gateway_android/unit_test/borad_test/uart/uart2/uart.c

200 lines
4.5 KiB
C

#include "uart.h"
int fd = -1;
uart_cfg_t uart_cfg = {
.baudrate = 115200,
.dbit = 8,
.parity = 'N',
.sbit = 0,
};
static void io_handler(int sig, siginfo_t *info, void *context)
{
unsigned char buf[50] = {0};
int ret;
int n;
if(SIGRTMIN != sig)
return;
/* 判断串口是否有数据可读 */
if (POLL_IN == info->si_code) {
ret = read(fd, buf, 50); //一次最多读 50 个字节数据
printf("[ ");
for (n = 0; n < ret; n++)
printf("%hhx ", buf[n]);
printf("]\n");
}
}
int uart_Init(void)
{
/* 打开串口终端 */
fd = open(UART_DEV, O_RDWR | O_NOCTTY);
if (0 > fd) {
fprintf(stderr, "open error: %s: %s\n", UART_DEV, strerror(errno));
return -1;
}
setuart_cfg(&uart_cfg);
async_io_init();
return 0;
}
int setuart_cfg(const uart_cfg_t *cfg)
{
struct termios new_cfg = {0}; //将 new_cfg 对象清零
speed_t speed;
/* 设置为原始模式 */
cfmakeraw(&new_cfg);
/* 使能接收 */
new_cfg.c_cflag |= CREAD;
/* 设置波特率 */
switch (cfg->baudrate) {
case 1200: speed = B1200;
break;
case 1800: speed = B1800;
break;
case 2400: speed = B2400;
break;
case 4800: speed = B4800;
break;
case 9600: speed = B9600;
break;
case 19200: speed = B19200;
break;
case 38400: speed = B38400;
break;
case 57600: speed = B57600;
break;
case 115200: speed = B115200;
break;
case 230400: speed = B230400;
break;
case 460800: speed = B460800;
break;
case 500000: speed = B500000;
break;
default: //默认配置为 115200
speed = B115200;
printf("default baud rate: 115200\n");
break;
}
if (0 > cfsetspeed(&new_cfg, speed)) {
fprintf(stderr, "cfsetspeed error: %s\n", strerror(errno));
return -1;
}
/* 设置数据位大小 */
new_cfg.c_cflag &= ~CSIZE; //将数据位相关的比特位清零
switch (cfg->dbit) {
case 5:
new_cfg.c_cflag |= CS5;
break;
case 6:
new_cfg.c_cflag |= CS6;
break;
case 7:
new_cfg.c_cflag |= CS7;
break;
case 8:
new_cfg.c_cflag |= CS8;
break;
default: //默认数据位大小为 8
new_cfg.c_cflag |= CS8;
printf("default data bit size: 8\n");
break;
}
/* 设置奇偶校验 */
switch (cfg->parity) {
case 'N': //无校验
new_cfg.c_cflag &= ~PARENB;
new_cfg.c_iflag &= ~INPCK;
break;
case 'O': //奇校验
new_cfg.c_cflag |= (PARODD | PARENB);
new_cfg.c_iflag |= INPCK;
break;
case 'E': //偶校验
new_cfg.c_cflag |= PARENB;
new_cfg.c_cflag &= ~PARODD; /* 清除 PARODD 标志,配置为偶校验 */
new_cfg.c_iflag |= INPCK;
break;
default: //默认配置为无校验
new_cfg.c_cflag &= ~PARENB;
new_cfg.c_iflag &= ~INPCK;
printf("default parity: N\n");
break;
}
/* 设置停止位 */
switch (cfg->sbit) {
case 1: //1 个停止位
new_cfg.c_cflag &= ~CSTOPB;
break;
case 2: //2 个停止位
new_cfg.c_cflag |= CSTOPB;
break;
default: //默认配置为 1 个停止位
new_cfg.c_cflag &= ~CSTOPB;
printf("default stop bit size: 1\n");
break;
}
/* 将 MIN 和 TIME 设置为 0 */
new_cfg.c_cc[VTIME] = 0;
new_cfg.c_cc[VMIN] = 0;
/* 清空缓冲区 */
if (0 > tcflush(fd, TCIOFLUSH)) {
fprintf(stderr, "tcflush error: %s\n", strerror(errno));
return -1;
}
/* 写入配置、使配置生效 */
if (0 > tcsetattr(fd, TCSANOW, &new_cfg)) {
fprintf(stderr, "tcsetattr error: %s\n", strerror(errno));
return -1;
}
/* 配置 OK 退出 */
return 0;
}
void async_io_init(void)
{
struct sigaction sigatn;
int flag;
/* 使能异步 I/O */
flag = fcntl(fd, F_GETFL); //使能串口的异步 I/O 功能
flag |= O_ASYNC;
fcntl(fd, F_SETFL, flag);
/* 设置异步 I/O 的所有者 */
fcntl(fd, F_SETOWN, getpid());
/* 指定实时信号 SIGRTMIN 作为异步 I/O 通知信号 */
fcntl(fd, F_SETSIG, SIGRTMIN);
/* 为实时信号 SIGRTMIN 注册信号处理函数 */
sigatn.sa_sigaction = io_handler; //当串口有数据可读时,会跳转到 io_handler 函数
sigatn.sa_flags = SA_SIGINFO;
sigemptyset(&sigatn.sa_mask);
sigaction(SIGRTMIN, &sigatn, NULL);
}