jz4780_efuse.c
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// SPDX-License-Identifier: GPL-2.0+
/*
* JZ4780 EFUSE driver
*
* Copyright (c) 2014 Imagination Technologies
* Author: Alex Smith <alex.smith@imgtec.com>
*/
#include <common.h>
#include <asm/io.h>
#include <asm/unaligned.h>
#include <errno.h>
#include <mach/jz4780.h>
#include <wait_bit.h>
#define EFUSE_EFUCTRL 0xd0
#define EFUSE_EFUCFG 0xd4
#define EFUSE_EFUSTATE 0xd8
#define EFUSE_EFUDATA(n) (0xdc + ((n) * 4))
#define EFUSE_EFUCTRL_RD_EN BIT(0)
#define EFUSE_EFUCTRL_LEN_BIT 16
#define EFUSE_EFUCTRL_LEN_MASK 0x1f
#define EFUSE_EFUCTRL_ADDR_BIT 21
#define EFUSE_EFUCTRL_ADDR_MASK 0x1ff
#define EFUSE_EFUCTRL_CS BIT(30)
#define EFUSE_EFUCFG_RD_STROBE_BIT 16
#define EFUSE_EFUCFG_RD_STROBE_MASK 0xf
#define EFUSE_EFUCFG_RD_ADJ_BIT 20
#define EFUSE_EFUCFG_RD_ADJ_MASK 0xf
#define EFUSE_EFUSTATE_RD_DONE BIT(0)
static void jz4780_efuse_read_chunk(size_t addr, size_t count, u8 *buf)
{
void __iomem *regs = (void __iomem *)NEMC_BASE;
size_t i;
u32 val;
int ret;
val = EFUSE_EFUCTRL_RD_EN |
((count - 1) << EFUSE_EFUCTRL_LEN_BIT) |
(addr << EFUSE_EFUCTRL_ADDR_BIT) |
((addr > 0x200) ? EFUSE_EFUCTRL_CS : 0);
writel(val, regs + EFUSE_EFUCTRL);
ret = wait_for_bit_le32(regs + EFUSE_EFUSTATE,
EFUSE_EFUSTATE_RD_DONE, true, 10000, false);
if (ret)
return;
if ((count % 4) == 0) {
for (i = 0; i < count / 4; i++) {
val = readl(regs + EFUSE_EFUDATA(i));
put_unaligned(val, (u32 *)(buf + (i * 4)));
}
} else {
val = readl(regs + EFUSE_EFUDATA(0));
if (count > 2)
buf[2] = (val >> 16) & 0xff;
if (count > 1)
buf[1] = (val >> 8) & 0xff;
buf[0] = val & 0xff;
}
}
static inline int jz4780_efuse_chunk_size(size_t count)
{
if (count >= 32)
return 32;
else if ((count / 4) > 0)
return (count / 4) * 4;
else
return count % 4;
}
void jz4780_efuse_read(size_t addr, size_t count, u8 *buf)
{
size_t chunk;
while (count > 0) {
chunk = jz4780_efuse_chunk_size(count);
jz4780_efuse_read_chunk(addr, chunk, buf);
addr += chunk;
buf += chunk;
count -= chunk;
}
}
void jz4780_efuse_init(u32 ahb2_rate)
{
void __iomem *regs = (void __iomem *)NEMC_BASE;
u32 rd_adj, rd_strobe, tmp;
rd_adj = (((6500 * (ahb2_rate / 1000000)) / 1000000) + 0xf) / 2;
tmp = (((35000 * (ahb2_rate / 1000000)) / 1000000) - 4) - rd_adj;
rd_strobe = ((tmp + 0xf) / 2 < 7) ? 7 : (tmp + 0xf) / 2;
tmp = (rd_adj << EFUSE_EFUCFG_RD_ADJ_BIT) |
(rd_strobe << EFUSE_EFUCFG_RD_STROBE_BIT);
writel(tmp, regs + EFUSE_EFUCFG);
}