Contributors: 30
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| David Brownell |
1131 |
44.02% |
2 |
4.17% |
| Jiri Prchal |
349 |
13.59% |
3 |
6.25% |
| Andy Shevchenko |
325 |
12.65% |
11 |
22.92% |
| David Daney |
146 |
5.68% |
1 |
2.08% |
| Srinivas Kandagatla |
105 |
4.09% |
3 |
6.25% |
| Andrew Lunn |
96 |
3.74% |
1 |
2.08% |
| Alexandre Pereira da Silva |
68 |
2.65% |
1 |
2.08% |
| Ivo Sieben |
68 |
2.65% |
1 |
2.08% |
| Brad Bishop |
63 |
2.45% |
1 |
2.08% |
| Geert Uytterhoeven |
36 |
1.40% |
3 |
6.25% |
| Jan Lübbe |
33 |
1.28% |
1 |
2.08% |
| Kees Cook |
29 |
1.13% |
2 |
4.17% |
| Mark Brown |
29 |
1.13% |
1 |
2.08% |
| Mika Westerberg |
16 |
0.62% |
1 |
2.08% |
| Christophe Leroy |
15 |
0.58% |
1 |
2.08% |
| Gustavo A. R. Silva |
10 |
0.39% |
1 |
2.08% |
| Vadym Kochan |
8 |
0.31% |
1 |
2.08% |
| Doug Anderson |
8 |
0.31% |
1 |
2.08% |
| Bartosz Golaszewski |
6 |
0.23% |
1 |
2.08% |
| Alexandre Belloni |
5 |
0.19% |
1 |
2.08% |
| Anton Vorontsov |
5 |
0.19% |
1 |
2.08% |
| Devang Panchal |
4 |
0.16% |
1 |
2.08% |
| Nikolay Balandin |
4 |
0.16% |
1 |
2.08% |
| Sebastian Heutling |
3 |
0.12% |
1 |
2.08% |
| Wolfram Sang |
2 |
0.08% |
1 |
2.08% |
| Christian Eggers |
1 |
0.04% |
1 |
2.08% |
| Chris Wright |
1 |
0.04% |
1 |
2.08% |
| Rui Zhang |
1 |
0.04% |
1 |
2.08% |
| Thomas Gleixner |
1 |
0.04% |
1 |
2.08% |
| Axel Lin |
1 |
0.04% |
1 |
2.08% |
| Total |
2569 |
|
48 |
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for most of the SPI EEPROMs, such as Atmel AT25 models
* and Cypress FRAMs FM25 models.
*
* Copyright (C) 2006 David Brownell
*/
#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spi/eeprom.h>
#include <linux/spi/spi.h>
#include <linux/nvmem-provider.h>
/*
* NOTE: this is an *EEPROM* driver. The vagaries of product naming
* mean that some AT25 products are EEPROMs, and others are FLASH.
* Handle FLASH chips with the drivers/mtd/devices/m25p80.c driver,
* not this one!
*
* EEPROMs that can be used with this driver include, for example:
* AT25M02, AT25128B
*/
#define FM25_SN_LEN 8 /* serial number length */
#define EE_MAXADDRLEN 3 /* 24 bit addresses, up to 2 MBytes */
struct at25_data {
struct spi_eeprom chip;
struct spi_device *spi;
struct mutex lock;
unsigned addrlen;
struct nvmem_config nvmem_config;
struct nvmem_device *nvmem;
u8 sernum[FM25_SN_LEN];
u8 command[EE_MAXADDRLEN + 1];
};
#define AT25_WREN 0x06 /* latch the write enable */
#define AT25_WRDI 0x04 /* reset the write enable */
#define AT25_RDSR 0x05 /* read status register */
#define AT25_WRSR 0x01 /* write status register */
#define AT25_READ 0x03 /* read byte(s) */
#define AT25_WRITE 0x02 /* write byte(s)/sector */
#define FM25_SLEEP 0xb9 /* enter sleep mode */
#define FM25_RDID 0x9f /* read device ID */
#define FM25_RDSN 0xc3 /* read S/N */
#define AT25_SR_nRDY 0x01 /* nRDY = write-in-progress */
#define AT25_SR_WEN 0x02 /* write enable (latched) */
#define AT25_SR_BP0 0x04 /* BP for software writeprotect */
#define AT25_SR_BP1 0x08
#define AT25_SR_WPEN 0x80 /* writeprotect enable */
#define AT25_INSTR_BIT3 0x08 /* additional address bit in instr */
#define FM25_ID_LEN 9 /* ID length */
/*
* Specs often allow 5ms for a page write, sometimes 20ms;
* it's important to recover from write timeouts.
