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: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
index 8c81204..b027d48 100644 (file)
--- a/drivers/iio/adc/ina2xx-adc.c
+++ b/drivers/iio/adc/ina2xx-adc.c
@@ -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);