soc/tegra: Add efuse driver for Tegra

Implement fuse driver for Tegra20, Tegra30, Tegra114 and Tegra124. This
replaces functionality previously provided in arch/arm/mach-tegra, which
is removed in this patch.

While at it, move the only user of the global tegra_revision variable
over to tegra_sku_info.revision and export tegra_fuse_readl() to allow
drivers to read calibration fuses.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

20 files changed, 1047 insertions, 461 deletions

diff --git a/Documentation/ABI/testing/sysfs-driver-tegra-fuse b/Documentation/ABI/testing/sysfs-driver-tegra-fuse
new file mode 100644
index 000000000000..69f5af632657
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-tegra-fuse
@@ -0,0 +1,11 @@
+What:		/sys/devices/*/<our-device>/fuse
+Date:		February 2014
+Contact:	Peter De Schrijver <pdeschrijver@nvidia.com>
+Description:	read-only access to the efuses on Tegra20, Tegra30, Tegra114
+		and Tegra124 SoC's from NVIDIA. The efuses contain write once
+		data programmed at the factory. The data is layed out in 32bit
+		words in LSB first format. Each bit represents a single value
+		as decoded from the fuse registers. Bits order/assignment
+		exactly matches the HW registers, including any unused bits.
+Users:		any user space application which wants to read the efuses on
+		Tegra SoC's
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index 6fbfbb77dcd9..e8601bb56f98 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -2,7 +2,6 @@ asflags-y				+= -march=armv7-a
 
 obj-y                                   += io.o
 obj-y                                   += irq.o
-obj-y					+= fuse.o
 obj-y					+= pmc.o
 obj-y					+= flowctrl.o
 obj-y					+= powergate.o
@@ -13,13 +12,11 @@ obj-y					+= reset-handler.o
 obj-y					+= sleep.o
 obj-y					+= tegra.o
 obj-$(CONFIG_CPU_IDLE)			+= cpuidle.o
-obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= tegra20_speedo.o
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= sleep-tegra20.o
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= pm-tegra20.o
 ifeq ($(CONFIG_CPU_IDLE),y)
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= cpuidle-tegra20.o
 endif
-obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= tegra30_speedo.o
 obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= sleep-tegra30.o
 obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= pm-tegra30.o
 ifeq ($(CONFIG_CPU_IDLE),y)
@@ -28,7 +25,6 @@ endif
 obj-$(CONFIG_SMP)			+= platsmp.o headsmp.o
 obj-$(CONFIG_HOTPLUG_CPU)               += hotplug.o
 
-obj-$(CONFIG_ARCH_TEGRA_114_SOC)	+= tegra114_speedo.o
 obj-$(CONFIG_ARCH_TEGRA_114_SOC)	+= sleep-tegra30.o
 obj-$(CONFIG_ARCH_TEGRA_114_SOC)	+= pm-tegra30.o
 ifeq ($(CONFIG_CPU_IDLE),y)
diff --git a/arch/arm/mach-tegra/fuse.c b/arch/arm/mach-tegra/fuse.c
deleted file mode 100644
index b22e76a40965..000000000000
--- a/arch/arm/mach-tegra/fuse.c
+++ /dev/null
@@ -1,260 +0,0 @@
-/*
- * arch/arm/mach-tegra/fuse.c
- *
- * Copyright (C) 2010 Google, Inc.
- * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
- *
- * Author:
- *	Colin Cross <ccross@android.com>
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that 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.
