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>

arch/arm/mach-omap2/omap-iommu.c

@@ -10,6 +10,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/of.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/err.h>
@@ -58,6 +59,10 @@ static int __init omap_iommu_dev_init(struct omap_hwmod *oh, void *unused)
 
 static int __init omap_iommu_init(void)
 {
+	/* If dtb is there, the devices will be created dynamically */
+	if (of_have_populated_dt())
+		return -ENODEV;
+
 	return omap_hwmod_for_each_by_class("mmu", omap_iommu_dev_init, NULL);
 }
 /* must be ready before omap3isp is probed */

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 @@ static int omap_iommu_probe(struct platform_device *pdev)
 	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 @@ static int omap_iommu_remove(struct platform_device *pdev)
 	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),
 	},
 };