Hi Colin, Colin Parker <colin.foeparker@xxxxxxxxx> schrieb am Thu, 24. Aug 16:54: > From: Colin Parker <colin.parker@xxxxxxxxx> > > This results in inaccurate Humidity readings that tend to not fluxuate. > > Update the ordering of the register writes so that ctrl_meas is written > after ctrl_hum. This is taken from section 5.4.3 of the datasheet. > > "https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280_DS001-11.pdf"; this part of the patch is already covered by commit afb2c3851b: "iio: bmp280: properly initialize device for humidity reading" Andreas > > Also writes to the config register can be ignored if the device is in Normal Mode. > Change the device to sleep mode before updating the config register. > This has the nice side effect of guaranteeing that the regmap_update_bits > function actually updates the driver and not just verifies the setting in its cache. > > Signed-off-by: Colin Parker <colin.parker@xxxxxxxxx> > --- > drivers/iio/pressure/bmp280-core.c | 22 +++++++++++++++------- > 1 file changed, 15 insertions(+), 7 deletions(-) > > diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c > index d82b788..85aa24c 100644 > --- a/drivers/iio/pressure/bmp280-core.c > +++ b/drivers/iio/pressure/bmp280-core.c > @@ -559,10 +559,7 @@ static int bmp280_chip_config(struct bmp280_data *data) > BMP280_OSRS_PRESS_X(data->oversampling_press + 1); > > ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS, > - BMP280_OSRS_TEMP_MASK | > - BMP280_OSRS_PRESS_MASK | > - BMP280_MODE_MASK, > - osrs | BMP280_MODE_NORMAL); > + BMP280_MODE_MASK, BMP280_MODE_SLEEP); > if (ret < 0) { > dev_err(data->dev, > "failed to write ctrl_meas register\n"); > @@ -578,6 +575,17 @@ static int bmp280_chip_config(struct bmp280_data *data) > return ret; > } > > + ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS, > + BMP280_OSRS_TEMP_MASK | > + BMP280_OSRS_PRESS_MASK | > + BMP280_MODE_MASK, > + osrs | BMP280_MODE_NORMAL); > + if (ret < 0) { > + dev_err(data->dev, > + "failed to write ctrl_meas register\n"); > + return ret; > + } > + > return ret; > } > > @@ -597,14 +605,14 @@ static const struct bmp280_chip_info bmp280_chip_info = { > > static int bme280_chip_config(struct bmp280_data *data) > { > - int ret = bmp280_chip_config(data); > u8 osrs = BMP280_OSRS_HUMIDITIY_X(data->oversampling_humid + 1); > + int ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_HUMIDITY, > + BMP280_OSRS_HUMIDITY_MASK, osrs); > > if (ret < 0) > return ret; > > - return regmap_update_bits(data->regmap, BMP280_REG_CTRL_HUMIDITY, > - BMP280_OSRS_HUMIDITY_MASK, osrs); > + return bmp280_chip_config(data); > } > > static const struct bmp280_chip_info bme280_chip_info = { > -- > 2.1.4 > > -- > 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 -- -- 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
