在petalinux 通过AXI_GPIO操作电平,以zynq为例，vivado工程：
axi_gpio_n都是选择的一位输出：
管脚约束：
set_property SEVERITY {Warning} [get_drc_checks UCIO-1]
set_property SEVERITY {Warning} [get_drc_checks NSTD-1]
set_property PACKAGE_PIN J16 [get_ports AXI_GPIO_LED1_tri_o]
set_property IOSTANDARD LVCMOS33 [get_ports AXI_GPIO_LED1_tri_o]
set_property PACKAGE_PIN K16 [get_ports AXI_GPIO_LED2_tri_o]
set_property IOSTANDARD LVCMOS33 [get_ports {AXI_GPIO_LED2_tri_o}]
set_property PACKAGE_PIN G15 [get_ports AXI_GPIO_LED3_tri_o]
set_property IOSTANDARD LVCMOS33 [get_ports AXI_GPIO_LED3_tri_o]
set_property PACKAGE_PIN H15 [get_ports AXI_GPIO_LED4_tri_o]
set_property IOSTANDARD LVCMOS33 [get_ports AXI_GPIO_LED4_tri_o]
AXI_GPIO驱动在生成启动文件的时候，是默认编译的。
然后编译制作SD卡启动文件，然后写入程序测试：arm-linux-gnueabihf-gcc test_led.c -o test_led
#include<stdlib.h>
#include <fcntl.h>
#include <stdio.h>
int main(int argc, char **argv)
{
int valuefd,exportfd,directionfd;
exportfd = open("/sys/class/gpio/export", O_WRONLY); //打开设备
if(exportfd<0)
{
printf("open exportfd faild\n");
exit(1);
}
write(exportfd,"1023",4);
close(exportfd);
printf("1,exportfd open successful\n");
directionfd = open("/sys/class/gpio/gpio1023/direction", O_RDWR);
if(directionfd<0)
{
printf("open directionfd faild\n");
exit(1);
}
write(directionfd,"out",4);
close(directionfd);
printf("2,directionfd open successful\n");
valuefd = open("/sys/class/gpio/gpio1023/value", O_RDWR);
if(valuefd <0)
{
printf("open valuefd faild\n");
exit(1);
}
write(valuefd,"0",2);
usleep(200*1000);
write(valuefd,"1",2);
printf("3,valuefd open successful\n");
}
或者在zynq板子写入脚本测试
#!/bin/sh
gpio_test()
{
gpio=$1
echo $gpio > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio${gpio}/direction
for i in $(seq 1 3)
do
echo 0 >/sys/class/gpio/gpio${gpio}/value
sleep 1
echo 1 >/sys/class/gpio/gpio${gpio}/value
sleep 1
done
echo $gpio > /sys/class/gpio/unexport
}
gpio_test 897
gpio_test 1015
gpio_test 1019
gpio_test 1020
