at91_lcd.c

在arm上实现的lcd136驱动

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <asm/io.h>
#include <asm/uaccess.h>

#ifdef CONFIG_DEVFS_FS
#include <linux/devfs_fs_kernel.h>
#endif

#include "at91_lcd.h"

static int at91_lcd_base;
static int at91_lcd_major;

#ifdef CONFIG_DEVFS_FS
static devfs_handle_t lcd_device;                   
#endif

#define DELAY_TIME  20

static void at91_config_pio_lcd(void)
{
    /* disable LCD_CS_OUT I/O */
    AT91_SYS->PIOC_PDR = LCD_CS_OUT;   
    /* enable LCD_RS_OUT & LCD_BACK_LIGHT I/O */
    AT91_SYS->PIOC_PER = LCD_RS_OUT | LCD_BACK_LIGHT | LCD_RW_OUT;
    /* enable LCD_RS_OUT & LCD_BACK_LIGHT output */
    AT91_SYS->PIOC_OER = LCD_RS_OUT | LCD_BACK_LIGHT | LCD_RW_OUT;   

    /* set the bus interface characteristics */
//    AT91_SYS->EBI_SMC2_CSR[6] = (LCD_RWH | LCD_RWS | LCD_DBW | LCD_TDF | LCD_WSEN | LCD_NWS);
    AT91_SYS->EBI_SMC2_CSR[3] = (LCD_RWH | LCD_RWS | LCD_DBW | LCD_TDF | LCD_WSEN | LCD_NWS);

	AT91_SYS->PIOC_SODR = LCD_BACK_LIGHT;
			
}

static unsigned char lcd_get_status(void)
{
    AT91_SYS->PIOC_CODR = LCD_RS_OUT;  /* set LCD_RS_OUT low    D/nC =0 */
    AT91_SYS->PIOC_SODR = LCD_RW_OUT;  /* set LCD_RW_OUT low    R/nW =1 READ*/
    return inb(at91_lcd_base);
   	udelay(DELAY_TIME);	

}

static void lcd_write_control(char data)
{
    while((lcd_get_status() & 0x80) != 0);
    AT91_SYS->PIOC_CODR = LCD_RS_OUT;  /* set LCD_RS_OUT low    D/nC =0 COMMAND*/
    AT91_SYS->PIOC_CODR = LCD_RW_OUT;  /* set LCD_RW_OUT low    R/nW =0 WRITE */
    outb(data, at91_lcd_base);
   	udelay(DELAY_TIME);	
}

static void lcd_write_data(char data)
{
	/*printk("write data 0x%2X to LCD controllor\n\r", data);*/
    while((lcd_get_status() & 0x80) != 0);
    AT91_SYS->PIOC_SODR = LCD_RS_OUT;  /* set LCD_RS_OUT high   D/nC =1 DATA  */
    AT91_SYS->PIOC_CODR = LCD_RW_OUT;  /* set LCD_RW_OUT low    R/nW =0 WRITE */
    outb(data, at91_lcd_base);
   	udelay(DELAY_TIME);	

}

static void lcd_power_on(void)
{
}

static void lcd_power_off(void)
{
//    lcd_write_control(LCD_PWR_CTR);
}

/*static void lcd_cursor_column(char column)
{
	//printk("set cursor x to %d\n\r", column);
    lcd_write_control(LCD_SET_COL1 | (column >> 4));
    lcd_write_control(LCD_SET_COL2 | (column & 0x0f));
}

static void lcd_cursor_row(char row)
{
	//printk("set cursor y to %d\n\r", row);
    lcd_write_control(LCD_SET_PAGE | row);
}
*/
static void lcd_cls(void)//清屏
{

    lcd_write_control(0x01);

}

static int lcd_open(struct inode *inode, struct file *filp)
{
    int i,j;    

    MOD_INC_USE_COUNT;
    return 0;
}
                  
static int lcd_release(struct inode *inode, struct file *filp)
{
    MOD_DEC_USE_COUNT;
    return 0;
}

