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/*
* MTD SPI driver for ST M25Pxx (and similar) serial flash chips
*
* Author: Mike Lavender, mike@steroidmicros.com
*
* Copyright (c) 2005, Intec Automation Inc.
*
* Some parts are based on lart.c by Abraham Van Der Merwe
*
* Cleaned up and generalized based on mtd_dataflash.c
*
* This code is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/spi/spi.h>
#include <linux/spi/flash.h>
#include <linux/mtd/spi-nor.h>
#define MAX_CMD_SIZE 6
struct m25p {
struct spi_device *spi;
struct spi_nor spi_nor;
u8 command[MAX_CMD_SIZE];
};
static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
{
struct m25p *flash = nor->priv;
struct spi_device *spi = flash->spi;
int ret;
ret = spi_write_then_read(spi, &code, 1, val, len);
if (ret < 0)
dev_err(&spi->dev, "error %d reading %x\n", ret, code);
return ret;
}
static void m25p_addr2cmd(struct spi_nor *nor, unsigned int addr, u8 *cmd)
{
/* opcode is in cmd[0] */
cmd[1] = addr >> (nor->addr_width * 8 - 8);
cmd[2] = addr >> (nor->addr_width * 8 - 16);
cmd[3] = addr >> (nor->addr_width * 8 - 24);
cmd[4] = addr >> (nor->addr_width * 8 - 32);
}
static int m25p_cmdsz(struct spi_nor *nor)
{
return 1 + nor->addr_width;
}
static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
{
struct m25p *flash = nor->priv;
struct spi_device *spi = flash->spi;
flash->command[0] = opcode;
if (buf)
memcpy(&flash->command[1], buf, len);
return spi_write(spi, flash->command, len + 1);
}
static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
const u_char *buf)
{
struct m25p *flash = nor->priv;
struct spi_device *spi = flash->spi;
struct spi_transfer t[2] = {};
struct spi_message m;
int cmd_sz = m25p_cmdsz(nor);
ssize_t ret;
spi_message_init(&m);
if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
cmd_sz = 1;
flash->command[0] = nor->program_opcode;
m25p_addr2cmd(nor, to, flash->command);
t[0].tx_buf = flash->command;
t[0].len = cmd_sz;
spi_message_add_tail(&t[0], &m);
t[1].tx_buf = buf;
t[1].len = len;
spi_message_add_tail(&t[1], &m);
ret = spi_sync(spi, &m);
if (ret)
return ret;
ret = m.actual_length - cmd_sz;
if (ret < 0)
return -EIO;
return ret;
}
static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor)
{
switch (nor->flash_read) {
case SPI_NOR_DUAL:
return 2;
case SPI_NOR_QUAD:
return 4;
default:
return 0;
}
}
/*
* Read an address range from the nor chip. The address range
* may be any size provided it is within the physical boundaries.
*/
static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
u_char *buf)
{
struct m25p *flash = nor->priv;
struct spi_device *spi = flash->spi;
struct spi_transfer t[2];
struct spi_message m;
unsigned int dummy = nor->read_dummy;
ssize_t ret;
/* convert the dummy cycles to the number of bytes */
dummy /= 8;
if (spi_flash_read_supported(spi)) {
struct spi_flash_read_message msg;
memset(&msg, 0, sizeof(msg));
msg.buf = buf;
msg.from = from;
msg.len = len;
msg.read_opcode = nor->read_opcode;
msg.addr_width = nor->addr_width;
msg.dummy_bytes = dummy;
/* TODO: Support other combinations */
msg.opcode_nbits = SPI_NBITS_SINGLE;
msg.addr_nbits = SPI_NBITS_SINGLE;
msg.data_nbits = m25p80_rx_nbits(nor);
ret = spi_flash_read(spi, &msg);
if (ret < 0)
return ret;
return msg.retlen;
}
spi_message_init(&m);
memset(t, 0, (sizeof t));
flash->command[0] = nor->read_opcode;
m25p_addr2cmd(nor, from, flash->command);
t[0].tx_buf = flash->command;
t[0].len = m25p_cmdsz(nor) + dummy;
spi_message_add_tail(&t[0], &m);
t[1].rx_buf = buf;
t[1].rx_nbits = m25p80_rx_nbits(nor);
t[1].len = min3(len, spi_max_transfer_size(spi),
spi_max_message_size(spi) - t[0].len);
spi_message_add_tail(&t[1], &m);
ret = spi_sync(spi, &m);
if (ret)
return ret;
ret = m.actual_length - m25p_cmdsz(nor) - dummy;
if (ret < 0)
return -EIO;
return ret;
}
/*
* board specific setup should have ensured the SPI clock used here
* matches what the READ command supports, at least until this driver
* understands FAST_READ (for clocks over 25 MHz).