- *
- */
-
-#include <linux/clk.h>
-#include <linux/export.h>
-#include <linux/io.h>
-#include <linux/kernel.h>
-#include <linux/random.h>
-
-#include <soc/tegra/fuse.h>
-
-#include "apbio.h"
-#include "fuse.h"
-#include "iomap.h"
-
-/* Tegra20 only */
-#define FUSE_UID_LOW		0x108
-#define FUSE_UID_HIGH		0x10c
-
-/* Tegra30 and later */
-#define FUSE_VENDOR_CODE	0x200
-#define FUSE_FAB_CODE		0x204
-#define FUSE_LOT_CODE_0		0x208
-#define FUSE_LOT_CODE_1		0x20c
-#define FUSE_WAFER_ID		0x210
-#define FUSE_X_COORDINATE	0x214
-#define FUSE_Y_COORDINATE	0x218
-
-#define FUSE_SKU_INFO		0x110
-
-#define TEGRA20_FUSE_SPARE_BIT		0x200
-#define TEGRA30_FUSE_SPARE_BIT		0x244
-
-int tegra_sku_id;
-int tegra_cpu_process_id;
-int tegra_core_process_id;
-int tegra_cpu_speedo_id;		/* only exist in Tegra30 and later */
-int tegra_soc_speedo_id;
-enum tegra_revision tegra_revision;
-
-static struct clk *fuse_clk;
-static int tegra_fuse_spare_bit;
-static void (*tegra_init_speedo_data)(void);
-
-/* The BCT to use at boot is specified by board straps that can be read
- * through a APB misc register and decoded. 2 bits, i.e. 4 possible BCTs.
- */
-int tegra_bct_strapping;
-
-#define STRAP_OPT 0x008
-#define GMI_AD0 (1 << 4)
-#define GMI_AD1 (1 << 5)
-#define RAM_ID_MASK (GMI_AD0 | GMI_AD1)
-#define RAM_CODE_SHIFT 4
-
-static const char *tegra_revision_name[TEGRA_REVISION_MAX] = {
-	[TEGRA_REVISION_UNKNOWN] = "unknown",
-	[TEGRA_REVISION_A01]     = "A01",
-	[TEGRA_REVISION_A02]     = "A02",
-	[TEGRA_REVISION_A03]     = "A03",
-	[TEGRA_REVISION_A03p]    = "A03 prime",
-	[TEGRA_REVISION_A04]     = "A04",
-};
-
-static void tegra_fuse_enable_clk(void)
-{
-	if (IS_ERR(fuse_clk))
-		fuse_clk = clk_get_sys(NULL, "fuse");
-	if (IS_ERR(fuse_clk))
-		return;
-	clk_prepare_enable(fuse_clk);
-}
-
-static void tegra_fuse_disable_clk(void)
-{
-	if (IS_ERR(fuse_clk))
-		return;
-	clk_disable_unprepare(fuse_clk);
-}
-
-u32 tegra_fuse_readl(unsigned long offset)
-{
-	return tegra_apb_readl(TEGRA_FUSE_BASE + offset);
-}
-
-bool tegra_spare_fuse(int bit)
-{
-	bool ret;
-
-	tegra_fuse_enable_clk();
-
-	ret = tegra_fuse_readl(tegra_fuse_spare_bit + bit * 4);
-
-	tegra_fuse_disable_clk();
-
-	return ret;
-}
-
-static enum tegra_revision tegra_get_revision(u32 id)
-{
-	u32 minor_rev = (id >> 16) & 0xf;
-
-	switch (minor_rev) {
-	case 1:
-		return TEGRA_REVISION_A01;
-	case 2:
-		return TEGRA_REVISION_A02;
-	case 3:
-		if (tegra_get_chip_id() == TEGRA20 &&
-			(tegra_spare_fuse(18) || tegra_spare_fuse(19)))
-			return TEGRA_REVISION_A03p;
-		else
-			return TEGRA_REVISION_A03;
-	case 4:
-		return TEGRA_REVISION_A04;
-	default:
-		return TEGRA_REVISION_UNKNOWN;
-	}
-}
-
-static void tegra_get_process_id(void)
-{
-	u32 reg;
-
-	tegra_fuse_enable_clk();
-
-	reg = tegra_fuse_readl(tegra_fuse_spare_bit);
-	tegra_cpu_process_id = (reg >> 6) & 3;
-	reg = tegra_fuse_readl(tegra_fuse_spare_bit);
-	tegra_core_process_id = (reg >> 12) & 3;
-
-	tegra_fuse_disable_clk();
-}
-
-u32 tegra_read_chipid(void)
-{
-	return readl_relaxed(IO_ADDRESS(TEGRA_APB_MISC_BASE) + 0x804);
-}
-
-u8 tegra_get_chip_id(void)
