[PATCH v2 1/4] iio: pressure: dps310: support negative temperature values

From: Thomas Haemmerle
Date: Wed Apr 10 2024 - 06:37:35 EST


The current implementation interprets negative values returned from
`dps310_calculate_temp` as error codes.
This has a side effect that when negative temperature values are
calculated, they are interpreted as error.

Fix this by using the return value only for error handling and passing a
pointer for the value.

Fixes: ba6ec48e76bc ("iio: Add driver for Infineon DPS310")
Signed-off-by: Thomas Haemmerle <thomas.haemmerle@xxxxxxxxxxxxxxxxxxxx>
---
drivers/iio/pressure/dps310.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
index 1ff091b2f764..d0a516d56da4 100644
--- a/drivers/iio/pressure/dps310.c
+++ b/drivers/iio/pressure/dps310.c
@@ -730,7 +730,7 @@ static int dps310_read_pressure(struct dps310_data *data, int *val, int *val2,
}
}

-static int dps310_calculate_temp(struct dps310_data *data)
+static int dps310_calculate_temp(struct dps310_data *data, int *val)
{
s64 c0;
s64 t;
@@ -746,7 +746,9 @@ static int dps310_calculate_temp(struct dps310_data *data)
t = c0 + ((s64)data->temp_raw * (s64)data->c1);

/* Convert to milliCelsius and scale the temperature */
- return (int)div_s64(t * 1000LL, kt);
+ *val = (int)div_s64(t * 1000LL, kt);
+
+ return 0;
}

static int dps310_read_temp(struct dps310_data *data, int *val, int *val2,
@@ -768,11 +770,10 @@ static int dps310_read_temp(struct dps310_data *data, int *val, int *val2,
if (rc)
return rc;

- rc = dps310_calculate_temp(data);
- if (rc < 0)
+ rc = dps310_calculate_temp(data, val);
+ if (rc)
return rc;

- *val = rc;
return IIO_VAL_INT;

case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
--
2.34.1