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