Re: [PATCH v4 3/3] iio: adc: add support for Allwinner SoCs ADC

From: Quentin Schulz
Date: Mon Sep 05 2016 - 04:52:09 EST


On 05/09/2016 10:07, Peter Meerwald-Stadler wrote:
>
>>>> The Allwinner SoCs all have an ADC that can also act as a touchscreen
>>>> controller and a thermal sensor. This patch adds the ADC driver which is
>>>> based on the MFD for the same SoCs ADC.
>>>
>>> nitpicking ahead
>
>> [...]
>>>> +
>>>> +const unsigned int sun4i_gpadc_chan_select(unsigned int chan)
>>>
>>> static instead of const?
>
>> static const then?
>
> no, the const is redundant and ignored
> -Wignored-qualifiers gives a warning
>
> just static, no const
>
> see
> http://stackoverflow.com/questions/12052468/type-qualifiers-on-function-return-type
>

ACK. Thanks.

>>>> +{
>>>> + return SUN6I_GPADC_CTRL1_ADC_CHAN_SELECT(chan);
>>>> +}
>>>> +
>>>> +struct soc_specific {
>>>> + const int temp_offset;
>>>
>>> wondering why you constify every member?
>>>
>>
>> Because they're supposed to be fixed values? It won't change in runtime.
>> Is there any reason why I shouldn't do that?
>
> yes, but using the entire struct as const has the same effect;
> constifying individual members makes more sense if there are also
> non-const members
>
> nothing wrong, just unusual
>

So I would let all members non-const and then when using the struct
soc_specific as a member in a struct or as a variable I would prefix it
with const? That's what you mean by using the entire struct as const?

[...]

Thanks,
Quentin