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 v12 07/16] iio: afe: rescale: add INT_PLUS_{MICRO,NANO} support
Date: Sat, 8 Jan 2022 15:53:10 -0500 [thread overview]
Message-ID: <20220108205319.2046348-8-liambeguin@gmail.com> (raw)
In-Reply-To: <20220108205319.2046348-1-liambeguin@gmail.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 <liambeguin@gmail.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 65832dd09249..f833eb38f8bb 100644
--- a/drivers/iio/afe/iio-rescale.c
+++ b/drivers/iio/afe/iio-rescale.c
@@ -14,6 +14,7 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/property.h>
+#include <linux/units.h>
#include <linux/iio/afe/rescale.h>
#include <linux/iio/consumer.h>
@@ -23,6 +24,9 @@ int rescale_process_scale(struct rescale *rescale, int scale_type,
int *val, int *val2)
{
s64 tmp;
+ s32 rem;
+ u32 mult;
+ u32 neg;
switch (scale_type) {
case IIO_VAL_FRACTIONAL:
@@ -41,6 +45,37 @@ int rescale_process_scale(struct rescale *rescale, int scale_type,
tmp *= rescale->numerator;
tmp = div_s64(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 ? GIGA : MEGA;
+
+ /*
+ * 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:[~2022-01-08 20:53 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-08 20:53 [PATCH v12 00/16] iio: afe: add temperature rescaling support Liam Beguin
2022-01-08 20:53 ` [PATCH v12 01/16] iio: inkern: apply consumer scale on IIO_VAL_INT cases Liam Beguin
2022-01-08 20:53 ` [PATCH v12 02/16] iio: inkern: apply consumer scale when no channel scale is available Liam Beguin
2022-01-08 20:53 ` [PATCH v12 03/16] iio: inkern: make a best effort on offset calculation Liam Beguin
2022-01-08 20:53 ` [PATCH v12 04/16] iio: afe: rescale: use s64 for temporary scale calculations Liam Beguin
2022-01-08 20:53 ` [PATCH v12 05/16] iio: afe: rescale: reorder includes Liam Beguin
2022-01-08 20:53 ` [PATCH v12 06/16] iio: afe: rescale: expose scale processing function Liam Beguin
2022-01-09 13:07 ` Andy Shevchenko
2022-01-09 20:19 ` Peter Rosin
2022-01-09 20:25 ` Peter Rosin
2022-01-11 14:43 ` Liam Beguin
2022-01-11 14:35 ` Liam Beguin
2022-01-08 20:53 ` Liam Beguin [this message]
2022-01-09 12:48 ` [PATCH v12 07/16] iio: afe: rescale: add INT_PLUS_{MICRO,NANO} support Andy Shevchenko
2022-01-09 20:20 ` Peter Rosin
2022-01-11 14:33 ` Liam Beguin
2022-01-08 20:53 ` [PATCH v12 08/16] iio: afe: rescale: add offset support Liam Beguin
2022-01-08 20:53 ` [PATCH v12 09/16] iio: afe: rescale: fix accuracy for small fractional scales Liam Beguin
2022-01-09 13:02 ` Andy Shevchenko
2022-01-09 20:07 ` Peter Rosin
2022-01-08 20:53 ` [PATCH v12 10/16] iio: afe: rescale: reduce risk of integer overflow Liam Beguin
2022-01-08 20:53 ` [PATCH v12 11/16] iio: afe: rescale: make use of units.h Liam Beguin
2022-01-08 20:53 ` [PATCH v12 12/16] iio: test: add basic tests for the iio-rescale driver Liam Beguin
2022-01-08 20:53 ` [PATCH v12 13/16] iio: afe: rescale: add RTD temperature sensor support Liam Beguin
2022-01-08 20:53 ` [PATCH v12 14/16] iio: afe: rescale: add temperature transducers Liam Beguin
2022-01-08 20:53 ` [PATCH v12 15/16] dt-bindings: iio: afe: add bindings for temperature-sense-rtd Liam Beguin
2022-01-08 20:53 ` [PATCH v12 16/16] dt-bindings: iio: afe: add bindings for temperature transducers Liam Beguin
2022-01-09 13:10 ` [PATCH v12 00/16] iio: afe: add temperature rescaling support Andy Shevchenko
2022-01-30 14:39 ` Jonathan Cameron
2022-01-30 14:41 ` Jonathan Cameron
2022-01-30 14:59 ` Liam Beguin
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