misc: ds1682: Add NVMEM support

Add NVMEM support for the internal EEPROM.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Link: https://lore.kernel.org/r/20240315213540.1682964-1-sean.anderson@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/ds1682.c b/drivers/misc/ds1682.c
index 21fc5bc85c5c8cc198c86135484ab802fc94eb68..5f8dcd0e384865ef97bf4b58764141ca158f52b8 100644 (file)
--- 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;