[PATCH 2/3 v3] iio: adc: break out common code from SPMI VADC
Linus Walleij
linus.walleij at linaro.org
Tue Jan 17 06:25:14 PST 2017
The SPMI VADC and the earlier XOADC share a subset of
common code, so to be able to use the same code in both
drivers, we break out a separate file with the common code,
prefix exported functions that are no longer static with
qcom_* and bake an object qcom-vadc.o that contains both
files: qcom-vadc-common.o and qcom-spmi-vadc.o.
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-arm-msm at vger.kernel.org
Cc: Ivan T. Ivanov <iivanov.xz at gmail.com>
Cc: Andy Gross <andy.gross at linaro.org>
Cc: Bjorn Andersson <bjorn.andersson at linaro.org>
Cc: Stephen Boyd <sboyd at codeaurora.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla at linaro.org>
Cc: Rama Krishna Phani A <rphani at codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
ChangeLog v2->v3:
- Rewrite on top of Rama Krishna's changes. Now we use the
generic channel properties, calibration graph and prescale
settings in all VADC drivers. I did away with the vtable
indirection which I just don't see the point of, it's
better to just pass the type of conversion function around
and have a switch case select the conversion. It was done like
that in the vendor tree but it's not a good idea.
ChangeLog v1->v2:
- No changes just reposting
---
drivers/iio/adc/Makefile | 3 +-
drivers/iio/adc/qcom-spmi-vadc.c | 325 ++-----------------------------------
drivers/iio/adc/qcom-vadc-common.c | 228 ++++++++++++++++++++++++++
drivers/iio/adc/qcom-vadc-common.h | 103 ++++++++++++
4 files changed, 348 insertions(+), 311 deletions(-)
create mode 100644 drivers/iio/adc/qcom-vadc-common.c
create mode 100644 drivers/iio/adc/qcom-vadc-common.h
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 260d083a2b3f..f8fe647b7abe 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -41,7 +41,8 @@ obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
obj-$(CONFIG_NAU7802) += nau7802.o
obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
-obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
+qcom-vadc-y := qcom-vadc-common.o
+obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-vadc.o qcom-spmi-vadc.o
obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
obj-$(CONFIG_STX104) += stx104.o
obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
index 0a19761d656c..9e600bfd1765 100644
--- a/drivers/iio/adc/qcom-spmi-vadc.c
+++ b/drivers/iio/adc/qcom-spmi-vadc.c
@@ -28,6 +28,8 @@
#include <dt-bindings/iio/qcom,spmi-vadc.h>
+#include "qcom-vadc-common.h"
+
/* VADC register and bit definitions */
#define VADC_REVISION2 0x1
#define VADC_REVISION2_SUPPORTED_VADC 1
@@ -75,84 +77,10 @@
#define VADC_DATA 0x60 /* 16 bits */
-#define VADC_CONV_TIME_MIN_US 2000
-#define VADC_CONV_TIME_MAX_US 2100
-
-/* Min ADC code represents 0V */
-#define VADC_MIN_ADC_CODE 0x6000
-/* Max ADC code represents full-scale range of 1.8V */
-#define VADC_MAX_ADC_CODE 0xa800
-
-#define VADC_ABSOLUTE_RANGE_UV 625000
-#define VADC_RATIOMETRIC_RANGE 1800
-
-#define VADC_DEF_PRESCALING 0 /* 1:1 */
-#define VADC_DEF_DECIMATION 0 /* 512 */
-#define VADC_DEF_HW_SETTLE_TIME 0 /* 0 us */
-#define VADC_DEF_AVG_SAMPLES 0 /* 1 sample */
-#define VADC_DEF_CALIB_TYPE VADC_CALIB_ABSOLUTE
-
-#define VADC_DECIMATION_MIN 512
-#define VADC_DECIMATION_MAX 4096
-
-#define VADC_HW_SETTLE_DELAY_MAX 10000
-#define VADC_AVG_SAMPLES_MAX 512
-
-#define KELVINMIL_CELSIUSMIL 273150
-
-#define PMI_CHG_SCALE_1 -138890
-#define PMI_CHG_SCALE_2 391750000000LL
-
#define VADC_CHAN_MIN VADC_USBIN
#define VADC_CHAN_MAX VADC_LR_MUX3_BUF_PU1_PU2_XO_THERM
/**
- * 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
- * calibration.
