u-boot/drivers/misc/mxc_ocotp.c

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/*
* (C) Copyright 2013 ADVANSEE
* Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
*
* Based on Dirk Behme's
* https://github.com/dirkbehme/u-boot-imx6/blob/28b17e9/drivers/misc/imx_otp.c,
* which is based on Freescale's
* http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/drivers/misc/imx_otp.c?h=imx_v2009.08_1.1.0&id=9aa74e6,
* which is:
* Copyright (C) 2011 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <fuse.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/imx-regs.h>
#define BO_CTRL_WR_UNLOCK 16
#define BM_CTRL_WR_UNLOCK 0xffff0000
#define BV_CTRL_WR_UNLOCK_KEY 0x3e77
#define BM_CTRL_ERROR 0x00000200
#define BM_CTRL_BUSY 0x00000100
#define BO_CTRL_ADDR 0
#define BM_CTRL_ADDR 0x0000007f
#define BO_TIMING_STROBE_READ 16
#define BM_TIMING_STROBE_READ 0x003f0000
#define BV_TIMING_STROBE_READ_NS 37
#define BO_TIMING_RELAX 12
#define BM_TIMING_RELAX 0x0000f000
#define BV_TIMING_RELAX_NS 17
#define BO_TIMING_STROBE_PROG 0
#define BM_TIMING_STROBE_PROG 0x00000fff
#define BV_TIMING_STROBE_PROG_US 10
#define BM_READ_CTRL_READ_FUSE 0x00000001
#define BF(value, field) (((value) << BO_##field) & BM_##field)
#define WRITE_POSTAMBLE_US 2
static void wait_busy(struct ocotp_regs *regs, unsigned int delay_us)
{
while (readl(&regs->ctrl) & BM_CTRL_BUSY)
udelay(delay_us);
}
static void clear_error(struct ocotp_regs *regs)
{
writel(BM_CTRL_ERROR, &regs->ctrl_clr);
}
static int prepare_access(struct ocotp_regs **regs, u32 bank, u32 word,
int assert, const char *caller)
{
*regs = (struct ocotp_regs *)OCOTP_BASE_ADDR;
if (bank >= ARRAY_SIZE((*regs)->bank) ||
word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) >> 2 ||
!assert) {
printf("mxc_ocotp %s(): Invalid argument\n", caller);
return -EINVAL;
}
enable_ocotp_clk(1);
wait_busy(*regs, 1);
clear_error(*regs);
return 0;
}
static int finish_access(struct ocotp_regs *regs, const char *caller)
{
u32 err;
err = !!(readl(&regs->ctrl) & BM_CTRL_ERROR);
clear_error(regs);
enable_ocotp_clk(0);
if (err) {
printf("mxc_ocotp %s(): Access protect error\n", caller);
return -EIO;
}
return 0;
}
static int prepare_read(struct ocotp_regs **regs, u32 bank, u32 word, u32 *val,
const char *caller)
{
return prepare_access(regs, bank, word, val != NULL, caller);
}
int fuse_read(u32 bank, u32 word, u32 *val)
{
struct ocotp_regs *regs;
int ret;
ret = prepare_read(&regs, bank, word, val, __func__);
if (ret)
return ret;
*val = readl(&regs->bank[bank].fuse_regs[word << 2]);
return finish_access(regs, __func__);
}
static void set_timing(struct ocotp_regs *regs)
{
u32 ipg_clk;
u32 relax, strobe_read, strobe_prog;
u32 timing;
ipg_clk = mxc_get_clock(MXC_IPG_CLK);
relax = DIV_ROUND_UP(ipg_clk * BV_TIMING_RELAX_NS, 1000000000) - 1;
strobe_read = DIV_ROUND_UP(ipg_clk * BV_TIMING_STROBE_READ_NS,
1000000000) + 2 * (relax + 1) - 1;
strobe_prog = DIV_ROUND(ipg_clk * BV_TIMING_STROBE_PROG_US, 1000000) +
2 * (relax + 1) - 1;
timing = BF(strobe_read, TIMING_STROBE_READ) |
BF(relax, TIMING_RELAX) |
BF(strobe_prog, TIMING_STROBE_PROG);
clrsetbits_le32(&regs->timing, BM_TIMING_STROBE_READ | BM_TIMING_RELAX |
BM_TIMING_STROBE_PROG, timing);
}
static void setup_direct_access(struct ocotp_regs *regs, u32 bank, u32 word,
int write)
{
u32 wr_unlock = write ? BV_CTRL_WR_UNLOCK_KEY : 0;
u32 addr = bank << 3 | word;
set_timing(regs);
clrsetbits_le32(&regs->ctrl, BM_CTRL_WR_UNLOCK | BM_CTRL_ADDR,
BF(wr_unlock, CTRL_WR_UNLOCK) |
BF(addr, CTRL_ADDR));
}
int fuse_sense(u32 bank, u32 word, u32 *val)
{
struct ocotp_regs *regs;
int ret;
ret = prepare_read(&regs, bank, word, val, __func__);
if (ret)
return ret;
setup_direct_access(regs, bank, word, false);
writel(BM_READ_CTRL_READ_FUSE, &regs->read_ctrl);
wait_busy(regs, 1);
*val = readl(&regs->read_fuse_data);
return finish_access(regs, __func__);
}
static int prepare_write(struct ocotp_regs **regs, u32 bank, u32 word,
const char *caller)
{
return prepare_access(regs, bank, word, true, caller);
}
int fuse_prog(u32 bank, u32 word, u32 val)
{
struct ocotp_regs *regs;
int ret;
ret = prepare_write(&regs, bank, word, __func__);
if (ret)
return ret;
setup_direct_access(regs, bank, word, true);
writel(val, &regs->data);
wait_busy(regs, BV_TIMING_STROBE_PROG_US);
udelay(WRITE_POSTAMBLE_US);
return finish_access(regs, __func__);
}
int fuse_override(u32 bank, u32 word, u32 val)
{
struct ocotp_regs *regs;
int ret;
ret = prepare_write(&regs, bank, word, __func__);
if (ret)
return ret;
writel(val, &regs->bank[bank].fuse_regs[word << 2]);
return finish_access(regs, __func__);
}