#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/termios.h>

#include "k_file.h"
#include "k_debug.h"

int SetBaudrate(struct k_file *kfp, int rate) 
{
	struct termios ts;
	int speed=B19200;
	int rv=0;

	switch(rate) {
		case  9600:speed=B9600;break;
		case 19200:speed=B19200;break;
		case 38400:speed=B38400;break;
		default: return -EINVAL;
	}
	rv = K_IOCTL(kfp,TCGETS, &ts);
	if( rv<0 ) {
		_E("K_IOCTL failed (%d)\n",rv);
		return rv;
	}
	_D("*** old ***\n");
	_D("i:0x%08x\n",ts.c_iflag); ts.c_iflag = 0x0000;
	_D("o:0x%08x\n",ts.c_oflag); ts.c_oflag = 0x0004;
	_D("c:0x%08x\n",ts.c_cflag); ts.c_cflag = 0x0cbd;
	_D("l:0x%08x\n",ts.c_lflag); ts.c_lflag = 0x0a30;
	ts.c_cflag = (ts.c_cflag & 0xfff0) | speed;
	rv = K_IOCTL(kfp,TCSETS, &ts);
	if( rv<0 ) {
		_E("K_IOCTL failed (%d)\n",rv);
		return rv;
	}
	rv = K_IOCTL(kfp,TCGETS, &ts);
	if( rv<0 ) {
		_E("K_IOCTL failed (%d)\n",rv);
		return rv;
	}
	_D("*** new ***\n");
	_D("i:0x%08x\n",ts.c_iflag); ts.c_iflag = 0;
	_D("o:0x%08x\n",ts.c_oflag); ts.c_oflag = 0;
	_D("c:0x%08x\n",ts.c_cflag); ts.c_cflag = 0;
	_D("l:0x%08x\n",ts.c_lflag); ts.c_lflag = 0;
	return 0;
}



int k_ioctl(struct k_file *kfp, unsigned int cmd, unsigned long data)
{
	int rv=-1;
	if( kfp->filp->f_op->ioctl && kfp->filp->f_dentry->d_inode ) {
		mm_segment_t oldfs;
		oldfs = get_fs();
		set_fs( KERNEL_DS );
		//rv = kfp->filp->f_op->ioctl( kfp->filp->f_dentry->d_inode, kfp->filp, cmd, data );
		rv = kfp->filp->f_op->ioctl( 0, kfp->filp, cmd, data );
		set_fs(oldfs);
	}
	else {
		_D("[k_ioctl] ioctl not supported\n");
	}
	
	return rv;	
}

void k_close(struct k_file *kfp)
{
	if( kfp==NULL ) return;
	if( kfp->filp ) filp_close( kfp->filp, NULL );
	kfree( kfp );
}

loff_t k_seek(struct k_file *kfp, loff_t offset, int mode)
{
	mm_segment_t oldfs;
	oldfs = get_fs();
	set_fs( KERNEL_DS );
	set_fs(oldfs);
	return 0;	
}

ssize_t k_read(struct k_file *kfp, char __user *buffer, size_t size)
{
	ssize_t len=0;
	mm_segment_t oldfs;
	
	oldfs = get_fs();
	set_fs( KERNEL_DS );
	
	//_D("read(%d)",(int)size);
	len = kfp->filp->f_op->read( kfp->filp, buffer, size, &(kfp->filp->f_pos) );
	//_D("->%d\n",len);
	
	set_fs(oldfs);
	
	return len;	
}

ssize_t k_write(struct k_file *kfp, char __user *buffer, size_t size)
{
	ssize_t len=0;
	mm_segment_t oldfs;

	oldfs = get_fs();
	set_fs( KERNEL_DS );
	
	//_D("write(%d)",(int)size);
	len = kfp->filp->f_op->write( kfp->filp, buffer, size, &(kfp->filp->f_pos) );
	//_D("->%d\n",len);
	
	set_fs(oldfs);
	return len;	
}

int k_select(struct k_file *kfp)
{
	mm_segment_t oldfs;
	oldfs = get_fs();
	set_fs( KERNEL_DS );
	set_fs(oldfs);
	return 0;
}

static struct k_file_ops k_fops = {
	.close = k_close,
	.seek = k_seek,
	.read = k_read,
	.write = k_write,
	.select = k_select,
	.ioctl = k_ioctl
};

struct k_file * k_open( char *name, int flags, int mode )
{
	struct k_file *kfp=NULL;
	struct file *filp=NULL;
	
	filp = filp_open( name, flags, mode );
	if( IS_ERR(filp) ||
	    filp->f_op==NULL ||
	    filp->f_op->read==NULL ||
	    (filp->f_op->write==NULL && flags!=O_RDONLY)
	) {
		_E("filp_open of [%s] failed (%d)\n",name,(int)filp);
		filp=NULL;
		goto failed;
	}

	kfp = kmalloc( sizeof( struct k_file ), GFP_KERNEL );
	if( kfp==NULL ) {
		_E("kmalloc failed\n");
		goto failed;
	}

	kfp->filp = filp;
	kfp->ops  = &k_fops;
	if( filp->f_dentry && filp->f_dentry->d_inode ) {
		kfp->size = filp->f_dentry->d_inode->i_size;		
	}

	return kfp;
failed:
	if( kfp  ) kfree( kfp );
	if( filp ) filp_close( filp, NULL );
	return NULL;
}