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Subject[PATCH V1]iio: adc: spmi-vadc: Changes to support different scaling
Date
Add changes to support different scale functions to convert adc code to
physical units.

Signed-off-by: Rama Krishna Phani A <rphani@codeaurora.org>
---
drivers/iio/adc/qcom-spmi-vadc.c | 319 ++++++++++++++++++++++++++++++---------
1 file changed, 249 insertions(+), 70 deletions(-)

diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
index c2babe5..e605a9d 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
@@ -84,7 +84,7 @@
#define VADC_MAX_ADC_CODE 0xa800

#define VADC_ABSOLUTE_RANGE_UV 625000
-#define VADC_RATIOMETRIC_RANGE_UV 1800000
+#define VADC_RATIOMETRIC_RANGE 1800

#define VADC_DEF_PRESCALING 0 /* 1:1 */
#define VADC_DEF_DECIMATION 0 /* 512 */
@@ -92,6 +92,8 @@
#define VADC_DEF_AVG_SAMPLES 0 /* 1 sample */
#define VADC_DEF_CALIB_TYPE VADC_CALIB_ABSOLUTE

+#define VADC_DEF_SCALE_FN SCALE_DEFAULT
+
#define VADC_DECIMATION_MIN 512
#define VADC_DECIMATION_MAX 4096

@@ -100,9 +102,43 @@

#define KELVINMIL_CELSIUSMIL 273150

+#define PMI_CHG_SCALE_1 -138890
+#define PMI_CHG_SCALE_2 391750000000
+
#define VADC_CHAN_MIN VADC_USBIN
#define VADC_CHAN_MAX VADC_LR_MUX3_BUF_PU1_PU2_XO_THERM

+/**
+ * enum vadc_scale_fn_type - Scaling function to convert ADC code to
+ * physical scaled units for the channel.
+ * %SCALE_DEFAULT: Default scaling to convert raw adc code to voltage (uV).
+ * %SCALE_THERM_100K_PULLUP: Returns temperature in millidegC.
+ * Uses a mapping table with 100K pullup.
+ * %SCALE_PMIC_THERM: Returns result in milli degree's Centigrade.
+ * %SCALE_XOTHERM: Returns XO thermistor voltage in millidegC.
+ * %SCALE_PMI_CHG_TEMP: Conversion for PMI CHG temp
+ * %SCALE_NONE: Do not use this scaling type.
+ */
+enum vadc_scale_fn_type {
+ SCALE_DEFAULT = 0,
+ SCALE_THERM_100K_PULLUP,
+ SCALE_PMIC_THERM,
+ SCALE_XOTHERM,
+ SCALE_PMI_CHG_TEMP,
+ SCALE_NONE,
+};
+
+/**
+ * struct vadc_map_pt - Map the graph representation for ADC channel
+ * @x: Represent the ADC digitized code.
+ * @y: Represent the physical data which can be temperature, voltage,
+ * resistance.
+ */
+struct vadc_map_pt {
+ s32 x;
+ s32 y;
+};
+
/*
* VADC_CALIB_ABSOLUTE: uses the 625mV and 1.25V as reference channels.
* VADC_CALIB_RATIOMETRIC: uses the reference voltage (1.8V) and GND for
@@ -148,6 +184,9 @@ struct vadc_prescale_ratio {
* start of conversion.
* @avg_samples: ability to provide single result from the ADC
* that is an average of multiple measurements.
+ *@scale_function: Represents the scaling function to convert voltage
+ * physical units desired by the client for the channel.
+ * Referenced from enum vadc_scale_fn_type.
*/
struct vadc_channel_prop {
unsigned int channel;
@@ -156,6 +195,7 @@ struct vadc_channel_prop {
unsigned int prescale;
unsigned int hw_settle_time;
unsigned int avg_samples;
+ unsigned int scale_function;
};

/**
@@ -197,6 +237,44 @@ struct vadc_priv {
{.num = 1, .den = 10}
};

