[PATCH] iio: pressure: bmp280: fix temp compensation

From: Irina Tirdea
Date: Wed Apr 08 2015 - 11:26:29 EST


Temperature reads on bmp280 device always return 0,
due to a missing step in the compensation formula
(data->tfine is never initialized).

Initialize data->tfine value so we get correct
temperature and pressure values.

Signed-off-by: Irina Tirdea <irina.tirdea@xxxxxxxxx>
---
drivers/iio/pressure/bmp280.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
index 7c623e2..a2602d8 100644
--- a/drivers/iio/pressure/bmp280.c
+++ b/drivers/iio/pressure/bmp280.c
@@ -172,6 +172,7 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data,
var2 = (((((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1]))) *
((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1])))) >> 12) *
((s32)(s16)le16_to_cpu(buf[T3]))) >> 14;
+ data->t_fine = var1 + var2;

return (data->t_fine * 5 + 128) >> 8;
}
--
1.9.1

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