-{
-	u32 id = tegra_read_chipid();
-
-	return (id >> 8) & 0xff;
-}
-
-static void __init tegra20_fuse_init_randomness(void)
-{
-	u32 randomness[2];
-
-	randomness[0] = tegra_fuse_readl(FUSE_UID_LOW);
-	randomness[1] = tegra_fuse_readl(FUSE_UID_HIGH);
-
-	add_device_randomness(randomness, sizeof(randomness));
-}
-
-/* Applies to Tegra30 or later */
-static void __init tegra30_fuse_init_randomness(void)
-{
-	u32 randomness[7];
-
-	randomness[0] = tegra_fuse_readl(FUSE_VENDOR_CODE);
-	randomness[1] = tegra_fuse_readl(FUSE_FAB_CODE);
-	randomness[2] = tegra_fuse_readl(FUSE_LOT_CODE_0);
-	randomness[3] = tegra_fuse_readl(FUSE_LOT_CODE_1);
-	randomness[4] = tegra_fuse_readl(FUSE_WAFER_ID);
-	randomness[5] = tegra_fuse_readl(FUSE_X_COORDINATE);
-	randomness[6] = tegra_fuse_readl(FUSE_Y_COORDINATE);
-
-	add_device_randomness(randomness, sizeof(randomness));
-}
-
-void __init tegra_init_fuse(void)
-{
-	u32 id;
-	u32 randomness[5];
-	u8 chip_id;
-
-	u32 reg = readl(IO_ADDRESS(TEGRA_CLK_RESET_BASE + 0x48));
-	reg |= 1 << 28;
-	writel(reg, IO_ADDRESS(TEGRA_CLK_RESET_BASE + 0x48));
-
-	/*
-	 * Enable FUSE clock. This needs to be hardcoded because the clock
-	 * subsystem is not active during early boot.
-	 */
-	reg = readl(IO_ADDRESS(TEGRA_CLK_RESET_BASE + 0x14));
-	reg |= 1 << 7;
-	writel(reg, IO_ADDRESS(TEGRA_CLK_RESET_BASE + 0x14));
-	fuse_clk = ERR_PTR(-EINVAL);
-
-	reg = tegra_fuse_readl(FUSE_SKU_INFO);
-	randomness[0] = reg;
-	tegra_sku_id = reg & 0xFF;
-
-	reg = tegra_apb_readl(TEGRA_APB_MISC_BASE + STRAP_OPT);
-	randomness[1] = reg;
-	tegra_bct_strapping = (reg & RAM_ID_MASK) >> RAM_CODE_SHIFT;
-
-	id = tegra_read_chipid();
-	randomness[2] = id;
-	chip_id = (id >> 8) & 0xff;
-
-	switch (chip_id) {
-	case TEGRA20:
-		tegra_fuse_spare_bit = TEGRA20_FUSE_SPARE_BIT;
-		tegra_init_speedo_data = &tegra20_init_speedo_data;
-		break;
-	case TEGRA30:
-		tegra_fuse_spare_bit = TEGRA30_FUSE_SPARE_BIT;
-		tegra_init_speedo_data = &tegra30_init_speedo_data;
-		break;
-	case TEGRA114:
-		tegra_init_speedo_data = &tegra114_init_speedo_data;
-		break;
-	default:
-		pr_warn("Tegra: unknown chip id %d\n", chip_id);
-		tegra_fuse_spare_bit = TEGRA20_FUSE_SPARE_BIT;
-		tegra_init_speedo_data = &tegra_get_process_id;
-	}
-
-	tegra_revision = tegra_get_revision(id);
-	tegra_init_speedo_data();
-	randomness[3] = (tegra_cpu_process_id << 16) | tegra_core_process_id;
-	randomness[4] = (tegra_cpu_speedo_id << 16) | tegra_soc_speedo_id;
-
-	add_device_randomness(randomness, sizeof(randomness));
-	switch (chip_id) {
-	case TEGRA20:
-		tegra20_fuse_init_randomness();
-		break;
-	case TEGRA30:
-	case TEGRA114:
-	default:
-		tegra30_fuse_init_randomness();
-		break;
-	}
-
-	pr_info("Tegra Revision: %s SKU: %d CPU Process: %d Core Process: %d\n",
-		tegra_revision_name[tegra_revision],
-		tegra_sku_id, tegra_cpu_process_id,
-		tegra_core_process_id);
-}
diff --git a/arch/arm/mach-tegra/fuse.h b/arch/arm/mach-tegra/fuse.h
deleted file mode 100644
index 48a48861c19b..000000000000
--- a/arch/arm/mach-tegra/fuse.h
+++ /dev/null
@@ -1,60 +0,0 @@
-/*
- * Copyright (C) 2010 Google, Inc.
- * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
- *
- * Author:
- *	Colin Cross <ccross@android.com>
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that 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_FUSE_H
-#define __MACH_TEGRA_FUSE_H
-
-#define SKU_ID_T20	8
-#define SKU_ID_T25SE	20
-#define SKU_ID_AP25	23
-#define SKU_ID_T25	24
-#define SKU_ID_AP25E	27
-#define SKU_ID_T25E	28
-
-#ifndef __ASSEMBLY__
-
-extern int tegra_sku_id;
-extern int tegra_cpu_process_id;
-extern int tegra_core_process_id;
-extern int tegra_cpu_speedo_id;		/* only exist in Tegra30 and later */
-extern int tegra_soc_speedo_id;
-
-unsigned long long tegra_chip_uid(void);
-bool tegra_spare_fuse(int bit);
-u32 tegra_fuse_readl(unsigned long offset);
-
-#ifdef CONFIG_ARCH_TEGRA_2x_SOC
-void tegra20_init_speedo_data(void);
-#else
-static inline void tegra20_init_speedo_data(void) {}
-#endif
-
-#ifdef CONFIG_ARCH_TEGRA_3x_SOC
-void tegra30_init_speedo_data(void);
-#else
-static inline void tegra30_init_speedo_data(void) {}
-#endif
-
-#ifdef CONFIG_ARCH_TEGRA_114_SOC
-void tegra114_init_speedo_data(void);
-#else
-static inline void tegra114_init_speedo_data(void) {}
-#endif
-#endif /* __ASSEMBLY__ */
-
-#endif
diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
index f94fdf89d457..5377495d41b8 100644
--- a/arch/arm/mach-tegra/reset.c
+++ b/arch/arm/mach-tegra/reset.c
@@ -25,7 +25,6 @@
 #include <asm/firmware.h>
 #include <asm/hardware/cache-l2x0.h>
 
-#include "fuse.h"
 #include "iomap.h"
 #include "irammap.h"
 #include "reset.h"
diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c
index a359931c5952..c0faae8c0822 100644
--- a/arch/arm/mach-tegra/tegra.c
+++ b/arch/arm/mach-tegra/tegra.c
@@ -104,7 +104,8 @@ static void __init tegra_dt_init(void)
 		goto out;
 
 	soc_dev_attr->family = kasprintf(GFP_KERNEL, "Tegra");
-	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%d", tegra_revision);
+	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%d",
+					   tegra_sku_info.revision);
 	soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "%u", tegra_get_chip_id());
 
 	soc_dev = soc_device_register(soc_dev_attr);
diff --git a/drivers/misc/fuse/Makefile b/drivers/misc/fuse/Makefile
new file mode 100644
index 000000000000..0679c4febc89
--- /dev/null
+++ b/drivers/misc/fuse/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 0f7c44793b29..3b1b95d932d1 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_ARCH_QCOM)		+= qcom/
+obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
diff --git a/drivers/soc/tegra/Makefile b/drivers/soc/tegra/Makefile
new file mode 100644
index 000000000000..236600f91bb3
--- /dev/null
