Commit Graph

5 Commits

Author SHA1 Message Date
Hartmut Knaack 44cf3798a3 iio:pressure:bmp280: cleanup
The calculations for temperature and pressure compensation were already slightly
optimized in comparison to the datasheet. So, it makes sense to optimize even a
bit more, making proper use of C operators:
  - variable t in bmp280_compensate_temp() can be eliminated by directly
    returning the result of the relevant equation.
  - make use of the += operator and eliminate an unnecessary parenthesis level in
    bmp280_compensate_press().
When the initialization of the ctrl_meas register fails, the error message will
now mention the right register name.
During probe, i2c_set_clientdata() is called, although it is not necessary. Drop
it.

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Reviewed-by: Vlad Dogaru <vlad.dogaru@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-12-26 10:32:34 +00:00
Vlad Dogaru 0f8994b18a iio: bmp280: refactor compensation code
This version of the code avoids extra memory copy operations and is
somewhat smaller in code size.

Signed-off-by: Vlad Dogaru <vlad.dogaru@intel.com>
Acked-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-12-12 12:28:25 +00:00
Hartmut Knaack 81ebe850a0 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>
2014-11-05 15:58:35 +00:00
Vlad Dogaru 46ee98a206 bmp280: use correct routine for division
The proper way to divide two signed 64-bit values is to use div64_s64.

Signed-off-by: Vlad Dogaru <vlad.dogaru@intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-10-25 10:44:54 +01:00
Vlad Dogaru d5c94568cc iio: add bmp280 pressure and temperature driver
Minimal implementation, can read temperature and data using direct mode.

Datasheet available at
<http://ae-bst.resource.bosch.com/media/products/dokumente/bmp280/BST-BMP280-DS001-09.pdf>

Signed-off-by: Vlad Dogaru <vlad.dogaru@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-10-22 20:28:27 +01:00