Re: STMicroelectronics accelerometers driver.

[Lars-Peter Clausen <lars@metafoo.de>]

Hi,

On 10/31/2012 03:27 PM, Denis CIOCCA wrote:
> Hi Lars-Peter,
> 
> I'm trying modified the driver to change the fullscale attribute and use 
> the in_accel_*_scale attribute.
> My question is that:
> 
> - the in_accel_*_scale attribute rappresent the conversion value from 
> raw data sensor to m/s2, if I use only this value, how can I know what 
> is the maximum full scale associated to the value?

Unfortunately there is currently no way in IIO to specify minimum or maximum
values for a given channel. But you are welcome to come up with one, I think
this will be useful for other drivers as well.

> 
> - how can I view a list of available values? I have to create scale 
> attribute on sysfs? If the last point is true, it is so redundant what I 
> did before?

You should add a scale_available attribute. Some ADC drivers implement this,
you could use them as an example.

- Lars

> 
> 
> Thanks,
> 
> Denis
> 
> 
> On 10/29/2012 11:30 AM, Lars-Peter Clausen wrote:
>> On 10/29/2012 11:24 AM, Denis CIOCCA wrote:
>>>
>>>> There is no attachment attached to this mail.
>>> my was a question. You prefer I attach all source code or the last modified?
>>>
>>>
>>>>> I don't find IIO_G_TO_M_S_2 in the framework code, but I added this
>>>>> macro in my source code. It is exatly?
>>>>
>>>> It's in the latest IIO tree and also in staging/staging-next. The definition is
>>>>
>>>> +#define IIO_DEGREE_TO_RAD(deg) (((deg) * 314159ULL + 9000000ULL) \
>>>> 	/ 18000000ULL)
>>>
>>> Sorry but I'm lost. The relation from IIO_DEGREE_TO_RAD and IIO_G_TO_M_S_2?
>>>
>>
>> Sorry, too early in the morning, copied the wrong line.
>>
>> +#define IIO_G_TO_M_S_2(g) ((g) * 980665ULL / 100000ULL)
>>
>> Btw. the full patch can be found here:
>>   http://comments.gmane.org/gmane.linux.kernel.iio/5777
>>
>> - Lars
>>