iommu/omap: Register driver before setting IOMMU ops

Move the registration of the OMAP IOMMU platform driver before
setting the IOMMU callbacks on the platform bus. This causes
the IOMMU devices to be probed first before the .add_device()
callback is invoked for all registered devices, and allows
the iommu_group support to be added to the OMAP IOMMU driver.

While at this, also check for the return status from bus_set_iommu.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/omap-iommu.c

@@ -1299,6 +1299,7 @@ static int __init omap_iommu_init(void)
 	const unsigned long flags = SLAB_HWCACHE_ALIGN;
 	size_t align = 1 << 10; /* L2 pagetable alignement */
 	struct device_node *np;
+	int ret;
 
 	np = of_find_matching_node(NULL, omap_iommu_of_match);
 	if (!np)
@@ -1312,11 +1313,25 @@ static int __init omap_iommu_init(void)
 		return -ENOMEM;
 	iopte_cachep = p;
 
-	bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
-
 	omap_iommu_debugfs_init();
 
-	return platform_driver_register(&omap_iommu_driver);
+	ret = platform_driver_register(&omap_iommu_driver);
+	if (ret) {
+		pr_err("%s: failed to register driver\n", __func__);
+		goto fail_driver;
+	}
+
+	ret = bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
+	if (ret)
+		goto fail_bus;
+
+	return 0;
+
+fail_bus:
+	platform_driver_unregister(&omap_iommu_driver);
+fail_driver:
+	kmem_cache_destroy(iopte_cachep);
+	return ret;
 }
 subsys_initcall(omap_iommu_init);
 /* must be ready before omap3isp is probed */