- */
-enum vadc_calibration {
- VADC_CALIB_ABSOLUTE = 0,
- VADC_CALIB_RATIOMETRIC
-};
-
-/**
- * struct vadc_linear_graph - Represent ADC characteristics.
- * @dy: numerator slope to calculate the gain.
- * @dx: denominator slope to calculate the gain.
- * @gnd: A/D word of the ground reference used for the channel.
- *
- * Each ADC device has different offset and gain parameters which are
- * computed to calibrate the device.
- */
-struct vadc_linear_graph {
- s32 dy;
- s32 dx;
- s32 gnd;
-};
-
-/**
- * struct vadc_prescale_ratio - Represent scaling ratio for ADC input.
- * @num: the inverse numerator of the gain applied to the input channel.
- * @den: the inverse denominator of the gain applied to the input channel.
- */
-struct vadc_prescale_ratio {
- u32 num;
- u32 den;
-};
-
-/**
* struct vadc_channel_prop - VADC channel property.
* @channel: channel number, refer to the channel list.
* @calibration: calibration type.
@@ -162,9 +90,8 @@ 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_fn: Represents the scaling function to convert voltage
+ * @scale_fn_type: 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;
@@ -173,7 +100,7 @@ struct vadc_channel_prop {
unsigned int prescale;
unsigned int hw_settle_time;
unsigned int avg_samples;
- unsigned int scale_fn;
+ enum vadc_scale_fn_type scale_fn_type;
};
/**
@@ -204,35 +131,6 @@ struct vadc_priv {
struct mutex lock;
};
-/**
- * struct vadc_scale_fn - Scaling function prototype
- * @scale: Function pointer to one of the scaling functions
- * which takes the adc properties, channel properties,
- * and returns the physical result.
- */
-struct vadc_scale_fn {
- int (*scale)(struct vadc_priv *, const struct vadc_channel_prop *,
- u16, int *);
-};
-
-/**
- * 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
- */
-enum vadc_scale_fn_type {
- SCALE_DEFAULT = 0,
- SCALE_THERM_100K_PULLUP,
- SCALE_PMIC_THERM,
- SCALE_XOTHERM,
- SCALE_PMI_CHG_TEMP,
-};
-
static const struct vadc_prescale_ratio vadc_prescale_ratios[] = {
{.num = 1, .den = 1},
{.num = 1, .den = 3},
@@ -244,44 +142,6 @@ static const struct vadc_prescale_ratio vadc_prescale_ratios[] = {
{.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);
@@ -553,159 +413,6 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc)
return ret;
}
-static int vadc_map_voltage_temp(const struct vadc_map_pt *pts,
- u32 tablesize, s32 input, s64 *output)
-{
- 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) && (pts[i].x < input)) {
- /* table entry is less than measured*/
- /* value and table is descending, stop */
- break;
- } else if ((!descending) &&
- (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);
- }
-
- 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)
- *scale_voltage +=
- vadc->graph[prop->calibration].dx;
-
- if (*scale_voltage < 0)
- *scale_voltage = 0;
-}
-
-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;
-
- 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 0;
-}
-
-static int vadc_scale_therm(struct vadc_priv *vadc,
- const struct vadc_channel_prop *prop, u16 adc_code,
- int *result_mdec)
-{
- s64 voltage = 0, result = 0;
-
- vadc_scale_calib(vadc, adc_code, prop, &voltage);
-
- if (prop->calibration == VADC_CALIB_ABSOLUTE)
- voltage = div64_s64(voltage, 1000);
-
- vadc_map_voltage_temp(adcmap_100k_104ef_104fb,
