iommu/exynos: Add callback for initializing devices from device tree

This patch adds implementation of of_xlate callback, which prepares
masters device for attaching to IOMMU. This callback is called during
creating devices from device tree.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/exynos-iommu.c

@@ -1146,6 +1146,33 @@ static void exynos_iommu_remove_device(struct device *dev)
 	iommu_group_remove_device(dev);
 }
 
+static int exynos_iommu_of_xlate(struct device *dev,
+				 struct of_phandle_args *spec)
+{
+	struct exynos_iommu_owner *owner = dev->archdata.iommu;
+	struct platform_device *sysmmu = of_find_device_by_node(spec->np);
+	struct sysmmu_drvdata *data;
+
+	if (!sysmmu)
+		return -ENODEV;
+
+	data = platform_get_drvdata(sysmmu);
+	if (!data)
+		return -ENODEV;
+
+	if (!owner) {
+		owner = kzalloc(sizeof(*owner), GFP_KERNEL);
+		if (!owner)
+			return -ENOMEM;
+
+		INIT_LIST_HEAD(&owner->controllers);
+		dev->archdata.iommu = owner;
+	}
+
+	list_add_tail(&data->owner_node, &owner->controllers);
+	return 0;
+}
+
 static struct iommu_ops exynos_iommu_ops = {
 	.domain_alloc = exynos_iommu_domain_alloc,
 	.domain_free = exynos_iommu_domain_free,
@@ -1158,6 +1185,7 @@ static struct iommu_ops exynos_iommu_ops = {
 	.add_device = exynos_iommu_add_device,
 	.remove_device = exynos_iommu_remove_device,
 	.pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
+	.of_xlate = exynos_iommu_of_xlate,
 };
 
 static bool init_done;