On 14/03/16 10:20, Marc Titinger wrote: > The user (or an init script) may setup RShunt via sysfs after the > driver was initialized, for instance based on the EEPROM contents > of a modular probe. The calibration register must be set accordingly. > > Signed-off-by: Marc Titinger <marc.titinger@xxxxxxxxxxxx> > --- > v2 of http://www.spinics.net/lists/linux-iio/msg23402.html: > > - remove unnecessary line insertions > - cleanup leftover unused variable (build warning) > - patch 2/2 is unchanged (see v1) Err, can't find it for some reason. Anyhow, applied this one to the togreg branch of iio.git - pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > drivers/iio/adc/ina2xx-adc.c | 39 ++++++++++++++++++++++++--------------- > 1 file changed, 24 insertions(+), 15 deletions(-) > > diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c > index 65909d5..4e56fe3 100644 > --- a/drivers/iio/adc/ina2xx-adc.c > +++ b/drivers/iio/adc/ina2xx-adc.c > @@ -350,6 +350,23 @@ static ssize_t ina2xx_allow_async_readout_store(struct device *dev, > return len; > } > > +/* > + * Set current LSB to 1mA, shunt is in uOhms > + * (equation 13 in datasheet). We hardcode a Current_LSB > + * of 1.0 x10-6. The only remaining parameter is RShunt. > + * There is no need to expose the CALIBRATION register > + * to the user for now. But we need to reset this register > + * if the user updates RShunt after driver init, e.g upon > + * reading an EEPROM/Probe-type value. > + */ > +static int ina2xx_set_calibration(struct ina2xx_chip_info *chip) > +{ > + u16 regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor, > + chip->shunt_resistor); > + > + return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval); > +} > + > static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val) > { > if (val <= 0 || val > chip->config->calibration_factor) > @@ -385,6 +402,11 @@ static ssize_t ina2xx_shunt_resistor_store(struct device *dev, > if (ret) > return ret; > > + /* Update the Calibration register */ > + ret = ina2xx_set_calibration(chip); > + if (ret) > + return ret; > + > return len; > } > > @@ -602,24 +624,11 @@ static const struct iio_info ina2xx_info = { > /* Initialize the configuration and calibration registers. */ > static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config) > { > - u16 regval; > - int ret; > - > - ret = regmap_write(chip->regmap, INA2XX_CONFIG, config); > + int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config); > if (ret) > return ret; > > - /* > - * Set current LSB to 1mA, shunt is in uOhms > - * (equation 13 in datasheet). We hardcode a Current_LSB > - * of 1.0 x10-6. The only remaining parameter is RShunt. > - * There is no need to expose the CALIBRATION register > - * to the user for now. > - */ > - regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor, > - chip->shunt_resistor); > - > - return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval); > + return ina2xx_set_calibration(chip); > } > > static int ina2xx_probe(struct i2c_client *client, > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
