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authorDimitri Fedrau <dima.fedrau@gmail.com>2024-04-24 20:59:10 +0200
committerJonathan Cameron <jonathan.cameron@huawei.com>2024-05-03 11:48:56 +0100
commit827dca3129708a8465bde90c86c2e3c38e62dd4f (patch)
tree04274c6c1e843e6b07de683cacc3dc405931d2ac /drivers/iio
parent51fafb3cd7fcf4f4682693b4d2883e2a5bfffe33 (diff)
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iio: temperature: mcp9600: Fix temperature reading for negative values
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@gmail.com> Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com> Tested-by: Andrew Hepp <andrew.hepp@ahepp.dev> Link: https://lore.kernel.org/r/20240424185913.1177127-1-dima.fedrau@gmail.com Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/temperature/mcp9600.c3
1 files changed, 2 insertions, 1 deletions
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;
}