Cubieboard 4 GPIO控制举例
#/bin/bashmount -t debugfs debugfs /mnt
cd /mnt/sunxi_pinctrl
#set the PH9 pin as output port .If type "echo PH9 0 > function" ,set the PH9 pin as input port
echo PH9 1 > function
#set the PH9 pin as low level
echo PH9 0 > data
sleep 1
#set the PH9 pin as high level
echo PH9 1 > data
echo PH8 1 > function
echo PH8 1 > data
补充其他gpio控制方法：
以控制 cc-a80 的uart4_tx为例子：
新建一个test.c#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <time.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/select.h>
#include <pthread.h>
#include <unistd.h>
#include <sched.h>
#include <errno.h>
#define SW_PORTC_IO_BASE0x06000800
int main() {
unsigned int * pc;
int fd, i;
char * ptr;
unsigned int addr_start, addr_offset, PageSize, PageMask, data;
PageSize = sysconf(_SC_PAGESIZE);
PageMask = (~(PageSize-1));
addr_start = SW_PORTC_IO_BASE & PageMask;
addr_offset = SW_PORTC_IO_BASE & ~PageMask;
fd = open("/dev/mem", O_RDWR);
if(fd < 0) {
perror("Unable to open /dev/mem");
return(-1);
}
pc = mmap(0, PageSize*2, PROT_READ|PROT_WRITE, MAP_SHARED, fd, addr_start);
if(pc == MAP_FAILED) {
perror("Unable to mmap file");
printf("pc:%lx\n", (unsigned long)pc);
return(-1);
}
printf("PageSize:%8.8x\tPageMask:%8.8x\naddr_start:%8.8x\taddr_offset:%8.8x\n",PageSize,PageMask,addr_start,addr_offset);
printf("pc:%8.8x\n", *(unsigned int *)pc);
ptr = (char *)pc + addr_offset;
//the PG12 is UART4-TX in the board ,set it as output port
data = *(unsigned int *)(ptr+0xdc);
data &= ~(7<<16);
data |= 1<<16;
*(unsigned int *)(ptr+0xdc) = data;
//set it high level
data = *(unsigned int *)(ptr+0xe8);
data |= 1<<12;
*(unsigned int *)(ptr+0xe8) = data;
//set it low level
//data = *(unsigned int *)(ptr+0xe8);
//data &= ~(1<<12);
//*(unsigned int *)(ptr+0xe8) = data;
return 0;
}最后在板子上gcc test.c -o test。只看下注释理解用法。
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