mini2440 觸摸屏調試程式記錄

今天看了一下s3c2440的touch screen control借口，完成了裸機程式的調試，把代碼記錄如下

其他的代碼和前面做的實驗基本一樣，隻是在ad中斷裡面添加了對于觸摸屏的處理，初始化ad的函數有了一點點修改，隻記錄ad.c

ad.c

#define		ADCCON		(*((volatile unsigned long*)(0x58000000)))
#define		ADCTSC		(*((volatile unsigned long*)(0x58000004)))
#define		ADCDLY		(*((volatile unsigned long*)(0x58000008)))
#define		ADCDAT0		(*((volatile unsigned long*)(0x5800000C)))
#define		ADCDAT1		(*((volatile unsigned long*)(0x58000010)))

#define		SUBSRCPND	(*((volatile unsigned long*)(0X4A000018)))
#define		SRCPND		(*((volatile unsigned long*)(0X4A000000)))
#define		INTPND		(*((volatile unsigned long*)(0X4A000010)))

#define		PURE_RED	0b0000011111100000

extern void change_num_string(unsigned short num, char *buffer);
extern void put_char(char ch);
extern void put_string(char *string);


unsigned short read_ad(unsigned char chanel_num)
{
	/*
		enable prescale operation, the value of prescaling is 49+1=50
		PCLK has been set to 50MHz, so the clock of ad conventer is 1MHz
	*/
	ADCCON = (1<<14)|(49<<6)|(chanel_num<<3);

	//set ad conventer to normal working mode
	ADCTSC &= ~(1<<2);

	//set ADCCON[0] to 1 in order to starting converting operation
    ADCCON |= 1;

    //wait converting operation to start, at that moment ADCCON[0] will be cleared
    while (ADCCON & 1);

    //wait till convertion operatioin stops
    while (!(ADCCON&(1<<15)));

    //return the result (10bits)
    return (unsigned short)(ADCDAT0 & 0x3ff);
}

void init_ad(unsigned char chanel_num)
{
	/*
		enable prescale operation, the value of prescaling is 49+1=50
		PCLK has been set to 50MHz, so the clock of ad conventer is 1MHz
	*/
	//ADCCON = (1<<14)|(49<<6)|(chanel_num<<3);
	ADCCON = (1<<14)|(49<<6);

	/*
		after touch screen interrupt happens, cpu will delay 1/3.68M*50000 = 13.5ms
		and start the ad converting operation for x and y
	*/
	ADCDLY = 50000;

	//set ad conventer to normal working mode and waiting for touch screen down interrupt
	ADCTSC = 0b011010011;
}

inline void start_ad()
{
	//set ADCCON[0] to 1 in order to starting converting operation
    ADCCON |= 1;
}

void delay(int times);

void ad_interrupt_handler()
{
	if(SUBSRCPND&(1<<10)) //standard ad interrupt
	{
		char buffer[4];
		int x, y;

		unsigned short adc_result = ADCDAT0&0x3ff;
		x = adc_result;

		put_string("x:0x");
		change_num_string(x, buffer);
		put_string(buffer);

		adc_result = ADCDAT1&0x3ff;
		y = adc_result;
		put_string(" y:0x");
		change_num_string(y, buffer);
		put_string(buffer);

		put_char('\r');

		delay(10); //give com0 enough time to print information

		//wait screen up interrupt
		ADCTSC = 0b111010011;
	
		//clear ad screen interrupt 
		SUBSRCPND = SUBSRCPND;
		SRCPND |= (1<<31);
		INTPND = INTPND;
	}
	else if(SUBSRCPND&(1<<9)) //touch screen interrupt
	{
		//put_string("touch screen interrupt!\r\n");
		if(ADCTSC & (1<<8)) //it is touch up interrupt currently
		{
			ADCTSC = 0b011010011;
			//put_string("touch screen up interrupt!\r\n");
			//clear touch screen interrupt 
			SUBSRCPND = SUBSRCPND;
			SRCPND |= (1<<31);
			INTPND = INTPND;
		}
		else //it is touch down interrupt currently
		{
			//put_string("touch screen down interrupt!\r\n");
			//clear touch screen interrupt first, so that standard ad interrupt can be served
			SUBSRCPND = SUBSRCPND;
			SRCPND |= (1<<31);
			INTPND = INTPND;
			ADCTSC = 0x0c; //auto xy mode
			ADCCON |= (1<<0); //start the ad converting operation
		}
	}
}
           

顯示16進制的xy坐标的ad轉換結果：