From 3c324a40b7c3e6f95fde81c77f5cae6426a5e071 Mon Sep 17 00:00:00 2001 From: Dimitri Fedrau Date: Wed, 24 Apr 2024 20:59:10 +0200 Subject: 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 Reviewed-by: Marcelo Schmitt Tested-by: Andrew Hepp Link: https://lore.kernel.org/r/20240424185913.1177127-1-dima.fedrau@gmail.com Cc: Signed-off-by: Jonathan Cameron --- 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 46845804292bf..7a3eef5d5e752 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; } -- cgit 1.2.3-korg