blob: df513f7d89672ab90210234a740c003c5341ce0f [file] [log] [blame]
/*
* Copyright (c) 2019 Peter Bigot Consulting, LLC
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <drivers/adc.h>
int adc_gain_invert(enum adc_gain gain,
int32_t *value)
{
struct gain_desc {
uint8_t mul;
uint8_t div;
};
static const struct gain_desc gains[] = {
[ADC_GAIN_1_6] = {.mul = 6, .div = 1},
[ADC_GAIN_1_5] = {.mul = 5, .div = 1},
[ADC_GAIN_1_4] = {.mul = 4, .div = 1},
[ADC_GAIN_1_3] = {.mul = 3, .div = 1},
[ADC_GAIN_1_2] = {.mul = 2, .div = 1},
[ADC_GAIN_2_3] = {.mul = 3, .div = 2},
[ADC_GAIN_1] = {.mul = 1, .div = 1},
[ADC_GAIN_2] = {.mul = 1, .div = 2},
[ADC_GAIN_3] = {.mul = 1, .div = 3},
[ADC_GAIN_4] = {.mul = 1, .div = 4},
[ADC_GAIN_8] = {.mul = 1, .div = 8},
[ADC_GAIN_16] = {.mul = 1, .div = 16},
[ADC_GAIN_32] = {.mul = 1, .div = 32},
[ADC_GAIN_64] = {.mul = 1, .div = 64},
[ADC_GAIN_128] = {.mul = 1, .div = 128},
};
int rv = -EINVAL;
if ((uint8_t)gain < ARRAY_SIZE(gains)) {
const struct gain_desc *gdp = &gains[gain];
if ((gdp->mul != 0) && (gdp->div != 0)) {
*value = (gdp->mul * *value) / gdp->div;
rv = 0;
}
}
return rv;
}