From: Liam Beguin <liambeguin@gmail.com>
To: liambeguin@gmail.com, peda@axentia.se, jic23@kernel.org,
andy.shevchenko@gmail.com, lars@metafoo.de
Cc: linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
devicetree@vger.kernel.org, robh+dt@kernel.org
Subject: [PATCH v11 05/15] iio: afe: rescale: add INT_PLUS_{MICRO,NANO} support
Date: Tue, 21 Dec 2021 22:46:36 -0500 [thread overview]
Message-ID: <20211222034646.222189-6-liambeguin@gmail.com> (raw)
In-Reply-To: <20211222034646.222189-1-liambeguin@gmail.com>
From: Liam Beguin <lvb@xiphos.com>
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: Liam Beguin <lvb@xiphos.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
---
drivers/iio/afe/iio-rescale.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c
index d0669fd8eac5..190a83e08008 100644
--- a/drivers/iio/afe/iio-rescale.c
+++ b/drivers/iio/afe/iio-rescale.c
@@ -17,11 +17,15 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/property.h>
+#include <linux/units.h>
int rescale_process_scale(struct rescale *rescale, int scale_type,
int *val, int *val2)
{
unsigned long long tmp;
+ s32 rem;
+ u32 mult;
+ u32 neg;
switch (scale_type) {
case IIO_VAL_FRACTIONAL:
@@ -40,6 +44,37 @@ int rescale_process_scale(struct rescale *rescale, int scale_type,
tmp *= rescale->numerator;
do_div(tmp, 1000000000LL);
*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 ? NANO : MICRO;
+
+ /*
+ * 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;
default:
return -EOPNOTSUPP;
--
2.34.0
next prev parent reply other threads:[~2021-12-22 3:47 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-22 3:46 [PATCH v11 00/15] iio: afe: add temperature rescaling support Liam Beguin
2021-12-22 3:46 ` [PATCH v11 01/15] iio: inkern: apply consumer scale on IIO_VAL_INT cases Liam Beguin
2021-12-22 3:46 ` [PATCH v11 02/15] iio: inkern: apply consumer scale when no channel scale is available Liam Beguin
2021-12-22 3:46 ` [PATCH v11 03/15] iio: inkern: make a best effort on offset calculation Liam Beguin
2021-12-22 3:46 ` [PATCH v11 04/15] iio: afe: rescale: expose scale processing function Liam Beguin
2021-12-22 10:21 ` Andy Shevchenko
2021-12-22 18:20 ` Liam Beguin
2021-12-22 18:52 ` Andy Shevchenko
2021-12-22 19:42 ` Liam Beguin
2021-12-22 19:50 ` Andy Shevchenko
2021-12-22 20:04 ` Liam Beguin
2021-12-22 3:46 ` Liam Beguin [this message]
2021-12-22 3:46 ` [PATCH v11 06/15] iio: afe: rescale: add offset support Liam Beguin
2021-12-22 3:46 ` [PATCH v11 07/15] iio: afe: rescale: use s64 for temporary scale calculations Liam Beguin
2021-12-22 12:25 ` Andy Shevchenko
2021-12-22 18:21 ` Liam Beguin
2021-12-22 3:46 ` [PATCH v11 08/15] iio: afe: rescale: fix accuracy for small fractional scales Liam Beguin
2021-12-22 12:27 ` Andy Shevchenko
2021-12-22 3:46 ` [PATCH v11 09/15] iio: afe: rescale: reduce risk of integer overflow Liam Beguin
2021-12-22 12:29 ` Andy Shevchenko
2021-12-22 18:38 ` Liam Beguin
2021-12-22 18:56 ` Andy Shevchenko
2021-12-22 19:58 ` Liam Beguin
2021-12-22 21:32 ` Andy Shevchenko
2022-01-08 16:34 ` Liam Beguin
2022-01-08 17:55 ` Andy Shevchenko
2021-12-22 3:46 ` [PATCH v11 10/15] iio: afe: rescale: make use of units.h Liam Beguin
2021-12-22 12:33 ` Andy Shevchenko
2021-12-22 18:50 ` Liam Beguin
2021-12-22 18:59 ` Andy Shevchenko
2021-12-22 3:46 ` [PATCH v11 11/15] iio: test: add basic tests for the iio-rescale driver Liam Beguin
2021-12-22 12:38 ` Andy Shevchenko
2021-12-22 19:13 ` Liam Beguin
2021-12-22 3:46 ` [PATCH v11 12/15] iio: afe: rescale: add RTD temperature sensor support Liam Beguin
2021-12-22 3:46 ` [PATCH v11 13/15] iio: afe: rescale: add temperature transducers Liam Beguin
2021-12-22 12:40 ` Andy Shevchenko
2021-12-22 3:46 ` [PATCH v11 14/15] dt-bindings: iio: afe: add bindings for temperature-sense-rtd Liam Beguin
2021-12-22 3:46 ` [PATCH v11 15/15] dt-bindings: iio: afe: add bindings for temperature transducers Liam Beguin
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