kernel-ark/arch/arm/mach-tegra/fuse.c
Colin Cross 73625e3e2e [ARM] tegra: Add support for reading fuses
The Tegra SOC contains fuses to identify the CPU type and
bin, and a unique id.  The CPU info is required to determine
the correct voltages for each cpu and core frequency.

Signed-off-by: Colin Cross <ccross@android.com>
2010-10-21 18:12:09 -07:00

85 lines
1.9 KiB
C

/*
* 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;
}