serialport access in kernel space

I want to use serial port in kernel space, I have found some code which was in user space, I tried to convert the codes to work in kernel space...

this is my code

#include <linux/termios.h>#include <linux/unistd.h>#include <linux/signal.h>#include <linux/fcntl.h>#include <linux/types.h>#include <linux/socket.h>#include <linux/in.h>struct file * fp;...struct termios termAttr;struct sigaction saio;oldfs = get_fs();set_fs(KERNEL_DS);fp = filp_open("/dev/ttymxc0", O_RDWR | O_NOCTTY | O_NDELAY,0);if(fp == NULL)    printk(KERN_ALERT "Serial openning error!!.\n");else{    saio.sa_handler = signal_handler_IO;    saio.sa_flags = 0;    saio.sa_restorer = NULL;    sigaction(SIGIO,&saio,NULL);    fcntl(fp, F_SETFL, O_NDELAY|FASYNC);    fcntl(fp, F_SETOWN, THIS_MODULE);    tcgetattr(fp,&termAttr);    cfsetispeed(&termAttr,B115200);    cfsetospeed(&termAttr,B115200);    termAttr.c_cflag &= ~PARENB;    termAttr.c_cflag &= ~CSTOPB;    termAttr.c_cflag &= ~CSIZE;    termAttr.c_cflag |= CS8;    termAttr.c_cflag |= (CLOCAL | CREAD);    termAttr.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);    termAttr.c_iflag &= ~(IXON | IXOFF | IXANY);    termAttr.c_oflag &= ~OPOST;    tcsetattr(fp,TCSANOW,&termAttr);    printk(KERN_ALERT "Serial configured....\n");    vfs_write(fp, "HI",2, NULL);    filp_close(fp, NULL);    set_fs(oldfs);}

while compiling, I got following errors:

note: each undeclared identifier is reported only once for each function it appears inerror: implicit declaration of function 'sigaction' [-Werror=implicit-function-declaration]                  sigaction(SIGIO,&saio,NULL);                  ^error: implicit declaration of function 'fcntl' [-Werror=implicit-function-declaration]                          fcntl(fp, F_SETFL, O_NDELAY|FASYNC);                          ^error: implicit declaration of function 'tcgetattr' [-Werror=implicit-function-declaration]                  tcgetattr(fp,&termAttr);                  ^error: implicit declaration of function 'cfsetispeed' [-Werror=implicit-function-declaration]                  cfsetispeed(&termAttr,B115200);                  ^error: implicit declaration of function 'cfsetospeed' [-Werror=implicit-function-declaration]                  cfsetospeed(&termAttr,B115200);                  ^error: implicit declaration of function 'tcsetattr' [-Werror=implicit-function-declaration]

I am cross compiling this driver and I already compiled Linux source, I have searched for this functions in my Linux source code but I did not find any of this functions! what should I use instead of this functions?

Edit 1:

I have changed my code into this:

    //serial   struct ktermios termAttr;   struct sigaction saio;   loff_t pos =0;   struct tty_struct *tty;           serialfp = file_open("/dev/ttyS1", O_RDWR | O_NOCTTY | O_NDELAY,0);           if(serialfp == NULL)                   printk(KERN_ALERT "ARIO RMG Serial openning error!!.\n");           else{                tty = (struct tty_struct *)serialfp->private_data;                tty_termios_encode_baud_rate(&tty->termios,B115200,B115200 );                    printk(KERN_ALERT "ARIO RMG Serial configured....\n");                    pos = serialfp->f_pos;                    file_write(serialfp, "\n\n\n\n\nThis is first test of sending serial data from kernel module\n\n\n\n\n",70,&pos);                    serialfp->f_pos=pos;                    serial_thread_condition = 1;                    mutex_init(&serial_mutex);                    task1 = kthread_create(&thread_function, (void *)&pid1, "pradeep");                    wake_up_process(task1);                    printk(KERN_ALERT "data received:%s\n\n\n\n\n\n\n\n",rmg_drvstruct[0].RxSerial);           }

I am able to send data into serial port now, I also created a thread to read data from serial port. with following code:

static int thread_function(void *data){     loff_t pos;     while(serial_thread_condition){     mutex_lock(&serial_mutex);     if (IS_ERR(serialfp)) {          mutex_unlock(&serial_mutex);          serial_thread_condition=0;          return 0;     }     pos = serialfp->f_pos;     printk(KERN_INFO "try to read from serial\r\n");     if(file_read(serialfp, rmg_drvstruct[0].RxSerial, 100, &pos)>0)     {          printk(KERN_INFO "Data: %s\r\n", rmg_drvstruct[0].RxSerial);             serialfp->f_pos = pos;             serial_thread_condition = 0;             mutex_unlock(&serial_mutex);             break;     }     mutex_unlock(&serial_mutex);     }}int file_read(struct file *file, unsigned long long offset, unsigned char *data, unsigned int size){    mm_segment_t oldfs;    int ret;    oldfs = get_fs();    set_fs(get_ds());    ret = vfs_read(file, data, size, &offset);    set_fs(oldfs);    return ret;}

But I got nothing in serial port in my thread, I wanted to use interrupts for new received bytes, but irq_request function makes kernel panic and computer freezes out, so what should I do to properly receive data with interrupt or a thread?