touchpanel.c

最常用的嵌入式LINUX字符设备驱动：触摸屏和小键盘驱动。触摸屏使用SPI接口

/************************************************************
文档类型: 原代码 
项目编号: 
文档编号: 
修订版本: v1.0
生成日期: 2001.11.9
文档作者: 张继周,何雄伦
审    核: 
************************************************************
相关文档: uClinux的触摸屏驱动程序
 
文档编号      说明 

************************************************************
修订版本: v1.1
修订说明: 增加了对触摸屏坐标的校验功能
生成日期: 2002.3.28
文档作者: 何雄伦
审    核: 
************************************************************
修订版本: v1.1
修订说明: 增加了将DX,DY,SCX,SCY值写到FLASH
生成日期: 2002.5.23
文档作者: 周泽明
审    核: 
************************************************************/

#include <linux/kernel.h>
#include <asm/MC68VZ328.h>
#include <asm/segment.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/tqueue.h>
#include <linux/interrupt.h>

/* 触摸屏的两种状态:PEN_DOWN为笔按下状态;PEN_UP为笔没有按下状态 */
#define PEN_DOWN	1
#define PEN_UP		2

/* 时钟中断的间隔,每隔固定的时间片就检查笔的状态(按下或没按下) */
#define DELAY		20

/*The size of keyboard input buffer.*/
#define MAX_BUF_COUNT 5000
/* 触摸屏设备号 */
unsigned int touch_major = 98;
/* 笔状态变量,默认没按下 */
static unsigned char flag = PEN_UP;
/* 触摸屏的数据缓冲区(循环队列) */
static unsigned char pen_buf[MAX_BUF_COUNT];
static int pstart,pend,count;

/* The touch pannel wait queque */
static struct wait_queque *touch_wait;


/* 触摸屏当前笔的位置和上次按下的位置 */
static struct pos {
	unsigned short x;
	unsigned short y;
}pre_pos,cur_pos;

// [Added++] by Aavan, 2002/09/05
int gOldX = 0;
int gOldY = 0;
int gX = 0;
int gY = 0;
// [Added--]

// 由于触摸屏的抖动问题,使用一个滤波器对坐标值滤波
struct {
	unsigned int x[5];
	unsigned int y[5];
	unsigned short count;
}filter;

// 存放手写字的轨迹
struct trackbuf{
	unsigned char track[20000];
	unsigned int endpos;
	unsigned int pointcount;
	// flag == 0:一个字的轨迹还未结束;flag == 1:一个字的轨迹结束了;
	unsigned char flag;
}pointbuf;

// 手写输入键盘在屏幕上的位置;当笔落在这个范围内的时候,
// 作为鼠标;在这个范围以外,作为手写轨迹
struct keyboard{
	unsigned int x;
	unsigned int y;
	unsigned int x1;
	unsigned int y1;
}boardrect;

// 0:送轨迹;1:不送轨迹
static unsigned char sendtrack;

// 0:没进入了输入键盘;1:进入了键盘
static unsigned char keyflag = 0;

// 0:触笔模拟鼠标;1:触笔正进行坐标校验;2:触笔正进行手写输入
static unsigned char collateflag = 0;
// 判断当前要定位的位置,0:左上角;1:右下角
static unsigned char collatepos = 0;

unsigned int DX = 151;//179;	// LCD左上角位置在触摸屏上的X坐标
unsigned int DY = 119;//183;	// LCD左上角位置在触摸屏上的Y坐标
unsigned int DX1;	// LCD右下角位置在触摸屏上的X坐标
unsigned int DY1;	// LCD右下角位置在触摸屏上的Y坐标
float SCX = 0.185f;//0.189f;	// SCX = 320/(DX1-DX)
float SCY = 0.135f;//0.149f;	// SCY = 240/(DY1-DY)

// 设备文件正在使用标志
static unsigned char useflag = 0;

// LCD显示缓存指针
static unsigned char *videobuf;
// 定义显示缓存尺寸
#define VIDEOLEN	38400
// 定义一行象素的尺寸
#define LINELEN		160
// 备份显示缓存
static unsigned char videobackup[VIDEOLEN];

static unsigned int writedelay = 0;

// 定义手写输入字轨迹的灰度值
static unsigned char greyvalue = 0xff;

static unsigned char notmask[2] = { 0x0f, 0xf0};
static char shift[2] = {4,0};

// 在FLASH中保存SCX,SCY,DX,DY的值,打开设备时读入这些值,
// 在每次校正时重新把这几个值写到FLASH中保存,并在前五个字节里
// 写入"FLASH"作为标志.从FLASH中读这几个值,如果前五个字节不是
// "FLASH",表示SCX,SCY,DX,DY的值还没有烧到FLASH中,就使用缺省的值.
// format: "FLASH",DX,DY,SCX,SCY.
#define FLASHBLKID 	0
#define OFFSET		0
#define INTLEN		sizeof(unsigned int)
#define FLOATLEN	sizeof(float)
#define LENGTH		(5+2*INTLEN+2*FLOATLEN)

// this value used to save port d data
static unsigned char pddata;

extern int freadflash(const int fd,const int off,unsigned char *buf,const unsigned int len);
extern int fwriteflash(const int fd,const int off,unsigned char *buf,const unsigned int len);

/************************************************************
函数原型: static void drawpixel(unsigned int x, unsigned int y)
功    能: Draw a pixel to LCD.
输入参数: x,y:location the pixel.
返 回 值: NULL.
************************************************************/
unsigned char *addr;

