Commit e5c2ce6b authored by Stefan Brüns's avatar Stefan Brüns Committed by Jonathan Cameron
Browse files

iio: adc: Fix polling of INA219 conversion ready flag 



While the INA226 has a conversion ready flag (CVRF) in the R/W Mask/Enable
register with read-to-clear semantics, the corresponding bit of the INA219
(CNVR) is part of the bus voltage register. The flag is cleared by reading
the power register.

Signed-off-by: default avatarStefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 7b34697e

drivers/iio/adc/ina2xx-adc.c

+29 −7
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ 


#define INA226_MASK_ENABLE		0x06

#define INA226_CVRF			BIT(3)

#define INA219_CNVR			BIT(1)



#define INA2XX_MAX_REGISTERS            8
@@ -592,6 +593,7 @@ 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);
@@ -603,22 +605,30 @@ static int ina2xx_work_buffer(struct iio_dev *indio_dev) 
	 * we check the ConVersionReadyFlag.

	 * On hardware that supports using the ALERT pin to toggle a

	 * GPIO a triggered buffer could be used instead.

	 * For now, we pay for that extra read of the ALERT register

	 * For now, we do an extra read of the MASK_ENABLE register (INA226)

	 * resp. the BUS_VOLTAGE register (INA219).

	 */

	if (!chip->allow_async_readout)

		do {

			ret = regmap_read(chip->regmap, INA226_MASK_ENABLE,

					  &alert);

			if (chip->config->chip_id == ina226) {

				ret = regmap_read(chip->regmap,

						  INA226_MASK_ENABLE, &alert);

				alert &= INA226_CVRF;

			} else {

				ret = regmap_read(chip->regmap,

						  INA2XX_BUS_VOLTAGE, &alert);

				alert &= INA219_CNVR;

				cnvr_need_clear = alert;

			}



			if (ret < 0)

				return ret;



			alert &= INA226_CVRF;

		} while (!alert);



	/*

	 * Single register reads: bulk_read will not work with ina226

	 * as there is no auto-increment of the address register for

	 * data length longer than 16bits.

	 * Single register reads: bulk_read will not work with ina226/219

	 * as there is no auto-increment of the register pointer.

	 */

	for_each_set_bit(bit, indio_dev->active_scan_mask,

			 indio_dev->masklength) {
@@ -630,6 +640,18 @@ 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);