+++ b/drivers/soc/tegra/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_ARCH_TEGRA) += fuse/
diff --git a/drivers/soc/tegra/fuse/Makefile b/drivers/soc/tegra/fuse/Makefile
new file mode 100644
index 000000000000..3af357da91f3
--- /dev/null
+++ b/drivers/soc/tegra/fuse/Makefile
@@ -0,0 +1,8 @@
+obj-y					+= fuse-tegra.o
+obj-y					+= fuse-tegra30.o
+obj-y					+= tegra-apbmisc.o
+obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= fuse-tegra20.o
+obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= speedo-tegra20.o
+obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= speedo-tegra30.o
+obj-$(CONFIG_ARCH_TEGRA_114_SOC)	+= speedo-tegra114.o
+obj-$(CONFIG_ARCH_TEGRA_124_SOC)	+= speedo-tegra124.o
diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
new file mode 100644
index 000000000000..03742edcfe83
--- /dev/null
+++ b/drivers/soc/tegra/fuse/fuse-tegra.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2013-2014, 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/kobject.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+
+#include <soc/tegra/fuse.h>
+
+#include "fuse.h"
+
+static u32 (*fuse_readl)(const unsigned int offset);
+static int fuse_size;
+struct tegra_sku_info tegra_sku_info;
+
+static const char *tegra_revision_name[TEGRA_REVISION_MAX] = {
+	[TEGRA_REVISION_UNKNOWN] = "unknown",
+	[TEGRA_REVISION_A01]     = "A01",
+	[TEGRA_REVISION_A02]     = "A02",
+	[TEGRA_REVISION_A03]     = "A03",
+	[TEGRA_REVISION_A03p]    = "A03 prime",
+	[TEGRA_REVISION_A04]     = "A04",
+};
+
+static u8 fuse_readb(const unsigned int offset)
+{
+	u32 val;
+
+	val = fuse_readl(round_down(offset, 4));
+	val >>= (offset % 4) * 8;
+	val &= 0xff;
+
+	return val;
+}
+
+static ssize_t fuse_read(struct file *fd, struct kobject *kobj,
+			struct bin_attribute *attr, char *buf,
+			loff_t pos, size_t size)
+{
+	int i;
+
+	if (pos < 0 || pos >= fuse_size)
+		return 0;
+
+	if (size > fuse_size - pos)
+		size = fuse_size - pos;
+
+	for (i = 0; i < size; i++)
+		buf[i] = fuse_readb(pos + i);
+
+	return i;
+}
+
+static struct bin_attribute fuse_bin_attr = {
+	.attr = { .name = "fuse", .mode = S_IRUGO, },
+	.read = fuse_read,
+};
+
+static const struct of_device_id car_match[] __initconst = {
+	{ .compatible = "nvidia,tegra20-car", },
+	{ .compatible = "nvidia,tegra30-car", },
+	{ .compatible = "nvidia,tegra114-car", },
+	{ .compatible = "nvidia,tegra124-car", },
+	{},
+};
+
+static void tegra_enable_fuse_clk(void __iomem *base)
+{
+	u32 reg;
+
+	reg = readl_relaxed(base + 0x48);
+	reg |= 1 << 28;
+	writel(reg, base + 0x48);
+
+	/*
+	 * Enable FUSE clock. This needs to be hardcoded because the clock
+	 * subsystem is not active during early boot.