static int lcd_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
{
    switch(cmd) {
        case LCD_POWER:
	    {
/*          int data;
	        if(get_user(data, (int *)arg))  return -EFAULT;
            if(data)  lcd_power_on();
            else  lcd_power_off();
*/            
	        break;
        }
        case LCD_DISPLAY:
	    {
//            int data;
//	        if(get_user(data, (int *)arg))  return -EFAULT;
	        /*printk("LCD display is turned %s\n\r", data?"on":"off");*/
//            if(!data)  lcd_write_control(LCD_DSP_CTR);
//            else  lcd_write_control(LCD_DSP_CTR | 0x01);
	        break;
        }
        case LCD_BACKLIGHT:
	    {
            char data;
	        if(get_user(data, (char *)arg))  return -EFAULT;
            if(data)  AT91_SYS->PIOC_SODR = LCD_BACK_LIGHT;
            else  AT91_SYS->PIOC_CODR = LCD_BACK_LIGHT;
	        return 0;
        }
        case LCD_CLEAR:
            lcd_cls();
	        break;
        case LCD_CURSOR_X:
        {
/*
			int data;
	        if(get_user(data, (int *)arg))  return -EFAULT;
            lcd_cursor_column((char)data );
*/
	        break;
        }
        case LCD_CURSOR_Y:
        {
/*
            int data;
	        if(get_user(data, (int *)arg))  return -EFAULT;
            lcd_cursor_row((char)data);
*/
	        break;
        }
        case LCD_CURSOR_XY:
        {
            int data;
//	        if(get_user(data, (int *)arg))  return -EFAULT;
	        get_user(data, (int *)arg);
            lcd_write_control((char)data);
	        break;
        }
        case LCD_WRITE:
        {
            char data;
//	        if(get_user(data, (char *)arg))  return -EFAULT;
	        get_user(data, (char *)arg);
            lcd_write_data(data);
	        break;
        }
        default:
//            return -EINVAL;
	        break;

    }

    return 0;
}


static struct file_operations lcd_fops =
{
    owner:	THIS_MODULE,
    open:		lcd_open,
    release:	lcd_release,
    ioctl:		lcd_ioctl
};

static int __init at91_lcd_init(void)
{
    int i,j;    


    printk(KERN_INFO "lcd: S6B0719 160x105 LCD pannel, ");

#ifdef CONFIG_DEVFS_FS 
    at91_lcd_major = devfs_register_chrdev(0, "lcd", &lcd_fops);
#else
    at91_lcd_major = register_chrdev(0, "lcd", &lcd_fops);
#endif
    if(at91_lcd_major < 0) {
	    printk(KERN_WARNING "lcd: unable to get major for lcd driver\n");
	    return at91_lcd_major;
    }
 
#ifdef CONFIG_DEVFS_FS 
    lcd_device = devfs_register(NULL, "lcd", DEVFS_FL_DEFAULT, at91_lcd_major, 0,
                         S_IFCHR | S_IRUGO | S_IWUGO, &lcd_fops, NULL);
#endif

    at91_lcd_base = (unsigned long) ioremap(LCD_ACCESS_ADDR, SZ_1K);
    if(!at91_lcd_base) {
	    printk("ioremap AT91 LCD failed\n");
	    return -EIO;
    }

    at91_config_pio_lcd();

    printk("lcd 4*16 char driver loading\n");
    
    for(i=3;i>0;i--)
	{
        lcd_write_control(0x30);
        j=j;
	}
	lcd_write_control(0x38);
	lcd_write_control(0x0c);
	lcd_write_control(0x06);
	lcd_write_control(0x02);
	lcd_write_control(0x01);
	
	for(i=255;i>0;i--)j=j;	
	lcd_write_control(0x40);
	
	lcd_write_data(0);	
	lcd_write_data(0);	
	lcd_write_data(0);	
	lcd_write_data(0);	
	lcd_write_data(0);	
	lcd_write_data(0x1f);	
	lcd_write_data(0x0e);	
	lcd_write_data(4);	
	lcd_write_data(4);	
	lcd_write_data(0xe);	
	lcd_write_data(0x1f);	
	lcd_write_data(0);	
	lcd_write_data(0);	
	lcd_write_data(0);	
	lcd_write_data(0);	
	lcd_write_data(0);	
	
	lcd_write_control(0x80);  //display "OK!"
	lcd_write_data('O');
	udelay(DELAY_TIME);	
	lcd_write_control(0x81);
	lcd_write_data('K');	
	udelay(DELAY_TIME);
	lcd_write_control(0x82);
	lcd_write_data('!');	
	udelay(DELAY_TIME);	
	lcd_write_control(0x83);
	lcd_write_data(' ');	
	udelay(DELAY_TIME);

    printk("lcd 4*16 char driver loaded  \n");

    return 0;
}
 
static void __exit at91_lcd_exit(void)
{
#ifdef CONFIG_DEVFS_FS 
    devfs_unregister(lcd_device);
    if(devfs_unregister_chrdev(at91_lcd_major, "lcd")) {
#else
    if(unregister_chrdev(at91_lcd_major, "lcd")) {
#endif
        printk(KERN_ERR "lcd: unable to release major %d for LCD driver\n", at91_lcd_major);
    }
}

module_init(at91_lcd_init);
module_exit(at91_lcd_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LCD driver for net tester");
MODULE_AUTHOR("Jim Lao");