Commit 79d0df36 authored by Armin Wolf's avatar Armin Wolf Committed by Greg Kroah-Hartman
Browse files

eeprom: ee1004: Add nvmem support 



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: default avatarArmin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240625063459.429953-2-W_Armin@gmx.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 55d57ef6

drivers/misc/eeprom/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -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

drivers/misc/eeprom/ee1004.c

+38 −20
Original line number Diff line number Diff line
@@ -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,