嵌入式linux驱动-触摸屏笔记

一、开发环境

1、内核：Linux 2.6.22.6；

2、JZ2440v3

3、ubuntu 9.10

二、过程

三、程序

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

//#include 

#include 
#include 

static struct input_dev *myts_dev;
static struct timer_list ts_time;
	
struct ts_regs{
	unsigned long adccon;
	unsigned long adctsc;
	unsigned long adcdly;
	unsigned long adcdat0;
	unsigned long adcdat1;
	unsigned long adcupdn;
};
static volatile struct ts_regs *ts_regs;

static int enter_pen_up_mode(void)
{
	ts_regs->adctsc=0x1d3;
return 0;
}
static void enter_pen_down_mode(void)
{
	ts_regs->adctsc=0xd3;
}

static void enter_measure_xy_mode(void)
{
	ts_regs->adctsc=(1<<3)|(1<<2)|(3<<0);
}

static void start_adc(void)
{
	ts_regs->adccon |=(1<<0);
}

static int filter_ts(int x[],int y[])
{
	#define ERR_LIMIT 10

	int avr_x, avr_y;
	int det_x, det_y;

	avr_x = (x[0] + x[1])/2;
	avr_y = (y[0] + y[1])/2;

	det_x = (x[2] > avr_x) ? (x[2] - avr_x) : (avr_x - x[2]);
	det_y = (y[2] > avr_y) ? (y[2] - avr_y) : (avr_y - y[2]);

	if ((det_x > ERR_LIMIT) || (det_y > ERR_LIMIT))
		return 0;

	avr_x = (x[1] + x[2])/2;
	avr_y = (y[1] + y[2])/2;

	det_x = (x[3] > avr_x) ? (x[3] - avr_x) : (avr_x - x[3]);
	det_y = (y[3] > avr_y) ? (y[3] - avr_y) : (avr_y - y[3]);

	if ((det_x > ERR_LIMIT) || (det_y > ERR_LIMIT))
		return 0;
	return 1;
}


static int adc_irq(int irq,void  *dev_id)
{
	static int cnt;
	static int x[4],y[4];

	int adcdat0,adcdat1;
	adcdat0=ts_regs->adcdat0 & 0x3ff;
	adcdat1=ts_regs->adcdat1 & 0x3ff;
	if(ts_regs->adcdat0 &(1<<15))
	{	//已经松开
		cnt=0;
		input_report_abs(myts_dev, ABS_PRESSURE, 0);
		input_report_key(myts_dev, BTN_TOUCH,0);
		input_sync(myts_dev);
		enter_pen_down_mode();
	}
	else
	{
		//未松开
		x[cnt]=adcdat0;
		y[cnt]=adcdat1;
		++cnt;
		if(cnt==4)
		{	if(filter_ts( x,y))
			//printk("adc_irq cnt=%d,x=%d,y=%d \n",cnt,(x[0]+x[1]+x[2]+x[3])/4,(y[0]+y[1]+y[2]+y[3])/4);
			input_report_abs(myts_dev, ABS_X, (x[0]+x[1]+x[2]+x[3])/4);
			input_report_abs(myts_dev, ABS_Y, (y[0]+y[1]+y[2]+y[3])/4);
			input_report_abs(myts_dev, ABS_PRESSURE, 1);
			input_report_key(myts_dev, BTN_TOUCH, 1);
			input_sync(myts_dev);
			cnt=0;
			enter_pen_up_mode();
			
			//启动定时器处理长按滑动的情况
			mod_timer(&ts_time, jiffies+HZ/100);
			
		}
		else
		{
			enter_measure_xy_mode();
			start_adc();
		}
		
	}

	return IRQ_HANDLED;
}

static void ts_timer_function(unsigned long data)
{

	if(ts_regs->adcdat0 &(1<<15))
	{	//已经松开，进入等待按下模式
		
		input_report_abs(myts_dev, ABS_PRESSURE, 0);
		input_report_key(myts_dev, BTN_TOUCH,0);
		input_sync(myts_dev);
		enter_pen_down_mode();
	}
	else
	{//否则再次启动转换测量xy坐标
		enter_measure_xy_mode();
		start_adc();

	}
	//return IRQ_HANDLED;
}


static int pen_updown_irq(int irq,void  *dev_id)
{
	if(ts_regs->adcdat0 &(1<<15))
	{
		printk("pen_up!\n");
		enter_pen_down_mode();
	}	
	else
	{
		printk("pen_down!\n");
		//enter_pen_up_mode();
		enter_measure_xy_mode();
		start_adc();

	}
	
	return IRQ_HANDLED;

}

static int ts_init(void)
{
	static struct clk *adc_clock;
		
	//1.分配一个input_dev结构体
	myts_dev=input_allocate_device();
	
	//2设置
		//2.1能产生那类事件
	set_bit(EV_KEY,myts_dev->evbit);
	set_bit(EV_ABS,myts_dev->evbit);


		//2.2能产生这类事件里的那类事件
	set_bit(BTN_TOUCH,myts_dev->keybit);
		
	input_set_abs_params(myts_dev, ABS_X, 0, 0x3FF, 0, 0);
	input_set_abs_params(myts_dev, ABS_Y, 0, 0x3FF, 0, 0);
	input_set_abs_params(myts_dev, ABS_PRESSURE, 0, 1, 0, 0);

	//3注册
	input_register_device(myts_dev);


	//4硬件相关的操作
		//4.1使能时钟
		adc_clock = clk_get(NULL, "adc");
		clk_enable(adc_clock);
		//4.2设置s3c2410触摸屏寄存器
		ts_regs=ioremap(0x58000000, sizeof(struct ts_regs));
		ts_regs->adccon=(1<<14)|(49<<6);

		request_irq(IRQ_TC, pen_updown_irq, IRQF_SAMPLE_RANDOM,"ts_action", NULL);
		request_irq(IRQ_ADC, adc_irq, IRQF_SAMPLE_RANDOM,"ts_adc", NULL);

		//优化延时
		ts_regs->adcdly=0xffff;

//使用定时器	处理	长按滑动的情况
	init_timer(&ts_time);
	ts_time.function=ts_timer_function;
	add_timer(&ts_time);
	
		enter_pen_down_mode();
	return 0;
}

static void ts_exit(void)
{

	free_irq(IRQ_TC, NULL);
	free_irq(IRQ_ADC, NULL);
	iounmap(ts_regs);
	input_unregister_device(myts_dev);
	input_free_device(myts_dev);
	del_timer(&ts_time);
}

module_init(ts_init);
module_exit(ts_exit);

MODULE_LICENSE("GPL");