4316302292
When we added the "jedec,spi-nor" compatible string for use in this
driver, we added it as a modalias option. The modalias can be derived in
different ways for platform devices vs. device tree (of_*) matching. But
for device tree matching (the primary target of this identifier string),
the modalias is determined from the first entry in the 'compatible'
property. IOW, the following properties would bind to this driver:
// Option (a), modalias = "spi-nor"
compatible = "jedec,spi-nor";
// Option (b), modalias = "spi-nor"
compatible = "idontknowwhatimdoing,spi-nor";
But the following would not:
// Option (c), modalias = "shinynewdevice"
compatible = "myvendor,shinynewdevice", "jedec,spi-nor";
So, we'd like to match (a) and (c) (even when we don't have an explicit
entry for "shinynewdevice"), and we'd rather not allow (b).
To do this, we
(1) always (for devices without specific platform data) pass the
modalias to the spi-nor library;
(2) rework the spi-nor library to not reject "bad" names, and
instead just fall back to autodetection; and
(3) add the .of_match_table to properly catch all "jedec,spi-nor".
This allows (a) and (c) without warnings, and rejects (b).
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
325 lines
8.2 KiB
C
325 lines
8.2 KiB
C
/*
|
|
* 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;
|
|
struct mtd_info mtd;
|
|
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,
|
|
int wr_en)
|
|
{
|
|
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 void m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
|
|
size_t *retlen, 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);
|
|
|
|
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);
|
|
|
|
spi_sync(spi, &m);
|
|
|
|
*retlen += m.actual_length - cmd_sz;
|
|
}
|
|
|
|
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 int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
|
|
size_t *retlen, 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;
|
|
|
|
/* convert the dummy cycles to the number of bytes */
|
|
dummy /= 8;
|
|
|
|
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 = len;
|
|
spi_message_add_tail(&t[1], &m);
|
|
|
|
spi_sync(spi, &m);
|
|
|
|
*retlen = m.actual_length - m25p_cmdsz(nor) - dummy;
|
|
return 0;
|
|
}
|
|
|
|
static int m25p80_erase(struct spi_nor *nor, loff_t offset)
|
|
{
|
|
struct m25p *flash = nor->priv;
|
|
|
|
dev_dbg(nor->dev, "%dKiB at 0x%08x\n",
|
|
flash->mtd.erasesize / 1024, (u32)offset);
|
|
|
|
/* Set up command buffer. */
|
|
flash->command[0] = nor->erase_opcode;
|
|
m25p_addr2cmd(nor, offset, flash->command);
|
|
|
|
spi_write(flash->spi, flash->command, m25p_cmdsz(nor));
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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 mtd_part_parser_data ppdata;
|
|
struct flash_platform_data *data;
|
|
struct m25p *flash;
|
|
struct spi_nor *nor;
|
|
enum read_mode mode = SPI_NOR_NORMAL;
|
|
char *flash_name = NULL;
|
|
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->erase = m25p80_erase;
|
|
nor->write_reg = m25p80_write_reg;
|
|
nor->read_reg = m25p80_read_reg;
|
|
|
|
nor->dev = &spi->dev;
|
|
nor->mtd = &flash->mtd;
|
|
nor->priv = flash;
|
|
|
|
spi_set_drvdata(spi, flash);
|
|
flash->mtd.priv = nor;
|
|
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)
|
|
flash->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
|
|
flash_name = spi->modalias;
|
|
|
|
ret = spi_nor_scan(nor, flash_name, mode);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ppdata.of_node = spi->dev.of_node;
|
|
|
|
return mtd_device_parse_register(&flash->mtd, NULL, &ppdata,
|
|
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->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[] = {
|
|
/*
|
|
* Entries not used in DTs that should be safe to drop after replacing
|
|
* them with "nor-jedec" in platform data.
|
|
*/
|
|
{"s25sl064a"}, {"w25x16"}, {"m25p10"}, {"m25px64"},
|
|
|
|
/*
|
|
* Entries that were used in DTs without "nor-jedec" fallback and should
|
|
* be kept for backward compatibility.
|
|
*/
|
|
{"at25df321a"}, {"at25df641"}, {"at26df081a"},
|
|
{"mr25h256"},
|
|
{"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"},
|
|
|
|
{ },
|
|
};
|
|
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",
|
|
.owner = THIS_MODULE,
|
|
.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");
|