On 04/14/2016 05:28 PM, Gregor Boirie wrote:
> Greetings,
>
> I'm trying to use an st_pressure based sensor to sample pressure
> data using generic_buffer tool. However it seems that it does not
> support data packed onto 24 bits samples.
> st_pressure driver defines scan_type for my device as:
> <code>
> /* ... */
> .scan_type = {
> .sign = 'u',
> .realbits = 24,
> .storagebits = 24,
> .endianness = IIO_LE,
> },
> </code>
>
> What is the proper way to make this work ? Using 32 bits storagebits
> field ? Enhance generic_buffer to support 24 bits samples ? Anything
> else ??
>
> It seems iio_compute_scan_bytes consider sample data as a simple byte
> stream. So I'm wondering what are the alignment constraints for sample
> start address ? Should they be aligned onto their natural "word"
> boundaries, i.e. 16 bits for u16, 32 bits for u32, etc... ? And for
> 24 bits samples ?
IIO really only supports powers of two >= 8 for the storagebits size.
Everything else is undefined.
Samples are aligned to their storage size.
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
