2 files changed, 51 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/include/mach/tegra-ahb.h b/arch/arm/mach-tegra/include/mach/tegra-ahb.h
new file mode 100644
index 000000000000..e0f8c84b1d8c
--- /dev/null
+++ b/arch/arm/mach-tegra/include/mach/tegra-ahb.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#ifndef __MACH_TEGRA_AHB_H__
+#define __MACH_TEGRA_AHB_H__
+
+extern int tegra_ahb_enable_smmu(struct device_node *ahb);
+
+#endif  /* __MACH_TEGRA_AHB_H__ */
diff --git a/drivers/amba/tegra-ahb.c b/drivers/amba/tegra-ahb.c
index 106a780d29a0..aa0b1f160528 100644
--- a/drivers/amba/tegra-ahb.c
+++ b/drivers/amba/tegra-ahb.c
@@ -76,6 +76,10 @@
 
 #define AHB_ARBITRATION_AHB_MEM_WRQUE_MST_ID    0xf8
 
+#define AHB_ARBITRATION_XBAR_CTRL_SMMU_INIT_DONE BIT(17)
+
+static struct platform_driver tegra_ahb_driver;
+
 static const u32 tegra_ahb_gizmo[] = {
         AHB_ARBITRATION_DISABLE,
         AHB_ARBITRATION_PRIORITY_CTRL,
@@ -124,6 +128,34 @@ static inline void gizmo_writel(struct tegra_ahb *ahb, u32 value, u32 offset)
         writel(value, ahb->regs + offset);
 }
 
+#ifdef CONFIG_ARCH_TEGRA_3x_SOC
+static int tegra_ahb_match_by_smmu(struct device *dev, void *data)
+{
+        struct tegra_ahb *ahb = dev_get_drvdata(dev);
+        struct device_node *dn = data;
+
+        return (ahb->dev->of_node == dn) ? 1 : 0;
+}
+
+int tegra_ahb_enable_smmu(struct device_node *dn)
+{
+        struct device *dev;
+        u32 val;
+        struct tegra_ahb *ahb;
+
+        dev = driver_find_device(&tegra_ahb_driver.driver, NULL, dn,
+                                 tegra_ahb_match_by_smmu);
+        if (!dev)
+                return -EPROBE_DEFER;
+        ahb = dev_get_drvdata(dev);
+        val = gizmo_readl(ahb, AHB_ARBITRATION_XBAR_CTRL);
+        val |= AHB_ARBITRATION_XBAR_CTRL_SMMU_INIT_DONE;
+        gizmo_writel(ahb, val, AHB_ARBITRATION_XBAR_CTRL);
+        return 0;
+}
+EXPORT_SYMBOL(tegra_ahb_enable_smmu);
+#endif
+
 static int tegra_ahb_suspend(struct device *dev)
 {
         int i;