[PATCH v2 3/7] iio: adc: ina2xx: Remove unneeded dummy read to clear CNVR flag

From: Stefan BrÃns
Date: Thu Dec 21 2017 - 13:33:59 EST


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 BrÃns <stefan.bruens@xxxxxxxxxxxxxx>
---

Changes in v2: None

drivers/iio/adc/ina2xx-adc.c | 14 --------------
1 file changed, 14 deletions(-)

diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
index 8c8120406f52..b027d485398b 100644
--- 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);
--
2.15.1