From: Paul Cercueil paul@crapouillou.net
commit e55245d115bb9054cb72cdd5dda5660f4484873a upstream.
The AD7192 provides a specific channel configuration where both negative and positive inputs are connected to AIN2. This was represented in the ad7192 driver as a IIO channel with .channel = 2 and .extended_name set to "shorted".
The problem with this approach, is that the driver provided two IIO channels with the identifier .channel = 2; one "shorted" and the other not. This goes against the IIO ABI, as a channel identifier should be unique.
Address this issue by changing "shorted" channels to being differential instead, with channel 2 vs. itself, as we're actually measuring AIN2 vs. itself.
Note that the fix tag is for the commit that moved the driver out of staging. The bug existed before that, but backporting would become very complex further down and unlikely to happen.
Fixes: b581f748cce0 ("staging: iio: adc: ad7192: move out of staging") Signed-off-by: Paul Cercueil paul@crapouillou.net Co-developed-by: Alisa Roman alisa.roman@analog.com Signed-off-by: Alisa Roman alisa.roman@analog.com Reviewed-by: Nuno Sa nuno.sa@analog.com Link: https://lore.kernel.org/r/20230330102100.17590-1-paul@crapouillou.net Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/adc/ad7192.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
--- a/drivers/iio/adc/ad7192.c +++ b/drivers/iio/adc/ad7192.c @@ -898,10 +898,6 @@ static const struct iio_info ad7195_info __AD719x_CHANNEL(_si, _channel1, -1, _address, NULL, IIO_VOLTAGE, \ BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info)
-#define AD719x_SHORTED_CHANNEL(_si, _channel1, _address) \ - __AD719x_CHANNEL(_si, _channel1, -1, _address, "shorted", IIO_VOLTAGE, \ - BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info) - #define AD719x_TEMP_CHANNEL(_si, _address) \ __AD719x_CHANNEL(_si, 0, -1, _address, NULL, IIO_TEMP, 0, NULL)
@@ -909,7 +905,7 @@ static const struct iio_chan_spec ad7192 AD719x_DIFF_CHANNEL(0, 1, 2, AD7192_CH_AIN1P_AIN2M), AD719x_DIFF_CHANNEL(1, 3, 4, AD7192_CH_AIN3P_AIN4M), AD719x_TEMP_CHANNEL(2, AD7192_CH_TEMP), - AD719x_SHORTED_CHANNEL(3, 2, AD7192_CH_AIN2P_AIN2M), + AD719x_DIFF_CHANNEL(3, 2, 2, AD7192_CH_AIN2P_AIN2M), AD719x_CHANNEL(4, 1, AD7192_CH_AIN1), AD719x_CHANNEL(5, 2, AD7192_CH_AIN2), AD719x_CHANNEL(6, 3, AD7192_CH_AIN3), @@ -923,7 +919,7 @@ static const struct iio_chan_spec ad7193 AD719x_DIFF_CHANNEL(2, 5, 6, AD7193_CH_AIN5P_AIN6M), AD719x_DIFF_CHANNEL(3, 7, 8, AD7193_CH_AIN7P_AIN8M), AD719x_TEMP_CHANNEL(4, AD7193_CH_TEMP), - AD719x_SHORTED_CHANNEL(5, 2, AD7193_CH_AIN2P_AIN2M), + AD719x_DIFF_CHANNEL(5, 2, 2, AD7193_CH_AIN2P_AIN2M), AD719x_CHANNEL(6, 1, AD7193_CH_AIN1), AD719x_CHANNEL(7, 2, AD7193_CH_AIN2), AD719x_CHANNEL(8, 3, AD7193_CH_AIN3),