3 files changed, 83 insertions, 7 deletions

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index b0ec0e9f27e..b78c401ffa7 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -123,6 +123,45 @@ int pm_runtime_idle(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(pm_runtime_idle);
 
+
+/**
+ * update_pm_runtime_accounting - Update the time accounting of power states
+ * @dev: Device to update the accounting for
+ *
+ * In order to be able to have time accounting of the various power states
+ * (as used by programs such as PowerTOP to show the effectiveness of runtime
+ * PM), we need to track the time spent in each state.
+ * update_pm_runtime_accounting must be called each time before the
+ * runtime_status field is updated, to account the time in the old state
+ * correctly.
+ */
+void update_pm_runtime_accounting(struct device *dev)
+{
+        unsigned long now = jiffies;
+        int delta;
+
+        delta = now - dev->power.accounting_timestamp;
+
+        if (delta < 0)
+                delta = 0;
+
+        dev->power.accounting_timestamp = now;
+
+        if (dev->power.disable_depth > 0)
+                return;
+
+        if (dev->power.runtime_status == RPM_SUSPENDED)
+                dev->power.suspended_jiffies += delta;
+        else
+                dev->power.active_jiffies += delta;
+}
+
+static void __update_runtime_status(struct device *dev, enum rpm_status status)
+{
+        update_pm_runtime_accounting(dev);
+        dev->power.runtime_status = status;
+}
+
 /**
  * __pm_runtime_suspend - Carry out run-time suspend of given device.
  * @dev: Device to suspend.
@@ -197,7 +236,7 @@ int __pm_runtime_suspend(struct device *dev, bool from_wq)
                 goto repeat;
         }
 
-        dev->power.runtime_status = RPM_SUSPENDING;
+        __update_runtime_status(dev, RPM_SUSPENDING);
         dev->power.deferred_resume = false;
 
         if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) {
@@ -228,7 +267,7 @@ int __pm_runtime_suspend(struct device *dev, bool from_wq)
         }
 
         if (retval) {
-                dev->power.runtime_status = RPM_ACTIVE;
+                __update_runtime_status(dev, RPM_ACTIVE);
                 if (retval == -EAGAIN || retval == -EBUSY) {
                         if (dev->power.timer_expires == 0)
                                 notify = true;
@@ -237,7 +276,7 @@ int __pm_runtime_suspend(struct device *dev, bool from_wq)
                         pm_runtime_cancel_pending(dev);
                 }
         } else {
-                dev->power.runtime_status = RPM_SUSPENDED;
+                __update_runtime_status(dev, RPM_SUSPENDED);
                 pm_runtime_deactivate_timer(dev);
 
                 if (dev->parent) {
@@ -381,7 +420,7 @@ int __pm_runtime_resume(struct device *dev, bool from_wq)
                 goto repeat;
         }
 
-        dev->power.runtime_status = RPM_RESUMING;
+        __update_runtime_status(dev, RPM_RESUMING);
 
         if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) {
                 spin_unlock_irq(&dev->power.lock);
@@ -411,10 +450,10 @@ int __pm_runtime_resume(struct device *dev, bool from_wq)
         }
 
         if (retval) {
-                dev->power.runtime_status = RPM_SUSPENDED;
+                __update_runtime_status(dev, RPM_SUSPENDED);
                 pm_runtime_cancel_pending(dev);
         } else {
-                dev->power.runtime_status = RPM_ACTIVE;
+                __update_runtime_status(dev, RPM_ACTIVE);
                 if (parent)
                         atomic_inc(&parent->power.child_count);
         }
@@ -848,7 +887,7 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status)
         }
 
  out_set:
-        dev->power.runtime_status = status;
+        __update_runtime_status(dev, status);
         dev->power.runtime_error = 0;
  out:
         spin_unlock_irqrestore(&dev->power.lock, flags);
@@ -1077,6 +1116,7 @@ void pm_runtime_init(struct device *dev)
         dev->power.request_pending = false;
         dev->power.request = RPM_REQ_NONE;
         dev->power.deferred_resume = false;
+        dev->power.accounting_timestamp = jiffies;
         INIT_WORK(&dev->power.work, pm_runtime_work);
 
         dev->power.timer_expires = 0;
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 1eca50c8e7c..e56b4388fe6 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -6,6 +6,7 @@
 #include <linux/string.h>
 #include <linux/pm_runtime.h>
 #include <asm/atomic.h>
+#include <linux/jiffies.h>
 #include "power.h"
 
 /*
@@ -111,6 +112,33 @@ static ssize_t control_store(struct device * dev, struct device_attribute *attr,
 
 static DEVICE_ATTR(control, 0644, control_show, control_store);
 
+static ssize_t rtpm_active_time_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        int ret;
+        spin_lock_irq(&dev->power.lock);
+        update_pm_runtime_accounting(dev);
+        ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies));
+        spin_unlock_irq(&dev->power.lock);
+        return ret;
+}
+
+static DEVICE_ATTR(runtime_active_time, 0444, rtpm_active_time_show, NULL);
+
+static ssize_t rtpm_suspended_time_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        int ret;
+        spin_lock_irq(&dev->power.lock);
+        update_pm_runtime_accounting(dev);
+        ret = sprintf(buf, "%i\n",
+                jiffies_to_msecs(dev->power.suspended_jiffies));
+        spin_unlock_irq(&dev->power.lock);
+        return ret;
+}
+
+static DEVICE_ATTR(runtime_suspended_time, 0444, rtpm_suspended_time_show, NULL);
+
 static ssize_t rtpm_status_show(struct device *dev,
                                 struct device_attribute *attr, char *buf)
 {
@@ -254,6 +282,8 @@ static struct attribute * power_attrs[] = {
 #ifdef CONFIG_PM_RUNTIME
         &dev_attr_control.attr,
         &dev_attr_runtime_status.attr,
+        &dev_attr_runtime_suspended_time.attr,
+        &dev_attr_runtime_active_time.attr,
 #endif
         &dev_attr_wakeup.attr,
 #ifdef CONFIG_PM_SLEEP
diff --git a/include/linux/pm.h b/include/linux/pm.h
index b417fc46f3f..52e8c55ff31 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -477,9 +477,15 @@ struct dev_pm_info {
         enum rpm_request        request;
         enum rpm_status         runtime_status;
         int                     runtime_error;
+        unsigned long           active_jiffies;
+        unsigned long           suspended_jiffies;
+        unsigned long           accounting_timestamp;
 #endif
 };
 
+extern void update_pm_runtime_accounting(struct device *dev);
+
+
 /*
  * The PM_EVENT_ messages are also used by drivers implementing the legacy
  * suspend framework, based on the ->suspend() and ->resume() callbacks common