+/* Voltage to temperature */
+static const struct vadc_map_pt adcmap_100k_104ef_104fb[] = {
+ {1758, -40},
+ {1742, -35},
+ {1719, -30},
+ {1691, -25},
+ {1654, -20},
+ {1608, -15},
+ {1551, -10},
+ {1483, -5},
+ {1404, 0},
+ {1315, 5},
+ {1218, 10},
+ {1114, 15},
+ {1007, 20},
+ {900, 25},
+ {795, 30},
+ {696, 35},
+ {605, 40},
+ {522, 45},
+ {448, 50},
+ {383, 55},
+ {327, 60},
+ {278, 65},
+ {237, 70},
+ {202, 75},
+ {172, 80},
+ {146, 85},
+ {125, 90},
+ {107, 95},
+ {92, 100},
+ {79, 105},
+ {68, 110},
+ {59, 115},
+ {51, 120},
+ {44, 125}
+};
+
static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
{
return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
@@ -418,7 +496,7 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc)
u16 read_1, read_2;
int ret;

- vadc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE_UV;
+ vadc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE;
vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;

prop = vadc_get_channel(vadc, VADC_REF_1250MV);
@@ -468,27 +546,128 @@ 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 int vadc_map_voltage_temp(const struct vadc_map_pt *pts,
+ u32 tablesize, s32 input, s64 *output)
{
- const struct vadc_prescale_ratio *prescale;
- s64 voltage;
+ bool descending = 1;
+ u32 i = 0;
+
+ if (!pts)
+ return -EINVAL;
+
+ /* Check if table is descending or ascending */
+ if (tablesize > 1) {
+ if (pts[0].x < pts[1].x)
+ descending = 0;
+ }
+
+ while (i < tablesize) {
+ if ((descending == 1) && (pts[i].x < input)) {
+ /* table entry is less than measured*/
+ /* value and table is descending, stop */
+ break;
+ } else if ((descending == 0) &&
+ (pts[i].x > input)) {
+ /* table entry is greater than measured*/
+ /*value and table is ascending, stop */
+ break;
+ }
+ i++;
+ }
+
+ if (i == 0) {
+ *output = pts[0].y;
+ } else if (i == tablesize) {
+ *output = pts[tablesize - 1].y;
+ } else {
+ /* result is between search_index and search_index-1 */
+ /* interpolate linearly */
+ *output = (((s32)((pts[i].y - pts[i - 1].y) *
+ (input - pts[i - 1].x)) /
+ (pts[i].x - pts[i - 1].x)) +
+ pts[i - 1].y);
+ }

- voltage = adc_code - vadc->graph[prop->calibration].gnd;
- voltage *= vadc->graph[prop->calibration].dx;
- voltage = div64_s64(voltage, vadc->graph[prop->calibration].dy);
+ return 0;
+}

+static void vadc_scale_calib(struct vadc_priv *vadc, u16 adc_code,
+ const struct vadc_channel_prop *prop,
+ s64 *scale_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)
- voltage += vadc->graph[prop->calibration].dx;
+ *scale_voltage +=
+ vadc->graph[prop->calibration].dx;

- if (voltage < 0)
- voltage = 0;
+ if (*scale_voltage < 0)
+ *scale_voltage = 0;
+}

- prescale = &vadc_prescale_ratios[prop->prescale];
+static s64 vadc_scale_fn(struct vadc_priv *vadc,
+ const struct vadc_channel_prop *prop, u16 adc_code)
+{
+ const struct vadc_prescale_ratio *prescale;
+ s64 voltage = 0, result = 0;
+ int ret;

- voltage = voltage * prescale->den;
+ switch (prop->scale_function) {

- return div64_s64(voltage, prescale->num);
+ case SCALE_DEFAULT:
+ vadc_scale_calib(vadc, adc_code, prop, &voltage);
+
+ prescale = &vadc_prescale_ratios[prop->prescale];
+ voltage = voltage * prescale->den;
+ return div64_s64(voltage, prescale->num);
+
+ case SCALE_THERM_100K_PULLUP:
+ case SCALE_XOTHERM:
+ vadc_scale_calib(vadc, adc_code, prop, &voltage);
+
+ if (prop->calibration == VADC_CALIB_ABSOLUTE)
+ do_div(voltage, 1000);
+
+ vadc_map_voltage_temp(adcmap_100k_104ef_104fb,
+ ARRAY_SIZE(adcmap_100k_104ef_104fb),
+ voltage, &result);
+ result *= 1000;
+ return result;
+
+ case SCALE_PMIC_THERM:
+ vadc_scale_calib(vadc, adc_code, prop, &voltage);
+
+ if (voltage > 0) {
+ prescale = &vadc_prescale_ratios[prop->prescale];
+ voltage = voltage * prescale->den;
+ do_div(voltage, prescale->num * 2);
+ } else {
+ voltage = 0;
+ }
+
+ voltage -= KELVINMIL_CELSIUSMIL;
+
+ return voltage;
+
+ case SCALE_PMI_CHG_TEMP:
+ vadc_scale_calib(vadc, adc_code, prop, &voltage);
+ prescale = &vadc_prescale_ratios[prop->prescale];
+ voltage = voltage * prescale->den;
+
+ voltage = div64_s64(voltage, prescale->num);
+ voltage = ((PMI_CHG_SCALE_1) * (voltage * 2));
+ voltage = (voltage + PMI_CHG_SCALE_2);
+ return div64_s64(voltage, 1000000);
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
}

static int vadc_decimation_from_dt(u32 value)
@@ -552,11 +731,8 @@ static int vadc_read_raw(struct iio_dev *indio_dev,
if (ret)
break;

- *val = vadc_calibrate(vadc, prop, adc_code);
+ *val = vadc_scale_fn(vadc, prop, adc_code);

- /* 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 +740,8 @@ 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;
@@ -613,11 +785,13 @@ struct vadc_channels {
}, \

#define VADC_CHAN_TEMP(_dname, _pre) \
- VADC_CHAN(_dname, IIO_TEMP, BIT(IIO_CHAN_INFO_PROCESSED), _pre) \
+ VADC_CHAN(_dname, IIO_TEMP, \
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_PROCESSED), \
+ _pre) \

#define VADC_CHAN_VOLT(_dname, _pre) \
- VADC_CHAN(_dname, IIO_VOLTAGE, \
- BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
+ VADC_CHAN(_dname, IIO_VOLTAGE, \
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_PROCESSED),\
_pre) \

/*
@@ -637,12 +811,11 @@ struct vadc_channels {
VADC_CHAN_TEMP(DIE_TEMP, 0)
VADC_CHAN_VOLT(REF_625MV, 0)
VADC_CHAN_VOLT(REF_1250MV, 0)
- VADC_CHAN_VOLT(CHG_TEMP, 0)
+ VADC_CHAN_TEMP(CHG_TEMP, 0)
VADC_CHAN_VOLT(SPARE1, 0)
VADC_CHAN_VOLT(SPARE2, 0)
VADC_CHAN_VOLT(GND_REF, 0)
VADC_CHAN_VOLT(VDD_VADC, 0)
-
VADC_CHAN_VOLT(P_MUX1_1_1, 0)
VADC_CHAN_VOLT(P_MUX2_1_1, 0)
VADC_CHAN_VOLT(P_MUX3_1_1, 0)
@@ -659,7 +832,6 @@ struct vadc_channels {
VADC_CHAN_VOLT(P_MUX14_1_1, 0)
VADC_CHAN_VOLT(P_MUX15_1_1, 0)
VADC_CHAN_VOLT(P_MUX16_1_1, 0)
-
VADC_CHAN_VOLT(P_MUX1_1_3, 1)
VADC_CHAN_VOLT(P_MUX2_1_3, 1)
VADC_CHAN_VOLT(P_MUX3_1_3, 1)
@@ -676,7 +848,6 @@ struct vadc_channels {
VADC_CHAN_VOLT(P_MUX14_1_3, 1)
VADC_CHAN_VOLT(P_MUX15_1_3, 1)
VADC_CHAN_VOLT(P_MUX16_1_3, 1)
-
VADC_CHAN_VOLT(LR_MUX1_BAT_THERM, 0)
VADC_CHAN_VOLT(LR_MUX2_BAT_ID, 0)
VADC_CHAN_VOLT(LR_MUX3_XO_THERM, 0)
@@ -690,42 +861,40 @@ struct vadc_channels {
VADC_CHAN_VOLT(AMUX_PU1, 0)
VADC_CHAN_VOLT(AMUX_PU2, 0)
VADC_CHAN_VOLT(LR_MUX3_BUF_XO_THERM, 0)
-
- VADC_CHAN_VOLT(LR_MUX1_PU1_BAT_THERM, 0)
+ VADC_CHAN_TEMP(LR_MUX1_PU1_BAT_THERM, 0)
VADC_CHAN_VOLT(LR_MUX2_PU1_BAT_ID, 0)
- VADC_CHAN_VOLT(LR_MUX3_PU1_XO_THERM, 0)
- VADC_CHAN_VOLT(LR_MUX4_PU1_AMUX_THM1, 0)
- VADC_CHAN_VOLT(LR_MUX5_PU1_AMUX_THM2, 0)
- VADC_CHAN_VOLT(LR_MUX6_PU1_AMUX_THM3, 0)
+ VADC_CHAN_TEMP(LR_MUX3_PU1_XO_THERM, 0)
+ VADC_CHAN_TEMP(LR_MUX4_PU1_AMUX_THM1, 0)
+ VADC_CHAN_TEMP(LR_MUX5_PU1_AMUX_THM2, 0)
+ VADC_CHAN_TEMP(LR_MUX6_PU1_AMUX_THM3, 0)
VADC_CHAN_VOLT(LR_MUX7_PU1_AMUX_HW_ID, 0)
- VADC_CHAN_VOLT(LR_MUX8_PU1_AMUX_THM4, 0)
- VADC_CHAN_VOLT(LR_MUX9_PU1_AMUX_THM5, 0)
+ VADC_CHAN_TEMP(LR_MUX8_PU1_AMUX_THM4, 0)
+ VADC_CHAN_TEMP(LR_MUX9_PU1_AMUX_THM5, 0)
VADC_CHAN_VOLT(LR_MUX10_PU1_AMUX_USB_ID, 0)
- VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_XO_THERM, 0)
-
- VADC_CHAN_VOLT(LR_MUX1_PU2_BAT_THERM, 0)
+ VADC_CHAN_TEMP(LR_MUX3_BUF_PU1_XO_THERM, 0)
+ VADC_CHAN_TEMP(LR_MUX1_PU2_BAT_THERM, 0)
VADC_CHAN_VOLT(LR_MUX2_PU2_BAT_ID, 0)
- VADC_CHAN_VOLT(LR_MUX3_PU2_XO_THERM, 0)
- VADC_CHAN_VOLT(LR_MUX4_PU2_AMUX_THM1, 0)
- VADC_CHAN_VOLT(LR_MUX5_PU2_AMUX_THM2, 0)
- VADC_CHAN_VOLT(LR_MUX6_PU2_AMUX_THM3, 0)
+ VADC_CHAN_TEMP(LR_MUX3_PU2_XO_THERM, 0)
+ VADC_CHAN_TEMP(LR_MUX4_PU2_AMUX_THM1, 0)
+ VADC_CHAN_TEMP(LR_MUX5_PU2_AMUX_THM2, 0)
+ VADC_CHAN_TEMP(LR_MUX6_PU2_AMUX_THM3, 0)
VADC_CHAN_VOLT(LR_MUX7_PU2_AMUX_HW_ID, 0)
- VADC_CHAN_VOLT(LR_MUX8_PU2_AMUX_THM4, 0)
- VADC_CHAN_VOLT(LR_MUX9_PU2_AMUX_THM5, 0)
+ VADC_CHAN_TEMP(LR_MUX8_PU2_AMUX_THM4, 0)
+ VADC_CHAN_TEMP(LR_MUX9_PU2_AMUX_THM5, 0)
VADC_CHAN_VOLT(LR_MUX10_PU2_AMUX_USB_ID, 0)
- VADC_CHAN_VOLT(LR_MUX3_BUF_PU2_XO_THERM, 0)
-
- VADC_CHAN_VOLT(LR_MUX1_PU1_PU2_BAT_THERM, 0)
+ VADC_CHAN_TEMP(LR_MUX3_BUF_PU2_XO_THERM, 0)
+ VADC_CHAN_TEMP(LR_MUX1_PU1_PU2_BAT_THERM, 0)
VADC_CHAN_VOLT(LR_MUX2_PU1_PU2_BAT_ID, 0)
- VADC_CHAN_VOLT(LR_MUX3_PU1_PU2_XO_THERM, 0)
- VADC_CHAN_VOLT(LR_MUX4_PU1_PU2_AMUX_THM1, 0)
- VADC_CHAN_VOLT(LR_MUX5_PU1_PU2_AMUX_THM2, 0)
- VADC_CHAN_VOLT(LR_MUX6_PU1_PU2_AMUX_THM3, 0)
+ VADC_CHAN_TEMP(LR_MUX3_PU1_PU2_XO_THERM, 0)
+ VADC_CHAN_TEMP(LR_MUX4_PU1_PU2_AMUX_THM1, 0)
+ VADC_CHAN_TEMP(LR_MUX5_PU1_PU2_AMUX_THM2, 0)
+ VADC_CHAN_TEMP(LR_MUX6_PU1_PU2_AMUX_THM3, 0)
VADC_CHAN_VOLT(LR_MUX7_PU1_PU2_AMUX_HW_ID, 0)
- VADC_CHAN_VOLT(LR_MUX8_PU1_PU2_AMUX_THM4, 0)
- VADC_CHAN_VOLT(LR_MUX9_PU1_PU2_AMUX_THM5, 0)
+ VADC_CHAN_TEMP(LR_MUX8_PU1_PU2_AMUX_THM4, 0)
+ VADC_CHAN_TEMP(LR_MUX9_PU1_PU2_AMUX_THM5, 0)
VADC_CHAN_VOLT(LR_MUX10_PU1_PU2_AMUX_USB_ID, 0)
- VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_PU2_XO_THERM, 0)
+ VADC_CHAN_TEMP(LR_MUX3_BUF_PU1_PU2_XO_THERM, 0)
+
};

static int vadc_get_dt_channel_data(struct device *dev,
@@ -802,6 +971,11 @@ static int vadc_get_dt_channel_data(struct device *dev,
prop->avg_samples = VADC_DEF_AVG_SAMPLES;
}

+ ret = of_property_read_u32(node, "qcom,scale-function",
+ &prop->scale_function);
+ if (ret)
+ prop->scale_function = SCALE_DEFAULT;
+
if (of_property_read_bool(node, "qcom,ratiometric"))
prop->calibration = VADC_CALIB_RATIOMETRIC;
else
@@ -850,9 +1024,9 @@ static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)

iio_chan->channel = prop.channel;
iio_chan->datasheet_name = vadc_chan->datasheet_name;
+ iio_chan->extend_name = child->name;
iio_chan->info_mask_separate = vadc_chan->info_mask;
iio_chan->type = vadc_chan->type;
- iio_chan->indexed = 1;
iio_chan->address = index++;

iio_chan++;
@@ -964,16 +1138,21 @@ static int vadc_probe(struct platform_device *pdev)
if (ret)
return ret;

- irq_eoc = platform_get_irq(pdev, 0);
- if (irq_eoc < 0) {
- if (irq_eoc == -EPROBE_DEFER || irq_eoc == -EINVAL)
- return irq_eoc;
- vadc->poll_eoc = true;
- } else {
- ret = devm_request_irq(dev, irq_eoc, vadc_isr, 0,
- "spmi-vadc", vadc);
- if (ret)
- return ret;
+ vadc->poll_eoc = of_property_read_bool(node,
+ "qcom,vadc-poll-eoc");
+
+ if (!vadc->poll_eoc) {
+ irq_eoc = platform_get_irq(pdev, 0);
+ if (irq_eoc < 0) {
+ if (irq_eoc == -EPROBE_DEFER || irq_eoc == -EINVAL)
+ return irq_eoc;
+ vadc->poll_eoc = true;
+ } else {
+ ret = devm_request_irq(dev, irq_eoc, vadc_isr, 0,
+ "spmi-vadc", vadc);
+ if (ret)
+ return ret;
+ }
}

ret = vadc_reset(vadc);
--
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