initial commit

by_serial.c

@@ -0,0 +1,219 @@
+#include "by_serial.h"
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <termios.h>
+#include "logc/log.h"
+
+int by_serial_init(by_serial_t *serial_port, const char *dev_name)
+{
+  serial_port->dev_name_len = strlen(dev_name);
+  assert(0 < serial_port->dev_name_len);
+  strcpy(serial_port->dev_name_str, dev_name);
+
+  int fd;
+  fd = open(serial_port->dev_name_str, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
+  if (fd < 0) {
+    log_error("open uart device error");
+    return -1;
+  } else {
+    serial_port->fd = fd;
+    by_serial_set_baudrate(serial_port, 115200);
+    by_serial_set_parity(serial_port, 8, 1, 'N');
+    log_info("serial %s init successful", serial_port->dev_name_str);
+    return 0;
+  }
+}
+
+int by_serial_set_baudrate(by_serial_t *serial_port, int baudrate)
+{
+  int index       = 0;
+  int status      = 0;
+  int speed_arr[] = {
+      B115200,
+      B38400,
+      B19200,
+      B9600,
+      B4800,
+      B2400,
+      B1200};
+  int name_arr[] = {
+      115200,
+      38400,
+      19200,
+      9600,
+      4800,
+      2400,
+      1200};
+  struct termios Opt = {0};
+
+  tcgetattr(serial_port->fd, &Opt);
+  for (index = 0; index < sizeof(speed_arr) / sizeof(int); index++) {
+    if (baudrate == name_arr[index]) {
+
+      /*设置前 flush*/
+      tcflush(serial_port->fd, TCIOFLUSH);
+      cfsetispeed(&Opt, speed_arr[index]);
+      cfsetospeed(&Opt, speed_arr[index]);
+
+      /*tcsetattr(串口描述符，立即使用或者其他标示，指向 termios 的指针)，通过
+      tcsetattr 函数把新的属性设置到串口上。*/
+      status = tcsetattr(serial_port->fd, TCSANOW, &Opt);
+      if (0 != status) {
+        log_error("tcsetattr COM error");
+        return -1;
+      }
+
+      /*设置后 flush*/
+      tcflush(serial_port->fd, TCIOFLUSH);
+      return 0;
+    }
+  }
+
+  return 0;
+}
+
+int by_serial_set_parity(by_serial_t *serial_port, int databits, int stopbits, char parity)
+{
+  struct termios Opt = {0};
+
+  if (0 != tcgetattr(serial_port->fd, &Opt)) {
+    log_error("tcgetattr COM error");
+    return -1;
+  }
+
+  Opt.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); /*Input*/
+  Opt.c_oflag &= ~OPOST;                          /*Output*/
+
+  Opt.c_iflag &= ~ICRNL;  // 禁止将输入的 CR 转换为 NL
+  Opt.c_iflag &= ~(IXON); // 清 bit 位 关闭流控字符
+
+  /*设置数据位，取值为 7 或 8*/
+  Opt.c_cflag &= ~CSIZE;
+  switch (databits) {
+    case 7:
+      Opt.c_cflag |= CS7;
+      break;
+    case 8:
+      Opt.c_cflag |= CS8;
+      break;
+    default:
+      log_error("Unsupported data size");
+      return -1;
+      break;
+  }
+
+  /*设置停止位，取值为 1 或 2*/
+  switch (stopbits) {
+    case 1:
+      Opt.c_cflag &= ~CSTOPB;
+      break;
+    case 2:
+      Opt.c_cflag |= CSTOPB;
+      break;
+    default:
+      log_error("Unsupported stop bits");
+      return -1;
+      break;
+  }
+
+  /*设置校验位，取值为 E,N,O,S*/
+  switch (parity) {
+    case 'e':
+    case 'E': {
+      Opt.c_cflag |= PARENB;  /*Enable parity*/
+      Opt.c_cflag &= ~PARODD; /*转换为偶效验*/
+      Opt.c_iflag |= INPCK;   /*Disnable parity checking*/
+    } break;
+    case 'n':
+    case 'N': {
+      Opt.c_cflag &= ~PARENB; /*Clear parity enable*/
+      Opt.c_iflag &= ~INPCK;  /*Enable parity checking*/
+    } break;
+    case 'o':
+    case 'O': {
+      Opt.c_cflag |= (PARODD | PARENB); /*设置为奇效验*/
+      Opt.c_iflag |= INPCK;             /*Disnable parity checking*/
+    } break;
+    case 's': /*as no parity*/
+    case 'S': /*as no parity*/
+    {
+      Opt.c_cflag &= ~PARENB;
+      Opt.c_cflag &= ~CSTOPB;
+    } break;
+    default:
+      log_error("Unsupported parity\n");
+      return -1;
+      break;
+  }
+
+  /*设置结构体输入校验位*/
+  if ('n' != parity) {
+    Opt.c_iflag |= INPCK;
+  }
+
+  tcflush(serial_port->fd, TCIFLUSH);
+  Opt.c_cc[VTIME] = 150; /*设置超时 15 秒*/
+  Opt.c_cc[VMIN]  = 0;   /*更新结构体并立即执行*/
+  if (0 != tcsetattr(serial_port->fd, TCSANOW, &Opt)) {
+    log_error("tcsetattr COM error");
+    return -1;
+  }
+
+  return 0;
+}
+
+int by_serial_write(by_serial_t *serial_port, const char *buff, const int len)
+{
+  int len_t;
+
+  if (serial_port->fd < 0) {
+    return -1;
+  }
+
+  len_t = write(serial_port->fd, buff, len);
+
+  if (0 > len_t) {
+    // log_error("write buff failed");
+    return -1;
+  } else {
+    // printf("write buff successful %d/%d\r\n", len_t, len);
+    return 0;
+  }
+}
+
+int by_serial_read(by_serial_t *serial_port, char *buff, const int len)
+{
+  if (1 > by_serial_get_used_buffer_len(serial_port)) {
+    return -1;
+  }
+
+  int len_t = -1;
+
+  if (serial_port->fd < 0) {
+    return -1;
+  }
+
+  len_t = read(serial_port->fd, buff, len);
+
+  if (0 > len_t) {
+    // log_error("read buff failed");
+    return -1;
+  } else {
+    // printf("read buff successful %d/%d\r\n", len_t, len);
+    return len_t;
+  }
+}
+
+int by_serial_get_used_buffer_len(by_serial_t *serial_port)
+{
+  int used_len = 0;
+  ioctl(serial_port->fd, FIONREAD, &used_len);
+  return used_len;
+}