+	 */
+	reg = readl(base + 0x14);
+	reg |= 1 << 7;
+	writel(reg, base + 0x14);
+}
+
+int tegra_fuse_readl(unsigned long offset, u32 *value)
+{
+	if (!fuse_readl)
+		return -EPROBE_DEFER;
+
+	*value = fuse_readl(offset);
+
+	return 0;
+}
+EXPORT_SYMBOL(tegra_fuse_readl);
+
+int tegra_fuse_create_sysfs(struct device *dev, int size,
+		     u32 (*readl)(const unsigned int offset))
+{
+	if (fuse_size)
+		return -ENODEV;
+
+	fuse_bin_attr.size = size;
+	fuse_bin_attr.read = fuse_read;
+
+	fuse_size = size;
+	fuse_readl = readl;
+
+	return device_create_bin_file(dev, &fuse_bin_attr);
+}
+
+void __init tegra_init_fuse(void)
+{
+	struct device_node *np;
+	void __iomem *car_base;
+
+	tegra_init_apbmisc();
+
+	np = of_find_matching_node(NULL, car_match);
+	car_base = of_iomap(np, 0);
+	if (car_base) {
+		tegra_enable_fuse_clk(car_base);
+		iounmap(car_base);
+	} else {
+		pr_err("Could not enable fuse clk. ioremap tegra car failed.\n");
+		return;
+	}
+
+	if (tegra_get_chip_id() == TEGRA20)
+		tegra20_init_fuse_early();
+	else
+		tegra30_init_fuse_early();
+
+	pr_info("Tegra Revision: %s SKU: %d CPU Process: %d Core Process: %d\n",
+		tegra_revision_name[tegra_sku_info.revision],
+		tegra_sku_info.sku_id, tegra_sku_info.cpu_process_id,
+		tegra_sku_info.core_process_id);
+	pr_debug("Tegra CPU Speedo ID %d, Soc Speedo ID %d\n",
+		tegra_sku_info.cpu_speedo_id, tegra_sku_info.soc_speedo_id);
+}
diff --git a/drivers/soc/tegra/fuse/fuse-tegra20.c b/drivers/soc/tegra/fuse/fuse-tegra20.c
new file mode 100644
index 000000000000..7a9d0e045490
--- /dev/null
+++ b/drivers/soc/tegra/fuse/fuse-tegra20.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2013-2014, 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Based on drivers/misc/eeprom/sunxi_sid.c
+ */
+
+#include <linux/device.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/random.h>
+
+#include <soc/tegra/fuse.h>
+
+#include "fuse.h"
+
+#define FUSE_BEGIN	0x100
+#define FUSE_SIZE	0x1f8
+#define FUSE_UID_LOW	0x08
+#define FUSE_UID_HIGH	0x0c
+
+static phys_addr_t fuse_phys;
+static struct clk *fuse_clk;
+static void __iomem __initdata *fuse_base;
+
+static u32 tegra20_fuse_readl(const unsigned int offset)
+{
+	int ret;
+	u32 val;
+
+	clk_prepare_enable(fuse_clk);
+
+	ret = tegra_apb_readl_using_dma(fuse_phys + FUSE_BEGIN + offset, &val);
+
+	clk_disable_unprepare(fuse_clk);
+
+	return (ret < 0) ? 0 : val;
+}
+
+static const struct of_device_id tegra20_fuse_of_match[] = {
+	{ .compatible = "nvidia,tegra20-efuse" },
+	{},
+};
+
+static int tegra20_fuse_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+
+	fuse_clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(fuse_clk)) {
+		dev_err(&pdev->dev, "missing clock");
+		return PTR_ERR(fuse_clk);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+	fuse_phys = res->start;
+
+	if (tegra_fuse_create_sysfs(&pdev->dev, FUSE_SIZE, tegra20_fuse_readl))
+		return -ENODEV;
+
+	dev_dbg(&pdev->dev, "loaded\n");
+
+	return 0;
+}
+
+static struct platform_driver tegra20_fuse_driver = {
