On 3/19/25 9:57 AM, Marcelo Schmitt wrote: > When SPI `bits_per_word` is not set, SPI transfers default 8-bit word size > and ADC data gets stored in big-endian format in memory. Because of that, > the IIO driver requests ADC data to be rearranged from BE to CPU > endianness. However, with `bits_per_word` set to the number of ADC > precision bits, transfers use larger word sizes that get stored in > 'in-memory wordsizes' and can be read in CPU endianness. > > Use proper `bits_per_word` size for SPI transfers thus saving the driver > from requesting endianness conversions. With that, shifting the buffer > data is also no longer needed. This change has no impact on IIO device > functionality. > > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@xxxxxxxxxx> > --- This is a breaking change. Some SPI controllers, like RPi can only do 8-bit transfers, so this driver would stop working on those platforms. Also, if anyone made software already that depended on the big-endian ordering without checking the scan_type attribute, it would break that software. I would leave this as-is (drop this patch) and just make it: .endianness = _offl ? IIO_CPU : IIO_BE, in the next patch.
