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path: root/drivers/misc/eeprom/at25.c
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Diffstat (limited to 'drivers/misc/eeprom/at25.c')
-rw-r--r--drivers/misc/eeprom/at25.c160
1 files changed, 111 insertions, 49 deletions
diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index c627e4174cc..634f72929e1 100644
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -10,7 +10,6 @@
*/
#include <linux/kernel.h>
-#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/delay.h>
@@ -19,7 +18,7 @@
#include <linux/spi/spi.h>
#include <linux/spi/eeprom.h>
-
+#include <linux/of.h>
/*
* NOTE: this is an *EEPROM* driver. The vagaries of product naming
@@ -50,6 +49,7 @@ struct at25_data {
#define AT25_SR_BP1 0x08
#define AT25_SR_WPEN 0x80 /* writeprotect enable */
+#define AT25_INSTR_BIT3 0x08 /* Additional address bit in instr */
#define EE_MAXADDRLEN 3 /* 24 bit addresses, up to 2 MBytes */
@@ -75,6 +75,7 @@ at25_ee_read(
ssize_t status;
struct spi_transfer t[2];
struct spi_message m;
+ u8 instr;
if (unlikely(offset >= at25->bin.size))
return 0;
@@ -84,7 +85,12 @@ at25_ee_read(
return count;
cp = command;
- *cp++ = AT25_READ;
+
+ instr = AT25_READ;
+ if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR)
+ if (offset >= (1U << (at25->addrlen * 8)))
+ instr |= AT25_INSTR_BIT3;
+ *cp++ = instr;
/* 8/16/24-bit address is written MSB first */
switch (at25->addrlen) {
@@ -167,14 +173,14 @@ at25_ee_write(struct at25_data *at25, const char *buf, loff_t off,
/* For write, rollover is within the page ... so we write at
* most one page, then manually roll over to the next page.
*/
- bounce[0] = AT25_WRITE;
mutex_lock(&at25->lock);
do {
unsigned long timeout, retries;
unsigned segment;
unsigned offset = (unsigned) off;
- u8 *cp = bounce + 1;
+ u8 *cp = bounce;
int sr;
+ u8 instr;
*cp = AT25_WREN;
status = spi_write(at25->spi, cp, 1);
@@ -184,6 +190,12 @@ at25_ee_write(struct at25_data *at25, const char *buf, loff_t off,
break;
}
+ instr = AT25_WRITE;
+ if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR)
+ if (offset >= (1U << (at25->addrlen * 8)))
+ instr |= AT25_INSTR_BIT3;
+ *cp++ = instr;
+
/* 8/16/24-bit address is written MSB first */
switch (at25->addrlen) {
default: /* case 3 */
@@ -289,33 +301,93 @@ static ssize_t at25_mem_write(struct memory_accessor *mem, const char *buf,
/*-------------------------------------------------------------------------*/
+static int at25_np_to_chip(struct device *dev,
+ struct device_node *np,
+ struct spi_eeprom *chip)
+{
+ u32 val;
+
+ memset(chip, 0, sizeof(*chip));
+ strncpy(chip->name, np->name, sizeof(chip->name));
+
+ if (of_property_read_u32(np, "size", &val) == 0 ||
+ of_property_read_u32(np, "at25,byte-len", &val) == 0) {
+ chip->byte_len = val;
+ } else {
+ dev_err(dev, "Error: missing \"size\" property\n");
+ return -ENODEV;
+ }
+
+ if (of_property_read_u32(np, "pagesize", &val) == 0 ||
+ of_property_read_u32(np, "at25,page-size", &val) == 0) {
+ chip->page_size = (u16)val;
+ } else {
+ dev_err(dev, "Error: missing \"pagesize\" property\n");
+ return -ENODEV;
+ }
+
+ if (of_property_read_u32(np, "at25,addr-mode", &val) == 0) {
+ chip->flags = (u16)val;
+ } else {
+ if (of_property_read_u32(np, "address-width", &val)) {
+ dev_err(dev,
+ "Error: missing \"address-width\" property\n");
+ return -ENODEV;
+ }
+ switch (val) {
+ 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 (of_find_property(np, "read-only", NULL))
+ chip->flags |= EE_READONLY;
+ }
+ return 0;
+}
+
static int at25_probe(struct spi_device *spi)
{
struct at25_data *at25 = NULL;
- const struct spi_eeprom *chip;
+ struct spi_eeprom chip;
+ struct device_node *np = spi->dev.of_node;
int err;
int sr;
int addrlen;
