diff options
Diffstat (limited to 'src/hc32f460/adc.c')
| -rw-r--r-- | src/hc32f460/adc.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/hc32f460/adc.c b/src/hc32f460/adc.c new file mode 100644 index 00000000..ef1e58fb --- /dev/null +++ b/src/hc32f460/adc.c @@ -0,0 +1,155 @@ +// ADC functions on Huada HC32F460 +// +// Copyright (C) 2022 Steven Gotthardt <gotthardt@gmail.com> +// +// This file may be distributed under the terms of the GNU GPLv3 license. + +#include "generic/misc.h" // timer_from_us +#include "command.h" // shutdown +#include "board/gpio.h" // gpio_adc_setup +#include "board/internal.h" // GPIO +#include "sched.h" // sched_shutdown + +// library +#include "hc32f460_adc.h" +#include "hc32f460_pwc.h" +#include "hc32f460_gpio.h" + +#define ADC_RESOLUTION_12BIT (12u) +#define ADC_RESOLUTION_10BIT (10u) +#define ADC_RESOLUTION_8BIT (8u) + +#define ADC1_RESOLUTION (ADC_RESOLUTION_12BIT) +#define ADC1_PRECISION (1ul << ADC1_RESOLUTION) + +#if ADC1_RESOLUTION == ADC_RESOLUTION_12BIT +#define AdcResolution AdcResolution_12Bit +#elif ADC1_RESOLUTION == ADC_RESOLUTION_10BIT +#define AdcResolution AdcResolution_10Bit +#else +#define AdcResolution AdcResolution_8Bit +#endif + + +/* Timeout value definitions. Found in example code */ +#define TIMEOUT_VAL (30u) + +DECL_CONSTANT("ADC_MAX", ADC1_PRECISION-1); + +// These pins can be used for ADC +static const uint8_t adc_gpio[] = { + GPIO('A', 0), // Chan 0 + GPIO('A', 1), // Chan 1 + GPIO('A', 2), // Chan 2 + GPIO('A', 3), // Chan 3 + GPIO('A', 4), // Chan 4 + GPIO('A', 5), // Chan 5 + GPIO('A', 6), // Chan 6 + GPIO('A', 7), // Chan 7 + GPIO('B', 0), // Chan 8 + GPIO('B', 1), // Chan 9 + GPIO('C', 0), // Chan 10 // TBed on TriGorilla + GPIO('C', 1), // Chan 11 // THead on TriGorilla + GPIO('C', 2), // Chan 12 + GPIO('C', 3), // Chan 13 + GPIO('C', 4), // Chan 14 // TBed on aquilla + GPIO('C', 5), // Chan 15 // THead on aquilla +}; + + +struct gpio_adc +gpio_adc_setup(uint32_t gpio) +{ + // validate pin in adc_pins table + int chan; + for (chan=0; ; chan++) + { + if (chan >= ARRAY_SIZE(adc_gpio)) + { + shutdown("Not a valid ADC pin"); + } + if (adc_gpio[chan] == gpio) + { + break; + } + } + + // set as analog + gpio_peripheral(gpio, Pin_Mode_Ana, 0); + + uint8_t sampleTime[ARRAY_SIZE(adc_gpio)] = { TIMEOUT_VAL }; // all chans + stc_adc_ch_cfg_t stcAdcChan; + stcAdcChan.u32Channel = 1 << chan; + stcAdcChan.u8Sequence = ADC_SEQ_A; // all conversions are in SEQ A + stcAdcChan.pu8SampTime = sampleTime; + ADC_AddAdcChannel(M4_ADC1, &stcAdcChan); + + return (struct gpio_adc){ .chan = chan }; +} + + +// Try to sample a value. Returns zero if sample ready, otherwise +// returns the number of clock ticks the caller should wait before +// retrying this function. +uint32_t +gpio_adc_sample(struct gpio_adc g) +{ + // true if the sequence is finished + if (ADC_GetEocFlag(M4_ADC1, ADC_SEQ_A)) + { + // all conversions are done - clear the flag + ADC_ClrEocFlag(M4_ADC1, ADC_SEQ_A); + return 0; + } + else if (M4_ADC1->STR & 1) + { + // running but not done yet + return timer_from_us(TIMEOUT_VAL/2); + } + else + { + // not running - so start + ADC_StartConvert(M4_ADC1); + } + + return timer_from_us(TIMEOUT_VAL); +} + + +// Read a value; use only after gpio_adc_sample() returns zero +uint16_t +gpio_adc_read(struct gpio_adc g) +{ + // return the one we want... + return ADC_GetValue(M4_ADC1, g.chan); +} + + +// Cancel a sample that may have been started with gpio_adc_sample() +void +gpio_adc_cancel_sample(struct gpio_adc g) +{ + ADC_StopConvert(M4_ADC1); +} + + +// The clocks are already set by the loader. +// There is ADC1 and ADC2. Sequences do all channels at once. +void +adc_init(void) +{ + // PCLK2 (ADC clock) is 'divide by 4', Max ADC clock is 60MHz + stc_adc_init_t stcAdcInit = {0}; + stcAdcInit.enResolution = AdcResolution; // see define above + stcAdcInit.enDataAlign = AdcDataAlign_Right; + stcAdcInit.enAutoClear = AdcClren_Disable; + stcAdcInit.enScanMode = AdcMode_SAOnce; + + // power-on ADC + PWC_Fcg3PeriphClockCmd(PWC_FCG3_PERIPH_ADC1, Enable); + + // only using ADC1 + ADC_Init(M4_ADC1, &stcAdcInit); +} + +DECL_INIT(adc_init); |