From: Irina Tirdea <irina.tirdea@intel.com>
Date: Wed, 8 Apr 2015 15:26:12 +0000 (+0300)
Subject: iio: pressure: bmp280: fix temp compensation
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=abad398337f038f5822e53c55eff5b0820ef7efe;p=linux-beck.git

iio: pressure: bmp280: fix temp compensation

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@intel.com>
Reviewed-by: Vlad Dogaru <vlad.dogaru@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
---

diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
index 7c623e2bd633..a2602d8dd6d5 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;
 }