[PATCH 2/3] iio: adc: ad7768-1: prevent one-shot mode with wideband filter

From: Jonathan Santos

Date: Wed Feb 04 2026 - 07:33:53 EST


The AD7768-1 datasheet specifies that the wideband low ripple FIR filter
is only available in continuous conversion mode and should not be used
with one-shot mode to avoid malfunction and incorrect data.

Add filter type checks in ad7768_scan_direct() to skip one-shot mode
switching when wideband filter is configured.

Signed-off-by: Jonathan Santos <Jonathan.Santos@xxxxxxxxxx>
---
drivers/iio/adc/ad7768-1.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
index 8d39b71703ae..374614ea97ac 100644
--- a/drivers/iio/adc/ad7768-1.c
+++ b/drivers/iio/adc/ad7768-1.c
@@ -463,14 +463,17 @@ static int ad7768_scan_direct(struct iio_dev *indio_dev)
struct ad7768_state *st = iio_priv(indio_dev);
int readval, ret;

- ret = ad7768_set_mode(st, AD7768_ONE_SHOT);
- if (ret < 0)
- return ret;
+ /* Wideband filter is not available in One-Shot conversion mode */
+ if (st->filter_type != AD7768_FILTER_WIDEBAND) {
+ ret = ad7768_set_mode(st, AD7768_ONE_SHOT);
+ if (ret < 0)
+ return ret;

- /* One-shot mode requires a SYNC pulse to generate a new sample */
- ret = ad7768_send_sync_pulse(st);
- if (ret)
- return ret;
+ /* One-shot mode requires a SYNC pulse to generate a new sample */
+ ret = ad7768_send_sync_pulse(st);
+ if (ret)
+ return ret;
+ }

reinit_completion(&st->completion);

@@ -496,9 +499,11 @@ static int ad7768_scan_direct(struct iio_dev *indio_dev)
* Any SPI configuration of the AD7768-1 can only be
* performed in continuous conversion mode.
*/
- ret = ad7768_set_mode(st, AD7768_CONTINUOUS);
- if (ret < 0)
- return ret;
+ if (st->filter_type != AD7768_FILTER_WIDEBAND) {
+ ret = ad7768_set_mode(st, AD7768_CONTINUOUS);
+ if (ret < 0)
+ return ret;
+ }

return readval;
}
--
2.34.1