linux/arch/arm/mach-tegra/fuse.c

132 lines
3.2 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 <linux/export.h>
#include <mach/iomap.h>
#include "fuse.h"
#include "apbio.h"
#define FUSE_UID_LOW 0x108
#define FUSE_UID_HIGH 0x10c
#define FUSE_SKU_INFO 0x110
#define FUSE_SPARE_BIT 0x200
int tegra_sku_id;
int tegra_cpu_process_id;
int tegra_core_process_id;
int tegra_chip_id;
enum tegra_revision tegra_revision;
/* 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 inline u32 tegra_fuse_readl(unsigned long offset)
{
return tegra_apb_readl(TEGRA_FUSE_BASE + offset);
}
static inline bool get_spare_fuse(int bit)
{
return tegra_fuse_readl(FUSE_SPARE_BIT + bit * 4);
}
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_chip_id == TEGRA20 &&
(get_spare_fuse(18) || get_spare_fuse(19)))
return TEGRA_REVISION_A03p;
else
return TEGRA_REVISION_A03;
case 4:
return TEGRA_REVISION_A04;
default:
return TEGRA_REVISION_UNKNOWN;
}
}
void tegra_init_fuse(void)
{
u32 id;
u32 reg = readl(IO_TO_VIRT(TEGRA_CLK_RESET_BASE + 0x48));
reg |= 1 << 28;
writel(reg, IO_TO_VIRT(TEGRA_CLK_RESET_BASE + 0x48));
reg = tegra_fuse_readl(FUSE_SKU_INFO);
tegra_sku_id = reg & 0xFF;
reg = tegra_fuse_readl(FUSE_SPARE_BIT);
tegra_cpu_process_id = (reg >> 6) & 3;
reg = tegra_fuse_readl(FUSE_SPARE_BIT);
tegra_core_process_id = (reg >> 12) & 3;
reg = tegra_apb_readl(TEGRA_APB_MISC_BASE + STRAP_OPT);
tegra_bct_strapping = (reg & RAM_ID_MASK) >> RAM_CODE_SHIFT;
id = readl_relaxed(IO_ADDRESS(TEGRA_APB_MISC_BASE) + 0x804);
tegra_chip_id = (id >> 8) & 0xff;
tegra_revision = tegra_get_revision(id);
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);
}
unsigned long long tegra_chip_uid(void)
{
unsigned long long lo, hi;
lo = tegra_fuse_readl(FUSE_UID_LOW);
hi = tegra_fuse_readl(FUSE_UID_HIGH);
return (hi << 32ull) | lo;
}
EXPORT_SYMBOL(tegra_chip_uid);