[PATCH v5 1/5] staging: iio: adc: ad7816: Allow channel 7 for all devices

Gabriel Shahrouzi
2025-04-20T01:49:13Z

According to the datasheet on page 9 under the channel selection table,
all devices (AD7816/7/8) are able to use the channel marked as 7. This
channel is used for diagnostic purposes by routing the internal 1.23V
bandgap source through the MUX to the input of the ADC.

Modify the channel validation logic to permit channel 7 for all
supported device types.

Fixes: 7924425db04a ("staging: iio: adc: new driver for AD7816 devices")
Cc: stable@vger.kernel.org
Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com>
---
drivers/staging/iio/adc/ad7816.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/iio/adc/ad7816.c b/drivers/staging/iio/adc/ad7816.c
index 6c14d7bcdd675..a44b0c8c82b12 100644
--- a/drivers/staging/iio/adc/ad7816.c
+++ b/drivers/staging/iio/adc/ad7816.c
@@ -190,11 +190,11 @@ static ssize_t ad7816_store_channel(struct device *dev,
dev_err(&chip->spi_dev->dev, "Invalid channel id %lu for %s.\n",
data, indio_dev->name);
return -EINVAL;
- } else if (strcmp(indio_dev->name, "ad7818") == 0 && data > 1) {
+ } else if (strcmp(indio_dev->name, "ad7818") == 0 && data > 1 && data != AD7816_CS_MASK) {
dev_err(&chip->spi_dev->dev,
"Invalid channel id %lu for ad7818.\n", data);
return -EINVAL;
- } else if (strcmp(indio_dev->name, "ad7816") == 0 && data > 0) {
+ } else if (strcmp(indio_dev->name, "ad7816") == 0 && data > 0 && data != AD7816_CS_MASK) {
dev_err(&chip->spi_dev->dev,
"Invalid channel id %lu for ad7816.\n", data);
return -EINVAL;
--
2.43.0