linux-kernel - Re: [PATCH v2 2/3] iio: adc: Support ROHM BD79112 ADC/GPIO

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <09dc1c16-00bb-4b37-8c98-b0463e35b36a@gmail.com>
Date: Mon, 8 Sep 2025 08:07:59 +0300
From: Matti Vaittinen <mazziesaccount@...il.com>
To: Jonathan Cameron <jic23@...nel.org>
Cc: Andy Shevchenko <andriy.shevchenko@...el.com>,
 Matti Vaittinen <matti.vaittinen@...rohmeurope.com>,
 David Lechner <dlechner@...libre.com>, Nuno Sá
 <nuno.sa@...log.com>, Andy Shevchenko <andy@...nel.org>,
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>, Linus Walleij
 <linus.walleij@...aro.org>, Bartosz Golaszewski <brgl@...ev.pl>,
 Marcelo Schmitt <marcelo.schmitt@...log.com>,
 Javier Carrasco <javier.carrasco.cruz@...il.com>,
 Tobias Sperling <tobias.sperling@...ting.com>,
 Antoniu Miclaus <antoniu.miclaus@...log.com>,
 Trevor Gamblin <tgamblin@...libre.com>, Esteban Blanc <eblanc@...libre.com>,
 Herve Codina <herve.codina@...tlin.com>,
 Ramona Alexandra Nechita <ramona.nechita@...log.com>,
 Eason Yang <j2anfernee@...il.com>,
 Pop Ioan Daniel <pop.ioan-daniel@...log.com>, linux-iio@...r.kernel.org,
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-gpio@...r.kernel.org
Subject: Re: [PATCH v2 2/3] iio: adc: Support ROHM BD79112 ADC/GPIO

On 07/09/2025 14:16, Jonathan Cameron wrote:
> 
>>>> +/* ADC channels as named in the data-sheet */
>>>> +static const char * const bd79112_chan_names[] = {
>>>> +	"AGIO0A", "AGIO1A", "AGIO2A", "AGIO3A", "AGIO4A",	/* 0 - 4 */
>>>> +	"AGIO5A", "AGIO6A", "AGIO7A", "AGIO8A", "AGIO9A",	/* 5 - 9 */
>>>> +	"AGIO10A", "AGIO11A", "AGIO12A", "AGIO13A", "AGIO14A",	/* 10 - 14 */
>>>> +	"AGIO15A", "AGIO0B", "AGIO1B", "AGIO2B", "AGIO3B",	/* 15 - 19 */
>>>> +	"AGIO4B", "AGIO5B", "AGIO6B", "AGIO7B", "AGIO8B",	/* 20 - 24 */
>>>> +	"AGIO9B", "AGIO10B", "AGIO11B", "AGIO12B", "AGIO13B",	/* 25 - 29 */
>>>> +	"AGIO14B", "AGIO15B",					/* 30 - 31 */
>>>
>>> O-o-key, but why not power-of-two per line (esp. taking into account
>>> the whole size)? (Whatever, it's not something I would fight for.)
>>
>> I just filled the rows to the maximum width, while keeping the item
>> count same for each row and adding the comment.
>>
>> I'm not really sure having 4 items / row, and adding one row more would
>> be much better, but not much worse either. I can do this if you think
>> it's better. (No need to even fight for that).
> 
> In this case I'd do it in 4s purely because then the B ones start on
> a new line and that looks nicer ;)

Ok.

>>
>>>> +};
>>>
>>> ...
>>>    
>>>> +	data->vref_mv = ret / 1000;
>>>
>>> Yeah, mV, (MICRO / MILLI) and other things I leave to other people to discuss.
>>
>> Thanks Andy. I've a feeling we were somewhat stuck on this discussion
>> anyways. I suppose it's nice to hear other's opinions if someone else
>> really cares. This was approaching bikeshedding.
>>
> I'll just throw a quick comment in here.
> 
> I'm absolutely in favour of the defines as they help in several ways.
> - Stop counting 0s when there are lots of them.

I do agree on this when there is more than 3 zeroes. Although, for 
example 100 * 1000 is still clear to me. 100 * MILLI is not quite as 
obvious (again, to me).

> - Provide information on the unit conversion not otherwise visible
>    where they happen to be used (often avoids need for local variables etc).

Speaking only on my behalf but I'd rather see the local variables 
instead of constructs like (MICRO / MILLI) - which does not really feel 
right to me.

> - Consistency across a code base.

This probably means much more to a subsystem maintainer than to me! :) 
I'd still claim that consistency could be also achieved by consistently 
using dividers like / 1000 :)

> In this particular case none apply strongly enough to force the issue.
> Even so I'd prefer the units.h macros are used for the consistency reason
> but I won't refuse to merge the driver over this.
> 
> One of those perfect (to me) being the enemy of good cases.
> 
> p.s. Matti, 3 versions in 4 days?  Perhaps slow down a little.

I should've indeed throttled sending the versions a bit. I just did 
fixes suggested by Andy/David immediately - and then I thought I could 
just do a decent change-log for reviewers, and send them while at it.

I didn't consider someone like You who will probably skim through all 
the versions and discussion. Sorry!

Thanks for the input!

Yours,
	-- Matti