ACPI: property: Use data node name and reg property for graphs

Instead of using the port and endpoint properties, rely on the names of
the port and endpoint nodes as well as the reg property, as on DT.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/property.c

@@ -1027,6 +1027,26 @@ struct fwnode_handle *acpi_node_get_parent(const struct fwnode_handle *fwnode)
 	return NULL;
 }
 
+/*
+ * Return true if the node is an ACPI graph node. Called on either ports
+ * or endpoints.
+ */
+static bool is_acpi_graph_node(struct fwnode_handle *fwnode,
+			       const char *str)
+{
+	unsigned int len = strlen(str);
+	const char *name;
+
+	if (!len || !is_acpi_data_node(fwnode))
+		return false;
+
+	name = to_acpi_data_node(fwnode)->name;
+
+	return (fwnode_property_present(fwnode, "reg") &&
+		!strncmp(name, str, len) && name[len] == '@') ||
+		fwnode_property_present(fwnode, str);
+}
+
 /**
  * acpi_graph_get_next_endpoint - Get next endpoint ACPI firmware node
  * @fwnode: Pointer to the parent firmware node
@@ -1045,8 +1065,14 @@ static struct fwnode_handle *acpi_graph_get_next_endpoint(
 	if (!prev) {
 		do {
 			port = fwnode_get_next_child_node(fwnode, port);
-			/* Ports must have port property */
-			if (fwnode_property_present(port, "port"))
+			/*
+			 * The names of the port nodes begin with "port@"
+			 * followed by the number of the port node and they also
+			 * have a "reg" property that also has the number of the
+			 * port node. For compatibility reasons a node is also
+			 * recognised as a port node from the "port" property.
+			 */
+			if (is_acpi_graph_node(port, "port"))
 				break;
 		} while (port);
 	} else {
@@ -1061,12 +1087,18 @@ static struct fwnode_handle *acpi_graph_get_next_endpoint(
 		port = fwnode_get_next_child_node(fwnode, port);
 		if (!port)
 			break;
-		if (fwnode_property_present(port, "port"))
+		if (is_acpi_graph_node(port, "port"))
 			endpoint = fwnode_get_next_child_node(port, NULL);
 	}
 
-	/* Endpoints must have "endpoint" property */
-	if (!fwnode_property_present(endpoint, "endpoint"))
+	/*
+	 * The names of the endpoint nodes begin with "endpoint@" followed by
+	 * the number of the endpoint node and they also have a "reg" property
+	 * that also has the number of the endpoint node. For compatibility
+	 * reasons a node is also recognised as an endpoint node from the
+	 * "endpoint" property.
+	 */
+	if (!is_acpi_graph_node(endpoint, "endpoint"))
 		return NULL;
 
 	return endpoint;
@@ -1139,8 +1171,7 @@ acpi_graph_get_remote_endpoint(const struct fwnode_handle *__fwnode)
 
 	fwnode = acpi_graph_get_child_prop_value(fwnode, "port", port_nr);
 
-	return acpi_graph_get_child_prop_value(fwnode, "endpoint",
-					       endpoint_nr);
+	return acpi_graph_get_child_prop_value(fwnode, "endpoint", endpoint_nr);
 }
 
 static bool acpi_fwnode_device_is_available(const struct fwnode_handle *fwnode)
@@ -1217,8 +1248,10 @@ static int acpi_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
 
 	endpoint->local_fwnode = fwnode;
 
-	fwnode_property_read_u32(port_fwnode, "port", &endpoint->port);
-	fwnode_property_read_u32(fwnode, "endpoint", &endpoint->id);
+	if (fwnode_property_read_u32(port_fwnode, "reg", &endpoint->port))
+		fwnode_property_read_u32(port_fwnode, "port", &endpoint->port);
+	if (fwnode_property_read_u32(fwnode, "reg", &endpoint->id))
+		fwnode_property_read_u32(fwnode, "endpoint", &endpoint->id);
 
 	return 0;
 }