- ARRAY_SIZE(adcmap_100k_104ef_104fb),
- voltage, &result);
- result *= 1000;
- *result_mdec = result;
-
- return 0;
-}
-
-static int vadc_scale_die_temp(struct vadc_priv *vadc,
- const struct vadc_channel_prop *prop,
- u16 adc_code, int *result_mdec)
-{
- const struct vadc_prescale_ratio *prescale;
- s64 voltage = 0;
- u64 temp; /* Temporary variable for do_div */
-
- vadc_scale_calib(vadc, adc_code, prop, &voltage);
-
- if (voltage > 0) {
- prescale = &vadc_prescale_ratios[prop->prescale];
- temp = voltage * prescale->den;
- do_div(temp, prescale->num * 2);
- voltage = temp;
- } else {
- voltage = 0;
- }
-
- voltage -= KELVINMIL_CELSIUSMIL;
- *result_mdec = voltage;
-
- return 0;
-}
-
-static int vadc_scale_chg_temp(struct vadc_priv *vadc,
- const struct vadc_channel_prop *prop,
- u16 adc_code, int *result_mdec)
-{
- const struct vadc_prescale_ratio *prescale;
- s64 voltage = 0, result = 0;
-
- 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);
- result = div64_s64(voltage, 1000000);
- *result_mdec = result;
-
- return 0;
-}
-
-static int vadc_decimation_from_dt(u32 value)
-{
- if (!is_power_of_2(value) || value < VADC_DECIMATION_MIN ||
- value > VADC_DECIMATION_MAX)
- return -EINVAL;
-
- return __ffs64(value / VADC_DECIMATION_MIN);
-}
-
static int vadc_prescaling_from_dt(u32 num, u32 den)
{
unsigned int pre;
@@ -742,14 +449,6 @@ static int vadc_avg_samples_from_dt(u32 value)
return __ffs64(value);
}
-static struct vadc_scale_fn scale_fn[] = {
- [SCALE_DEFAULT] = {vadc_scale_volt},
- [SCALE_THERM_100K_PULLUP] = {vadc_scale_therm},
- [SCALE_PMIC_THERM] = {vadc_scale_die_temp},
- [SCALE_XOTHERM] = {vadc_scale_therm},
- [SCALE_PMI_CHG_TEMP] = {vadc_scale_chg_temp},
-};
-
static int vadc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2,
long mask)
@@ -766,7 +465,13 @@ static int vadc_read_raw(struct iio_dev *indio_dev,
if (ret)
break;
- scale_fn[prop->scale_fn].scale(vadc, prop, adc_code, val);
+ ret = qcom_vadc_scale(prop->scale_fn_type,
+ &vadc->graph[prop->calibration],
+ &vadc_prescale_ratios[prop->prescale],
+ (prop->calibration == VADC_CALIB_ABSOLUTE),
+ adc_code, val);
+ if (ret)
+ break;
return IIO_VAL_INT;
case IIO_CHAN_INFO_RAW:
@@ -809,7 +514,7 @@ struct vadc_channels {
unsigned int prescale_index;
enum iio_chan_type type;
long info_mask;
- unsigned int scale_fn;
+ enum vadc_scale_fn_type scale_fn_type;
};
#define VADC_CHAN(_dname, _type, _mask, _pre, _scale) \
@@ -818,7 +523,7 @@ struct vadc_channels {
.prescale_index = _pre, \
.type = _type, \
.info_mask = _mask, \
- .scale_fn = _scale \
+ .scale_fn_type = _scale \
}, \
#define VADC_NO_CHAN(_dname, _type, _mask, _pre) \
@@ -976,7 +681,7 @@ static int vadc_get_dt_channel_data(struct device *dev,
ret = of_property_read_u32(node, "qcom,decimation", &value);
if (!ret) {
- ret = vadc_decimation_from_dt(value);
+ ret = qcom_vadc_decimation_from_dt(value);
if (ret < 0) {
dev_err(dev, "%02x invalid decimation %d\n",
chan, value);
@@ -1068,7 +773,7 @@ static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
return ret;
}
- prop.scale_fn = vadc_chans[prop.channel].scale_fn;
+ prop.scale_fn_type = vadc_chans[prop.channel].scale_fn_type;
vadc->chan_props[index] = prop;
vadc_chan = &vadc_chans[prop.channel];
diff --git a/drivers/iio/adc/qcom-vadc-common.c b/drivers/iio/adc/qcom-vadc-common.c
