On Sun, Mar 22, 2020 at 9:57 PM Deepak R Varma <mh12gx2825@xxxxxxxxx> wrote: > > Current implementation of the function ad7192_get_available_filter_freq > repeats calculation of output data rate a few times. We can simplify > these steps by refactoring out the calculation of fADC. This would also > addresses the checkpatch warning of line exceeding 80 character. I'm not sure you did an equivalent changes. I believe in the original code precision is better. Consider low clock frequencies when 10 bit right shift may hide some bits of the division. Care to write a python script to check the precision between old and new code? ... > - /* Formulas for filter at page 25 of the datasheet */ > - fadc = DIV_ROUND_CLOSEST(st->fclk, > - AD7192_SINC4_FILTER * AD7192_MODE_RATE(st->mode)); > - freq[0] = DIV_ROUND_CLOSEST(fadc * 240, 1024); > + fadc = DIV_ROUND_CLOSEST(st->fclk, AD7192_MODE_RATE(st->mode) * 1024); > > - fadc = DIV_ROUND_CLOSEST(st->fclk, > - AD7192_SINC3_FILTER * AD7192_MODE_RATE(st->mode)); > - freq[1] = DIV_ROUND_CLOSEST(fadc * 240, 1024); > - > - fadc = DIV_ROUND_CLOSEST(st->fclk, AD7192_MODE_RATE(st->mode)); > - freq[2] = DIV_ROUND_CLOSEST(fadc * 230, 1024); > - freq[3] = DIV_ROUND_CLOSEST(fadc * 272, 1024); > + /* Formulas for filter at page 25 of the datasheet */ > + freq[0] = DIV_ROUND_CLOSEST(fadc * 240, AD7192_SINC4_FILTER); > + freq[1] = DIV_ROUND_CLOSEST(fadc * 240, AD7192_SINC3_FILTER); > + freq[2] = fadc * 230; > + freq[3] = fadc * 272; -- With Best Regards, Andy Shevchenko
