On 4/14/24 8:58 AM, Alisa-Dariana Roman wrote:
> On 13.04.2024 22:10, David Lechner wrote:
>> On Sat, Apr 13, 2024 at 10:12 AM Alisa-Dariana Roman
>> <alisadariana@xxxxxxxxx> wrote:
>>>
>>> AINCOM should actually be a supply. If present and it has a non-zero
>>> voltage, the pseudo-differential channels are configured as single-ended
>>> with an offset. Otherwise, they are configured as differential channels
>>> between AINx and AINCOM pins.
>>>
>>> Signed-off-by: Alisa-Dariana Roman <alisa.roman@xxxxxxxxxx>
>>> ---
>>> drivers/iio/adc/ad7192.c | 53 +++++++++++++++++++++++++++++++++++++---
>>> 1 file changed, 49 insertions(+), 4 deletions(-)
>
> ...
>
>>> @@ -745,6 +746,9 @@ static int ad7192_read_raw(struct iio_dev *indio_dev,
>>> /* Kelvin to Celsius */
>>
>> Not related to this patch, but I'm not a fan of the way the
>> temperature case writes over *val (maybe clean that up using a switch
>> statement instead in another patch while we are working on this?).
>> Adding the else if to this makes it even harder to follow.
>>
>>> if (chan->type == IIO_TEMP)
>>> *val -= 273 * ad7192_get_temp_scale(unipolar);
>>> + else if (st->aincom_mv && chan->channel2 == -1)
>>
>> I think the logic should be !chan->differential instead of
>> chan->channel2 = -1 (more explanation on this below).
>>
>>> + *val += DIV_ROUND_CLOSEST_ULL((u64)st->aincom_mv * 1000000000,
>>> + st->scale_avail[gain][1]);
>>> return IIO_VAL_INT;
>
> Hi David,
>
> I am very grateful for your suggestions!
>
> case IIO_CHAN_INFO_OFFSET:
> if (!unipolar)
> *val = -(1 << (chan->scan_type.realbits - 1));
> else
> *val = 0;
> switch(chan->type) {
> case IIO_VOLTAGE:
> if (st->aincom_mv && !chan->differential)
> *val += DIV_ROUND_CLOSEST_ULL((u64)st->aincom_mv * 1000000000,
> st->scale_avail[gain][1]);
> return IIO_VAL_INT;
> /* Kelvin to Celsius */
> case IIO_TEMP:
> *val -= 273 * ad7192_get_temp_scale(unipolar);
> return IIO_VAL_INT;
> default:
> return -EINVAL;
> }
>
> I added a switch because it looks neater indeed. But I would keep the if else for the unipolar in order not to have duplicate code. Is this alright?
>
I didn't notice before that the temperature channel could also be
unipolor or bipolar, so yes this seems fine.
