On 7/23/23 13:41, Jonathan Cameron wrote:
>>>> +
>>>> + if (mode == MCP4728_VREF_EXTERNAL_VDD &&
>>>> + data->channel_data[chan->channel].g_mode == MCP4728_GAIN_X2) {
>>>> + dev_warn(&data->client->dev,
>>>> + "CH%d: Gain x2 not effective when vref is vdd, force to x1",
>>>> + chan->channel);
>>> Even better if you don't present the option at all and wrap it up in the
>>> standard ABI of _scale
>>>
>> I think that the solution could be:
>>
>> - Removing custom ABI (vref/gain)
>>
>> - Initialize them at device tree level using two 4-elements arrays.
> If doing with device tree, they should reflect something that is a characteristic
> of how the chips is wired up. So you would need to explain why that is the case here.
>
> However, I'm still not understanding why _SCALE is not appropriate here. We have
> a small set of options with well defined scales.
SCALE is appropriate. I didn't know that scale_available was a standard ABI.
I will follow the implementation done n https://github.com/torvalds/linux/blob/c2782531397f5cb19ca3f8f9c17727f1cdf5bee8/drivers/iio/dac/ad5592r-base.c#L487
