irqdomain: Make __irq_domain_add() less OF-dependent

__irq_domain_add() relies in some places on the fact that the fwnode
can be only of type OF. This prevents refactoring of the code to support
other types of fwnode. Make it less OF-dependent by switching it
to use the fwnode directly where it makes sense.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200520164927.39090-1-andriy.shevchenko@linux.intel.com

kernel/irq/irqdomain.c

@@ -132,14 +132,13 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size,
 				    const struct irq_domain_ops *ops,
 				    void *host_data)
 {
-	struct device_node *of_node = to_of_node(fwnode);
 	struct irqchip_fwid *fwid;
 	struct irq_domain *domain;
 
 	static atomic_t unknown_domains;
 
 	domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
-			      GFP_KERNEL, of_node_to_nid(of_node));
+			      GFP_KERNEL, of_node_to_nid(to_of_node(fwnode)));
 	if (!domain)
 		return NULL;
 
@@ -177,15 +176,15 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size,
 
 		domain->fwnode = fwnode;
 #endif
-	} else if (of_node) {
+	} else if (is_of_node(fwnode)) {
 		char *name;
 
 		/*
-		 * DT paths contain '/', which debugfs is legitimately
+		 * fwnode paths contain '/', which debugfs is legitimately
 		 * unhappy about. Replace them with ':', which does
 		 * the trick and is not as offensive as '\'...
 		 */
-		name = kasprintf(GFP_KERNEL, "%pOF", of_node);
+		name = kasprintf(GFP_KERNEL, "%pfw", fwnode);
 		if (!name) {
 			kfree(domain);
 			return NULL;
@@ -210,7 +209,7 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size,
 		domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
 	}
 
-	of_node_get(of_node);
+	fwnode_handle_get(fwnode);
 
 	/* Fill structure */
 	INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL);
@@ -259,7 +258,7 @@ void irq_domain_remove(struct irq_domain *domain)
 
 	pr_debug("Removed domain %s\n", domain->name);
 
-	of_node_put(irq_domain_get_of_node(domain));
+	fwnode_handle_put(domain->fwnode);
 	if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
 		kfree(domain->name);
 	kfree(domain);