#define drawpixel(x,y)	{					\
	addr = videobuf;					\
	addr += (x>>1) + (y << 7) + (y << 5);			\
	*addr = greyvalue;					\
	addr += LINELEN;					\
	*addr = greyvalue;					\
}

static int xdelta;			/* width of rectangle around line */
static int ydelta;			/* height of rectangle around line */
static int xinc;			/* increment for moving x coordinate */
static int yinc;			/* increment for moving y coordinate */
static int rem;			/* current remainder */
	
static void drawline(unsigned int x1,unsigned int y1,unsigned int x2,unsigned int y2)
{
	xdelta = x2 - x1;
	ydelta = y2 - y1;
	if (xdelta < 0) xdelta = -xdelta;
	if (ydelta < 0) ydelta = -ydelta;
	xinc = (x2 > x1) ? 1 : -1;
	yinc = (y2 > y1) ? 1 : -1;
	
	drawpixel(x1,y1);
	if (xdelta >= ydelta)
	{
		rem = xdelta >> 1;
		for(;;)
		{
			x1 += xinc;
			rem += ydelta;
			if (rem >= xdelta)
			{
				rem -= xdelta;
				y1 += yinc;
			}
			drawpixel(x1,y1);
			if(x1 == x2)
				break;
		}
	}
	else
	{
		rem = ydelta >> 1;
		for(;;)
		{
			y1 += yinc;
			rem += xdelta;
			if (rem >= ydelta)
			{
				rem -= ydelta;
				x1 += xinc;
			}
			drawpixel(x1,y1);
			if(y1 == y2)
				break;
		}
	}
}

/************************************************************
函数原型: static int touch_read(struct inode *node, struct file *fp,
		    unsigned char *ubuf, int ucount);
功    能: Read the data of touch panel.
输入参数: unsigned char *ubuf:the input data buffer point,the buffer save
		data of x and y value and pen status(down or up) of touch
		panel.
	  int ucount:it must be 5.
返 回 值: if readed successful then return 5,if the user buffer error then
		return -1,and no data to read then return 0.
************************************************************/
static int touch_read(struct inode *node, struct file *fp,
		    unsigned char *ubuf, int ucount)
{
	if (verify_area(VERIFY_WRITE, ubuf, 5) == -EFAULT)
		return -1;
	
	if (count == 0)
		return 0;

	put_user(pen_buf[pend],ubuf);
	put_user(pen_buf[pend+1],ubuf+1);
	put_user(pen_buf[pend+2],ubuf+2);
	put_user(pen_buf[pend+3],ubuf+3);
	put_user(pen_buf[pend+4],ubuf+4);
	count --;
	pend +=5 ;
	
	if (pend >= MAX_BUF_COUNT) pend = 0;
	return 5;
}

/************************************************************
函数原型: static int touch_open(struct inode *node, struct file *fp);
功    能: this function open the touch panel.
输入参数: struct inode *node:not used.
	  struct file *fp:not used.
返 回 值: it always open successful,so it return 0.
************************************************************/
static int touch_open(struct inode *node, struct file *fp)
{
	unsigned char *save,*p,*q;
	int i;
/*
	save = kmalloc(LENGTH,GFP_KERNEL);
	if (NULL == save)
		printk("kmalloc failure.\n");
	else
	{
		p = save;
		if (freadflash(FLASHBLKID ,OFFSET,save,LENGTH))
			printk("read flash error!\n");
		else if ( (0x46 == *p++) && (0x4c == *p++) &&
			 (0x41 == *p++) && (0x53 == *p++) &&
			 (0x48 == *p++) )
			{
				q = (unsigned char*)&DX;
				for (i=0;i<INTLEN;i++)
					*q++ = *p++;
				q = (unsigned char*)&DY;
				for (i=0;i<INTLEN;i++)
					*q++ = *p++;
				q = (unsigned char*)&SCX;
				for (i=0;i<FLOATLEN;i++)
					*q++ = *p++;
				q = (unsigned char*)&SCY;
				for (i=0;i<FLOATLEN;i++)
					*q++ = *p++;
		
				printk("read flast -- DX = %d\n",DX);
				printk("read flast -- DY = %d\n",DY);
				printk("read flast -- SCX = %d\n",(unsigned int)(SCX*1000));
				printk("read flast -- SCY = %d\n",(unsigned int)(SCY*1000));
			}
		kfree(save);
	}
*/
	if (useflag == 0)
	{
		// 如果驱动是第一次打开,则作为鼠标打开
		pstart = 0;
		pend = 0;
		count = 0;
		
		useflag = 1;
	}
	// 不是第一次打开,作为手写输入
	return 0;
}

/************************************************************
函数原型: touch_close(struct inode *node, struct file *fp);
功    能: this function close the touch panel.
输入参数: all arguments don't used.
返 回 值: it has no any return value.
************************************************************/
static void touch_close(struct inode *node, struct file *fp)
{
	useflag = 0;
}

static int touch_select(struct inode *inode,struct file *file,int mode,select_table *table)
{
	if (mode == SEL_IN)
	{
		if (count)
		{
			return 1;
		}
		select_wait(&touch_wait,table);
	}
	return 0;
}

static unsigned char resourchflag = 0;

// This function added by xionglun.he 2002.3.28
static int touch_ioctl(struct inode *inode,struct file *filp,unsigned int cmd,unsigned long arg)
{
	struct trackbuf *pbuf;
	struct keyboard *prect;
	unsigned char *save,*p,*q;
	int i;
	
	switch (cmd)
	{
	case 1:
		// 开始校验
		collateflag = 1;
		pre_pos.x = 0;
		pre_pos.y = 0;
		cur_pos.x = 0;
		cur_pos.y = 0;

		if (arg == 0)
			collatepos = 0;
		else
			collatepos = 1;