From e5c2ce6bacfa98fdfc6fe984833656fabaeecd2b Mon Sep 17 00:00:00 2001 From: Stefan Brüns Date: Wed, 24 May 2017 02:09:07 +0200 Subject: iio: adc: Fix polling of INA219 conversion ready flag MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Stefan Brüns Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ina2xx-adc.c | 36 +++++++++++++++++++++++++++++------- 1 file changed, 29 insertions(+), 7 deletions(-) (limited to 'drivers/iio') diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c index 232c0b80d658..68884d26b50c 100644 --- a/drivers/iio/adc/ina2xx-adc.c +++ b/drivers/iio/adc/ina2xx-adc.c @@ -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); -- cgit v1.2.3