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Date: Sat, 6 Apr 2024 16:10:31 +0100
From: Jonathan Cameron <jic23@kernel.org>
To: David Lechner <dlechner@baylibre.com>
Cc: "Ceclan, Dumitru" <mitrutzceclan@gmail.com>, dumitru.ceclan@analog.com,
 Lars-Peter Clausen <lars@metafoo.de>, Michael Hennerich
 <Michael.Hennerich@analog.com>, 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
Subject: Re: [PATCH 6/6] iio: adc: ad7173: Add support for AD411x devices
Message-ID: <20240406161031.6192f4f4@jic23-huawei>
In-Reply-To: <CAMknhBFZKKim4JyXLpHY=EoyW4ZPp03aHte5xy0ZkDnW16sfeA@mail.gmail.com>
References: <20240401-ad4111-v1-0-34618a9cc502@analog.com>
	<20240401-ad4111-v1-6-34618a9cc502@analog.com>
	<CAMknhBFdtv84E_S4wa4UW0pO2yiUEk9=jn=_i4F=b8VHdR6v+w@mail.gmail.com>
	<c7c26d36-ab08-420c-b634-8eb6d9cee9b5@gmail.com>
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> >  
> > >> +               case IIO_CURRENT:
> > >> +                       *val = ad7173_get_ref_voltage_milli(st, ch->cfg.ref_sel);
> > >> +                       *val /= AD4111_SHUNT_RESISTOR_OHM;
> > >> +                       *val2 = chan->scan_type.realbits - !!(ch->cfg.bipolar);  
> > >
> > > Static analysis tools like to complain about using bool as int.
> > > Probably more clear to write it as (ch->cfg.bipolar ? 1 : 0) anyway.
> > >  
> > Maybe it does not apply here, but i followed this advice:
> >
> > Andy Shevchenko V1 of AD7173 (named initially ad717x)
> > "  
> > > +     return (bool)(value & mask);  
> >
> > This is weird. You have int which you get from bool, wouldn't be better
> > to use
> > !!(...) as other GPIO drivers do?  
> 
> As long as the build bots don't complain, there isn't a reason to
> change it. It is just a matter of personal preference at that point.
> 
> I got a sparse warning for something like this recently [1], but maybe
> that case was just because it was inside of a FIELD_PREP() using it as
> bit logic instead of addition and we won't get any warnings here.
> 
> [1]: https://lore.kernel.org/linux-iio/20240129195611.701611-3-dlechner@baylibre.com/

It was common to use !! for a number of years, but then it got a
comment from Linus Torvalds making reasonable point that it isn't
easy to read, so slight preference these days is for a ternary.