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Date: Wed, 3 Apr 2024 12:55:17 +0300
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Subject: Re: [PATCH 6/6] iio: adc: ad7173: Add support for AD411x devices
To: David Lechner <dlechner@baylibre.com>, dumitru.ceclan@analog.com
Cc: Lars-Peter Clausen <lars@metafoo.de>,
 Michael Hennerich <Michael.Hennerich@analog.com>,
 Jonathan Cameron <jic23@kernel.org>, Rob Herring <robh@kernel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
 Conor Dooley <conor+dt@kernel.org>, linux-iio@vger.kernel.org,
 devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20240401-ad4111-v1-0-34618a9cc502@analog.com>
 <20240401-ad4111-v1-6-34618a9cc502@analog.com>
 <CAMknhBFdtv84E_S4wa4UW0pO2yiUEk9=jn=_i4F=b8VHdR6v+w@mail.gmail.com>
 <CAMknhBHf_9kFfLySJmRyoUS6UFfTeLW3bfEi1-3ApEDHyyVhCw@mail.gmail.com>
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From: "Ceclan, Dumitru" <mitrutzceclan@gmail.com>
In-Reply-To: <CAMknhBHf_9kFfLySJmRyoUS6UFfTeLW3bfEi1-3ApEDHyyVhCw@mail.gmail.com>
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On 02/04/2024 17:00, David Lechner wrote:
> On Mon, Apr 1, 2024 at 2:45 PM David Lechner <dlechner@baylibre.com> wrote:
>>
>> On Mon, Apr 1, 2024 at 10:10 AM Dumitru Ceclan via B4 Relay
>> <devnull+dumitru.ceclan.analog.com@kernel.org> wrote:

..

>>>                 *chan = ad7173_channel_template;
>>>                 chan->address = chan_index;
>>>                 chan->scan_index = chan_index;
>>> -               chan->channel = ain[0];
>>> -               chan->channel2 = ain[1];
>>> -               chan->differential = true;
>>>
>>> -               chan_st_priv->ain = AD7173_CH_ADDRESS(ain[0], ain[1]);
>>> +               if (reg >= AD4111_CURRENT_CHAN_CUTOFF) {
>>> +                       chan->type = IIO_CURRENT;
>>> +                       chan->channel = ain[0];
>>> +                       chan_st_priv->ain = ad4111_current_channel_config[ain[0]];
>>> +               } else {
>>> +                       chan->channel = ain[0];
>>> +                       chan->channel2 = ain[1];
>>> +                       chan->differential = true;
>>
>> Expecting chan->differential = false when ADCIN15 is configured for
>> pseudo-differential inputs.
>>
>> Also, perhaps missed in previous reviews, I would expect
>> chan->differential = false when channels are used as single-ended.
>>
> 
> After sleeping on it, I came to the concision that these parts are
> probably too complex to try to worry about differential vs.
> pseudo-differential/single-ended (what the datasheet calls
> single-ended is really pseudo-differential).
> 
> So I take back my comments about expecting differential = false in those cases.

Alrighty then