On Mon, Oct 06, 2014 at 02:22:58PM +0300, Vlad Dogaru wrote: > 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@xxxxxxxxx> > --- > > Changes since v1: > * report processed values instead of raw ones; > * use regmap cache for calibration registers; > * check chip id register on probe; > * minor style fixes. > > I couldn't find an entry for in_pressure_input in the ABI specification, so I > assume the units for kilopascal, just as for the raw value. If needed, I can > send a patch to add in_pressure_input to the ABI. > > drivers/iio/pressure/Kconfig | 11 + > drivers/iio/pressure/Makefile | 1 + > drivers/iio/pressure/bmp280.c | 455 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 467 insertions(+) > create mode 100644 drivers/iio/pressure/bmp280.c [...] > +static u32 bmp280_compensate_press(struct bmp280_data *data, > + struct bmp280_comp_press *comp, > + s32 adc_press) > +{ > + s64 var1, var2, p; > + > + var1 = ((s64) data->t_fine) - 128000; > + var2 = var1 * var1 * (s64) comp->dig_p6; > + var2 = var2 + ((var1 * (s64) comp->dig_p5) << 17); > + var2 = var2 + (((s64) comp->dig_p4) << 35); > + var1 = ((var1 * var1 * (s64) comp->dig_p3) >> 8) + > + ((var1 * (s64) comp->dig_p2) << 12); > + var1 = (((((s64) 1) << 47) + var1)) * ((s64) comp->dig_p1) >> 33; > + > + if (var1 == 0) > + return 0; > + > + p = 1048576 - adc_press; > + p = (((p << 31) - var2) * 3125) / var1; This 64bit division causes trouble on x86. Considering the patch made it to the testing branch, but not to 'togreg', would you prefer I submit a v3 or an incremental fix? Thanks, Vlad -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
