iommu/omap: Convert to generic_single_device_group()

Use the new helper.

For some reason omap will probe its driver even if it doesn't load an
iommu driver. Keep this working by keeping a bool to track if the iommu
driver was started.

Signed-off-by: Jason Gunthorpe <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Joerg Roedel <[e-mail]>

drivers/iommu/omap-iommu.c

···
 	platform_set_drvdata(pdev, obj);
 
 	if (omap_iommu_can_register(pdev)) {
-		obj->group = iommu_group_alloc();
-		if (IS_ERR(obj->group))
-			return PTR_ERR(obj->group);
-
 		err = iommu_device_sysfs_add(&obj->iommu, obj->dev, NULL,
 					     obj->name);
 		if (err)
-			goto out_group;
+			return err;
 
 		err = iommu_device_register(&obj->iommu, &omap_iommu_ops, &pdev->dev);
 		if (err)
 			goto out_sysfs;
+		obj->has_iommu_driver = true;
 	}
 
 	pm_runtime_enable(obj->dev);
···
 
 out_sysfs:
 	iommu_device_sysfs_remove(&obj->iommu);
-out_group:
-	iommu_group_put(obj->group);
 	return err;
 }
 
···
 {
 	struct omap_iommu *obj = platform_get_drvdata(pdev);
 
-	if (obj->group) {
-		iommu_group_put(obj->group);
-		obj->group = NULL;
-
+	if (obj->has_iommu_driver) {
 		iommu_device_sysfs_remove(&obj->iommu);
 		iommu_device_unregister(&obj->iommu);
 	}
···
 
 }
 
-static struct iommu_group *omap_iommu_device_group(struct device *dev)
-{
-	struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
-	struct iommu_group *group = ERR_PTR(-EINVAL);
-
-	if (!arch_data)
-		return ERR_PTR(-ENODEV);
-
-	if (arch_data->iommu_dev)
-		group = iommu_group_ref_get(arch_data->iommu_dev->group);
-
-	return group;
-}
-
 static const struct iommu_ops omap_iommu_ops = {
 	.identity_domain = &omap_iommu_identity_domain,
 	.domain_alloc_paging = omap_iommu_domain_alloc_paging,
 	.probe_device	= omap_iommu_probe_device,
 	.release_device	= omap_iommu_release_device,
-	.device_group	= omap_iommu_device_group,
+	.device_group	= generic_single_device_group,
 	.pgsize_bitmap	= OMAP_IOMMU_PGSIZES,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= omap_iommu_attach_dev,

drivers/iommu/omap-iommu.h

···
 	u32 id;
 
 	struct iommu_device iommu;
-	struct iommu_group *group;
+	bool has_iommu_driver;
 
 	u8 pwrst;
 };