Commit c68013f3 authored by Stefan Brüns's avatar Stefan Brüns Committed by Greg Kroah-Hartman
Browse files

iio: adc: ina2xx: Remove unneeded dummy read to clear CNVR flag 

Although the datasheet states the CNVR flag is cleared by reading the
BUS_VOLTAGE register, it is actually cleared by reading any of the
voltage/current/power registers.

The behaviour has been confirmed by TI support:
http://e2e.ti.com/support/amplifiers/current-shunt-monitors/f/931/p/647053/2378282



Signed-off-by: default avatarStefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d456d61f

drivers/iio/adc/ina2xx-adc.c

+0 −14
Original line number Diff line number Diff line
@@ -705,7 +705,6 @@ static int ina2xx_work_buffer(struct iio_dev *indio_dev) 
	int bit, ret, i = 0;

	s64 time_a, time_b;

	unsigned int alert;

	int cnvr_need_clear = 0;



	time_a = iio_get_time_ns(indio_dev);
@@ -730,7 +729,6 @@ static int ina2xx_work_buffer(struct iio_dev *indio_dev) 
				ret = regmap_read(chip->regmap,

						  INA2XX_BUS_VOLTAGE, &alert);

				alert &= INA219_CNVR;

				cnvr_need_clear = alert;

			}



			if (ret < 0)
@@ -752,18 +750,6 @@ static int ina2xx_work_buffer(struct iio_dev *indio_dev) 
			return ret;



		data[i++] = val;



		if (INA2XX_SHUNT_VOLTAGE + bit == INA2XX_POWER)

			cnvr_need_clear = 0;

	}



	/* Dummy read on INA219 power register to clear CNVR flag */

	if (cnvr_need_clear && chip->config->chip_id == ina219) {

		unsigned int val;



		ret = regmap_read(chip->regmap, INA2XX_POWER, &val);

		if (ret < 0)

			return ret;

	}



	time_b = iio_get_time_ns(indio_dev);