*/
static int m25p_probe(struct spi_device *spi)
{
struct flash_platform_data *data;
struct m25p *flash;
struct spi_nor *nor;
enum read_mode mode = SPI_NOR_NORMAL;
char *flash_name;
int ret;
data = dev_get_platdata(&spi->dev);
flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
if (!flash)
return -ENOMEM;
nor = &flash->spi_nor;
/* install the hooks */
nor->read = m25p80_read;
nor->write = m25p80_write;
nor->write_reg = m25p80_write_reg;
nor->read_reg = m25p80_read_reg;
nor->dev = &spi->dev;
spi_nor_set_flash_node(nor, spi->dev.of_node);
nor->priv = flash;
spi_set_drvdata(spi, flash);
flash->spi = spi;
if (spi->mode & SPI_RX_QUAD)
mode = SPI_NOR_QUAD;
else if (spi->mode & SPI_RX_DUAL)
mode = SPI_NOR_DUAL;
if (data && data->name)
nor->mtd.name = data->name;
/* For some (historical?) reason many platforms provide two different
* names in flash_platform_data: "name" and "type". Quite often name is
* set to "m25p80" and then "type" provides a real chip name.
* If that's the case, respect "type" and ignore a "name".
*/
if (data && data->type)
flash_name = data->type;
else if (!strcmp(spi->modalias, "spi-nor"))
flash_name = NULL; /* auto-detect */
else
flash_name = spi->modalias;
ret = spi_nor_scan(nor, flash_name, mode);
if (ret)
return ret;
return mtd_device_register(&nor->mtd, data ? data->parts : NULL,
data ? data->nr_parts : 0);
}
static int m25p_remove(struct spi_device *spi)
{
struct m25p *flash = spi_get_drvdata(spi);
/* Clean up MTD stuff. */
return mtd_device_unregister(&flash->spi_nor.mtd);
}
/*
* Do NOT add to this array without reading the following:
*
* Historically, many flash devices are bound to this driver by their name. But
* since most of these flash are compatible to some extent, and their
* differences can often be differentiated by the JEDEC read-ID command, we
* encourage new users to add support to the spi-nor library, and simply bind
* against a generic string here (e.g., "jedec,spi-nor").
*
* Many flash names are kept here in this list (as well as in spi-nor.c) to
* keep them available as module aliases for existing platforms.
*/
static const struct spi_device_id m25p_ids[] = {
/*
* Allow non-DT platform devices to bind to the "spi-nor" modalias, and
* hack around the fact that the SPI core does not provide uevent
* matching for .of_match_table
*/
{"spi-nor"},
/*
* Entries not used in DTs that should be safe to drop after replacing
* them with "spi-nor" in platform data.
*/
{"s25sl064a"}, {"w25x16"}, {"m25p10"}, {"m25px64"},
/*
* Entries that were used in DTs without "jedec,spi-nor" fallback and
* should be kept for backward compatibility.
*/
{"at25df321a"}, {"at25df641"}, {"at26df081a"},
{"mx25l4005a"}, {"mx25l1606e"}, {"mx25l6405d"}, {"mx25l12805d"},
{"mx25l25635e"},{"mx66l51235l"},
{"n25q064"}, {"n25q128a11"}, {"n25q128a13"}, {"n25q512a"},
{"s25fl256s1"}, {"s25fl512s"}, {"s25sl12801"}, {"s25fl008k"},
{"s25fl064k"},
{"sst25vf040b"},{"sst25vf016b"},{"sst25vf032b"},{"sst25wf040"},
{"m25p40"}, {"m25p80"}, {"m25p16"}, {"m25p32"},
{"m25p64"}, {"m25p128"},
{"w25x80"}, {"w25x32"}, {"w25q32"}, {"w25q32dw"},
{"w25q80bl"}, {"w25q128"}, {"w25q256"},
/* Flashes that can't be detected using JEDEC */
{"m25p05-nonjedec"}, {"m25p10-nonjedec"}, {"m25p20-nonjedec"},
{"m25p40-nonjedec"}, {"m25p80-nonjedec"}, {"m25p16-nonjedec"},
{"m25p32-nonjedec"}, {"m25p64-nonjedec"}, {"m25p128-nonjedec"},
/* Everspin MRAMs (non-JEDEC) */
{ "mr25h256" }, /* 256 Kib, 40 MHz */
{ "mr25h10" }, /* 1 Mib, 40 MHz */
{ "mr25h40" }, /* 4 Mib, 40 MHz */
{ },
};
MODULE_DEVICE_TABLE(spi, m25p_ids);
static const struct of_device_id m25p_of_table[] = {
/*
* Generic compatibility for SPI NOR that can be identified by the
* JEDEC READ ID opcode (0x9F). Use this, if possible.
*/
{ .compatible = "jedec,spi-nor" },
{}
};
MODULE_DEVICE_TABLE(of, m25p_of_table);
static struct spi_driver m25p80_driver = {
.driver = {
.name = "m25p80",
.of_match_table = m25p_of_table,
},
.id_table = m25p_ids,
.probe = m25p_probe,
.remove = m25p_remove,
/* REVISIT: many of these chips have deep power-down modes, which
* should clearly be entered on suspend() to minimize power use.
* And also when they're otherwise idle...
*/
};
module_spi_driver(m25p80_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mike Lavender");
MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips");