summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRama Krishna Phani A <rphani@codeaurora.org>2016-12-09 18:01:49 +0300
committerJonathan Cameron <jic23@kernel.org>2016-12-10 20:25:48 +0300
commitba71704af4a0aae0d9e5812dbdd7bca95e181b14 (patch)
tree065b2c809d853636e838413c1f7ae6087c0c165b
parent29e90cd79f523e6cfbccf4d2b106bebaaac9cdcc (diff)
downloadlinux-ba71704af4a0aae0d9e5812dbdd7bca95e181b14.tar.xz
iio: adc: spmi-vadc: Update function for generic voltage conversion
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@codeaurora.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
-rw-r--r--drivers/iio/adc/qcom-spmi-vadc.c52
1 files changed, 28 insertions, 24 deletions
diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
index c2babe50a0d8..93c0639e21a3 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 @@ err:
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) \
/*