Add NVMEM support for the internal EEPROM.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
---

 drivers/misc/ds1682.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/misc/ds1682.c b/drivers/misc/ds1682.c
index 21fc5bc85c5c..5f8dcd0e3848 100644
--- a/drivers/misc/ds1682.c
+++ b/drivers/misc/ds1682.c
@@ -32,6 +32,7 @@
 #include <linux/i2c.h>
 #include <linux/string.h>
 #include <linux/list.h>
+#include <linux/nvmem-provider.h>
 #include <linux/sysfs.h>
 #include <linux/ctype.h>
 #include <linux/hwmon-sysfs.h>
@@ -197,11 +198,43 @@ static const struct bin_attribute ds1682_eeprom_attr = {
 	.write = ds1682_eeprom_write,
 };
 
+static int ds1682_nvmem_read(void *priv, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	struct i2c_client *client = priv;
+	int ret;
+
+	ret = i2c_smbus_read_i2c_block_data(client, DS1682_REG_EEPROM + offset,
+					    bytes, val);
+	return ret < 0 ? ret : 0;
+}
+
+static int ds1682_nvmem_write(void *priv, unsigned int offset, void *val,
+			      size_t bytes)
+{
+	struct i2c_client *client = priv;
+	int ret;
+
+	ret = i2c_smbus_write_i2c_block_data(client, DS1682_REG_EEPROM + offset,
+					     bytes, val);
+	return ret < 0 ? ret : 0;
+}
+
 /*
  * Called when a ds1682 device is matched with this driver
  */
 static int ds1682_probe(struct i2c_client *client)
 {
+	struct nvmem_config config = {
+		.dev = &client->dev,
+		.owner = THIS_MODULE,
+		.type = NVMEM_TYPE_EEPROM,
+		.reg_read = ds1682_nvmem_read,
+		.reg_write = ds1682_nvmem_write,
+		.size = DS1682_EEPROM_SIZE,
+		.priv = client,
+	};
+	struct nvmem_device *nvmem;
 	int rc;
 
 	if (!i2c_check_functionality(client->adapter,
@@ -211,6 +244,10 @@ static int ds1682_probe(struct i2c_client *client)
 		goto exit;
 	}
 
+	nvmem = devm_nvmem_register(&client->dev, &config);
+	if (IS_ENABLED(CONFIG_NVMEM) && IS_ERR(nvmem))
+		return PTR_ERR(nvmem);
+
 	rc = sysfs_create_group(&client->dev.kobj, &ds1682_group);
 	if (rc)
 		goto exit;
-- 
2.35.1.1320.gc452695387.dirty