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From: Adam Rizkalla <ajarizzo@gmail.com>
To: linux-iio@vger.kernel.org
Cc: Jonathan Cameron <jic23@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Angel Iglesias <ang.iglesiasg@gmail.com>,
	Adam Rizkalla <ajarizzo@gmail.com>
Subject: [PATCH] iio: pressure: bmp280: Fix BMP580 temperature reading
Date: Thu, 25 Apr 2024 01:22:49 -0500	[thread overview]
Message-ID: <Zin2udkXRD0+GrML@adam-asahi.lan> (raw)

Fix overflow issue when storing BMP580 temperature reading and
properly preserve sign of 24-bit data.

Signed-off-by: Adam Rizkalla <ajarizzo@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index fe8734468ed3..e79c9715bb28 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -1393,12 +1393,12 @@ static int bmp580_read_temp(struct bmp280_data *data, int *val, int *val2)
 
 	/*
 	 * Temperature is returned in Celsius degrees in fractional
-	 * form down 2^16. We rescale by x1000 to return milli Celsius
-	 * to respect IIO ABI.
+	 * form down 2^16. We rescale by x1000 to return millidegrees
+	 * Celsius to respect IIO ABI.
 	 */
-	*val = raw_temp * 1000;
-	*val2 = 16;
-	return IIO_VAL_FRACTIONAL_LOG2;
+	raw_temp = sign_extend32(raw_temp, 23);
+	*val = ((s64)raw_temp * 1000) / (1 << 16);
+	return IIO_VAL_INT;
 }
 
 static int bmp580_read_press(struct bmp280_data *data, int *val, int *val2)
-- 
2.40.1


             reply	other threads:[~2024-04-25  6:22 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-25  6:22 Adam Rizkalla [this message]
2024-04-28 13:40 ` [PATCH] iio: pressure: bmp280: Fix BMP580 temperature reading Jonathan Cameron
2024-05-02 13:05   ` Replying to: " Vasileios Amoiridis
2024-05-02 15:44 ` Angel Iglesias
2024-05-02 17:16   ` Replying to: [PATCH] iio " Vasileios Amoiridis
2024-05-02 18:15     ` Adam Rizkalla
2024-05-03  7:13       ` Angel Iglesias
2024-05-05 18:02         ` Jonathan Cameron

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