From: Liam Beguin <liambeguin@gmail.com>
To: liambeguin@gmail.com, peda@axentia.se, jic23@kernel.org,
lars@metafoo.de, pmeerw@pmeerw.net
Cc: linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
devicetree@vger.kernel.org, robh+dt@kernel.org
Subject: [PATCH v7 05/13] iio: afe: rescale: add INT_PLUS_{MICRO,NANO} support
Date: Sun, 1 Aug 2021 15:39:52 -0400 [thread overview]
Message-ID: <20210801194000.3646303-6-liambeguin@gmail.com> (raw)
In-Reply-To: <20210801194000.3646303-1-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>
---
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..615f5d9cbb8b 100644
--- a/drivers/iio/afe/iio-rescale.c
+++ b/drivers/iio/afe/iio-rescale.c
@@ -22,6 +22,9 @@ int rescale_process_scale(struct rescale *rescale, int scale_type,
int *val, int *val2)
{
unsigned long long tmp;
+ u32 mult;
+ u32 rem;
+ u32 neg;
switch (scale_type) {
case IIO_VAL_FRACTIONAL:
@@ -40,6 +43,38 @@ 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:
+ if (scale_type == IIO_VAL_INT_PLUS_NANO)
+ mult = 1000000000LL;
+ else
+ mult = 1000000LL;
+ /*
+ * For IIO_VAL_INT_PLUS_{MICRO,NANO} scale types if *val OR
+ * *val2 is negative the schan scale is negative
+ */
+ 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;
--
2.30.1.489.g328c10930387
next prev parent reply other threads:[~2021-08-01 19:40 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-01 19:39 [PATCH v7 00/13] iio: afe: add temperature rescaling support Liam Beguin
2021-08-01 19:39 ` [PATCH v7 01/13] iio: inkern: apply consumer scale on IIO_VAL_INT cases Liam Beguin
2021-08-01 19:39 ` [PATCH v7 02/13] iio: inkern: apply consumer scale when no channel scale is available Liam Beguin
2021-08-01 19:39 ` [PATCH v7 03/13] iio: inkern: make a best effort on offset calculation Liam Beguin
2021-08-01 19:39 ` [PATCH v7 04/13] iio: afe: rescale: expose scale processing function Liam Beguin
2021-08-01 19:39 ` Liam Beguin [this message]
2021-08-01 19:39 ` [PATCH v7 06/13] iio: afe: rescale: add offset support Liam Beguin
2021-08-01 19:39 ` [PATCH v7 07/13] iio: afe: rescale: reduce risk of integer overflow Liam Beguin
2021-08-01 19:39 ` [PATCH v7 08/13] iio: afe: rescale: fix precision on fractional log scale Liam Beguin
2021-08-02 9:17 ` Peter Rosin
2021-08-15 22:14 ` Liam Beguin
2021-08-01 19:39 ` [PATCH v7 09/13] iio: test: add basic tests for the iio-rescale driver Liam Beguin
2021-08-01 19:39 ` [PATCH v7 10/13] iio: afe: rescale: add RTD temperature sensor support Liam Beguin
2021-08-01 19:39 ` [PATCH v7 11/13] iio: afe: rescale: add temperature transducers Liam Beguin
2021-08-01 19:39 ` [PATCH v7 12/13] dt-bindings: iio: afe: add bindings for temperature-sense-rtd Liam Beguin
2021-08-01 19:40 ` [PATCH v7 13/13] dt-bindings: iio: afe: add bindings for temperature transducers Liam Beguin
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