[PATCH v7 8/9] iommu/exynos: support for device tree

[PATCH v7 8/9] iommu/exynos: support for device tree

[Cho KyongHo]

This commit adds device tree support for System MMU.
This also include the following changes and enhancements:

* use managed device helper functions.
Simplyfies System MMU device driver.

* use only a single clock descriptor.
System MMU device descriptor is seperate if it is imposible to make
a single clock descriptor to make a device descriptor for a group of
System MMUs.

* removed dbgname member from sysmmu_drvdata structure.
debugging kernel message for a System MMU is distinguisheable with the
name of device descroptors.

Signed-off-by: Cho KyongHo <pullip.cho-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
---
 drivers/iommu/Kconfig        |    5 +-
 drivers/iommu/exynos-iommu.c |  192 ++++++++++++++++++------------------------
 2 files changed, 83 insertions(+), 114 deletions(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index c332fb9..d45f3c9 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -168,16 +168,15 @@ config TEGRA_IOMMU_SMMU
 
 config EXYNOS_IOMMU
 	bool "Exynos IOMMU Support"
-	depends on ARCH_EXYNOS && EXYNOS_DEV_SYSMMU
+	depends on ARCH_EXYNOS
 	select IOMMU_API
+	default n
 	help
 	  Support for the IOMMU(System MMU) of Samsung Exynos application
 	  processor family. This enables H/W multimedia accellerators to see
 	  non-linear physical memory chunks as a linear memory in their
 	  address spaces
 
-	  If unsure, say N here.
-
 config EXYNOS_IOMMU_DEBUG
 	bool "Debugging log for Exynos IOMMU"
 	depends on EXYNOS_IOMMU
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 6793661..b151e51 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -26,6 +26,7 @@
 #include <linux/list.h>
 #include <linux/memblock.h>
 #include <linux/export.h>
+#include <linux/of.h>
 
 #include <asm/cacheflush.h>
 #include <asm/pgtable.h>
@@ -170,15 +171,14 @@ struct sysmmu_drvdata {
 	struct list_head node; /* entry of exynos_iommu_domain.clients */
 	struct device *sysmmu;	/* System MMU's device descriptor */
 	struct device *dev;	/* Owner of system MMU */
-	char *dbgname;
 	int nsfrs;
-	void __iomem **sfrbases;
-	struct clk *clk[2];
+	struct clk *clk;
 	int activations;
 	spinlock_t lock;
 	struct iommu_domain *domain;
 	sysmmu_fault_handler_t fault_handler;
 	unsigned long pgtable;
+	void __iomem *sfrbases[0];
 };
 
 static bool set_sysmmu_active(struct sysmmu_drvdata *data)
@@ -385,8 +385,8 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
 	if (!ret && (itype != SYSMMU_FAULT_UNKNOWN))
 		__raw_writel(1 << itype, data->sfrbases[i] + REG_INT_CLEAR);
 	else
-		dev_dbg(data->sysmmu, "(%s) %s is not handled.\n",
-				data->dbgname, sysmmu_fault_name[itype]);
+		dev_dbg(data->sysmmu, "%s is not handled.\n",
+				sysmmu_fault_name[itype]);
 
 	if (itype != SYSMMU_FAULT_UNKNOWN)
 		sysmmu_unblock(data->sfrbases[i]);
@@ -410,10 +410,8 @@ static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
 	for (i = 0; i < data->nsfrs; i++)
 		__raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL);
 
-	if (data->clk[1])
-		clk_disable(data->clk[1]);
-	if (data->clk[0])
-		clk_disable(data->clk[0]);
+	if (data->clk)
+		clk_disable(data->clk);
 
 	disabled = true;
 	data->pgtable = 0;
@@ -422,10 +420,10 @@ finish:
 	spin_unlock_irqrestore(&data->lock, flags);
 
 	if (disabled)
-		dev_dbg(data->sysmmu, "(%s) Disabled\n", data->dbgname);
+		dev_dbg(data->sysmmu, "Disabled\n");
 	else
-		dev_dbg(data->sysmmu, "(%s) %d times left to be disabled\n",
-					data->dbgname, data->activations);
+		dev_dbg(data->sysmmu, "%d times left to be disabled\n",
+					data->activations);
 
 	return disabled;
 }
@@ -452,14 +450,12 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
 			ret = 1;
 		}
 
