Files
linux/drivers/mtd/spi-nor/sst.c
Sanjaikumar V S a0f64241d3 mtd: spi-nor: sst: Fix write enable before AAI sequence
When writing to SST flash starting at an odd address, a single byte is
first programmed using the byte program (BP) command. After this
operation completes, the flash hardware automatically clears the Write
Enable Latch (WEL) bit.

If an AAI (Auto Address Increment) word program sequence follows, it
requires WEL to be set. Without re-enabling writes, the AAI sequence
fails.

Add spi_nor_write_enable() after the odd-address byte program when more
data needs to be written. Use a local boolean for clarity.

Fixes: b199489d37 ("mtd: spi-nor: add the framework for SPI NOR")
Cc: stable@vger.kernel.org
Signed-off-by: Sanjaikumar V S <sanjaikumar.vs@dicortech.com>
Tested-by: Hendrik Donner <hd@os-cillation.de>
Reviewed-by: Hendrik Donner <hd@os-cillation.de>
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
2026-03-30 14:24:38 +00:00

286 lines
6.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2005, Intec Automation Inc.
* Copyright (C) 2014, Freescale Semiconductor, Inc.
*/
#include <linux/mtd/spi-nor.h>
#include "core.h"
/* SST flash_info mfr_flag. Used to specify SST byte programming. */
#define SST_WRITE BIT(0)
#define SST26VF_CR_BPNV BIT(3)
static int sst26vf_nor_lock(struct spi_nor *nor, loff_t ofs, u64 len)
{
return -EOPNOTSUPP;
}
static int sst26vf_nor_unlock(struct spi_nor *nor, loff_t ofs, u64 len)
{
int ret;
/* We only support unlocking the entire flash array. */
if (ofs != 0 || len != nor->params->size)
return -EINVAL;
ret = spi_nor_read_cr(nor, nor->bouncebuf);
if (ret)
return ret;
if (!(nor->bouncebuf[0] & SST26VF_CR_BPNV)) {
dev_dbg(nor->dev, "Any block has been permanently locked\n");
return -EINVAL;
}
return spi_nor_global_block_unlock(nor);
}
static int sst26vf_nor_is_locked(struct spi_nor *nor, loff_t ofs, u64 len)
{
return -EOPNOTSUPP;
}
static const struct spi_nor_locking_ops sst26vf_nor_locking_ops = {
.lock = sst26vf_nor_lock,
.unlock = sst26vf_nor_unlock,
.is_locked = sst26vf_nor_is_locked,
};
static int sst26vf_nor_late_init(struct spi_nor *nor)
{
nor->params->locking_ops = &sst26vf_nor_locking_ops;
return 0;
}
static const struct spi_nor_fixups sst26vf_nor_fixups = {
.late_init = sst26vf_nor_late_init,
};
static const struct flash_info sst_nor_parts[] = {
{
.id = SNOR_ID(0x62, 0x16, 0x12),
.name = "sst25wf020a",
.size = SZ_256K,
.flags = SPI_NOR_HAS_LOCK,
.no_sfdp_flags = SECT_4K,
}, {
.id = SNOR_ID(0x62, 0x16, 0x13),
.name = "sst25wf040b",
.size = SZ_512K,
.flags = SPI_NOR_HAS_LOCK,
.no_sfdp_flags = SECT_4K,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x01),
.name = "sst25wf512",
.size = SZ_64K,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
.mfr_flags = SST_WRITE,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x02),
.name = "sst25wf010",
.size = SZ_128K,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
.mfr_flags = SST_WRITE,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x03),
.name = "sst25wf020",
.size = SZ_256K,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
.mfr_flags = SST_WRITE,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x04),
.name = "sst25wf040",
.size = SZ_512K,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
.mfr_flags = SST_WRITE,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x05),
.name = "sst25wf080",
.size = SZ_1M,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
.mfr_flags = SST_WRITE,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x41),
.name = "sst25vf016b",