*/
#define EE_TIMEOUT 25
/*-------------------------------------------------------------------------*/
#define io_limit PAGE_SIZE /* bytes */
static int at25_ee_read(void *priv, unsigned int offset,
void *val, size_t count)
{
struct at25_data *at25 = priv;
char *buf = val;
size_t max_chunk = spi_max_transfer_size(at25->spi);
unsigned int msg_offset = offset;
size_t bytes_left = count;
size_t segment;
u8 *cp;
ssize_t status;
struct spi_transfer t[2];
struct spi_message m;
u8 instr;
if (unlikely(offset >= at25->chip.byte_len))
return -EINVAL;
if ((offset + count) > at25->chip.byte_len)
count = at25->chip.byte_len - offset;
if (unlikely(!count))
return -EINVAL;
do {
segment = min(bytes_left, max_chunk);
cp = at25->command;
instr = AT25_READ;
if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR)
if (msg_offset >= BIT(at25->addrlen * 8))
instr |= AT25_INSTR_BIT3;
mutex_lock(&at25->lock);
*cp++ = instr;
/* 8/16/24-bit address is written MSB first */
switch (at25->addrlen) {
default: /* case 3 */
*cp++ = msg_offset >> 16;
fallthrough;
case 2:
*cp++ = msg_offset >> 8;
fallthrough;
case 1:
case 0: /* can't happen: for better code generation */
*cp++ = msg_offset >> 0;
}
spi_message_init(&m);
memset(t, 0, sizeof(t));
t[0].tx_buf = at25->command;
t[0].len = at25->addrlen + 1;
spi_message_add_tail(&t[0], &m);
t[1].rx_buf = buf;
t[1].len = segment;
spi_message_add_tail(&t[1], &m);
status = spi_sync(at25->spi, &m);
mutex_unlock(&at25->lock);
if (status)
return status;
msg_offset += segment;
buf += segment;
bytes_left -= segment;
} while (bytes_left > 0);
dev_dbg(&at25->spi->dev, "read %zu bytes at %d\n",
count, offset);
return 0;
}
/* Read extra registers as ID or serial number */
static int fm25_aux_read(struct at25_data *at25, u8 *buf, uint8_t command,
int len)
{
int status;
struct spi_transfer t[2];
struct spi_message m;
spi_message_init(&m);
memset(t, 0, sizeof(t));
t[0].tx_buf = at25->command;
t[0].len = 1;
spi_message_add_tail(&t[0], &m);
t[1].rx_buf = buf;
t[1].len = len;
spi_message_add_tail(&t[1], &m);
mutex_lock(&at25->lock);
at25->command[0] = command;
status = spi_sync(at25->spi, &m);
dev_dbg(&at25->spi->dev, "read %d aux bytes --> %d\n", len, status);
mutex_unlock(&at25->lock);
return status;
}
static ssize_t sernum_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct at25_data *at25;
at25 = dev_get_drvdata(dev);
return sysfs_emit(buf, "%*ph\n", (int)sizeof(at25->sernum), at25->sernum);
}
static DEVICE_ATTR_RO(sernum);
static struct attribute *sernum_attrs[] = {
&dev_attr_sernum.attr,
NULL,
};
ATTRIBUTE_GROUPS(sernum);
static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
{
struct at25_data *at25 = priv;
size_t maxsz = spi_max_transfer_size(at25->spi);
const char *buf = val;
int status = 0;
unsigned buf_size;
u8 *bounce;
if (unlikely(off >= at25->chip.byte_len))
return -EFBIG;
if ((off + count) > at25->chip.byte_len)
count = at25->chip.byte_len - off;
if (unlikely(!count))
return -EINVAL;
/* Temp buffer starts with command and address */
buf_size = at25->chip.page_size;
if (buf_size > io_limit)
buf_size = io_limit;
bounce = kmalloc(buf_size + at25->addrlen + 1, GFP_KERNEL);
if (!bounce)
return -ENOMEM;
/*
* For write, rollover is within the page ... so we write at
* most one page, then manually roll over to the next page.
