Re: [PATCH 3/5] iio: adc: ad7606: add offset and phase calibration support

[David Lechner <dlechner@baylibre.com>]

On 4/30/25 11:14 AM, David Lechner wrote:
> On 4/30/25 10:36 AM, Nuno Sá wrote:
>> On Tue, 2025-04-29 at 15:06 +0200, Angelo Dureghello wrote:
>>> From: Angelo Dureghello <adureghello@baylibre.com>
>>>
>>>

...

>>> +
>>> +	val += start_val;
>>
>> Shouldn't this be val -= start_val?
>>
>> I also don't think we have any strict rules in the ABI for units for these kind
>> of interfaces so using "raw" values is easier. But FWIW, I think we could have
>> this in mv (would naturally depend on scale) 
>>
>> - Nuno Sá
>>
> 
> From testing, it seems to be working as expected for me, so I think this is
> correct. The register value is not signed. 0x80 is no offset.
> 

Heh, you are actually quite right. Even though it working correctly, it is
because the value that gets written to the register is val & 0xFF, so adding
or subtracting here basically has the same effect. But subtracting is the more
logical way to do it. (I tested it that way too just to be 100% sure.)