/**
 *	of_node_is_pci - Test if a node a pci host
 *	@node: node to compare
 *
 *	returns 1 for PCI hosts and 0 for anything else
 *
 *	This function is meant to be called from
 *	of_find_phb_node as a helper. We compare both
 *	the compatible and the device_type properties
 *	to known strings used to indicate PCI hosts.
 */
static int of_node_is_pci(struct device_node *node)
{
	if (!node)
		return 0;

	if (device_is_compatible(node, "pci") ||
	    device_is_compatible(node, "ht")  ||
	    device_is_compatible(node, "pcie"))
		return 1;

	if (!node->type)
		return 0;

	if (!strcasecmp(node->type, "pci")  ||
	    !strcasecmp(node->type, "ht")   ||
	    !strcasecmp(node->type, "pcie"))
		return 1;

	return 0;
}

/**
 *
 *	of_find_phb_node - Iterate all PCI host bridge device nodes
 *
 *	@from:	The node to start searching from or NULL, the node
 *		you pass will not be searched, only the next one
 *		will; typically, you pass what the previous call
 *		returned. of_node_put() will be called on it
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 *
 *	since we only want to return host bridges, not pci-pci
 *	bridges, check if the parent is not also a pci host.
 */
struct device_node *of_find_phb_node(struct device_node *from)
{
	struct device_node *np;

	read_lock(&devtree_lock);
	np = from ? from->allnext : allnodes;
	for (; np; np = np->allnext) {
		if (of_node_is_pci(np) &&
		    !of_node_is_pci(np->parent))
			break;
	}
	if (np)
		of_node_get(np);
	if (from)
		of_node_put(from);
	read_unlock(&devtree_lock);
	return np;
}