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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2015-2016 Reinhard Pfau <reinhard.pfau@gdsys.cc>
*/
#include <config.h>
#include <common.h>
#include <errno.h>
#include <asm/io.h>
#include <asm/arch/cpu.h>
#include <asm/arch/efuse.h>
#include <asm/arch/soc.h>
#include <linux/mbus.h>
#if defined(CONFIG_MVEBU_EFUSE_FAKE)
#define DRY_RUN
#else
#undef DRY_RUN
#endif
#define MBUS_EFUSE_BASE 0xF6000000
#define MBUS_EFUSE_SIZE BIT(20)
#define MVEBU_EFUSE_CONTROL (MVEBU_REGISTER(0xE4008))
enum {
MVEBU_EFUSE_CTRL_PROGRAM_ENABLE = (1 << 31),
};
struct mvebu_hd_efuse {
u32 bits_31_0;
u32 bits_63_32;
u32 bit64;
u32 reserved0;
};
#ifndef DRY_RUN
static struct mvebu_hd_efuse *efuses =
(struct mvebu_hd_efuse *)(MBUS_EFUSE_BASE + 0xF9000);
#else
static struct mvebu_hd_efuse efuses[EFUSE_LINE_MAX + 1];
#endif
static int efuse_initialised;
static struct mvebu_hd_efuse *get_efuse_line(int nr)
{
if (nr < 0 || nr > 63 || !efuse_initialised)
return NULL;
return efuses + nr;
}
static void enable_efuse_program(void)
{
#ifndef DRY_RUN
setbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);
#endif
}
static void disable_efuse_program(void)
{
#ifndef DRY_RUN
clrbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);
#endif
}
static int do_prog_efuse(struct mvebu_hd_efuse *efuse,
struct efuse_val *new_val, u32 mask0, u32 mask1)
{
struct efuse_val val;
val.dwords.d[0] = readl(&efuse->bits_31_0);
val.dwords.d[1] = readl(&efuse->bits_63_32);
val.lock = readl(&efuse->bit64);
if (val.lock & 1)
return -EPERM;
val.dwords.d[0] |= (new_val->dwords.d[0] & mask0);
val.dwords.d[1] |= (new_val->dwords.d[1] & mask1);
val.lock |= new_val->lock;
writel(val.dwords.d[0], &efuse->bits_31_0);
mdelay(1);
writel(val.dwords.d[1], &efuse->bits_63_32);
mdelay(1);
writel(val.lock, &efuse->bit64);
mdelay(5);
return 0;
}
static int prog_efuse(int nr, struct efuse_val *new_val, u32 mask0, u32 mask1)
{
struct mvebu_hd_efuse *efuse;
int res = 0;
res = mvebu_efuse_init_hw();
if (res)
return res;
efuse = get_efuse_line(nr);
if (!efuse)
return -ENODEV;
if (!new_val)
return -EINVAL;
/* only write a fuse line with lock bit */
if (!new_val->lock)
return -EINVAL;
/* according to specs ECC protection bits must be 0 on write */
if (new_val->bytes.d[7] & 0xFE)
return -EINVAL;
if (!new_val->dwords.d[0] && !new_val->dwords.d[1] && (mask0 | mask1))
return 0;
enable_efuse_program();
res = do_prog_efuse(efuse, new_val, mask0, mask1);
disable_efuse_program();
return res;
}
int mvebu_efuse_init_hw(void)
{
int ret;
if (efuse_initialised)
return 0;
ret = mvebu_mbus_add_window_by_id(
CPU_TARGET_SATA23_DFX, 0xA, MBUS_EFUSE_BASE, MBUS_EFUSE_SIZE);
if (ret)
return ret;
efuse_initialised = 1;
return 0;
}
int mvebu_read_efuse(int nr, struct efuse_val *val)
{
struct mvebu_hd_efuse *efuse;
int res;
res = mvebu_efuse_init_hw();
if (res)
return res;
efuse = get_efuse_line(nr);
if (!efuse)
return -ENODEV;
if (!val)
return -EINVAL;
val->dwords.d[0] = readl(&efuse->bits_31_0);
val->dwords.d[1] = readl(&efuse->bits_63_32);
val->lock = readl(&efuse->bit64);
return 0;
}
int mvebu_write_efuse(int nr, struct efuse_val *val)
{
return prog_efuse(nr, val, ~0, ~0);
}
int mvebu_lock_efuse(int nr)
{
struct efuse_val val = {
.lock = 1,
};
return prog_efuse(nr, &val, 0, 0);
}
/*
* wrapper funcs providing the fuse API
*
* we use the following mapping:
* "bank" -> eFuse line
* "word" -> 0: bits 0-31
* 1: bits 32-63
* 2: bit 64 (lock)
*/
static struct efuse_val prog_val;
static int valid_prog_words;
int fuse_read(u32 bank, u32 word, u32 *val)
{
struct efuse_val fuse_line;
int res;
if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
return -EINVAL;
res = mvebu_read_efuse(bank, &fuse_line);
if (res)
return res;
if (word < 2)
*val = fuse_line.dwords.d[word];
else
*val = fuse_line.lock;
return res;
}
int fuse_sense(u32 bank, u32 word, u32 *val)
{
/* not supported */
return -ENOSYS;
}
int fuse_prog(u32 bank, u32 word, u32 val)
{
int res = 0;
/*
* NOTE: Fuse line should be written as whole.
* So how can we do that with this API?
* For now: remember values for word == 0 and word == 1 and write the
* whole line when word == 2.
* This implies that we always require all 3 fuse prog cmds (one for
* for each word) to write a single fuse line.
* Exception is a single write to word 2 which will lock the fuse line.
*
* Hope that will be OK.
*/
if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
return -EINVAL;
if (word < 2) {
prog_val.dwords.d[word] = val;
valid_prog_words |= (1 << word);
} else if ((valid_prog_words & 3) == 0 && val) {
res = mvebu_lock_efuse(bank);
valid_prog_words = 0;
} else if ((valid_prog_words & 3) != 3 || !val) {
res = -EINVAL;
} else {
prog_val.lock = val != 0;
res = mvebu_write_efuse(bank, &prog_val);
valid_prog_words = 0;
}
return res;
}
int fuse_override(u32 bank, u32 word, u32 val)
{
/* not supported */
return -ENOSYS;
}