = __pm_genpd_poweron(genpd);
+	mutex_unlock(&genpd->lock);
+
+	return ret;
+}
+
+/**
+ * pm_genpd_runtime_resume - Resume a device belonging to I/O power domain.
+ * @dev: Device to resume.
+ *
+ * Carry out a runtime resume of a device under the assumption that its
+ * pwr_domain field points to the domain member of an object of type
+ * struct generic_power_domain representing a power domain consisting of I/O
+ * devices.
+ */
+static int pm_genpd_runtime_resume(struct device *dev)
+{
+	struct generic_power_domain *genpd;
+	int ret;
+
+	dev_dbg(dev, "%s()\n", __func__);
+
+	if (IS_ERR_OR_NULL(dev->pwr_domain))
+		return -EINVAL;
+
+	genpd = container_of(dev->pwr_domain,
+			     struct generic_power_domain, domain);
+
+	ret = pm_genpd_poweron(genpd);
+	if (ret)
+		return ret;
+
+	if (genpd->start_device)
+		genpd->start_device(dev);
+
+	return 0;
+}
+
+#else
+
+#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 power domain.
+ * @genpd: Power domain to add the device to.
+ * @dev: Device to be added.
+ */
+int pm_genpd_add_device(struct generic_power_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);
+
+	list_for_each_entry(dle, &genpd->device_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;
+	list_add_tail(&dle->node, &genpd->device_list);
+
+	spin_lock_irq(&dev->power.lock);
+	dev->pwr_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 power domain.
+ * @genpd: Power domain to remove the device from.
+ * @dev: Device to be removed.
+ */
+int pm_genpd_remove_device(struct generic_power_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->device_list, node) {
+		if (dle->dev != dev)
+			continue;
+
+		spin_lock_irq(&dev->power.lock);
+		dev->pwr_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 power domain.
+ * @genpd: Master power domain to add the subdomain to.
+ * @new_subdomain: Subdomain to be added.
+ */
+int pm_genpd_add_subdomain(struct generic_power_domain *genpd,
+			   struct generic_power_domain *new_subdomain)
+{
+	struct generic_power_domain *subdomain;
+	int ret = 0;
+
+	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(new_subdomain))
+		return -EINVAL;
+
+	mutex_lock(&genpd->lock);
+
+	list_for_each_entry(subdomain, &genpd->subdomain_list, node)
+		if (subdomain == new_subdomain) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+	mutex_lock(&new_subdomain->lock);
+	list_add_tail(&new_subdomain->node, &genpd->subdomain_list);
+	new_subdomain->master = genpd;
+	mutex_unlock(&new_subdomain->lock);
+
+ out:
+	mutex_unlock(&genpd->lock);
+
+	return ret;
+}
+
+/**
+ * pm_genpd_remove_subdomain - Remove a subdomain from an I/O power domain.
+ * @genpd: Master power domain to remove the subdomain from.
+ * @target: Subdomain to be removed.
+ */
+int pm_genpd_remove_subdomain(struct generic_power_domain *genpd,
+			      struct generic_power_domain *target)
+{
+	struct generic_power_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->subdomain_list, node) {
+		if (subdomain != target)
+			continue;
+
+		mutex_lock(&subdomain->lock);
+		list_del(&subdomain->node);
+		subdomain->master = NULL;
+		mutex_unlock(&subdomain->lock);
+
+		ret = 0;
+		break;
+	}
+
+	mutex_unlock(&genpd->lock);
+
+	return ret;
+}
+
+/**
+ * pm_genpd_init - Initialize an I/O power domain object.
+ * @genpd: Power domain object to initialize.
+ */
+void pm_genpd_init(struct generic_power_domain *genpd,
+		   struct dev_power_governor *gov, bool is_off)
+{
+	if (IS_ERR_OR_NULL(genpd))
+		return;
+
+	INIT_LIST_HEAD(&genpd->node);
+	genpd->master = NULL;
+	INIT_LIST_HEAD(&genpd->device_list);
+	INIT_LIST_HEAD(&genpd->subdomain_list);
+	mutex_init(&genpd->lock);
+	genpd->gov = gov;
+	genpd->in_progress = 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;
+}