-		dev_dbg(data->sysmmu, "(%s) Already enabled\n", data->dbgname);
+		dev_dbg(data->sysmmu, "Already enabled\n");
 		goto finish;
 	}
 
-	if (data->clk[0])
-		clk_enable(data->clk[0]);
-	if (data->clk[1])
-		clk_enable(data->clk[1]);
+	if (data->clk)
+		clk_enable(data->clk);
 
 	data->pgtable = pgtable;
 
@@ -479,7 +475,7 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
 
 	data->domain = domain;
 
-	dev_dbg(data->sysmmu, "(%s) Enabled\n", data->dbgname);
+	dev_dbg(data->sysmmu, "Enabled\n");
 finish:
 	spin_unlock_irqrestore(&data->lock, flags);
 
@@ -495,7 +491,7 @@ int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
 
 	ret = pm_runtime_get_sync(data->sysmmu);
 	if (ret < 0) {
-		dev_dbg(data->sysmmu, "(%s) Failed to enable\n", data->dbgname);
+		dev_dbg(data->sysmmu, "Failed to enable\n");
 		return ret;
 	}
 
@@ -503,8 +499,8 @@ int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
 	if (WARN_ON(ret < 0)) {
 		pm_runtime_put(data->sysmmu);
 		dev_err(data->sysmmu,
-			"(%s) Already enabled with page table %#lx\n",
-			data->dbgname, data->pgtable);
+			"Already enabled with page table %#lx\n",
+			data->pgtable);
 	} else {
 		data->dev = dev;
 	}
@@ -540,9 +536,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova)
 			}
 		}
 	} else {
-		dev_dbg(data->sysmmu,
-			"(%s) Disabled. Skipping invalidating TLB.\n",
-			data->dbgname);
+		dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n");
 	}
 
 	spin_unlock_irqrestore(&data->lock, flags);
@@ -564,141 +558,117 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
 			}
 		}
 	} else {
-		dev_dbg(data->sysmmu,
-			"(%s) Disabled. Skipping invalidating TLB.\n",
-			data->dbgname);
+		dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n");
 	}
 
 	spin_unlock_irqrestore(&data->lock, flags);
 }
 
-static int exynos_sysmmu_probe(struct platform_device *pdev)
+static int __init exynos_sysmmu_probe(struct platform_device *pdev)
 {
 	int i, ret;
-	struct device *dev;
+	struct device *dev = &pdev->dev;
 	struct sysmmu_drvdata *data;
 
-	dev = &pdev->dev;
-
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
-	if (!data) {
-		dev_dbg(dev, "Not enough memory\n");
-		ret = -ENOMEM;
-		goto err_alloc;
+	if (pdev->num_resources == 0) {
+		dev_err(dev, "No System MMU resource defined\n");
+		return -ENODEV;
 	}
 
-	ret = dev_set_drvdata(dev, data);
-	if (ret) {
-		dev_dbg(dev, "Unabled to initialize driver data\n");
-		goto err_init;
+	data = devm_kzalloc(dev,
+			sizeof(*data) +
+			sizeof(*data->sfrbases) * (pdev->num_resources / 2),
+			GFP_KERNEL);
+	if (!data) {
+		dev_err(dev, "Not enough memory for initialization\n");
+		return -ENOMEM;
 	}
 
 	data->nsfrs = pdev->num_resources / 2;
-	data->sfrbases = kmalloc(sizeof(*data->sfrbases) * data->nsfrs,
-								GFP_KERNEL);
-	if (data->sfrbases == NULL) {
-		dev_dbg(dev, "Not enough memory\n");
-		ret = -ENOMEM;
-		goto err_init;
-	}
 
 	for (i = 0; i < data->nsfrs; i++) {
 		struct resource *res;
+
 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 		if (!res) {
-			dev_dbg(dev, "Unable to find IOMEM region\n");
-			ret = -ENOENT;
-			goto err_res;
+			dev_err(dev, "Unable to find IOMEM region\n");
+			return -ENOENT;
 		}
 
