Design of S3C2440 resistive touch screen driver

Design of S3C2440 resistive touch screen driver

Experiment: When the pen clicks on the touch screen, SecureCRT displays the X and Y coordinates of the contacts;

Objective: To test the resistance touch screen driver;

Development Board: S3C2440

 

/** All Rights Reserved (C) 2015, ZJU ** file name: ts. c * Content Abstract: Touch Screen configuration * Other Instructions: Development Board model: TX2440 * resistance screen * Current version: V1.0 * OPERATOR: Frank * completion date: 2015.12.22 **/# define ADCCON (* (volatile unsigned int *) 0x58000000) // ADC control register # define ADCTSC (* (volatile unsigned int *) 0x58000004) // ADC Touch Screen Control Register # define ADCDLY (* (volatile unsigned int *) 0x58000008) // ADC Start or interval delay register # define ADCDATA0 (* (volatile unsigned int *) 0 X5800000C) // ADC conversion data register # define ADCDATA1 (* (volatile unsigned int *) 0x58000010) // ADC conversion data register/* interrupt register */# define SRCPND (* (volatile unsigned long *) 0x4A000000) # define INTMSK (* (volatile unsigned long *) 0x4A000008) # define INTPND (* (volatile unsigned long *) 0x4A000010) # define effecffset (* (volatile unsigned long *) 0x4A000014) # define SUBSRCPND (* (volatile unsigned l Ong *) 0x4A000018) # define INTSUBMSK (* (volatile unsigned long *) 0x4A00001C) int xdata = 0; int ydata = 0; /*************************************** * **************************** Function Name: ts_Init () * Function Description: Touch Screen work initialization * Other Instructions: Configure ADC for touch screen work mode * creation date: 2015.12.22 *************************************** * ***************************/void Ts_Init (void) {/* 1. Set the adswitch clock */ADCCON = (1 <14) | (49 <6); // The adswitch frequency = PCLK/(Val + 1 ), set to 1 MHz/* 2. Interrupt shielding space */INTMSK = ~ (1 <31); INTSUBMSK = ~ (1 <9);/* 3. Enter the pending interrupt mode */ADCTSC = 0xd3;/*** clear the 7th-bit I (IRQ disable) in the CPSR register ), because in start. S to enable the total interrupt _ asm _ ("mrs r0, cpsr \ n" "bic r0, r0, r0, #0x80 \ n "" msr cpsr_c, r0 \ n "::);} /*************************************** * **************************** Function Name: ts_Handler () * Function Description: Touch Screen Interrupt Processing * Other Description: interrupt processing after the touch screen is pressed * creation date: 2015.12.22 *************************************** * **************************/void Ts_Handler (void) {/* 1. Start Automatic conversion of dynamic XY coordinates */ADCTSC = (1 <2); ADCCON | = (1 <0);/* 2. Wait until the conversion is complete */while (! (ADCCON & (1 <15);/* 3. Obtain coordinates */xdata = ADCDATA0 & 0x3ff; ydata = ADCDATA1 & 0x3ff; /* 4. Clear the press interrupt */SUBSRCPND | = (1 <9); SRCPND = (1 <31); INTPND = (1 <31 ); /* 5. Wait for the disconnection to start */ADCTSC = 0xd3; ADCTSC |=( 1 <8); while (1) {if (SUBSRCPND & (1 <9 )) break;}/* 6. Clear the pop-up interrupt */SUBSRCPND | = (1 <9); SRCPND = (1 <31); INTPND = (1 <31 ); // process the read X and Y coordinates printf ("X is % d, Y is % d \ n", xdata, ydata ); printf ("\ n \ r");/* 7. Wait for the interrupted press again */ADCTSC = 0xd3 ;}

The call program of the touch screen interrupt function in interrupt. c:

 

 

/*************************************** * **************************** Function Name: handle_int () * Function Description: Interrupt Processing Function * Other description: **************************************** * *************************/void handle_int () {/* determine the interrupt source */unsigned long value = * (Interrupt ffset); switch (value) {case 31: Ts_Handler (); // touch screen interrupt break; default: break ;}}