Commit e932d4f0 authored by Linus Walleij's avatar Linus Walleij Committed by Jonathan Cameron

iio: adc: break out common code from SPMI VADC

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-spmi-vadc.o that contains both
files: qcom-vadc-common.o and qcom-spmi-vadc-core.o.

As we need to follow the procedure for making a kernel module
or compiled in object from several files, but still want to
produce the same module name, rename the qcom-spmi-vadc.c
file to qcom-spmi-vadc-core.c so we can bake the two objects
into qcom-spmi-vadc.o

Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: Ivan T. Ivanov <iivanov.xz@gmail.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Rama Krishna Phani A <rphani@codeaurora.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 96b3c833
...@@ -496,6 +496,9 @@ config PALMAS_GPADC ...@@ -496,6 +496,9 @@ config PALMAS_GPADC
is used in smartphones and tablets and supports a 16 channel is used in smartphones and tablets and supports a 16 channel
general purpose ADC. general purpose ADC.
config QCOM_VADC_COMMON
tristate
config QCOM_SPMI_IADC config QCOM_SPMI_IADC
tristate "Qualcomm SPMI PMIC current ADC" tristate "Qualcomm SPMI PMIC current ADC"
depends on SPMI depends on SPMI
...@@ -514,6 +517,7 @@ config QCOM_SPMI_VADC ...@@ -514,6 +517,7 @@ config QCOM_SPMI_VADC
tristate "Qualcomm SPMI PMIC voltage ADC" tristate "Qualcomm SPMI PMIC voltage ADC"
depends on SPMI depends on SPMI
select REGMAP_SPMI select REGMAP_SPMI
select QCOM_VADC_COMMON
help help
This is the IIO Voltage ADC driver for Qualcomm QPNP VADC Chip. This is the IIO Voltage ADC driver for Qualcomm QPNP VADC Chip.
......
...@@ -48,6 +48,7 @@ obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o ...@@ -48,6 +48,7 @@ obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
obj-$(CONFIG_NAU7802) += nau7802.o obj-$(CONFIG_NAU7802) += nau7802.o
obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
obj-$(CONFIG_QCOM_VADC_COMMON) += qcom-vadc-common.o
obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
obj-$(CONFIG_RCAR_GYRO_ADC) += rcar-gyroadc.o obj-$(CONFIG_RCAR_GYRO_ADC) += rcar-gyroadc.o
obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
......
This diff is collapsed.
#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;
}
static 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;
}
static 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;
}
static 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;
}
static 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;
}
}
EXPORT_SYMBOL(qcom_vadc_scale);
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);
}
EXPORT_SYMBOL(qcom_vadc_decimation_from_dt);
/*
* Code shared between the different Qualcomm PMIC voltage ADCs
*/
#ifndef QCOM_VADC_COMMON_H
#define QCOM_VADC_COMMON_H
#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);
#endif /* QCOM_VADC_COMMON_H */
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