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"; 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
