| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 033/105] IIO: BME280: Updates to Humidity readings need ctrl_reg write! | Date | Tue, 10 Oct 2017 21:50:04 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Colin Parker <colin.parker@aclima.io>
commit 4b1f0c31f96c45e8521dd84aae50f2aa4aecfb7b upstream.
The ctrl_reg register needs to be written after any write to the humidity registers. The value written to the ctrl_reg register does not necessarily need to change, but a write operation must occur.
The regmap_update_bits functions will not write to a register if the register value matches the value to be written. This saves unnecessary bus operations. The change in this patch forces a bus write during the chip_config operation by switching to regmap_write_bits.
This will fix issues where the Humidity Sensor Oversampling bits are not updated after initialization.
Signed-off-by: Colin Parker <colin.parker@aclima.io> Acked-by: Andreas Klinger <ak@it-klinger.de> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/iio/pressure/bmp280-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/iio/pressure/bmp280-core.c +++ b/drivers/iio/pressure/bmp280-core.c @@ -558,7 +558,7 @@ static int bmp280_chip_config(struct bmp u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) | BMP280_OSRS_PRESS_X(data->oversampling_press + 1); - ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS, + ret = regmap_write_bits(data->regmap, BMP280_REG_CTRL_MEAS, BMP280_OSRS_TEMP_MASK | BMP280_OSRS_PRESS_MASK | BMP280_MODE_MASK,
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