+	.probe = tegra20_fuse_probe,
+	.driver = {
+		.name = "tegra20_fuse",
+		.owner = THIS_MODULE,
+		.of_match_table = tegra20_fuse_of_match,
+	}
+};
+
+static int __init tegra20_fuse_init(void)
+{
+	return platform_driver_register(&tegra20_fuse_driver);
+}
+postcore_initcall(tegra20_fuse_init);
+
+/* Early boot code. This code is called before the devices are created */
+
+u32 __init tegra20_fuse_early(const unsigned int offset)
+{
+	return readl_relaxed(fuse_base + FUSE_BEGIN + offset);
+}
+
+bool __init tegra20_spare_fuse_early(int spare_bit)
+{
+	u32 offset = spare_bit * 4;
+	bool value;
+
+	value = tegra20_fuse_early(offset + 0x100);
+
+	return value;
+}
+
+static void __init tegra20_fuse_add_randomness(void)
+{
+	u32 randomness[7];
+
+	randomness[0] = tegra_sku_info.sku_id;
+	randomness[1] = tegra_read_straps();
+	randomness[2] = tegra_read_chipid();
+	randomness[3] = tegra_sku_info.cpu_process_id << 16;
+	randomness[3] |= tegra_sku_info.core_process_id;
+	randomness[4] = tegra_sku_info.cpu_speedo_id << 16;
+	randomness[4] |= tegra_sku_info.soc_speedo_id;
+	randomness[5] = tegra20_fuse_early(FUSE_UID_LOW);
+	randomness[6] = tegra20_fuse_early(FUSE_UID_HIGH);
+
+	add_device_randomness(randomness, sizeof(randomness));
+}
+
+void __init tegra20_init_fuse_early(void)
+{
+	fuse_base = ioremap(TEGRA_FUSE_BASE, TEGRA_FUSE_SIZE);
+
+	tegra_init_revision();
+	tegra20_init_speedo_data(&tegra_sku_info);
+	tegra20_fuse_add_randomness();
+
+	iounmap(fuse_base);
+}
diff --git a/drivers/soc/tegra/fuse/fuse-tegra30.c b/drivers/soc/tegra/fuse/fuse-tegra30.c
new file mode 100644
index 000000000000..5999cf34ab70
--- /dev/null
+++ b/drivers/soc/tegra/fuse/fuse-tegra30.c
@@ -0,0 +1,224 @@
+/*
+ * Copyright (c) 2013-2014, 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/random.h>
+
+#include <soc/tegra/fuse.h>
+
+#include "fuse.h"
+
+#define FUSE_BEGIN	0x100
+
+/* Tegra30 and later */
+#define FUSE_VENDOR_CODE	0x100
+#define FUSE_FAB_CODE		0x104
+#define FUSE_LOT_CODE_0		0x108
+#define FUSE_LOT_CODE_1		0x10c
+#define FUSE_WAFER_ID		0x110
+#define FUSE_X_COORDINATE	0x114
+#define FUSE_Y_COORDINATE	0x118
+
+#define FUSE_HAS_REVISION_INFO	BIT(0)
+
+enum speedo_idx {
+	SPEEDO_TEGRA30 = 0,
+	SPEEDO_TEGRA114,
+	SPEEDO_TEGRA124,
+};
+
+struct tegra_fuse_info {
+	int		size;
+	int		spare_bit;
+	enum speedo_idx	speedo_idx;
+};
+
+static void __iomem *fuse_base;
+static struct clk *fuse_clk;
+static struct tegra_fuse_info *fuse_info;
+
+u32 tegra30_fuse_readl(const unsigned int offset)
+{
+	u32 val;
+
+	/*
+	 * early in the boot, the fuse clock will be enabled by
+	 * tegra_init_fuse()
+	 */
+
+	if (fuse_clk)
+		clk_prepare_enable(fuse_clk);
+
+	val = readl_relaxed(fuse_base + FUSE_BEGIN + offset);
+
+	if (fuse_clk)
+		clk_disable_unprepare(fuse_clk);
+
+	return val;
+}
+
+static struct tegra_fuse_info tegra30_info = {
+	.size			= 0x2a4,
+	.spare_bit		= 0x144,
+	.speedo_idx		= SPEEDO_TEGRA30,
+};
+
+static struct tegra_fuse_info tegra114_info = {
