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：
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static const struct file_operations tty_fops = {
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.llseek = no_llseek,
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.read = tty_read,
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.write = tty_write,
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.poll = tty_poll,
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.unlocked_ioctl = tty_ioctl,
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.compat_ioctl = tty_compat_ioctl,
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.open = tty_open,
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.release = tty_release,
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.fasync = tty_fasync,
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};
tty_ldisc_ops线路规程的函数指针：
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struct tty_ldisc_ops tty_ldisc_N_TTY = {
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.magic = TTY_LDISC_MAGIC,
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.name = "n_tty",
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.open = n_tty_open,
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.close = n_tty_close,
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.flush_buffer = n_tty_flush_buffer,
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.chars_in_buffer = n_tty_chars_in_buffer,
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.read = n_tty_read,
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.write = n_tty_write,
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.ioctl = n_tty_ioctl,
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.set_termios = n_tty_set_termios,
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.poll = n_tty_poll,
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.receive_buf = n_tty_receive_buf,
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.write_wakeup = n_tty_write_wakeup
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};
tty_operations的变量：
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static const struct tty_operations uart_ops = {
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.open = uart_open,
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.close = uart_close,
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.write = uart_write,
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.put_char = uart_put_char,
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.flush_chars = uart_flush_chars,
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.write_room = uart_write_room,
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.chars_in_buffer= uart_chars_in_buffer,
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.flush_buffer = uart_flush_buffer,
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.ioctl = uart_ioctl,
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.throttle = uart_throttle,
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.unthrottle = uart_unthrottle,
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.send_xchar = uart_send_xchar,
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.set_termios = uart_set_termios,
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.set_ldisc = uart_set_ldisc,
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.stop = uart_stop,
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.start = uart_start,
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.hangup = uart_hangup,
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.break_ctl = uart_break_ctl,
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.wait_until_sent= uart_wait_until_sent,
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#ifdef CONFIG_PROC_FS
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.proc_fops = &uart_proc_fops,
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#endif
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.tiocmget = uart_tiocmget,
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.tiocmset = uart_tiocmset,
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#ifdef CONFIG_CONSOLE_POLL
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.poll_init = uart_poll_init,
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.poll_get_char = uart_poll_get_char,
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.poll_put_char = uart_poll_put_char,
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#endif
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};
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
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