&axi_gpio_0 {
compatible = "generic-uio";
};axi_gpio_0: gpio@41200000 {
#gpio-cells = <2>;
compatible = "xlnx,xps-gpio-1.00.a";
gpio-controller ;
reg = <0x41200000 0x10000>;
xlnx,all-inputs = <0x0>;
xlnx,all-inputs-2 = <0x0>;
xlnx,all-outputs = <0x0>;
xlnx,all-outputs-2 = <0x0>;
xlnx,dout-default = <0x00000000>;
xlnx,dout-default-2 = <0x00000000>;
xlnx,gpio-width = <0x18>;
xlnx,gpio2-width = <0x20>;
xlnx,interrupt-present = <0x0>;
xlnx,is-dual = <0x0>;
xlnx,tri-default = <0xFFFFFFFF>;
xlnx,tri-default-2 = <0xFFFFFFFF>;
};#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#include <fcntl.h>
#define GPIO_MAP_SIZE 0x10000
#define GPIO_DATA_OFFSET 0x00
#define GPIO_TRI_OFFSET 0x04
#define GPIO_DATA2_OFFSET 0x08
#define GPIO_TRI2_OFFSET 0x0C
#define GPIO_GLOBAL_IRQ 0x11C
#define GPIO_IRQ_CONTROL 0x128
#define GPIO_IRQ_STATUS 0x120
volatile int counter;
inline void gpio_write(void *gpio_base, unsigned int offset, unsigned int value)
{
*((volatile unsigned *)(gpio_base + offset)) = value;
}
inline unsigned int gpio_read(void *gpio_base, unsigned int offset)
{
return *((volatile unsigned *)(gpio_base + offset));
}
unsigned int get_memory_size(char *sysfs_path_file)
{
FILE *size_fp;
unsigned int size;
// open the file that describes the memory range size that is based on the
// reg property of the node in the device tree
size_fp = fopen(sysfs_path_file, "r");
if (!size_fp) {
printf("unable to open the uio size file\n");
exit(-1);
}
// get the size which is an ASCII string such as 0xXXXXXXXX and then be stop
// using the file
fscanf(size_fp, "0x%08X", &size);
fclose(size_fp);
return size;
}
void wait_for_interrupt(int fd, void *gpio_ptr)
{
int pending = 0;
int reenable = 1;
unsigned int reg;
// block on the file waiting for an interrupt */
read(fd, (void *)&pending, sizeof(int));
counter = counter + 1;
// the interrupt occurred for the 1st GPIO channel so clear it
reg = gpio_read(gpio_ptr, GPIO_IRQ_STATUS);
if (reg)
gpio_write(gpio_ptr, GPIO_IRQ_STATUS, 1); //
// re-enable the interrupt in the interrupt controller thru the
// the UIO subsystem now that it's been handled
write(fd, (void *)&reenable, sizeof(int));
}
int main()
{
int uio1_fd;
void *ptr;
int gpio_size;
if ((uio1_fd = open("/dev/uio1", O_RDWR)) < 0)
{
perror("open uio1");
}
else{printf("uio1 opened \n");}
gpio_size = get_memory_size("/sys/class/uio/uio1/maps/map0/size");
ptr = mmap(NULL, gpio_size, PROT_READ|PROT_WRITE, MAP_SHARED, uio1_fd, 0);
if (ptr == MAP_FAILED) {
printf("Mmap call failure.\n");
return -1;
}
gpio_write(ptr, GPIO_TRI_OFFSET, 0xFF); // GPIO Channel 1 input
gpio_write(ptr, GPIO_GLOBAL_IRQ, 0x80000000); // GIER, 31. Bit
gpio_write(ptr, GPIO_IRQ_CONTROL, 1); // Channel 1 Interrupt enable
//wait for interrupt
while(1)
{
wait_for_interrupt(uio1_fd, ptr);
printf("Interrupt: %d", counter);
puts("");
}
munmap(ptr, gpio_size);
return 0;
}