*/
mutex_lock(&at25->lock);
do {
unsigned long timeout, retries;
unsigned segment;
unsigned offset = off;
u8 *cp = bounce;
int sr;
u8 instr;
*cp = AT25_WREN;
status = spi_write(at25->spi, cp, 1);
if (status < 0) {
dev_dbg(&at25->spi->dev, "WREN --> %d\n", status);
break;
}
instr = AT25_WRITE;
if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR)
if (offset >= BIT(at25->addrlen * 8))
instr |= AT25_INSTR_BIT3;
*cp++ = instr;
/* 8/16/24-bit address is written MSB first */
switch (at25->addrlen) {
default: /* case 3 */
*cp++ = offset >> 16;
fallthrough;
case 2:
*cp++ = offset >> 8;
fallthrough;
case 1:
case 0: /* can't happen: for better code generation */
*cp++ = offset >> 0;
}
/* Write as much of a page as we can */
segment = buf_size - (offset % buf_size);
if (segment > count)
segment = count;
if (segment > maxsz)
segment = maxsz;
memcpy(cp, buf, segment);
status = spi_write(at25->spi, bounce,
segment + at25->addrlen + 1);
dev_dbg(&at25->spi->dev, "write %u bytes at %u --> %d\n",
segment, offset, status);
if (status < 0)
break;
/*
* REVISIT this should detect (or prevent) failed writes
* to read-only sections of the EEPROM...
*/
/* Wait for non-busy status */
timeout = jiffies + msecs_to_jiffies(EE_TIMEOUT);
retries = 0;
do {
sr = spi_w8r8(at25->spi, AT25_RDSR);
if (sr < 0 || (sr & AT25_SR_nRDY)) {
dev_dbg(&at25->spi->dev,
"rdsr --> %d (%02x)\n", sr, sr);
/* at HZ=100, this is sloooow */
msleep(1);
continue;
}
if (!(sr & AT25_SR_nRDY))
break;
} while (retries++ < 3 || time_before_eq(jiffies, timeout));
if ((sr < 0) || (sr & AT25_SR_nRDY)) {
dev_err(&at25->spi->dev,
"write %u bytes offset %u, timeout after %u msecs\n",
segment, offset,
jiffies_to_msecs(jiffies -
(timeout - EE_TIMEOUT)));
status = -ETIMEDOUT;
break;
}
off += segment;
buf += segment;
count -= segment;
} while (count > 0);
mutex_unlock(&at25->lock);
kfree(bounce);
return status;
}
/*-------------------------------------------------------------------------*/
static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip)
{
u32 val;
int err;
strscpy(chip->name, "at25", sizeof(chip->name));
err = device_property_read_u32(dev, "size", &val);
if (err)
err = device_property_read_u32(dev, "at25,byte-len", &val);
if (err) {
dev_err(dev, "Error: missing \"size\" property\n");
return err;
}
chip->byte_len = val;
err = device_property_read_u32(dev, "pagesize", &val);
if (err)
err = device_property_read_u32(dev, "at25,page-size", &val);
if (err) {
dev_err(dev, "Error: missing \"pagesize\" property\n");
return err;
}
chip->page_size = val;
err = device_property_read_u32(dev, "address-width", &val);
if (err) {
err = device_property_read_u32(dev, "at25,addr-mode", &val);
if (err) {
dev_err(dev, "Error: missing \"address-width\" property\n");
return err;
}
chip->flags = (u16)val;
} else {
switch (val) {
case 9:
chip->flags |= EE_INSTR_BIT3_IS_ADDR;
fallthrough;
case 8:
chip->flags |= EE_ADDR1;
break;
case 16:
chip->flags |= EE_ADDR2;
break;
case 24:
chip->flags |= EE_ADDR3;
break;
default:
dev_err(dev,
"Error: bad \"address-width\" property: %u\n",
val);
return -ENODEV;
}
if (device_property_present(dev, "read-only"))
chip->flags |= EE_READONLY;
}
return 0;
}
static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip)
{
struct at25_data *at25 = container_of(chip, struct at25_data, chip);
u8 sernum[FM25_SN_LEN];
u8 id[FM25_ID_LEN];
int i;
strscpy(chip->name, "fm25", sizeof(chip->name));
/* Get ID of chip */
fm25_aux_read(at25, id, FM25_RDID, FM25_ID_LEN);
if (id[6] != 0xc2) {
dev_err(dev, "Error: no Cypress FRAM (id %02x)\n", id[6]);
return -ENODEV;
}
/* Set size found in ID */
if (id[7] < 0x21 || id[7] > 0x26) {
dev_err(dev, "Error: unsupported size (id %02x)\n", id[7]);
return -ENODEV;
}
chip->byte_len = BIT(id[7] - 0x21 + 4) * 1024;
if (chip->byte_len > 64 * 1024)
chip->flags |= EE_ADDR3;
else
chip->flags |= EE_ADDR2;
if (id[8]) {
fm25_aux_read(at25, sernum, FM25_RDSN, FM25_SN_LEN);
/* Swap byte order */
for (i = 0; i < FM25_SN_LEN; i++)
at25->sernum[i] = sernum[FM25_SN_LEN - 1 - i];
}
chip->page_size = PAGE_SIZE;
return 0;
}
static const struct of_device_id at25_of_match[] = {
{ .compatible = "atmel,at25" },
{ .compatible = "cypress,fm25" },
{ }
};
MODULE_DEVICE_TABLE(of, at25_of_match);
static const struct spi_device_id at25_spi_ids[] = {
{ .name = "at25" },
{ .name = "fm25" },
{ }
};
MODULE_DEVICE_TABLE(spi, at25_spi_ids);
static int at25_probe(struct spi_device *spi)
{
struct at25_data *at25 = NULL;
int err;
int sr;
struct spi_eeprom *pdata;
bool is_fram;
/*
* Ping the chip ... the status register is pretty portable,
* unlike probing manufacturer IDs. We do expect that system
* firmware didn't write it in the past few milliseconds!
