Re: extending /sys/.../iio:deviceX/in_accelX_power_mode

From: Crt Mori
Date: Tue Mar 01 2016 - 04:54:52 EST


On 1 March 2016 at 10:47, Martin Kepplinger <martink@xxxxxxxxx> wrote:
> Am 2016-03-01 um 10:38 schrieb Daniel Baluta:
>> On Tue, Mar 1, 2016 at 10:59 AM, Martin Kepplinger <martink@xxxxxxxxx> wrote:
>>> Would it be ok, if adding in_accelX_power_mode to a driver, to extend it
>>> so that in_accel_power_mode_available offers:
>>>
>>> low_noise low_power low_power_low_noise normal
>>>
>>> if there's a default "normal" mode, plus options to increase or decrease
>>> oversampling / power consumption for my device?
>>>
>>> Specifically I'm unsure about "low_power_low_noise" being enough
>>> user-friendly. The chip I work with just happens to offer these 4 modes.
>>> Would you leave out "low_power_low_noise" and go with
>>>
>>> low_noise low_power normal
>>>
>>> or is it not even desired to add "normal" to the list?
>>>
>>> Although strictly not necessary, I would add any new addition to the
>>> Documentation as well.
>>
>> The problem with this is that is not uniform across sensors. What
>> chip are you looking at?
>>
>> For example INV6500 has:
>> * sleep mode
>> * standby mode
>> * etc.
>>
>> Daniel.
>>
>
> I suspect these modes are something else. I'm looking at the mma8452
> driver, and it also has "active" "standby" and "sleep" modes, but I'm
> talking about different *power* (oversampling) configurations in
> "active" mode, which is what said sysfs file is about.
>
> But yes, it should be potenially uniform across sensors, which is why I
> would probably only add "normal" to the list. At least I can imagine
> that many devices have an oversampling mode called "normal".

If that is oversampling option then why don't you just use that as a
setup? Power mode does not sound like oversampling to me... Maybe you
should use a sampling_frequency parameter instead?

>
> A simple user interface is important so right now I think the best is to
> leave it as it is, and not to add complexity and every possible option
> for the user.
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