www.pudn.com > LCDRT12232F.rar > lcd_12232F.c
/* Copyright (c) 2007,9,18 北京华龙通有限公司事业二部一室
*
* 文件名称：lcd12232F.c
* 摘 要：使用Avalon总线的4×4键盘底层驱动。
*
* 当前版本：v1.1.0
* 日期：2008年2月18日
*/
#include
#include
#include
#include
#include
#include "lcd_12232F.h"
#define SUCCESS 0
static int Device_Open = 0;
static int line=1;
static char Message[BUF_LEN];
static char *Message_Ptr;
/*****************************************
* 定义用户程序访问外设接口函数
****************************************/
/*
* Function 1:device_open
*/
static int device_open(struct inode *inode, struct file *file)
{
if (Device_Open)
return -EBUSY;
Device_Open++;
Message_Ptr = Message;
try_module_get(THIS_MODULE);
return SUCCESS;
}
/*
* Function 2:device_release
*/
static int device_release(struct inode *inode, struct file *file)
{
Device_Open--;
module_put(THIS_MODULE);
return SUCCESS;
}
/*
* Function 3:device_read
*/
static ssize_t device_read(struct file *file,char __user * buffer,size_t length,loff_t * offset)
{
int bytes_read = 0;
if (*Message_Ptr == 0)
return 0;
while (length && *Message_Ptr) {
put_user(*(Message_Ptr++), buffer++);
length--;
bytes_read++;
}
return bytes_read;
}
/*
* Function 4:device_write
*/
static ssize_t device_write(struct file *file,const char __user * buffer, size_t length, loff_t * offset)
{
int ii;
unsigned char c;
switch(line)
{
case 1:
WriteNios(ADR_LCD_COMMAND,ADR_LCD_LINE1_OFFSET);
udelay(50);
for (ii = 0; ii < length && ii < BUF_LEN; ii++)
{
get_user(c, buffer + ii);
WriteNios(ADR_LCD_DATA, (unsigned long) c);
udelay(50);
}
if (length < BUF_LEN)
{
for (ii = length; ii < BUF_LEN; ii++)
{
WriteNios(ADR_LCD_DATA,0x20);
udelay(50);
} WriteNios(ADR_LCD_COMMAND,ADR_LCD_LINE2_OFFSET);
udelay(50);
for (ii = BUF_LEN; ii < BUF_LEN+BUF_LEN; ii++)
{
WriteNios(ADR_LCD_DATA,0x20);
udelay(50);
}
}
else //当用户缓冲区长度大于16bytes
{
//此时，用户数据已经将第一行写满，准备接着写第二行
WriteNios(ADR_LCD_COMMAND,ADR_LCD_LINE2_OFFSET);
udelay(50);
for (ii = BUF_LEN; ii < length && ii < BUF_LEN+BUF_LEN; ii++)
{
get_user(c, buffer + ii);
WriteNios(ADR_LCD_DATA,(unsigned long) c);
udelay(50);
}
if (length < BUF_LEN + BUF_LEN) //如果用户缓冲区数据长度小于或等于32bytes
{
for (ii = length; ii < BUF_LEN + BUF_LEN; ii++)
{
WriteNios(ADR_LCD_DATA, 0x20);
udelay(50);
}
}
}
break;
case 2:
WriteNios(ADR_LCD_COMMAND,ADR_LCD_LINE2_OFFSET);
udelay(50);
for (ii = 0; ii < length && ii < BUF_LEN; ii++)
{
get_user(c, buffer + ii);
WriteNios(ADR_LCD_DATA,(unsigned long) c);
udelay(50);
}
if (length < BUF_LEN ) //如果用户缓冲区数据长度小于或等于32bytes
{
for (ii = length; ii < BUF_LEN ; ii++)
{
WriteNios(ADR_LCD_DATA, 0x20);
udelay(50);
}
}
break;
}
return length;
}
/*
static ssize_t device_write(struct file *file,const char __user * buffer, size_t length, loff_t * offset)
{
int ii;
unsigned char c;
//0x80=10000000;代表设定DDRAM第一行地址到地址计数器AC，
WriteNios(ADR_LCD_COMMAND,ADR_LCD_LINE1_OFFSET);
udelay(50);
//length为用户缓冲区的长度，BUF_LEN=16
for (ii = 0; ii < length && ii < BUF_LEN; ii++)
{
get_user(c, buffer + ii);
//将从用户空间得到的字符c写到LCD的Data Register中
WriteNios(ADR_LCD_DATA, (unsigned long) c);
udelay(50);
}
if (length < BUF_LEN) //当用户缓冲区长度小于或等于16bytes
{
//将第一行其它写成空，0x20的ASCII值为空
for (ii = length; ii < BUF_LEN; ii++)
{
WriteNios(ADR_LCD_DATA,0x20);
udelay(50);
}
//将第二行其它全部写成空，0x20的ASCII值为空
WriteNios(ADR_LCD_COMMAND,ADR_LCD_LINE2_OFFSET);
udelay(50);
for (ii = BUF_LEN; ii < BUF_LEN+BUF_LEN; ii++)
{
WriteNios(ADR_LCD_DATA,0x20);
udelay(50);
}
}
else //当用户缓冲区长度大于16bytes
{
//此时，用户数据已经将第一行写满，准备接着写第二行
WriteNios(ADR_LCD_COMMAND,ADR_LCD_LINE2_OFFSET);
udelay(50);
for (ii = BUF_LEN; ii < length && ii < BUF_LEN+BUF_LEN; ii++)
{
get_user(c, buffer + ii);
WriteNios(ADR_LCD_DATA,(unsigned long) c);
udelay(50);
}
if (length < BUF_LEN + BUF_LEN) //如果用户缓冲区数据长度小于或等于32bytes
{
//将第二行未写满的DDRAM写成空
for (ii = length; ii < BUF_LEN + BUF_LEN; ii++)
{
WriteNios(ADR_LCD_DATA, 0x20);
udelay(50);
}
}
}
//返回从用户段写入内核段数据的长度
return length;
}
*/
/*
* Function 5:device_ioctl
*/
static int device_ioctl(struct inode *inode,struct file *file, unsigned int ioctl_num,unsigned long ioctl_param)
{
int i;
char *temp;
char ch;
switch (ioctl_num)
{
case IOCTL_WRITE: // 将temp指针指向用户空间的message数据，将这条信息设置为需要传递给LCD设备的信息
temp = (char *)ioctl_param; // 得到用户进程传递给ioctl函数的地址内的数据取出
get_user(ch, temp);
for (i = 0; ch && i < BUF_LEN + BUF_LEN; i++, temp++)
{
get_user(ch, temp);
} //解析这条message的长度,得到i值
if (i