new file mode 100644
index 000000000000..39f8152f06f1
--- /dev/null
+++ b/drivers/iio/adc/qcom-vadc-common.c
@@ -0,0 +1,228 @@
+#include <linux/bug.h>
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/math64.h>
+#include <linux/log2.h>
+#include <linux/err.h>
+
+#include "qcom-vadc-common.h"
+
+/* 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 qcom_vadc_map_voltage_temp(const struct vadc_map_pt *pts,
+ u32 tablesize, s32 input, s64 *output)
+{
+ 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) && (pts[i].x < input)) {
+ /* table entry is less than measured*/
+ /* value and table is descending, stop */
+ break;
+ } else if ((!descending) &&
+ (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);
+ }
+
+ return 0;
+}
+
+static void qcom_vadc_scale_calib(const struct vadc_linear_graph *calib_graph,
+ u16 adc_code,
+ bool absolute,
+ s64 *scale_voltage)
+{
+ *scale_voltage = (adc_code - calib_graph->gnd);
+ *scale_voltage *= calib_graph->dx;
+ *scale_voltage = div64_s64(*scale_voltage, calib_graph->dy);
+ if (absolute)
+ *scale_voltage += calib_graph->dx;
+
+ if (*scale_voltage < 0)
+ *scale_voltage = 0;
+}
+
+int qcom_vadc_scale_volt(const struct vadc_linear_graph *calib_graph,
+ const struct vadc_prescale_ratio *prescale,
+ bool absolute, u16 adc_code,
+ int *result_uv)
+{
+ s64 voltage = 0, result = 0;
+
+ qcom_vadc_scale_calib(calib_graph, adc_code, absolute, &voltage);
+
+ voltage = voltage * prescale->den;
+ result = div64_s64(voltage, prescale->num);
+ *result_uv = result;
+
+ return 0;
+}
+
+int qcom_vadc_scale_therm(const struct vadc_linear_graph *calib_graph,
+ const struct vadc_prescale_ratio *prescale,
+ bool absolute, u16 adc_code,
+ int *result_mdec)
+{
+ s64 voltage = 0, result = 0;
+ int ret;
+
+ qcom_vadc_scale_calib(calib_graph, adc_code, absolute, &voltage);
+
+ if (absolute)
+ voltage = div64_s64(voltage, 1000);
+
+ ret = qcom_vadc_map_voltage_temp(adcmap_100k_104ef_104fb,
+ ARRAY_SIZE(adcmap_100k_104ef_104fb),
+ voltage, &result);
+ if (ret)
+ return ret;
+
+ result *= 1000;
+ *result_mdec = result;
+
+ return 0;
+}
+
+int qcom_vadc_scale_die_temp(const struct vadc_linear_graph *calib_graph,
+ const struct vadc_prescale_ratio *prescale,
+ bool absolute,
+ u16 adc_code, int *result_mdec)
+{
+ s64 voltage = 0;
+ u64 temp; /* Temporary variable for do_div */
+
+ qcom_vadc_scale_calib(calib_graph, adc_code, absolute, &voltage);
+
+ if (voltage > 0) {
+ temp = voltage * prescale->den;
+ do_div(temp, prescale->num * 2);
+ voltage = temp;
+ } else {
+ voltage = 0;
+ }
+
+ voltage -= KELVINMIL_CELSIUSMIL;
+ *result_mdec = voltage;
+
+ return 0;
+}
+
+int qcom_vadc_scale_chg_temp(const struct vadc_linear_graph *calib_graph,
+ const struct vadc_prescale_ratio *prescale,
+ bool absolute,
+ u16 adc_code, int *result_mdec)
+{
+ s64 voltage = 0, result = 0;
+
+ qcom_vadc_scale_calib(calib_graph, adc_code, absolute, &voltage);
+
+ voltage = voltage * prescale->den;
+ voltage = div64_s64(voltage, prescale->num);
+ voltage = ((PMI_CHG_SCALE_1) * (voltage * 2));
+ voltage = (voltage + PMI_CHG_SCALE_2);
+ result = div64_s64(voltage, 1000000);
+ *result_mdec = result;
+
+ return 0;
+}
+
+int qcom_vadc_scale(enum vadc_scale_fn_type scaletype,
+ const struct vadc_linear_graph *calib_graph,
