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

Quentin Schulz quentin.schulz at free-electrons.com
Mon Sep 5 01:52:00 PDT 2016


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



More information about the linux-arm-kernel mailing list