iio:imu:adis16480: fix buffering for devices with no burst mode

The trigger handler defined in the driver assumes that burst mode is
being used. Hence, for devices that do not support it, we have to use
the adis library default trigger implementation.
Tested-by: Julia Pineda <julia.pineda@analog.com>
Fixes: 941f1308 ("iio: adis16480: support burst read function")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220114132608.241-1-nuno.sa@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/adis16480.c

@@ -1403,6 +1403,7 @@ static int adis16480_probe(struct spi_device *spi)
 {
 	const struct spi_device_id *id = spi_get_device_id(spi);
 	const struct adis_data *adis16480_data;
+	irq_handler_t trigger_handler = NULL;
 	struct iio_dev *indio_dev;
 	struct adis16480 *st;
 	int ret;
@@ -1474,8 +1475,12 @@ static int adis16480_probe(struct spi_device *spi)
 		st->clk_freq = st->chip_info->int_clk;
 	}
 
+	/* Only use our trigger handler if burst mode is supported */
+	if (adis16480_data->burst_len)
+		trigger_handler = adis16480_trigger_handler;
+
 	ret = devm_adis_setup_buffer_and_trigger(&st->adis, indio_dev,
-						 adis16480_trigger_handler);
+						 trigger_handler);
 	if (ret)
 		return ret;