从内核空间配置串行端口 [英] configuring serial port from kernel space
问题描述
如何在内核模块中配置串行端口.我正在初始化模块功能中执行此操作.相同的配置在userpsace中起作用.我正在使用以下代码配置串行端口.
How to configure the serial port in kernel module. I am doing this in init module function. same configuration is working in userpsace. I am using the below code to configure the serial port.
mm_segment_t oldfs;
oldfs = get_fs();
set_fs(KERNEL_DS);
fp = filp_open("/dev/ttyS0",O_RDWR | O_NOCTTY | O_NDELAY);
tty = (struct tty_struct *)fp->private_data;
setting the required configuration(tty->termios)
set_fs(oldfs);
推荐答案
几乎所有串行端口操作的功能都由drivers/tty/serial/serial_core.c
实现.如果您想以其他方式进行操作,请为include/linux/serial_core.h
Almost all functions of serial port operations are implemented by drivers/tty/serial/serial_core.c
. If you want to do it differently then provide your own functions for uart_ops
from include/linux/serial_core.h
struct uart_ops {
unsigned int (*tx_empty)(struct uart_port *);
void (*set_mctrl)(struct uart_port *, unsigned int mctrl);
unsigned int (*get_mctrl)(struct uart_port *);
void (*stop_tx)(struct uart_port *);
void (*start_tx)(struct uart_port *);
void (*send_xchar)(struct uart_port *, char ch);
void (*stop_rx)(struct uart_port *);
void (*enable_ms)(struct uart_port *);
void (*break_ctl)(struct uart_port *, int ctl);
int (*startup)(struct uart_port *);
void (*shutdown)(struct uart_port *);
void (*flush_buffer)(struct uart_port *);
void (*set_termios)(struct uart_port *, struct ktermios *new,
struct ktermios *old);
void (*set_ldisc)(struct uart_port *, int new);
void (*pm)(struct uart_port *, unsigned int state,
unsigned int oldstate);
int (*set_wake)(struct uart_port *, unsigned int state);
const char * (*type)(struct uart_port *);
void (*release_port)(struct uart_port *);
int (*request_port)(struct uart_port *);
void (*config_port)(struct uart_port *, int);
int (*verify_port)(struct uart_port *, struct serial_struct *);
int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
#ifdef CONFIG_CONSOLE_POLL
void (*poll_put_char)(struct uart_port *, unsigned char);
int (*poll_get_char)(struct uart_port *);
#endif
};
在您的情况下,您需要实现set_termios函数.另外,请查看uart_get_divisor()
以了解如何设置波特率.
In your case, you need to implement set_termios function. Also, look at uart_get_divisor()
to know how to set baud rate.
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