On 11/12/15 16:49, Marc Titinger wrote:
> Different probe modules use different resistor values. The front-end
> application may read a probe ID (from eeprom) and set the shunt value
> accordingly.
>
> Signed-off-by: Marc Titinger <mtitin...@baylibre.com>
Fair enough.
Applied.
> ---
> drivers/iio/adc/ina2xx-adc.c | 52
> +++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 46 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
> index 615c203..fe42872 100644
> --- a/drivers/iio/adc/ina2xx-adc.c
> +++ b/drivers/iio/adc/ina2xx-adc.c
> @@ -106,7 +106,7 @@ struct ina2xx_chip_info {
> struct task_struct *task;
> const struct ina2xx_config *config;
> struct mutex state_lock;
> - long rshunt;
> + unsigned int shunt_resistor;
> int avg;
> s64 prev_ns; /* track buffer capture time, check for underruns*/
> int int_time_vbus; /* Bus voltage integration time uS */
> @@ -353,6 +353,42 @@ static ssize_t ina2xx_allow_async_readout_store(struct
> device *dev,
> return len;
> }
>
> +static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int
> val)
> +{
> + if (val <= 0 || val > chip->config->calibration_factor)
> + return -EINVAL;
> +
> + chip->shunt_resistor = val;
> + return 0;
> +}
> +
> +static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
> +
> + return sprintf(buf, "%d\n", chip->shunt_resistor);
> +}
> +
> +static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
> + unsigned long val;
> + int ret;
> +
> + ret = kstrtoul((const char *) buf, 10, &val);
> + if (ret)
> + return ret;
> +
> + ret = set_shunt_resistor(chip, val);
> + if (ret)
> + return ret;
> +
> + return len;
> +}
>
> #define INA2XX_CHAN(_type, _index, _address) { \
> .type = (_type), \
> @@ -547,9 +583,14 @@ static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO |
> S_IWUSR,
> ina2xx_allow_async_readout_show,
> ina2xx_allow_async_readout_store, 0);
>
> +static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
> + ina2xx_shunt_resistor_show,
> + ina2xx_shunt_resistor_store, 0);
> +
> static struct attribute *ina2xx_attributes[] = {
> &iio_dev_attr_in_allow_async_readout.dev_attr.attr,
> &iio_const_attr_integration_time_available.dev_attr.attr,
> + &iio_dev_attr_in_shunt_resistor.dev_attr.attr,
> NULL,
> };
>
> @@ -581,7 +622,7 @@ static int ina2xx_init(struct ina2xx_chip_info *chip,
> unsigned int config)
> * to the user for now.
> */
> regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
> - chip->rshunt);
> + chip->shunt_resistor);
>
> return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
> }
> @@ -614,10 +655,9 @@ static int ina2xx_probe(struct i2c_client *client,
> val = INA2XX_RSHUNT_DEFAULT;
> }
>
> - if (val <= 0 || val > chip->config->calibration_factor)
> - return -ENODEV;
> -
> - chip->rshunt = val;
> + ret = set_shunt_resistor(chip, val);
> + if (ret)
> + return ret;
>
> mutex_init(&chip->state_lock);
>
>
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