.size = SZ_2M,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
.mfr_flags = SST_WRITE,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x4a),
.name = "sst25vf032b",
.size = SZ_4M,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
.mfr_flags = SST_WRITE,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x4b),
.name = "sst25vf064c",
.size = SZ_8M,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_4BIT_BP | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x8d),
.name = "sst25vf040b",
.size = SZ_512K,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
.mfr_flags = SST_WRITE,
}, {
.id = SNOR_ID(0xbf, 0x25, 0x8e),
.name = "sst25vf080b",
.size = SZ_1M,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K,
.mfr_flags = SST_WRITE,
}, {
.id = SNOR_ID(0xbf, 0x26, 0x41),
.name = "sst26vf016b",
.size = SZ_2M,
.no_sfdp_flags = SECT_4K | SPI_NOR_DUAL_READ,
}, {
.id = SNOR_ID(0xbf, 0x26, 0x42),
.name = "sst26vf032b",
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.fixups = &sst26vf_nor_fixups,
}, {
.id = SNOR_ID(0xbf, 0x26, 0x43),
.name = "sst26vf064b",
.size = SZ_8M,
.flags = SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE,
.no_sfdp_flags = SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ,
.fixups = &sst26vf_nor_fixups,
}, {
.id = SNOR_ID(0xbf, 0x26, 0x51),
.name = "sst26wf016b",
.size = SZ_2M,
.no_sfdp_flags = SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ,
}
};
static int sst_nor_write_data(struct spi_nor *nor, loff_t to, size_t len,
const u_char *buf)
{
u8 op = (len == 1) ? SPINOR_OP_BP : SPINOR_OP_AAI_WP;
int ret;
nor->program_opcode = op;
ret = spi_nor_write_data(nor, to, len, buf);
if (ret < 0)
return ret;
WARN(ret != len, "While writing %zu byte written %i bytes\n", len, ret);
return spi_nor_wait_till_ready(nor);
}
static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
struct spi_nor *nor = mtd_to_spi_nor(mtd);
size_t actual = 0;
int ret;
dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
ret = spi_nor_prep_and_lock(nor);
if (ret)
return ret;
ret = spi_nor_write_enable(nor);
if (ret)
goto out;
nor->sst_write_second = false;
/* Start write from odd address. */
if (to % 2) {
bool needs_write_enable = (len > 1);
/* write one byte. */
ret = sst_nor_write_data(nor, to, 1, buf);
if (ret < 0)
goto out;
to++;
actual++;
/*
* Byte program clears the write enable latch. If more
* data needs to be written using the AAI sequence,
* re-enable writes.
*/
if (needs_write_enable) {
ret = spi_nor_write_enable(nor);
if (ret)
goto out;
}
}
/* Write out most of the data here. */
for (; actual < len - 1; actual += 2) {
/* write two bytes. */
ret = sst_nor_write_data(nor, to, 2, buf + actual);
if (ret < 0)
goto out;
to += 2;
nor->sst_write_second = true;
}
nor->sst_write_second = false;
ret = spi_nor_write_disable(nor);
if (ret)
goto out;
ret = spi_nor_wait_till_ready(nor);
if (ret)
goto out;
/* Write out trailing byte if it exists. */
if (actual != len) {
ret = spi_nor_write_enable(nor);
if (ret)
goto out;
ret = sst_nor_write_data(nor, to, 1, buf + actual);
if (ret < 0)
goto out;
actual += 1;
ret = spi_nor_write_disable(nor);
}
out:
*retlen += actual;
spi_nor_unlock_and_unprep(nor);
return ret;
}
static int sst_nor_late_init(struct spi_nor *nor)
{
if (nor->info->mfr_flags & SST_WRITE)
nor->mtd._write = sst_nor_write;
return 0;
}
static const struct spi_nor_fixups sst_nor_fixups = {
.late_init = sst_nor_late_init,
};
const struct spi_nor_manufacturer spi_nor_sst = {
.name = "sst",
.parts = sst_nor_parts,
.nparts = ARRAY_SIZE(sst_nor_parts),
.fixups = &sst_nor_fixups,
};