+	.size			= 0x2a0,
+	.speedo_idx		= SPEEDO_TEGRA114,
+};
+
+static struct tegra_fuse_info tegra124_info = {
+	.size			= 0x300,
+	.speedo_idx		= SPEEDO_TEGRA124,
+};
+
+static const struct of_device_id tegra30_fuse_of_match[] = {
+	{ .compatible = "nvidia,tegra30-efuse", .data = &tegra30_info },
+	{ .compatible = "nvidia,tegra114-efuse", .data = &tegra114_info },
+	{ .compatible = "nvidia,tegra124-efuse", .data = &tegra124_info },
+	{},
+};
+
+static int tegra30_fuse_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *of_dev_id;
+
+	of_dev_id = of_match_device(tegra30_fuse_of_match, &pdev->dev);
+	if (!of_dev_id)
+		return -ENODEV;
+
+	fuse_clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(fuse_clk)) {
+		dev_err(&pdev->dev, "missing clock");
+		return PTR_ERR(fuse_clk);
+	}
+
+	platform_set_drvdata(pdev, NULL);
+
+	if (tegra_fuse_create_sysfs(&pdev->dev, fuse_info->size,
+				    tegra30_fuse_readl))
+		return -ENODEV;
+
+	dev_dbg(&pdev->dev, "loaded\n");
+
+	return 0;
+}
+
+static struct platform_driver tegra30_fuse_driver = {
+	.probe = tegra30_fuse_probe,
+	.driver = {
+		.name = "tegra_fuse",
+		.owner = THIS_MODULE,
+		.of_match_table = tegra30_fuse_of_match,
+	}
+};
+
+static int __init tegra30_fuse_init(void)
+{
+	return platform_driver_register(&tegra30_fuse_driver);
+}
+postcore_initcall(tegra30_fuse_init);
+
+/* Early boot code. This code is called before the devices are created */
+
+typedef void (*speedo_f)(struct tegra_sku_info *sku_info);
+
+static speedo_f __initdata speedo_tbl[] = {
+	[SPEEDO_TEGRA30]	= tegra30_init_speedo_data,
+	[SPEEDO_TEGRA114]	= tegra114_init_speedo_data,
+	[SPEEDO_TEGRA124]	= tegra124_init_speedo_data,
+};
+
+static void __init tegra30_fuse_add_randomness(void)
+{
+	u32 randomness[12];
+
+	randomness[0] = tegra_sku_info.sku_id;
+	randomness[1] = tegra_read_straps();
+	randomness[2] = tegra_read_chipid();
+	randomness[3] = tegra_sku_info.cpu_process_id << 16;
+	randomness[3] |= tegra_sku_info.core_process_id;
+	randomness[4] = tegra_sku_info.cpu_speedo_id << 16;
+	randomness[4] |= tegra_sku_info.soc_speedo_id;
+	randomness[5] = tegra30_fuse_readl(FUSE_VENDOR_CODE);
+	randomness[6] = tegra30_fuse_readl(FUSE_FAB_CODE);
+	randomness[7] = tegra30_fuse_readl(FUSE_LOT_CODE_0);
+	randomness[8] = tegra30_fuse_readl(FUSE_LOT_CODE_1);
+	randomness[9] = tegra30_fuse_readl(FUSE_WAFER_ID);
+	randomness[10] = tegra30_fuse_readl(FUSE_X_COORDINATE);
+	randomness[11] = tegra30_fuse_readl(FUSE_Y_COORDINATE);
+
+	add_device_randomness(randomness, sizeof(randomness));
+}
+
+static void __init legacy_fuse_init(void)
+{
+	switch (tegra_get_chip_id()) {
+	case TEGRA30:
+		fuse_info = &tegra30_info;
+		break;
+	case TEGRA114:
+		fuse_info = &tegra114_info;
+		break;
+	case TEGRA124:
+		fuse_info = &tegra124_info;
+		break;
+	default:
+		return;
+	}
+
+	fuse_base = ioremap(TEGRA_FUSE_BASE, TEGRA_FUSE_SIZE);
+}
+
+bool __init tegra30_spare_fuse(int spare_bit)
+{
+	u32 offset = fuse_info->spare_bit + spare_bit * 4;
+
+	return tegra30_f