*/
sr = spi_w8r8(spi, AT25_RDSR);
if (sr < 0 || sr & AT25_SR_nRDY) {
dev_dbg(&spi->dev, "rdsr --> %d (%02x)\n", sr, sr);
return -ENXIO;
}
at25 = devm_kzalloc(&spi->dev, sizeof(*at25), GFP_KERNEL);
if (!at25)
return -ENOMEM;
mutex_init(&at25->lock);
at25->spi = spi;
spi_set_drvdata(spi, at25);
is_fram = fwnode_device_is_compatible(dev_fwnode(&spi->dev), "cypress,fm25");
/* Chip description */
pdata = dev_get_platdata(&spi->dev);
if (pdata) {
at25->chip = *pdata;
} else {
if (is_fram)
err = at25_fram_to_chip(&spi->dev, &at25->chip);
else
err = at25_fw_to_chip(&spi->dev, &at25->chip);
if (err)
return err;
}
/* For now we only support 8/16/24 bit addressing */
if (at25->chip.flags & EE_ADDR1)
at25->addrlen = 1;
else if (at25->chip.flags & EE_ADDR2)
at25->addrlen = 2;
else if (at25->chip.flags & EE_ADDR3)
at25->addrlen = 3;
else {
dev_dbg(&spi->dev, "unsupported address type\n");
return -EINVAL;
}
at25->nvmem_config.type = is_fram ? NVMEM_TYPE_FRAM : NVMEM_TYPE_EEPROM;
at25->nvmem_config.name = dev_name(&spi->dev);
at25->nvmem_config.dev = &spi->dev;
at25->nvmem_config.read_only = at25->chip.flags & EE_READONLY;
at25->nvmem_config.root_only = true;
at25->nvmem_config.owner = THIS_MODULE;
at25->nvmem_config.compat = true;
at25->nvmem_config.base_dev = &spi->dev;
at25->nvmem_config.reg_read = at25_ee_read;
at25->nvmem_config.reg_write = at25_ee_write;
at25->nvmem_config.priv = at25;
at25->nvmem_config.stride = 1;
at25->nvmem_config.word_size = 1;
at25->nvmem_config.size = at25->chip.byte_len;
at25->nvmem = devm_nvmem_register(&spi->dev, &at25->nvmem_config);
if (IS_ERR(at25->nvmem))
return PTR_ERR(at25->nvmem);
dev_info(&spi->dev, "%d %s %s %s%s, pagesize %u\n",
(at25->chip.byte_len < 1024) ?
at25->chip.byte_len : (at25->chip.byte_len / 1024),
(at25->chip.byte_len < 1024) ? "Byte" : "KByte",
at25->chip.name, is_fram ? "fram" : "eeprom",
(at25->chip.flags & EE_READONLY) ? " (readonly)" : "",
at25->chip.page_size);
return 0;
}
/*-------------------------------------------------------------------------*/
static struct spi_driver at25_driver = {
.driver = {
.name = "at25",
.of_match_table = at25_of_match,
.dev_groups = sernum_groups,
},
.probe = at25_probe,
.id_table = at25_spi_ids,
};
module_spi_driver(at25_driver);
MODULE_DESCRIPTION("Driver for most SPI EEPROMs");
MODULE_AUTHOR("David Brownell");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:at25");