1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 995019063f6..8be4b29e38a 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -665,3 +665,59 @@ void acpi_dev_pm_detach(struct device *dev, bool power_off)
 	}
 }
 EXPORT_SYMBOL_GPL(acpi_dev_pm_detach);
+
+/**
+ * acpi_dev_pm_add_dependent - Add physical device depending for PM.
+ * @handle: Handle of ACPI device node.
+ * @depdev: Device depending on that node for PM.
+ */
+void acpi_dev_pm_add_dependent(acpi_handle handle, struct device *depdev)
+{
+	struct acpi_device_physical_node *dep;
+	struct acpi_device *adev;
+
+	if (!depdev || acpi_bus_get_device(handle, &adev))
+		return;
+
+	mutex_lock(&adev->physical_node_lock);
+
+	list_for_each_entry(dep, &adev->power_dependent, node)
+		if (dep->dev == depdev)
+			goto out;
+
+	dep = kzalloc(sizeof(*dep), GFP_KERNEL);
+	if (dep) {
+		dep->dev = depdev;
+		list_add_tail(&dep->node, &adev->power_dependent);
+	}
+
+ out:
+	mutex_unlock(&adev->physical_node_lock);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_pm_add_dependent);
+
+/**
+ * acpi_dev_pm_remove_dependent - Remove physical device depending for PM.
+ * @handle: Handle of ACPI device node.
+ * @depdev: Device depending on that node for PM.
+ */
+void acpi_dev_pm_remove_dependent(acpi_handle handle, struct device *depdev)
+{
+	struct acpi_device_physical_node *dep;
+	struct acpi_device *adev;
+
+	if (!depdev || acpi_bus_get_device(handle, &adev))
+		return;
+
+	mutex_lock(&adev->physical_node_lock);
+
+	list_for_each_entry(dep, &adev->power_dependent, node)
+		if (dep->dev == depdev) {
+			list_del(&dep->node);
+			kfree(dep);
+			break;
+		}
+
+	mutex_unlock(&adev->physical_node_lock);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_pm_remove_dependent);