generated from hulk/gd32f4xx_template_cmake_vscode
133 lines
4.6 KiB
C
133 lines
4.6 KiB
C
#include "rs485.h"
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#include "gd32f4xx_usart.h"
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#include "gd32f4xx_rcu.h"
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#include "gd32f4xx_gpio.h"
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#include "board_config.h"
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/* 独立接收环形缓冲区（与 debug 串口的 uart_ring_buffer 隔离），
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采用"预留一格"区分空/满，最大可用容量为 RS485_RX_BUFFER_SIZE-1 */
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static __IO uint8_t rs485_rx_buffer[RS485_RX_BUFFER_SIZE];
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static __IO uint8_t rs485_write_index = 0;
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static __IO uint8_t rs485_read_index = 0;
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static inline uint32_t rs485_irq_save(void) {
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uint32_t primask = __get_PRIMASK();
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__disable_irq();
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return primask;
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}
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static inline void rs485_irq_restore(uint32_t primask) {
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if ((primask & 0x1) == 0) {
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__enable_irq();
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}
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}
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/**
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* @brief 配置 RS485 收发引脚（PA9 TX / PA10 RX 复用，DE PA8 推挽输出）。
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*/
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static void rs485_gpio_config(void) {
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/* 使能 GPIOA 和 USART0 时钟 */
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rcu_periph_clock_enable(RS485_GPIO_RCU);
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rcu_periph_clock_enable(RS485_RCU);
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/* PA9 为 USART0_TX，PA10 为 USART0_RX（AF7） */
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gpio_af_set(RS485_GPIO_PORT, GPIO_AF_7, RS485_TX_PIN | RS485_RX_PIN);
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gpio_mode_set(RS485_GPIO_PORT, GPIO_MODE_AF, GPIO_PUPD_PULLUP, RS485_TX_PIN | RS485_RX_PIN);
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gpio_output_options_set(RS485_GPIO_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, RS485_TX_PIN | RS485_RX_PIN);
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/* DE 引脚为普通推挽输出，默认接收态 */
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rcu_periph_clock_enable(RS485_DE_RCU);
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gpio_mode_set(RS485_DE_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, RS485_DE_PIN);
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gpio_output_options_set(RS485_DE_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, RS485_DE_PIN);
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gpio_bit_reset(RS485_DE_PORT, RS485_DE_PIN);
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}
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void rs485_init(void) {
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rs485_gpio_config();
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/* 配置波特率、数据位、停止位等 */
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usart_deinit(RS485_PHY);
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usart_word_length_set(RS485_PHY, USART_WL_8BIT);
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usart_stop_bit_set(RS485_PHY, USART_STB_1BIT);
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usart_parity_config(RS485_PHY, USART_PM_NONE);
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usart_baudrate_set(RS485_PHY, RS485_BAUDRATE);
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usart_receive_config(RS485_PHY, USART_RECEIVE_ENABLE);
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usart_transmit_config(RS485_PHY, USART_TRANSMIT_ENABLE);
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usart_enable(RS485_PHY);
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/* 使能接收非空中断 */
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nvic_irq_enable(RS485_IRQ, 0, 0);
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usart_interrupt_enable(RS485_PHY, USART_INT_RBNE);
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}
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void rs485_send(const uint8_t *data, uint16_t len) {
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/* 半双工防冲突：发送期间暂停 RX 中断（若收发器 RE 独立使能，
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自己发出的字节会回环进 USART，既污染接收缓冲也可能与本方解析交错） */
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usart_interrupt_disable(RS485_PHY, USART_INT_RBNE);
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/* 进入发送态 */
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gpio_bit_set(RS485_DE_PORT, RS485_DE_PIN);
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for (uint16_t i = 0; i < len; i++) {
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/* 等待发送缓冲区空 */
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while (RESET == usart_flag_get(RS485_PHY, USART_FLAG_TBE)) {}
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usart_data_transmit(RS485_PHY, data[i]);
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}
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/* 等待最后一字节移位完成，再切回接收态（避免截断尾字节） */
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while (RESET == usart_flag_get(RS485_PHY, USART_FLAG_TC)) {}
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/* 回到接收态 */
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gpio_bit_reset(RS485_DE_PORT, RS485_DE_PIN);
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/* 丢弃发送期间挤入/回环进接收通道的残留字节（读 DATA 清 RBNE/ORE），
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并清空接收环形缓冲，避免垃圾字节污染后续协议帧 */
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(void)usart_data_receive(RS485_PHY);
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rs485_rx_clear();
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/* 恢复接收 */
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usart_interrupt_enable(RS485_PHY, USART_INT_RBNE);
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}
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uint8_t rs485_rx_available(void) {
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uint8_t w = rs485_write_index;
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uint8_t r = rs485_read_index;
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return (uint8_t)((w + RS485_RX_BUFFER_SIZE - r) % RS485_RX_BUFFER_SIZE);
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}
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int rs485_rx_get(void) {
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if (rs485_read_index == rs485_write_index) return -1; /* 空 */
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uint8_t data = rs485_rx_buffer[rs485_read_index];
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rs485_read_index = (rs485_read_index + 1) % RS485_RX_BUFFER_SIZE;
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return data;
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}
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void rs485_rx_clear(void) {
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uint32_t primask = rs485_irq_save();
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rs485_write_index = 0;
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rs485_read_index = 0;
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rs485_irq_restore(primask);
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}
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void rs485_irq_handler(void) {
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/* 处理USART0的接收中断 */
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if (usart_interrupt_flag_get(RS485_PHY, USART_INT_FLAG_RBNE)) {
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uint8_t data = usart_data_receive(RS485_PHY);
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uint32_t primask = rs485_irq_save();
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uint8_t next = (rs485_write_index + 1) % RS485_RX_BUFFER_SIZE;
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if (next != rs485_read_index) {
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/* 缓冲区未满 */
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rs485_rx_buffer[rs485_write_index] = data;
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rs485_write_index = next;
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}
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/* 缓冲满时丢弃 */
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rs485_irq_restore(primask);
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}
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/* 处理USART0的空闲中断（帧间隔提示，后续协议解析用） */
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if (usart_interrupt_flag_get(RS485_PHY, USART_INT_FLAG_IDLE)) {
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usart_interrupt_flag_clear(RS485_PHY, USART_INT_FLAG_IDLE);
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}
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}
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