Is this driver right?

hello,
I use a borad running MPC850 and HHL 2.2.14.I writed a parport LCD device driver,and successful intall into kernel(it can be seen in /proc/devceis ).But it didn't work,this drivers is portinged from a pSOS's driver(borad is same).

I have added a new line in mem.c
[...]

	plcd_init();

[...]
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#include <linux/init.h>
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/sched.h>
#include <linux/malloc.h>
#include <linux/fcntl.h>
#include <linux/delay.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/system.h>

#include "plcd.h"

#define IMAP_ADDR ((uint)0xfa200000) /*borad's IMMR values*/

#define G_BASE 0x0000 /*base address of Graphics RAM memory*/

#define A_BASE 0x1700 /*base address of Attribute RAM memory*/

#define T_BASE 0x1800 /*base address of Text RAM memory*/

#define CG_BASE 0x1c00 /*base address of CG-RAM memory*/

#define BYTES_PER_ROW 30 /*How many bytes per row on screen*/

                                                                  /*This will be 40 with 6x8 font ,30 with 8x8,for both Text &

                                                                Graphics modes in JM240x128A module. Font selection by FS pin on LCD module:

                                                                FS=High: 6x8 font. FS=Low: 8x8 font.*/

/*define Port D offset to immr*/
#define PDDAT_OFFSET 0x976
#define PDDIR_OFFSET 0x970
#define PDPAR_OFFSET 0x972

/*default the control lines to lcd are in output mode*/ #define WRHI plcd->pd_con |= 0x10
#define WRLO plcd->pd_con &= ~0x10

#define RDHI plcd->pd_con |= 0x08
#define RDLO plcd->pd_con &= ~0x08

#define CEHI
#define CELO

#define FSHI plcd->pd_con |= 0x04
#define FSLO plcd->pd_con &= ~0x04

#define CDHI plcd->pd_con |= 0x02
#define CDLO plcd->pd_con &= ~0x02

#define RSTHI plcd->pd_con |= 0x01
#define RSTLO plcd->pd_con &= ~0x01

#define DATAIN plcd->pd_dir=0x1f00
#define DATAOUT plcd->pd_dir=0x1fff

#define DATA plcd->pd_data

typedef struct parportlcd {

        volatile unsigned short pd_dir;

        volatile unsigned short pd_par;

        unsigned char   RESERVED[2];

        volatile unsigned char pd_con;

        volatile unsigned char pd_data;

}lcd;

static void mydelay(int t)

{

long j, k, i=0x1234;

    while(t--)

        {

        for (j=0; j<30; j++)

            k = j * i;

     }

}

static unsigned char shift( unsigned char src )

{
        unsigned char des=0;
        register int i;
        for(i = 0;i < 8;i++)
                {
                  des=des<<1;
                  des |= src & 0x01;
                  src=src>>1;
                }
        return des;
}

static int sget(void) /*get LCD display status byte*/ {

int lcd_status;
volatile lcd *plcd;
plcd=(lcd*)(( IMAP_ADDR & 0xffff0000)+PDDIR_OFFSET); DATAIN;
WRHI;
CDHI;
CELO;
RDLO;
lcd_status = DATA;
RDHI;
CEHI;
DATAOUT;
return (shift(lcd_status));
}

static void cput(int byte)
{
volatile lcd *plcd;
plcd=(lcd*)(( IMAP_ADDR & 0xffff0000)+PDDIR_OFFSET); CDHI;
RDHI;
DATA=shift(byte);
CELO;
WRLO;
CEHI;
WRHI;
}

int d_get(void)
{
int byte;
volatile lcd *plcd;
plcd=(lcd*)(( IMAP_ADDR & 0xffff0000)+PDDIR_OFFSET); DATAIN;
WRHI;
CDLO;
CELO;
RDLO;
byte = DATA;
CEHI;
RDHI;
DATAOUT;
return (shift(byte));
}

static void d_put(int byte)
{
volatile lcd *plcd;
plcd=(lcd*)(( IMAP_ADDR & 0xffff0000)+PDDIR_OFFSET); RDHI;
CDLO;
DATA = shift(byte);
CELO;
WRLO;
CEHI;
WRHI;
}

static void lcd_setpixel(int column,int row) {
unsigned int addr;
addr = G_BASE + (row * BYTES_PER_ROW)+ (column/8); d_put(addr & 0xff);
d_put(addr >> 8);
cput(ADPSET);
cput(BITSET|(7-(column%8)));
}
static int lcd_getpixel(int column,int row) {
unsigned int addr;
addr = G_BASE + (row * BYTES_PER_ROW)+ (column/8); d_put(addr & 0xff);
d_put(addr >> 8);
cput(ADPSET);
cput(RDUNC);
addr = d_get();
return (addr & (1 << (7-(column%8))));
}

static ssize_t plcd_read(struct file * file,char * buf,size_t length,loff_t *ppos) {
return 0;
}

static ssize_t plcd_write(struct file * file,char *buf,size_t length,loff_t *ppos) {
int x,y;
x=(int)buf[0];
y=(int)buf[1];
lcd_setpixel(x,y);
}

static ssize_t plcd_open(struct inode * inode,struct file * file) {
printk("Now will open lcd device!");
return 0;
}

static ssize_t plcd_release(struct inode *indoe,struct file * file) {
return 0;
}

static struct file_operations plcd_fops={
NULL,
plcd_read,
plcd_write,
NULL,
NULL,
NULL,
NULL,
plcd_open,
plcd_release,
NULL,
NULL
};

int plcd_init(void)

{
        int major;
        volatile lcd *plcd;
        plcd=(lcd*)(( IMAP_ADDR & 0xffff0000)+PDDIR_OFFSET);
        RSTHI;
        RSTLO;
        mydelay(10);
        RSTHI;
        CEHI; /*disable chip*/
        RDHI; /*disable reading from LCD*/
        WRHI; /*disable writing to LCD*/
        CDHI; /*command/status mode*/
        FSLO; /* 8x8 font;*/
        DATAOUT;

        major=register_chrdev(99,"PLCD",&plcd_fops);

        if(major>=0)
           printk("Successful install PLCD device!\nMajoe:%d\n&&&&&&&&&&&&&&&&&&&&&&\n",major);
        else
           printk("Can't instal PLCD device\n");
        return 0;

}

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

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