Commit 701ee14d authored by Liam Beguin's avatar Liam Beguin Committed by Jonathan Cameron
Browse files

iio: afe: rescale: add INT_PLUS_{MICRO,NANO} support 



Some ADCs use IIO_VAL_INT_PLUS_{NANO,MICRO} scale types.
Add support for these to allow using the iio-rescaler with them.

Signed-off-by: default avatarLiam Beguin <liambeguin@gmail.com>
Reviewed-by: default avatarPeter Rosin <peda@axentia.se>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220213025739.2561834-3-liambeguin@gmail.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent bc437f75

drivers/iio/afe/iio-rescale.c

+34 −0
Original line number Original line Diff line number Diff line
@@ -23,6 +23,9 @@ int rescale_process_scale(struct rescale *rescale, int scale_type, 
			  int *val, int *val2)

			  int *val, int *val2)

{

{

	s64 tmp;

	s64 tmp;

	s32 rem;

	u32 mult;

	u32 neg;





	switch (scale_type) {

	switch (scale_type) {

	case IIO_VAL_FRACTIONAL:

	case IIO_VAL_FRACTIONAL:
@@ -41,6 +44,37 @@ int rescale_process_scale(struct rescale *rescale, int scale_type, 
		tmp *= rescale->numerator;

		tmp *= rescale->numerator;

		tmp = div_s64(tmp, 1000000000LL);

		tmp = div_s64(tmp, 1000000000LL);

		*val = tmp;

		*val = tmp;

		return scale_type;

	case IIO_VAL_INT_PLUS_NANO:

	case IIO_VAL_INT_PLUS_MICRO:

		mult = scale_type == IIO_VAL_INT_PLUS_NANO ? 1000000000L : 1000000L;



		/*

		 * For IIO_VAL_INT_PLUS_{MICRO,NANO} scale types if either *val

		 * OR *val2 is negative the schan scale is negative, i.e.

		 * *val = 1 and *val2 = -0.5 yields -1.5 not -0.5.

		 */

		neg = *val < 0 || *val2 < 0;



		tmp = (s64)abs(*val) * abs(rescale->numerator);

		*val = div_s64_rem(tmp, abs(rescale->denominator), &rem);



		tmp = (s64)rem * mult + (s64)abs(*val2) * abs(rescale->numerator);

		tmp = div_s64(tmp, abs(rescale->denominator));



		*val += div_s64_rem(tmp, mult, val2);



		/*

		 * If only one of the rescaler elements or the schan scale is

		 * negative, the combined scale is negative.

		 */

		if (neg ^ ((rescale->numerator < 0) ^ (rescale->denominator < 0))) {

			if (*val)

				*val = -*val;

			else

				*val2 = -*val2;

		}



		return scale_type;

		return scale_type;

	default:

	default:

		return -EOPNOTSUPP;

		return -EOPNOTSUPP;