1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
new file mode 100644
index 0000000..325962d
--- /dev/null
+++ b/drivers/base/power/runtime.c
@@ -0,0 +1,81 @@
+/*
+ * drivers/base/power/runtime.c - Handling dynamic device power management.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ *
+ */
+
+#include <linux/device.h>
+#include "power.h"
+
+
+static void runtime_resume(struct device * dev)
+{
+	dev_dbg(dev, "resuming\n");
+	if (!dev->power.power_state)
+		return;
+	if (!resume_device(dev))
+		dev->power.power_state = 0;
+}
+
+
+/**
+ *	dpm_runtime_resume - Power one device back on.
+ *	@dev:	Device.
+ *
+ *	Bring one device back to the on state by first powering it
+ *	on, then restoring state. We only operate on devices that aren't
+ *	already on.
+ *	FIXME: We need to handle devices that are in an unknown state.
+ */
+
+void dpm_runtime_resume(struct device * dev)
+{
+	down(&dpm_sem);
+	runtime_resume(dev);
+	up(&dpm_sem);
+}
+
+
+/**
+ *	dpm_runtime_suspend - Put one device in low-power state.
+ *	@dev:	Device.
+ *	@state:	State to enter.
+ */
+
+int dpm_runtime_suspend(struct device * dev, pm_message_t state)
+{
+	int error = 0;
+
+	down(&dpm_sem);
+	if (dev->power.power_state == state)
+		goto Done;
+
+	if (dev->power.power_state)
+		runtime_resume(dev);
+
+	if (!(error = suspend_device(dev, state)))
+		dev->power.power_state = state;
+ Done:
+	up(&dpm_sem);
+	return error;
+}
+
+
+/**
+ *	dpm_set_power_state - Update power_state field.
+ *	@dev:	Device.
+ *	@state:	Power state device is in.
+ *
+ *	This is an update mechanism for drivers to notify the core
+ *	what power state a device is in. Device probing code may not
+ *	always be able to tell, but we need accurate information to
+ *	work reliably.
+ */
+void dpm_set_power_state(struct device * dev, pm_message_t state)
+{
+	down(&dpm_sem);
+	dev->power.power_state = state;
+	up(&dpm_sem);
+}