-		data->sfrbases[i] = ioremap(res->start, resource_size(res));
+		data->sfrbases[i] = devm_request_and_ioremap(dev, res);
 		if (!data->sfrbases[i]) {
-			dev_dbg(dev, "Unable to map IOMEM @ PA:%#x\n",
-							res->start);
-			ret = -ENOENT;
-			goto err_res;
+			dev_err(dev, "Unable to map IOMEM @ %#x\n", res->start);
+			return -EBUSY;
 		}
 	}
 
 	for (i = 0; i < data->nsfrs; i++) {
-		ret = platform_get_irq(pdev, i);
-		if (ret <= 0) {
-			dev_dbg(dev, "Unable to find IRQ resource\n");
-			goto err_irq;
+		int irq;
+
+		irq = platform_get_irq(pdev, i);
+		if (irq <= 0) {
+			dev_err(dev, "Unable to find IRQ resource\n");
+			return -ENOENT;
 		}
 
-		ret = request_irq(ret, exynos_sysmmu_irq, 0,
-					dev_name(dev), data);
+		ret = devm_request_irq(dev, irq, exynos_sysmmu_irq,
+					0, dev_name(dev), data);
 		if (ret) {
-			dev_dbg(dev, "Unabled to register interrupt handler\n");
-			goto err_irq;
+			dev_err(dev, "Unable to register handler to irq %d\n",
+				irq);
+			return ret;
 		}
 	}
 
-	if (dev_get_platdata(dev)) {
-		char *deli, *beg;
-		struct sysmmu_platform_data *platdata = dev_get_platdata(dev);
-
-		beg = platdata->clockname;
-
-		for (deli = beg; (*deli != '\0') && (*deli != ','); deli++)
-			/* NOTHING */;
+	pm_runtime_enable(dev);
 
-		if (*deli == '\0')
-			deli = NULL;
-		else
-			*deli = '\0';
+	__set_fault_handler(data, &default_fault_handler);
 
-		data->clk[0] = clk_get(dev, beg);
-		if (IS_ERR(data->clk[0])) {
-			data->clk[0] = NULL;
-			dev_dbg(dev, "No clock descriptor registered\n");
+	data->sysmmu = dev;
+	data->clk = devm_clk_get(dev, "sysmmu");
+	if (IS_ERR(data->clk)) {
+		dev_info(dev, "No gate clock found!\n");
+		data->clk = NULL;
+	} else {
+		struct clk *parent;
+		ret = clk_prepare(data->clk);
+		if (ret) {
+			dev_err(dev, "Failed to prepare gate clock!\n");
+			return ret;
 		}
 
-		if (data->clk[0] && deli) {
-			*deli = ',';
-			data->clk[1] = clk_get(dev, deli + 1);
-			if (IS_ERR(data->clk[1]))
-				data->clk[1] = NULL;
+		parent = devm_clk_get(dev, "master");
+		if (!IS_ERR(parent)) {
+			ret = clk_set_parent(data->clk, parent);
+			if (ret) {
+				dev_err(dev, "Failed to set parent clock!\n");
+				return ret;
+			}
 		}
-
-		data->dbgname = platdata->dbgname;
 	}
 
-	data->sysmmu = dev;
 	spin_lock_init(&data->lock);
 	INIT_LIST_HEAD(&data->node);
 
-	__set_fault_handler(data, &default_fault_handler);
-
-	if (dev->parent)
-		pm_runtime_enable(dev);
+	platform_set_drvdata(pdev, data);
+	dev_dbg(dev, "Probed and initialized\n");
 
-	dev_dbg(dev, "(%s) Initialized\n", data->dbgname);
-	return 0;
-err_irq:
-	while (i-- > 0) {
-		int irq;
-
-		irq = platform_get_irq(pdev, i);
-		free_irq(irq, data);
-	}
-err_res:
-	while (data->nsfrs-- > 0)
-		iounmap(data->sfrbases[data->nsfrs]);
-	kfree(data->sfrbases);
-err_init:
-	kfree(data);
-err_alloc:
-	dev_err(dev, "Failed to initialize\n");
 	return ret;
 }
 
-static struct platform_driver exynos_sysmmu_driver = {
-	.probe		= exynos_sysmmu_probe,
-	.driver		= {
+#ifdef CONFIG_OF
+static struct of_device_id sysmmu_of_match[] __initconst = {
+	{ .compatible	= "samsung,exynos4210-sysmmu", },
+	{ },
+};
+#endif
+
+static struct platform_driver exynos_sysmmu_driver __refdata = {
+	.probe	= exynos_sysmmu_probe,
+	.driver	= {
 		.owner		= THIS_MODULE,
 		.name		= "exynos-sysmmu",
+		.of_match_table	= of_match_ptr(sysmmu_of_match),
 	}
 };
 
-- 
1.7.2.5