diff options
Diffstat (limited to 'drivers/iio/adc/qcom-vadc-common.c')
| -rw-r--r-- | drivers/iio/adc/qcom-vadc-common.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/iio/adc/qcom-vadc-common.c b/drivers/iio/adc/qcom-vadc-common.c new file mode 100644 index 000000000..fe3d78267 --- /dev/null +++ b/drivers/iio/adc/qcom-vadc-common.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0 +#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 <linux/module.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); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Qualcomm ADC common functionality"); |