mfd: da9063: Occupy second I2C address

The second address can be used as a shortcut to access register pages
2+3. The driver does not use this feature yet. The second address should
still be marked as used, otherwise userspace could interfere with the
driver.

Signed-off-by: Wolfram Sang <[email protected]>
Reviewed-by: Peter Rosin <[email protected]>
Reviewed-by: Bartosz Golaszewski <[email protected]>
Reviewed-by: Kieran Bingham <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Lee Jones <[email protected]>

drivers/mfd/da9063-i2c.c

@@ -469,6 +469,9 @@ static int da9063_i2c_probe(struct i2c_client *i2c)
 		}
 	}
 
+	/* Reserve our unused second address so userspace won't interfere */
+	devm_i2c_new_dummy_device(&i2c->dev, i2c->adapter, i2c->addr + 1);
+
 	return da9063_device_init(da9063, i2c->irq);
 }