On Sat, 28 Oct 2017 23:12:46 +0200 Stefan Brüns <[email protected]> wrote:
> Lower bits of the INA219/220 bus voltage register are conversion > status flags, properly shift the value. > > When reading via IIO buffer, the value is passed on unaltered, > shifting is the responsibility of the user. > > Signed-off-by: Stefan Brüns <[email protected]> > I thought about sending this as a fix, but as you haven't marked it as such and the effect is very minor I haven't done so. Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > > Changes in v2: > - Apply to the shunt voltage, not bus voltage register > - Shift instead of masking the LSBs > > drivers/iio/adc/ina2xx-adc.c | 26 +++++++++++++++++--------- > 1 file changed, 17 insertions(+), 9 deletions(-) > > diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c > index 3aff9556678f..84094235ff7e 100644 > --- a/drivers/iio/adc/ina2xx-adc.c > +++ b/drivers/iio/adc/ina2xx-adc.c > @@ -44,7 +44,6 @@ > > #define INA226_MASK_ENABLE 0x06 > #define INA226_CVRF BIT(3) > -#define INA219_CNVR BIT(1) > > #define INA2XX_MAX_REGISTERS 8 > > @@ -79,6 +78,11 @@ > #define INA226_ITS_MASK GENMASK(5, 3) > #define INA226_SHIFT_ITS(val) ((val) << 3) > > +/* INA219 Bus voltage register, low bits are flags */ > +#define INA219_OVF BIT(0) > +#define INA219_CNVR BIT(1) > +#define INA219_BUS_VOLTAGE_SHIFT 3 > + > /* Cosmetic macro giving the sampling period for a full P=UxI cycle */ > #define SAMPLING_PERIOD(c) ((c->int_time_vbus + c->int_time_vshunt) \ > * c->avg) > @@ -112,7 +116,7 @@ struct ina2xx_config { > u16 config_default; > int calibration_factor; > int shunt_div; > - int bus_voltage_shift; > + int bus_voltage_shift; /* position of lsb */ > int bus_voltage_lsb; /* uV */ > int power_lsb; /* uW */ > enum ina2xx_ids chip_id; > @@ -135,7 +139,7 @@ static const struct ina2xx_config ina2xx_config[] = { > .config_default = INA219_CONFIG_DEFAULT, > .calibration_factor = 40960000, > .shunt_div = 100, > - .bus_voltage_shift = 3, > + .bus_voltage_shift = INA219_BUS_VOLTAGE_SHIFT, > .bus_voltage_lsb = 4000, > .power_lsb = 20000, > .chip_id = ina219, > @@ -170,6 +174,9 @@ static int ina2xx_read_raw(struct iio_dev *indio_dev, > else > *val = regval; > > + if (chan->address == INA2XX_BUS_VOLTAGE) > + *val >>= chip->config->bus_voltage_shift; > + > return IIO_VAL_INT; > > case IIO_CHAN_INFO_OVERSAMPLING_RATIO: > @@ -203,9 +210,9 @@ static int ina2xx_read_raw(struct iio_dev *indio_dev, > return IIO_VAL_FRACTIONAL; > > case INA2XX_BUS_VOLTAGE: > - /* processed (mV) = raw*lsb (uV) / (1000 << shift) */ > + /* processed (mV) = raw * lsb (uV) / 1000 */ > *val = chip->config->bus_voltage_lsb; > - *val2 = 1000 << chip->config->bus_voltage_shift; > + *val2 = 1000; > return IIO_VAL_FRACTIONAL; > > case INA2XX_POWER: > @@ -532,7 +539,7 @@ static ssize_t ina2xx_shunt_resistor_store(struct device > *dev, > * Sampling Freq is a consequence of the integration times of > * the Voltage channels. > */ > -#define INA219_CHAN_VOLTAGE(_index, _address) { \ > +#define INA219_CHAN_VOLTAGE(_index, _address, _shift) { \ > .type = IIO_VOLTAGE, \ > .address = (_address), \ > .indexed = 1, \ > @@ -544,7 +551,8 @@ static ssize_t ina2xx_shunt_resistor_store(struct device > *dev, > .scan_index = (_index), \ > .scan_type = { \ > .sign = 'u', \ > - .realbits = 16, \ > + .shift = _shift, \ > + .realbits = 16 - _shift, \ > .storagebits = 16, \ > .endianness = IIO_LE, \ > } \ > @@ -579,8 +587,8 @@ static const struct iio_chan_spec ina226_channels[] = { > }; > > static const struct iio_chan_spec ina219_channels[] = { > - INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE), > - INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE), > + INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE, 0), > + INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE, INA219_BUS_VOLTAGE_SHIFT), > INA219_CHAN(IIO_POWER, 2, INA2XX_POWER), > INA219_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT), > IIO_CHAN_SOFT_TIMESTAMP(4),
