[ARM] tegra: Add support for reading fuses

[karo-tx-linux.git] / arch / arm / mach-tegra / fuse.c

diff --git a/arch/arm/mach-tegra/fuse.c b/arch/arm/mach-tegra/fuse.c
new file mode 100644 (file)
index 0000000..1fa26d9
--- /dev/null
+++ b/arch/arm/mach-tegra/fuse.c
@@ -0,0 +1,84 @@
+/*
+ * arch/arm/mach-tegra/fuse.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * 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/kernel.h>
+#include <linux/io.h>
+
+#include <mach/iomap.h>
+
+#include "fuse.h"
+
+#define FUSE_UID_LOW           0x108
+#define FUSE_UID_HIGH          0x10c
+#define FUSE_SKU_INFO          0x110
+#define FUSE_SPARE_BIT         0x200
+
+static inline u32 fuse_readl(unsigned long offset)
+{
+       return readl(IO_TO_VIRT(TEGRA_FUSE_BASE + offset));
+}
+
+static inline void fuse_writel(u32 value, unsigned long offset)
+{
+       writel(value, IO_TO_VIRT(TEGRA_FUSE_BASE + offset));
+}
+
+void tegra_init_fuse(void)
+{
+       u32 reg = readl(IO_TO_VIRT(TEGRA_CLK_RESET_BASE + 0x48));
+       reg |= 1 << 28;
+       writel(reg, IO_TO_VIRT(TEGRA_CLK_RESET_BASE + 0x48));
+
+       pr_info("Tegra SKU: %d CPU Process: %d Core Process: %d\n",
+               tegra_sku_id(), tegra_cpu_process_id(),
+               tegra_core_process_id());
+}
+
+unsigned long long tegra_chip_uid(void)
+{
+       unsigned long long lo, hi;
+
+       lo = fuse_readl(FUSE_UID_LOW);
+       hi = fuse_readl(FUSE_UID_HIGH);
+       return (hi << 32ull) | lo;
+}
+
+int tegra_sku_id(void)
+{
+       int sku_id;
+       u32 reg = fuse_readl(FUSE_SKU_INFO);
+       sku_id = reg & 0xFF;
+       return sku_id;
+}
+
+int tegra_cpu_process_id(void)
+{
+       int cpu_process_id;
+       u32 reg = fuse_readl(FUSE_SPARE_BIT);
+       cpu_process_id = (reg >> 6) & 3;
+       return cpu_process_id;
+}
+
+int tegra_core_process_id(void)
+{
+       int core_process_id;
+       u32 reg = fuse_readl(FUSE_SPARE_BIT);
+       core_process_id = (reg >> 12) & 3;
+       return core_process_id;
+}