/* Chip description */
- chip = spi->dev.platform_data;
- if (!chip) {
- dev_dbg(&spi->dev, "no chip description\n");
- err = -ENODEV;
- goto fail;
- }
+ if (!spi->dev.platform_data) {
+ if (np) {
+ err = at25_np_to_chip(&spi->dev, np, &chip);
+ if (err)
+ return err;
+ } else {
+ dev_err(&spi->dev, "Error: no chip description\n");
+ return -ENODEV;
+ }
+ } else
+ chip = *(struct spi_eeprom *)spi->dev.platform_data;
/* For now we only support 8/16/24 bit addressing */
- if (chip->flags & EE_ADDR1)
+ if (chip.flags & EE_ADDR1)
addrlen = 1;
- else if (chip->flags & EE_ADDR2)
+ else if (chip.flags & EE_ADDR2)
addrlen = 2;
- else if (chip->flags & EE_ADDR3)
+ else if (chip.flags & EE_ADDR3)
addrlen = 3;
else {
dev_dbg(&spi->dev, "unsupported address type\n");
- err = -EINVAL;
- goto fail;
+ return -EINVAL;
}
/* Ping the chip ... the status register is pretty portable,
@@ -325,19 +397,17 @@ static int at25_probe(struct spi_device *spi)
sr = spi_w8r8(spi, AT25_RDSR);
if (sr < 0 || sr & AT25_SR_nRDY) {
dev_dbg(&spi->dev, "rdsr --> %d (%02x)\n", sr, sr);
- err = -ENXIO;
- goto fail;
+ return -ENXIO;
}
- if (!(at25 = kzalloc(sizeof *at25, GFP_KERNEL))) {
- err = -ENOMEM;
- goto fail;
- }
+ at25 = devm_kzalloc(&spi->dev, sizeof(struct at25_data), GFP_KERNEL);
+ if (!at25)
+ return -ENOMEM;
mutex_init(&at25->lock);
- at25->chip = *chip;
+ at25->chip = chip;
at25->spi = spi_dev_get(spi);
- dev_set_drvdata(&spi->dev, at25);
+ spi_set_drvdata(spi, at25);
at25->addrlen = addrlen;
/* Export the EEPROM bytes through sysfs, since that's convenient.
@@ -356,7 +426,7 @@ static int at25_probe(struct spi_device *spi)
at25->mem.read = at25_mem_read;
at25->bin.size = at25->chip.byte_len;
- if (!(chip->flags & EE_READONLY)) {
+ if (!(chip.flags & EE_READONLY)) {
at25->bin.write = at25_bin_write;
at25->bin.attr.mode |= S_IWUSR;
at25->mem.write = at25_mem_write;
@@ -364,10 +434,10 @@ static int at25_probe(struct spi_device *spi)
err = sysfs_create_bin_file(&spi->dev.kobj, &at25->bin);
if (err)
- goto fail;
+ return err;
- if (chip->setup)
- chip->setup(&at25->mem, chip->context);
+ if (chip.setup)
+ chip.setup(&at25->mem, chip.context);
dev_info(&spi->dev, "%Zd %s %s eeprom%s, pagesize %u\n",
(at25->bin.size < 1024)
@@ -375,47 +445,39 @@ static int at25_probe(struct spi_device *spi)
: (at25->bin.size / 1024),
(at25->bin.size < 1024) ? "Byte" : "KByte",
at25->chip.name,
- (chip->flags & EE_READONLY) ? " (readonly)" : "",
+ (chip.flags & EE_READONLY) ? " (readonly)" : "",
at25->chip.page_size);
return 0;
-fail:
- dev_dbg(&spi->dev, "probe err %d\n", err);
- kfree(at25);
- return err;
}
-static int __devexit at25_remove(struct spi_device *spi)
+static int at25_remove(struct spi_device *spi)
{
struct at25_data *at25;
- at25 = dev_get_drvdata(&spi->dev);
+ at25 = spi_get_drvdata(spi);
sysfs_remove_bin_file(&spi->dev.kobj, &at25->bin);
- kfree(at25);
return 0;
}
/*-------------------------------------------------------------------------*/
+static const struct of_device_id at25_of_match[] = {
+ { .compatible = "atmel,at25", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, at25_of_match);
+
static struct spi_driver at25_driver = {
.driver = {
.name = "at25",
.owner = THIS_MODULE,
+ .of_match_table = at25_of_match,
},
.probe = at25_probe,
- .remove = __devexit_p(at25_remove),
+ .remove = at25_remove,
};
-static int __init at25_init(void)
-{
- return spi_register_driver(&at25_driver);
-}
-module_init(at25_init);
-
-static void __exit at25_exit(void)
-{
- spi_unregister_driver(&at25_driver);
-}
-module_exit(at25_exit);
+module_spi_driver(at25_driver);
MODULE_DESCRIPTION("Driver for most SPI EEPROMs");
MODULE_AUTHOR("David Brownell");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 08:11:09 +0000