+#ifdef CONFIG_PM_RUNTIME
+static const char ctrl_auto[] = "auto";
+static const char ctrl_on[] = "on";
+
+static ssize_t control_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%s\n",
+ dev->power.runtime_auto ? ctrl_auto : ctrl_on);
+}
+
+static ssize_t control_store(struct device * dev, struct device_attribute *attr,
+ const char * buf, size_t n)
+{
+ char *cp;
+ int len = n;
+
+ cp = memchr(buf, '\n', n);
+ if (cp)
+ len = cp - buf;
+ if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
+ pm_runtime_allow(dev);
+ else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0)
+ pm_runtime_forbid(dev);
+ else
+ return -EINVAL;
+ return n;
+}
+
+static DEVICE_ATTR(control, 0644, control_show, control_store);
+#endif
+