Linux uart驱动框架

Linux内核提供了标准的UART驱动程序，可以通过以下步骤编写：

1. 首先需要定义一个结构体来存储串口设备数据。在该结构体中，包含一个uart_port结构体，用于与Linux内核通信，并包含一些设备特定的数据（例如波特率、数据位数、奇偶校验等）。

c

struct my_uart {struct uart_port port;// 设备特定的数据
};

1. 接下来，需要实现uart_ops结构体中的各个函数，这些函数将被内核调用以执行读取、写入和控制操作。

   static int my_uart_startup(struct uart_port *port)
   {// 执行初始化
   }static void my_uart_shutdown(struct uart_port *port)
   {// 执行清理工作
   }static void my_uart_set_termios(struct uart_port *port, struct ktermios *termios,struct ktermios *old)
   {// 设置波特率、数据位数等
   }static void my_uart_pm(struct uart_port *port, unsigned int state, unsigned int oldstate)
   {// 处理电源管理
   }static const char *my_uart_type(struct uart_port *port)
   {return "my_uart";
   }static void my_uart_release_port(struct uart_port *port)
   {// 释放串口端口
   }static int my_uart_request_port(struct uart_port *port)
   {// 请求串口端口
   }static irqreturn_t my_uart_irq(int irq, void *dev_id)
   {struct my_uart *uart = (struct my_uart *)dev_id;// 处理串口中断
   }static void my_uart_start_tx(struct uart_port *port)
   {// 开始发送数据
   }static void my_uart_stop_tx(struct uart_port *port)
   {// 停止发送数据
   }static void my_uart_enable_ms(struct uart_port *port)
   {// 启用Modem Status中断
   }static void my_uart_break_ctl(struct uart_port *port, int break_state)
   {// 控制发送BREAK信号
   }static int my_uart_startup(struct uart_port *port)
   {return 0;
   }// 定义uart_ops结构体，包含上述函数指针
   static const struct uart_ops my_uart_ops = {.startup        = my_uart_startup,.shutdown       = my_uart_shutdown,.set_termios    = my_uart_set_termios,.pm             = my_uart_pm,.type           = my_uart_type,.release_port   = my_uart_release_port,.request_port   = my_uart_request_port,.config_port    = my_uart_config_port,.suspend        = my_uart_suspend,.resume         = my_uart_resume,.tx_empty       = my_uart_tx_empty,.flush_buffer   = my_uart_flush_buffer,.set_mctrl      = my_uart_set_mctrl,.get_mctrl      = my_uart_get_mctrl,.stop_tx        = my_uart_stop_tx,.start_tx       = my_uart_start_tx,.send_xchar     = my_uart_send_xchar,.enable_ms      = my_uart_enable_ms,.break_ctl      = my_uart_break_ctl,.ioctl          = my_uart_ioctl,.flush_buffer   = my_uart_flush_buffer,.throttle       = my_uart_throttle,.unthrottle     = my_uart_unthrottle,.set_info       = my_uart_set_info,
   };

2. 最后，实现struct uart_driver结构体，该结构体用于向Linux内核注册驱动程序。

3. c

   static struct uart_driver my_uart_driver = {.owner      = THIS_MODULE,.driver_name= "my_uart",.dev_name   = "ttyMyUart",.major      = 0, // 动态分配主设备号.minor      = 0, // 设备编号从0开始.nr         = 1, // 设备数量为1.cons       = NULL,.uart_port  = {.ops            = &my_uart_ops,},
   };// 初始化函数
   static int __init my_uart_init(void)
   {int ret;// 注册UART驱动ret = uart_register_driver(&my_uart_driver);return 0;
   }