PM / Runtime: Implement autosuspend support

[pandora-kernel.git] / drivers / base / power / sysfs.c

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index b5708c4..0b1e46b 100644 (file)
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -75,6 +75,18 @@
  *     attribute is set to "enabled" by bus type code or device drivers and in
  *     that cases it should be safe to leave the default value.
  *
+ *     autosuspend_delay_ms - Report/change a device's autosuspend_delay value
+ *
+ *     Some drivers don't want to carry out a runtime suspend as soon as a
+ *     device becomes idle; they want it always to remain idle for some period
+ *     of time before suspending it.  This period is the autosuspend_delay
+ *     value (expressed in milliseconds) and it can be controlled by the user.
+ *     If the value is negative then the device will never be runtime
+ *     suspended.
+ *
+ *     NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
+ *     value are used only if the driver calls pm_runtime_use_autosuspend().
+ *
  *     wakeup_count - Report the number of wakeup events related to the device
  */
 
@@ -173,6 +185,33 @@ static ssize_t rtpm_status_show(struct device *dev,
 }
 
 static DEVICE_ATTR(runtime_status, 0444, rtpm_status_show, NULL);
+
+static ssize_t autosuspend_delay_ms_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       if (!dev->power.use_autosuspend)
+               return -EIO;
+       return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
+}
+
+static ssize_t autosuspend_delay_ms_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t n)
+{
+       long delay;
+
+       if (!dev->power.use_autosuspend)
+               return -EIO;
+
+       if (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay)
+               return -EINVAL;
+
+       pm_runtime_set_autosuspend_delay(dev, delay);
+       return n;
+}
+
+static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
+               autosuspend_delay_ms_store);
+
 #endif
 
 static ssize_t
@@ -428,6 +467,7 @@ static struct attribute *runtime_attrs[] = {
        &dev_attr_control.attr,
        &dev_attr_runtime_suspended_time.attr,
        &dev_attr_runtime_active_time.attr,
+       &dev_attr_autosuspend_delay_ms.attr,
        NULL,
 };
 static struct attribute_group pm_runtime_attr_group = {