diff options
| author | Hartmut Knaack <knaack.h@gmx.de> | 2014-10-31 01:22:00 +0000 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2014-11-05 15:58:35 +0000 |
| commit | 81ebe850a019ccb8bf0a429fb463d9bfc15ec298 (patch) | |
| tree | 7235e3aa02eebe7c6289f8b89c1e1c8d2cff16dd | |
| parent | c1b501564c98a94b48f4ed936737403108dc7300 (diff) | |
| download | linux-81ebe850a019ccb8bf0a429fb463d9bfc15ec298.tar.bz2 | |
iio:pressure:bmp280: fix pressure calculation
According to the datasheet and as defined in struct bmp280_comp_press, dig_p1 is
of type u16, while dig_p2 to dig_p9 are of type s16. In
bmp280_read_compensation_press(), values read from the device were treated as
the wrong type.
In bmp280_read_press() the fractional part of the measured pressure is
calculated wrong. A better way is to use *val for the raw pressure and *val2 for
the quotient and let the core do the proper conversion using IIO_VAL_FRACTIONAL.
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Acked-by: Vlad Dogaru <vlad.dogaru@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
| -rw-r--r-- | drivers/iio/pressure/bmp280.c | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c index ce29ff91bce7..75038dacfff1 100644 --- a/drivers/iio/pressure/bmp280.c +++ b/drivers/iio/pressure/bmp280.c @@ -176,15 +176,15 @@ static int bmp280_read_compensation_press(struct bmp280_data *data, return ret; } - comp->dig_p1 = (s16) le16_to_cpu(buf[0]); - comp->dig_p2 = (u16) le16_to_cpu(buf[1]); - comp->dig_p3 = (u16) le16_to_cpu(buf[2]); - comp->dig_p4 = (u16) le16_to_cpu(buf[3]); - comp->dig_p5 = (u16) le16_to_cpu(buf[4]); - comp->dig_p6 = (u16) le16_to_cpu(buf[5]); - comp->dig_p7 = (u16) le16_to_cpu(buf[6]); - comp->dig_p8 = (u16) le16_to_cpu(buf[7]); - comp->dig_p9 = (u16) le16_to_cpu(buf[8]); + comp->dig_p1 = (u16) le16_to_cpu(buf[0]); + comp->dig_p2 = (s16) le16_to_cpu(buf[1]); + comp->dig_p3 = (s16) le16_to_cpu(buf[2]); + comp->dig_p4 = (s16) le16_to_cpu(buf[3]); + comp->dig_p5 = (s16) le16_to_cpu(buf[4]); + comp->dig_p6 = (s16) le16_to_cpu(buf[5]); + comp->dig_p7 = (s16) le16_to_cpu(buf[6]); + comp->dig_p8 = (s16) le16_to_cpu(buf[7]); + comp->dig_p9 = (s16) le16_to_cpu(buf[8]); return 0; } @@ -309,10 +309,10 @@ static int bmp280_read_press(struct bmp280_data *data, adc_press = be32_to_cpu(tmp) >> 12; comp_press = bmp280_compensate_press(data, &comp, adc_press); - *val = comp_press / 256000; - *val2 = comp_press * 1000000 / 256000; + *val = comp_press; + *val2 = 256000; - return IIO_VAL_INT_PLUS_MICRO; + return IIO_VAL_FRACTIONAL; } static int bmp280_read_raw(struct iio_dev *indio_dev, |