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;
+}