Hi,
i am planing to test with some OMAPL138 GPIO pins making it as HIGH or LOW using LINUX in user space.
currently i am using LogicPD OMAPL138 experimenter board, and in that board i am using GPIO6[14] pin as a output its 18 pin on J3 connector, but i am not getting output.
actually i am going with below source code is it correct what am doing ? suggest me any other example ??
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
//#define GPIO_BASE 0x80840000
#define GPIO_BASE 0x01E26000 // Base address of GPIO OMAPL138
/* GPIO memory mapped registers */
volatile unsigned int *PDR; // Direction register
volatile unsigned int *PDATA; // Port output DATA
volatile unsigned int *PSET; // Setting register
volatile unsigned int *REVid; // Revision ID register
int main (void)
{
unsigned char *gpio;
int fd;
fd = open("/dev/mem", O_RDWR);
if (fd < 0)
{
perror("Failed to open /dev/mem");
return fd;
}
gpio = mmap(0, getpagesize(), PROT_READ|PROT_WRITE, MAP_SHARED, fd, GPIO_BASE);
REVid = (unsigned int *)(gpio + 0x00); // Output reg offset address
printf("REVid value = %x \n", *REVid); //Print the REVid value
PDR = (unsigned int *)(gpio + 0x10); // Output reg offset address bank 0
PDATA = (unsigned int *)(gpio + 0x88); //Direction Reg offset address
//PSET = (unsigned int *)(gpio + 0x8C); //setting Reg offset address
printf("PDR address = %x PDATA address= %x \n", ( unsigned )PDR, ( unsigned )PDATA); //Print the register address
// *PDATA = 0x00004000; //Port6[14] direction as output
*PDR = 0x00000000; //Port6[14] direction as output
//*PSET= 0xffffffff;
while(1)
{
*PDATA = 0xffffffff; //Port6[14]pin status as HIGH
//printf("GPIO pin HIGH \n");
//sleep(1);
//*PDATA = 0x00000000; //Port6[14]pin status as LOW
//printf("GPIO pin LOW \n");
//sleep(1);
}
return 0;
}
