libudev: device - add get_parent_with_subsystem()

1 files changed, 16 insertions, 0 deletions

diff --git a/udev/lib/libudev-device.c b/udev/lib/libudev-device.c
index a512537140..8e4360a7f4 100644
--- a/udev/lib/libudev-device.c
+++ b/udev/lib/libudev-device.c
@@ -404,6 +404,22 @@ struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
 	return udev_device->parent_device;
 }
 
+struct udev_device *udev_device_get_parent_with_subsystem(struct udev_device *udev_device, const char *subsystem)
+{
+	struct udev_device *parent;
+
+	parent = udev_device_get_parent(udev_device);
+	while (parent != NULL) {
+		const char *parent_subsystem;
+
+		parent_subsystem = udev_device_get_subsystem(parent);
+		if (parent_subsystem != NULL && strcmp(parent_subsystem, subsystem) == 0)
+			break;
+		parent = udev_device_get_parent(parent);
+	}
+	return parent;
+}
+
 /**
  * udev_device_get_udev:
  * @udev_device: udev device