From: Dimitri Fedrau <dima.fedrau@xxxxxxxxx>
commit 827dca3129708a8465bde90c86c2e3c38e62dd4f upstream.
Temperature is stored as 16bit value in two's complement format. Current
implementation ignores the sign bit. Make it aware of the sign bit by
using sign_extend32.
Fixes: 3f6b9598b6df ("iio: temperature: Add MCP9600 thermocouple EMF converter")
Signed-off-by: Dimitri Fedrau <dima.fedrau@xxxxxxxxx>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx>
Tested-by: Andrew Hepp <andrew.hepp@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240424185913.1177127-1-dima.fedrau@xxxxxxxxx
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iio/temperature/mcp9600.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
index 46845804292b..7a3eef5d5e75 100644
--- a/drivers/iio/temperature/mcp9600.c
+++ b/drivers/iio/temperature/mcp9600.c
@@ -52,7 +52,8 @@ static int mcp9600_read(struct mcp9600_data *data,
if (ret < 0)
return ret;
- *val = ret;
+
+ *val = sign_extend32(ret, 15);
return 0;
}
--
2.45.2
Patches currently in stable-queue which might be from dima.fedrau@xxxxxxxxx are
queue-6.9/iio-temperature-mcp9600-fix-temperature-reading-for-negative-values.patch
