lcd_driver.c

一个液晶驱动器的驱动源码

/*
 *  linux/drivers/video/lcd_driver.c 
 *  The driver for YXD-240128V6 LCD of stone board.
 */
static unsigned int lcd_text_start;
static unsigned int lcd_graph_start;
static void lcd_controller_init();	//controller reset,if we connect the rst pin to gpio
static int lcd_busy_check();		//write busy check,the other status,we ignore
static int lcd_cmd_in(); 		//write cmd code to lcd controller
static int lcd_data_in(); 		//write data to lcd controller
 
 


static void Write_LCD_CmdCode(unsigned char cmd) /* Command only command code write routine */
{
    if(!lcd_busy_check())return;
    lcd_cmd_in(cmd);
}

static void Write_LCD_CmdData(unsigned char cmd,unsigned char dat1,unsigned char dat2) /* Command whith paramater write (1 byte) routine */
{ 
    if(!lcd_busy_check())return;
    lcd_data_in(dat1);
    if(!lcd_busy_check())return;
    lcd_data_in(dat2);
    if(!lcd_busy_check())return;
    lcd_cmd_in(cmd);
}

static void lcd_Text_Home_Address(unsigned int addr) //set text home address in extern ram
{ 
    lcd_text_start=addr;
    Write_LCD_CmdData(0x40,addr%256,addr/256);		//value of addr must be set by user
}
    
static void lcd_Graph_Home_Address(unsigned int addr) //set graphic home address in extern ram
{
    lcd_graph_start=addr;
    Write_LCD_CmdData(0x42,addr%256,addr/256);
}    

static void lcd_Text_Address(unsigned char x, unsigned char y) //set text address in extern ram
{
    unsigned int xy;
    xy=y*32+x+lcd_text_start;
    Write_LCD_CmdData(0x24,xy%256,xy/256);
}

static void lcd_Graph_Address(unsigned char x,unsigned char y)//set graphic address in extern ram
{
    unsigned int xy;    
    xy=y*32+x+lcd_graph_start;
    Write_LCD_CmdData(0x24,xy%256,xy/256);
}

static void lcd_clear_data(void)
{
    int i=0;
    Write_LCD_Cmd(0x24,0,0);
    Write_LCD_Cmd(0xb0);
    for(i<0x2000;i++)lcd_data_in(0);
    Write_LCD_Cmd(0xb2);
}

static void Init_LCD(void)
{
    lcd_controller_init();		//hard ware reset
    Write_LCD_Cmd(0x90);		//display off
    lcd_clear_data();			//clear display ram
    Write_LCD_CmdData(0x41,0x20,0x00);/* Text area set = 32 columns */
    Write_LCD_CmdData(0x43,0x20,0x00);/* Graphic area set = 32 columns */
    Write_LCD_Cmd(0x89);
    Write_LCD_Cmd(0xa1);		//curse set
    Write_LCD_Cmd(0x9c);		//enable text and graph
}