GPIO port register map

GPIO Configuration register

Pin Number	GPIO name	Base Address	Offset	Name	Bit	Type	Description	Reset Value
15	GPX1.2	0x1340_0000	0x0C20	GPX1CON[2]	[11:8]	RW	0x0=input, 0x1=Output, 0x2=Reserved, 0x3=Reserved, 0x4=TraceData, 0x5 to 0xE=Reserved, 0xF=EXT_INT	0x00
18	GPX1.3			GPX1CON[3]	[15:12]
13	GPX1.5			GPX1CON[5]	[23:20]
17	GPX1.6			GPX1CON[6]	[27:24]
25	GPX1.7			GPX1CON[7]	[31:28]
26	GPX2.0		0x0C40	GPX2CON[0]	[3:0]
24	GPX2.1			GPX2CON[1]	[7:4]
20	GPX2.4			GPX2CON[4]	[19:16]
21	GPX2.5			GPX2CON[5]	[23:20]
19	GPX2.6			GPX2CON[6]	[27:24]
22	GPX2.7			GPX2CON[7]	[31:28]
27	GPX3.1		0x0C60	GPX3CON[1]	[7:4]
10	GPA2.4	0x1401_0000	0x0040	GPA2CON[4]	[19:16]
11	GPA2.5			GPA2CON[5]	[23:20]
9	GPA2.6			GPA2CON[6]	[27:24]
7	GPA2.7			GPA2CON[7]	[31:28]
16	GPB3.2		0x00C0	GPB3CON[2]	[11:8]
14	GPB3.3		0x00C0	GPB3CON[3]	[15:12]

GPIO Data register

GPIO name	Base Address	Offset	Name	Bit	Type	Description	Reset Value
GPX1[n]	0x1340_0000	0x0C24	GPX1DAT[7:0]	[7:0]	RWX	When you configure the port as input port, the corresponding bit is the pin state. When you configure the port as output port, the pin state is same as the corresponding bit. When you configure the port as functional pin, it reads the undefined value.	0x00
GPX2[n]		0x0C44	GPX2DAT[7:0]
GPX3[n]		0x0C64	GPX3DAT[7:0]
GPA2[n]	0x1401_0000	0x0044	GPA2DAT[7:0]
GPB3[n]	0x1401_0000	0x00C4	GPB3DAT[7:0]

GPIO Pull-up/down register

GPIO name	Base Address	Offset	Name	Bit	Type	Description	Reset Value
GPX1[n]	0x1340_0000	0x0C28	GPX1PUD[n]	[2n+1:2n] n = 0 to 7	RW	0x0=Disables pull-up/down, 0x1=Enables pull-down, 0x2=Reserved, 0x3=Enables pull-up	0x5555
GPX2[n]		0x0C48	GPX2PUD[n]
GPX3[n]		0x0C68	GPX3PUD[n]
GPA2[n]	0X1401_0000	0x0048	GPA2PUD[n]
GPB3[n]	0X1401_0000	0x00C8	GPB3PUD[n]

Memory mapped GPIO example

root@odroid:# gcc -o mmap_gpio mmap_gpio.c
root@odroid:# ./mmap_gpio
GPX1CON register : 0x100000f0                                                   
GPX1CON register : 0x100001f0                                                   
GPX1DAT register : 0x00000086                                                   
GPX1DAT register : 0x00000082

mmap_gpio.c

#include <stdio.h>                                                              
#include <fcntl.h>                                                              
#include <sys/mman.h>                                                           
#include <stdint.h>                                                             
 
static volatile uint32_t *gpio;                                                 
 
int main(int argc, char **argv)                                                 
{                                                                               
        int fd ;                                                                
 
        if ((fd = open ("/dev/mem", O_RDWR | O_SYNC) ) < 0) {                   
                printf("Unable to open /dev/mem\n");                            
                return -1;                                                      
        }                                                                       
 
        gpio = mmap(0, getpagesize(), PROT_READ|PROT_WRITE, MAP_SHARED, fd,     
                                                                0x13400000);    
        if (gpio < 0){                                                          
                printf("Mmap failed.\n");                                       
                return -1;                                                      
        }                                                                       
 
        // Print GPX1 configuration register.                                   
        printf("GPX1CON register : 0x%08x\n",                                   
                                *(unsigned int *)(gpio + (0x0c20 >> 2)));       
 
        // Set direction of GPX1.2 configuration register as out.               
        *(gpio + (0x0c20 >> 2)) |= (0x1 << 8);                                  
        printf("GPX1CON register : 0x%08x\n",                                   
                                *(unsigned int *)(gpio + (0x0c20 >> 2)));       
        // GPX1.2 High                                                          
        *(gpio + (0x0c24 >> 2)) |= (1 << 2);                                    
        printf("GPX1DAT register : 0x%08x\n",                                   
                                *(unsigned int *)(gpio + (0x0c24 >> 2)));       
        // GPX1.2 Low                                                           
        *(gpio + (0x0c24 >> 2)) &= ~(1 << 2);                                   
        printf("GPX1DAT register : 0x%08x\n",                                   
                                *(unsigned int *)(gpio + (0x0c24 >> 2)));       
 
        return 0;                                                               
}