串口驱动分析-初始化

串口驱动分析-初始化
1.串口驱动程序结构
/linux-tq2440/drivers/serial/samsung.c
2.串口驱动中的重要数据结构


在之前一篇中的tty_write,位于：

static const struct file_operations tty_fops = {
    .llseek        = no_llseek,
    .read        = tty_read,
    .write        = tty_write,
    .poll        = tty_poll,
    .unlocked_ioctl    = tty_ioctl,
    .compat_ioctl    = tty_compat_ioctl,
    .open        = tty_open,
    .release    = tty_release,
    .fasync        = tty_fasync,
};

tty_ldisc_ops线路规程的函数指针：

struct tty_ldisc_ops tty_ldisc_N_TTY = {
    .magic = TTY_LDISC_MAGIC,
    .name = "n_tty",
    .open = n_tty_open,
    .close = n_tty_close,
    .flush_buffer = n_tty_flush_buffer,
    .chars_in_buffer = n_tty_chars_in_buffer,
    .read = n_tty_read,
    .write = n_tty_write,
    .ioctl = n_tty_ioctl,
    .set_termios = n_tty_set_termios,
    .poll = n_tty_poll,
    .receive_buf = n_tty_receive_buf,
    .write_wakeup = n_tty_write_wakeup
};

tty_operations的变量：

static const struct tty_operations uart_ops = {
    .open        = uart_open,
    .close        = uart_close,
    .write        = uart_write,
    .put_char    = uart_put_char,
    .flush_chars    = uart_flush_chars,
    .write_room    = uart_write_room,
    .chars_in_buffer= uart_chars_in_buffer,
    .flush_buffer    = uart_flush_buffer,
    .ioctl        = uart_ioctl,
    .throttle    = uart_throttle,
    .unthrottle    = uart_unthrottle,
    .send_xchar    = uart_send_xchar,
    .set_termios    = uart_set_termios,
    .set_ldisc    = uart_set_ldisc,
    .stop        = uart_stop,
    .start        = uart_start,
    .hangup        = uart_hangup,
    .break_ctl    = uart_break_ctl,
    .wait_until_sent= uart_wait_until_sent,
#ifdef CONFIG_PROC_FS
    .proc_fops    = &uart_proc_fops,
#endif
    .tiocmget    = uart_tiocmget,
    .tiocmset    = uart_tiocmset,
#ifdef CONFIG_CONSOLE_POLL
    .poll_init    = uart_poll_init,
    .poll_get_char    = uart_poll_get_char,
    .poll_put_char    = uart_poll_put_char,
#endif
};

UART驱动程序结构：struct uart_driver        封装了tty_driver，使得底层的UART驱动无需关心tty_driver

UART端口结构： struct uart_port                用于描述一个UART端口（直接对应于一个串口）的I/O端口或者IO内存地址等信息。

UART相关操作函数结构: struct uart_ops      

UART状态结构： struct uart_state       设备私有信息结构体， 在uart_open()中: tty->driver_data = state; 在其他uart_xxx()中： struct uart_state *state = tty->driver_data; 就可以获取设备私有信息结构体。

UART信息结构: struct uart_info

3.分析代码流程

在tq2440中只需要注册uart_register_driver就行了
而在240中初始化uart_port、闯将属性文件、初始化动态频率调节

参考资料：http://www.cnblogs.com/hello2mhb/p/3341291.html