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eeprom: ee1004: Add nvmem support

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Currently the driver does not register a nvmem provider, which means
that userspace programs cannot access the ee1004 EEPROM through the
standard nvmem sysfs API.
Fix this by replacing the custom sysfs attribute with a standard nvmem
interface, which also takes care of backwards compatibility.

Tested on a Dell Inspiron 3505.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240625063459.429953-2-W_Armin@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Armin Wolf 2024-06-25 08:34:59 +02:00 committed by Greg Kroah-Hartman
parent 55d57ef6fa
commit 79d0df36b5
2 changed files with 40 additions and 20 deletions
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2
drivers/misc/eeprom/Kconfig
View file

@ -109,6 +109,8 @@ config EEPROM_IDT_89HPESX
config EEPROM_EE1004
tristate "SPD EEPROMs on DDR4 memory modules"
depends on I2C && SYSFS
select NVMEM
select NVMEM_SYSFS
help
Enable this driver to get read support to SPD EEPROMs following
the JEDEC EE1004 standard. These are typically found on DDR4

58
drivers/misc/eeprom/ee1004.c
View file

@ -16,6 +16,7 @@
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/nvmem-provider.h>
/*
* DDR4 memory modules use special EEPROMs following the Jedec EE1004
@ -145,13 +146,17 @@ static ssize_t ee1004_eeprom_read(struct i2c_client *client, char *buf,
return i2c_smbus_read_i2c_block_data_or_emulated(client, offset, count, buf);
}
static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
static int ee1004_read(void *priv, unsigned int off, void *val, size_t count)
{
struct i2c_client *client = kobj_to_i2c_client(kobj);
size_t requested = count;
int ret = 0;
struct i2c_client *client = priv;
char *buf = val;
int ret;
if (unlikely(!count))
return count;
if (off + count > EE1004_EEPROM_SIZE)
return -EINVAL;
/*
* Read data from chip, protecting against concurrent access to
@ -161,28 +166,21 @@ static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
while (count) {
ret = ee1004_eeprom_read(client, buf, off, count);
if (ret < 0)
goto out;
if (ret < 0) {
mutex_unlock(&ee1004_bus_lock);
return ret;
}
buf += ret;
off += ret;
count -= ret;
}
out:
mutex_unlock(&ee1004_bus_lock);
return ret < 0 ? ret : requested;
return 0;
}
static BIN_ATTR_RO(eeprom, EE1004_EEPROM_SIZE);
static struct bin_attribute *ee1004_attrs[] = {
&bin_attr_eeprom,
NULL
};
BIN_ATTRIBUTE_GROUPS(ee1004);
static void ee1004_probe_temp_sensor(struct i2c_client *client)
{
struct i2c_board_info info = { .type = "jc42" };
@ -220,7 +218,24 @@ static void ee1004_cleanup_bus_data(void *data)
static int ee1004_probe(struct i2c_client *client)
{
struct nvmem_config config = {
.dev = &client->dev,
.name = dev_name(&client->dev),
.id = NVMEM_DEVID_NONE,
.owner = THIS_MODULE,
.type = NVMEM_TYPE_EEPROM,
.read_only = true,
.root_only = false,
.reg_read = ee1004_read,
.size = EE1004_EEPROM_SIZE,
.word_size = 1,
.stride = 1,
.priv = client,
.compat = true,
.base_dev = &client->dev,
};
struct ee1004_bus_data *bd;
struct nvmem_device *ndev;
int err, cnr = 0;
/* Make sure we can operate on this adapter */
@ -272,6 +287,10 @@ static int ee1004_probe(struct i2c_client *client)
mutex_unlock(&ee1004_bus_lock);
ndev = devm_nvmem_register(&client->dev, &config);
if (IS_ERR(ndev))
return PTR_ERR(ndev);
dev_info(&client->dev,
"%u byte EE1004-compliant SPD EEPROM, read-only\n",
EE1004_EEPROM_SIZE);
@ -284,7 +303,6 @@ static int ee1004_probe(struct i2c_client *client)
static struct i2c_driver ee1004_driver = {
.driver = {
.name = "ee1004",
.dev_groups = ee1004_groups,
},
.probe = ee1004_probe,
.id_table = ee1004_ids,