iommu/omap: Add devicetree support

As OMAP2+ is moving to a full DT boot for all SoC families, commit
7ce93f3 "ARM: OMAP2+: Fix more missing data for omap3.dtsi file"
adds basic DT bits for OMAP3. But the driver is not yet converted,
so this will not work and driver will not be probed. Convert it!

The legacy boot mode is still supported until OMAP3 is converted
to DT-boot only.

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
[s-anna@ti.com: dev_name adaptation and improved error checking]
Signed-off-by: Suman Anna <s-anna@ti.com>
[tony@atomide.com: Ack for arch/arm/*omap* parts]
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 217952b..eb73ef2 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -23,6 +23,9 @@
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_iommu.h>
+#include <linux/of_irq.h>
 
 #include <asm/cacheflush.h>
 
@@ -936,17 +939,39 @@
 	struct omap_iommu *obj;
 	struct resource *res;
 	struct iommu_platform_data *pdata = pdev->dev.platform_data;
+	struct device_node *of = pdev->dev.of_node;
 
 	obj = devm_kzalloc(&pdev->dev, sizeof(*obj) + MMU_REG_SIZE, GFP_KERNEL);
 	if (!obj)
 		return -ENOMEM;
 
-	obj->nr_tlb_entries = pdata->nr_tlb_entries;
-	obj->name = pdata->name;
+	if (of) {
+		obj->name = dev_name(&pdev->dev);
+		obj->nr_tlb_entries = 32;
+		err = of_property_read_u32(of, "ti,#tlb-entries",
+					   &obj->nr_tlb_entries);
+		if (err && err != -EINVAL)
+			return err;
+		if (obj->nr_tlb_entries != 32 && obj->nr_tlb_entries != 8)
+			return -EINVAL;
+		/*
+		 * da_start and da_end are needed for omap-iovmm, so hardcode
+		 * these values as used by OMAP3 ISP - the only user for
+		 * omap-iovmm
+		 */
+		obj->da_start = 0;
+		obj->da_end = 0xfffff000;
+	} else {
+		obj->nr_tlb_entries = pdata->nr_tlb_entries;
+		obj->name = pdata->name;
+		obj->da_start = pdata->da_start;
+		obj->da_end = pdata->da_end;
+	}
+	if (obj->da_end <= obj->da_start)
+		return -EINVAL;
+
 	obj->dev = &pdev->dev;
 	obj->ctx = (void *)obj + sizeof(*obj);
-	obj->da_start = pdata->da_start;
-	obj->da_end = pdata->da_end;
 
 	spin_lock_init(&obj->iommu_lock);
 	mutex_init(&obj->mmap_lock);
@@ -987,11 +1012,20 @@
 	return 0;
 }
 
+static struct of_device_id omap_iommu_of_match[] = {
+	{ .compatible = "ti,omap2-iommu" },
+	{ .compatible = "ti,omap4-iommu" },
+	{ .compatible = "ti,dra7-iommu"	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, omap_iommu_of_match);
+
 static struct platform_driver omap_iommu_driver = {
 	.probe	= omap_iommu_probe,
 	.remove	= omap_iommu_remove,
 	.driver	= {
 		.name	= "omap-iommu",
+		.of_match_table = of_match_ptr(omap_iommu_of_match),
 	},
 };