On 09/12/16 15:01, Rama Krishna Phani A wrote:
> Several channels are supported in ADC of PMIC which can be used to
> measure voltage, temperature, current etc., Hardware provides
> readings for all channels in adc code. That adc code needs to be
> converted to voltage. Logic for conversion of adc code to voltage
> is common for all ADC channels(voltage, temperature, current
> .,etc). Implement separate function for generic conversion logic.
>
> Signed-off-by: Rama Krishna Phani A <rphani@xxxxxxxxxxxxxx>
Applied to the togreg branch of iio.git. Will be initially pushed out as
testing for the autobuilders to play with it.
thanks,
Jonathan
> ---
> drivers/iio/adc/qcom-spmi-vadc.c | 52 +++++++++++++++++++++-------------------
> 1 file changed, 28 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
> index c2babe5..93c0639 100644
> --- a/drivers/iio/adc/qcom-spmi-vadc.c
> +++ b/drivers/iio/adc/qcom-spmi-vadc.c
> @@ -1,5 +1,5 @@
> /*
> - * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
> *
> * This program is free software; you can redistribute it and/or modify
> * it under the terms of the GNU General Public License version 2 and
> @@ -468,27 +468,38 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc)
> return ret;
> }
>
> -static s32 vadc_calibrate(struct vadc_priv *vadc,
> - const struct vadc_channel_prop *prop, u16 adc_code)
> +static void vadc_scale_calib(struct vadc_priv *vadc, u16 adc_code,
> + const struct vadc_channel_prop *prop,
> + s64 *scale_voltage)
> {
> - const struct vadc_prescale_ratio *prescale;
> - s64 voltage;
> + *scale_voltage = (adc_code -
> + vadc->graph[prop->calibration].gnd);
> + *scale_voltage *= vadc->graph[prop->calibration].dx;
> + *scale_voltage = div64_s64(*scale_voltage,
> + vadc->graph[prop->calibration].dy);
> + if (prop->calibration == VADC_CALIB_ABSOLUTE)
> + *scale_voltage +=
> + vadc->graph[prop->calibration].dx;
>
> - voltage = adc_code - vadc->graph[prop->calibration].gnd;
> - voltage *= vadc->graph[prop->calibration].dx;
> - voltage = div64_s64(voltage, vadc->graph[prop->calibration].dy);
> + if (*scale_voltage < 0)
> + *scale_voltage = 0;
> +}
>
> - if (prop->calibration == VADC_CALIB_ABSOLUTE)
> - voltage += vadc->graph[prop->calibration].dx;
> +static int vadc_scale_volt(struct vadc_priv *vadc,
> + const struct vadc_channel_prop *prop, u16 adc_code,
> + int *result_uv)
> +{
> + const struct vadc_prescale_ratio *prescale;
> + s64 voltage = 0, result = 0;
>
> - if (voltage < 0)
> - voltage = 0;
> + vadc_scale_calib(vadc, adc_code, prop, &voltage);
>
> prescale = &vadc_prescale_ratios[prop->prescale];
> -
> voltage = voltage * prescale->den;
> + result = div64_s64(voltage, prescale->num);
> + *result_uv = result;
>
> - return div64_s64(voltage, prescale->num);
> + return 0;
> }
>
> static int vadc_decimation_from_dt(u32 value)
> @@ -552,11 +563,8 @@ static int vadc_read_raw(struct iio_dev *indio_dev,
> if (ret)
> break;
>
> - *val = vadc_calibrate(vadc, prop, adc_code);
> + vadc_scale_volt(vadc, prop, adc_code, val);
>
> - /* 2mV/K, return milli Celsius */
> - *val /= 2;
> - *val -= KELVINMIL_CELSIUSMIL;
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_RAW:
> prop = &vadc->chan_props[chan->address];
> @@ -564,12 +572,8 @@ static int vadc_read_raw(struct iio_dev *indio_dev,
> if (ret)
> break;
>
> - *val = vadc_calibrate(vadc, prop, adc_code);
> + *val = (int)adc_code;
> return IIO_VAL_INT;
> - case IIO_CHAN_INFO_SCALE:
> - *val = 0;
> - *val2 = 1000;
> - return IIO_VAL_INT_PLUS_MICRO;
> default:
> ret = -EINVAL;
> break;
> @@ -617,7 +621,7 @@ struct vadc_channels {
>
> #define VADC_CHAN_VOLT(_dname, _pre) \
> VADC_CHAN(_dname, IIO_VOLTAGE, \
> - BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
> + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_PROCESSED),\
> _pre) \
>
> /*
>
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