iio: dac: ad5593r: add check for i2c functionality

Make sure that the needed i2c functionality is supported during probe.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Link: https://lore.kernel.org/r/20220913073413.140475-3-nuno.sa@analog.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/dac/ad5593r.c

@@ -102,6 +102,10 @@ static const struct ad5592r_rw_ops ad5593r_rw_ops = {
 static int ad5593r_i2c_probe(struct i2c_client *i2c,
 		const struct i2c_device_id *id)
 {
+	if (!i2c_check_functionality(i2c->adapter,
+				     I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
+		return -EOPNOTSUPP;
+
 	return ad5592r_probe(&i2c->dev, id->name, &ad5593r_rw_ops);
 }