+ const struct vadc_prescale_ratio *prescale,
+ bool absolute,
+ u16 adc_code, int *result)
+{
+ switch (scaletype) {
+ case SCALE_DEFAULT:
+ return qcom_vadc_scale_volt(calib_graph, prescale,
+ absolute, adc_code,
+ result);
+ case SCALE_THERM_100K_PULLUP:
+ case SCALE_XOTHERM:
+ return qcom_vadc_scale_therm(calib_graph, prescale,
+ absolute, adc_code,
+ result);
+ case SCALE_PMIC_THERM:
+ return qcom_vadc_scale_die_temp(calib_graph, prescale,
+ absolute, adc_code,
+ result);
+ case SCALE_PMI_CHG_TEMP:
+ return qcom_vadc_scale_chg_temp(calib_graph, prescale,
+ absolute, adc_code,
+ result);
+ default:
+ return -EINVAL;
+ }
+}
+
+int qcom_vadc_decimation_from_dt(u32 value)
+{
+ if (!is_power_of_2(value) || value < VADC_DECIMATION_MIN ||
+ value > VADC_DECIMATION_MAX)
+ return -EINVAL;
+
+ return __ffs64(value / VADC_DECIMATION_MIN);
+}
diff --git a/drivers/iio/adc/qcom-vadc-common.h b/drivers/iio/adc/qcom-vadc-common.h
new file mode 100644
index 000000000000..aacf051f3c2a
--- /dev/null
+++ b/drivers/iio/adc/qcom-vadc-common.h
@@ -0,0 +1,103 @@
+/*
+ * Code shared between the different Qualcomm PMIC voltage ADCs
+ */
+
+#define VADC_CONV_TIME_MIN_US 2000
+#define VADC_CONV_TIME_MAX_US 2100
+
+/* Min ADC code represents 0V */
+#define VADC_MIN_ADC_CODE 0x6000
+/* Max ADC code represents full-scale range of 1.8V */
+#define VADC_MAX_ADC_CODE 0xa800
+
+#define VADC_ABSOLUTE_RANGE_UV 625000
+#define VADC_RATIOMETRIC_RANGE 1800
+
+#define VADC_DEF_PRESCALING 0 /* 1:1 */
+#define VADC_DEF_DECIMATION 0 /* 512 */
+#define VADC_DEF_HW_SETTLE_TIME 0 /* 0 us */
+#define VADC_DEF_AVG_SAMPLES 0 /* 1 sample */
+#define VADC_DEF_CALIB_TYPE VADC_CALIB_ABSOLUTE
+
+#define VADC_DECIMATION_MIN 512
+#define VADC_DECIMATION_MAX 4096
+
+#define VADC_HW_SETTLE_DELAY_MAX 10000
+#define VADC_AVG_SAMPLES_MAX 512
+
+#define KELVINMIL_CELSIUSMIL 273150
+
+#define PMI_CHG_SCALE_1 -138890
+#define PMI_CHG_SCALE_2 391750000000LL
+
+/**
+ * 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
+ * calibration.
+ */
+enum vadc_calibration {
+ VADC_CALIB_ABSOLUTE = 0,
+ VADC_CALIB_RATIOMETRIC
+};
+
+/**
+ * struct vadc_linear_graph - Represent ADC characteristics.
+ * @dy: numerator slope to calculate the gain.
+ * @dx: denominator slope to calculate the gain.
+ * @gnd: A/D word of the ground reference used for the channel.
+ *
+ * Each ADC device has different offset and gain parameters which are
+ * computed to calibrate the device.
+ */
+struct vadc_linear_graph {
+ s32 dy;
+ s32 dx;
+ s32 gnd;
+};
+
+/**
+ * struct vadc_prescale_ratio - Represent scaling ratio for ADC input.
+ * @num: the inverse numerator of the gain applied to the input channel.
+ * @den: the inverse denominator of the gain applied to the input channel.
+ */
+struct vadc_prescale_ratio {
+ u32 num;
+ u32 den;
+};
+
+/**
+ * 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
+ */
+enum vadc_scale_fn_type {
+ SCALE_DEFAULT = 0,
+ SCALE_THERM_100K_PULLUP,
+ SCALE_PMIC_THERM,
+ SCALE_XOTHERM,
+ SCALE_PMI_CHG_TEMP,
+};
+
+int qcom_vadc_scale(enum vadc_scale_fn_type scaletype,
+ const struct vadc_linear_graph *calib_graph,
+ const struct vadc_prescale_ratio *prescale,
+ bool absolute,
+ u16 adc_code, int *result_mdec);
+
+int qcom_vadc_decimation_from_dt(u32 value);
--
2.9.3
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