Re: [PATCH] iio: Add Maxim MAX11100 driver

[Jonathan Cameron <jic23@kernel.org>]

On 07/12/16 12:22, Geert Uytterhoeven wrote:
> Hi Jacopo,
> 
> On Wed, Dec 7, 2016 at 9:29 AM, jacopo@jmondi.org <jacopo@jmondi.org> wrote:
>> On 06/12/2016 22:00, Peter Meerwald-Stadler wrote:
>>> On Tue, 6 Dec 2016, Jacopo Mondi wrote:
>>>> Add IIO driver for Maxim MAX11100 single-channel ADC.
>>>> Support raw_read mode only.
>>>
>>> the read_raw() is supposed to return millivolts (after application of
>>> offset and scale); maybe need _SCALE?
>>
>> How can I return millivolts here? They vary in function of the supplied Vref
>> as ( V = val * Vref / (2 ^ 16 - 1)) where "val" is digital value output by
>> the ADC.
>> Since Vref can range from 3.8V to 5.25V, while it's typically 4.096V, isn't
>> it more appropriate to let userspace perform conversion to millivolts, as it
>> knows what Vref value is supplied to the ADC?
> 
> Specify Vref in DT?
More specifically specify that it's supplied by a regulator.. 
If it's a fixed supply then DT should describe it as a fixed regulator.
> 
> Which finally gives a good reason to add a DT binding document for
> MAX11100 ;-)
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
>