stm32g030f6t6 timer IC IRQ

main.c

#include <stdio.h>

#include "stm32g0xx_hal.h"

static TIM_HandleTypeDef tim;
static DMA_HandleTypeDef tim_dma;
static UART_HandleTypeDef uart;
UART_HandleTypeDef *_write_uart_handle = &uart; // for syscall.c

#define NEC_LEN 64
static uint16_t nec_data[NEC_LEN];
static unsigned nec_count = 0;

#define assert(x)                                                                                  \
	do {                                                                                           \
		if (!(x)) {                                                                                \
			printf("Assertion failed: " #x);                                                       \
			__disable_irq();                                                                       \
			while (true)                                                                           \
				;                                                                                  \
		}                                                                                          \
	} while (0)

void TIM3_IRQHandler(void) {
	HAL_TIM_IRQHandler(&tim);
}

void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim) {
	uint16_t value = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_1);
	nec_data[nec_count++] = value;
	if (nec_count >= 50) {
		HAL_TIM_IC_Stop_IT(htim, TIM_CHANNEL_1);
		for (unsigned i = 0; i < nec_count; i++) {
			printf("%d ", nec_data[i]);
		}
		printf("\r\n");
	}
}

int main(int argc, char *argv[]) {
	HAL_Init();

	RCC_OscInitTypeDef osc = {
		.OscillatorType = RCC_OSCILLATORTYPE_HSI,
		.HSIState = RCC_HSI_ON,
		.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT,
		.PLL.PLLState = RCC_PLL_ON,
		.PLL.PLLSource = RCC_PLLSOURCE_HSI,
		.PLL.PLLM = RCC_PLLM_DIV1,
		.PLL.PLLN = 8,
		.PLL.PLLP = RCC_PLLP_DIV2,
		.PLL.PLLR = RCC_PLLR_DIV2,
	};
	assert(HAL_RCC_OscConfig(&osc) == HAL_OK);

	RCC_ClkInitTypeDef clk = {
		.ClockType = RCC_CLOCKTYPE_ALL,
		.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK,
		.AHBCLKDivider = RCC_SYSCLK_DIV1,
		.APB1CLKDivider = RCC_HCLK_DIV1,
	};
	assert(HAL_RCC_ClockConfig(&clk, FLASH_LATENCY_2) == HAL_OK);

	__HAL_RCC_SYSCFG_CLK_ENABLE();
	__HAL_RCC_GPIOA_CLK_ENABLE();
	__HAL_RCC_DMA1_CLK_ENABLE();
	__HAL_RCC_USART1_CLK_ENABLE();
	__HAL_RCC_TIM3_CLK_ENABLE();

	HAL_NVIC_EnableIRQ(TIM3_IRQn);

	HAL_SYSCFG_EnableRemap(SYSCFG_REMAP_PA11);
	HAL_SYSCFG_EnableRemap(SYSCFG_REMAP_PA12);

	GPIO_InitTypeDef gpio = {};

	// Timer IC
	gpio.Mode = GPIO_MODE_AF_PP;
	gpio.Pull = GPIO_NOPULL;
	gpio.Speed = GPIO_SPEED_FREQ_MEDIUM;
	gpio.Alternate = GPIO_AF1_TIM3;
	gpio.Pin = GPIO_PIN_6;
	HAL_GPIO_Init(GPIOA, &gpio);

	// USART TX/RX
	gpio.Mode = GPIO_MODE_AF_PP;
	gpio.Pull = GPIO_NOPULL;
	gpio.Speed = GPIO_SPEED_FREQ_MEDIUM;
	gpio.Alternate = GPIO_AF1_USART1;
	gpio.Pin = GPIO_PIN_9 | GPIO_PIN_10;
	HAL_GPIO_Init(GPIOA, &gpio);

	tim_dma.Instance = DMA1_Channel1;
	tim_dma.Init.Mode = DMA_NORMAL;
	tim_dma.Init.MemInc = DMA_MINC_ENABLE;
	tim_dma.Init.PeriphInc = DMA_PINC_DISABLE;
	tim_dma.Init.Direction = DMA_PERIPH_TO_MEMORY;
	tim_dma.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
	tim_dma.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
	tim_dma.Init.Request = DMA_REQUEST_TIM3_CH1;
	HAL_DMA_Init(&tim_dma);
	__HAL_LINKDMA(&tim, hdma[TIM_DMA_ID_CC1], tim_dma);

	uart.Instance = USART1;
	uart.Init.Mode = UART_MODE_TX_RX;
	uart.Init.BaudRate = 115200;
	assert(HAL_UART_Init(&uart) == HAL_OK);

	tim.Instance = TIM3;
	tim.Init.Prescaler = 64 - 1;
	tim.Init.Period = ~0;
	assert(HAL_TIM_IC_Init(&tim) == HAL_OK);
	TIM_SlaveConfigTypeDef slave_cfg = {
		.SlaveMode = TIM_SLAVEMODE_RESET,
		.TriggerPolarity = TIM_TRIGGERPOLARITY_RISING,
		.InputTrigger = TIM_TS_TI1F_ED,
	};
	assert(HAL_TIM_SlaveConfigSynchro(&tim, &slave_cfg) == HAL_OK);
	TIM_IC_InitTypeDef chan_cfg = {
		.ICSelection = TIM_ICSELECTION_DIRECTTI,
		.ICPolarity = TIM_ICPOLARITY_FALLING,
	};
	assert(HAL_TIM_IC_ConfigChannel(&tim, &chan_cfg, TIM_CHANNEL_1) == HAL_OK);

	HAL_TIM_IC_Start_DMA(&tim, TIM_CHANNEL_1, (uint32_t *)nec_data, NEC_LEN);
	printf("TIM3 IC started\r\n");

	HAL_DMA_PollForTransfer(&tim_dma, HAL_DMA_FULL_TRANSFER, HAL_MAX_DELAY);
	printf("TIM3 IC DMA completed\r\n");

	while (true)
		;
	return 0;
}