【VisionFive 2单板计算机试用体验】移植libgpiod

官方有VisionFive.gpio，尝试下移植libgpiod到开发板。

一、安装GPIO库

1.1、下载源码

执行命令：

root@starfive:~# wget https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/snapshot/libgpiod-2.0.tar.gz
root@starfive:~# tar xvf libgpiod-2.0.tar.gz
root@starfive:~# apt-get install build-essential pkg-config m4 automake autoconf libtool autoconf-archive
root@starfive:~# apt-get install gcc g++
root@starfive:~# export CC=gcc
root@starfive:~# export CXX=g++

1.2、安装

root@starfive:~/libgpiod-2.0# ./autogen.sh --enable-tools=yes --prefix=/root/starfive/mylib_local
root@starfive:~/libgpiod-2.0# make
root@starfive:~/libgpiod-2.0# make install

安装完成后，生成的文件

二、测试

2.1、gpio.c

//#gpio.c

#include<stdio.h>
#include<unistd.h>
#include<gpiod.h>

#define PIN_IO2_46   46  //LD0
#define PIN_IO2_44   44  //LD1
#define PIN_IO2_61   61  //LD2
#define PIN_IO2_63   63  //ld3

#define PIN_IO2_42   42  //K2

int main() 
{
  struct gpiod_chip *gchip;
  struct gpiod_line_info *glinein, *glineout;
  struct gpiod_line_settings *gline_settings_in, *gline_settings_out;
  struct gpiod_line_config   *gline_config_in, *gline_config_out;
  struct gpiod_request_config *gline_request_config_in, *gline_request_config_out;
  struct gpiod_line_request   *gline_request_in, *gline_request_out;
  int offset_in[1] = {PIN_IO2_42};
  int offset_out[4] = {PIN_IO2_44, PIN_IO2_46, PIN_IO2_61, PIN_IO2_63};
  int value;

  if ((gchip=gpiod_chip_open("/dev/gpiochip0")) == NULL) 
  {
    perror("gpiod_chip_open");
    return 1;
  }


  gline_settings_in = gpiod_line_settings_new();
  if ((value=gpiod_line_settings_set_direction(gline_settings_in, GPIOD_LINE_DIRECTION_INPUT)) != 0) 
  {
    perror("gpiod_line_settings_set_direction");
  }

  gline_config_in = gpiod_line_config_new();
  value=gpiod_line_config_add_line_settings(gline_config_in, offset_in, 1, gline_settings_in);
  gline_request_config_in = gpiod_request_config_new();
  gline_request_in = gpiod_chip_request_lines(gchip, gline_request_config_in, gline_config_in);
  
  gline_settings_out = gpiod_line_settings_new();
  if (gpiod_line_settings_set_direction(gline_settings_out, GPIOD_LINE_DIRECTION_OUTPUT) != 0) 
  {
    perror("gpiod_line_settings_set_direction");
  }
  gline_config_out = gpiod_line_config_new();
  gpiod_line_config_add_line_settings(gline_config_out, offset_out, 4, gline_settings_out);
  gline_request_config_out = gpiod_request_config_new();
  gline_request_out = gpiod_chip_request_lines(gchip, gline_request_config_out, gline_config_out);

  value=gpiod_line_request_set_value(gline_request_out, PIN_IO2_46, 0);
  value=gpiod_line_request_set_value(gline_request_out, PIN_IO2_44, 1);
  value=gpiod_line_request_set_value(gline_request_out, PIN_IO2_61, 0);
  value=gpiod_line_request_set_value(gline_request_out, PIN_IO2_63, 1);

  sleep(1);

  for (int i = 0; i < 50; i++) {

      //value=gpiod_line_request_get_value(gline_request_in, PIN_IO2_42);
      //printf("PIN_IO2_42 = %d\\n", value);
      gpiod_line_request_set_value(gline_request_out, PIN_IO2_46, 1);
      gpiod_line_request_set_value(gline_request_out, PIN_IO2_44, 0);
      gpiod_line_request_set_value(gline_request_out, PIN_IO2_61, 1);
      gpiod_line_request_set_value(gline_request_out, PIN_IO2_63, 0);
      sleep(1);
      gpiod_line_request_set_value(gline_request_out, PIN_IO2_46, 0);
      gpiod_line_request_set_value(gline_request_out, PIN_IO2_44, 1);
      gpiod_line_request_set_value(gline_request_out, PIN_IO2_61, 0);
      gpiod_line_request_set_value(gline_request_out, PIN_IO2_63, 1);
      sleep(1);
  }

  gpiod_chip_close(gchip);
  return 0;
}

2.2、编译代码

在gpio.c所在的目录下编译

命令：
root@starfive:~# gcc -I/root/starfive/mylib_local/include -L/root/starfive/mylib_local/lib -o gpio gpio.c -lgpiod

2.3、设置路径

root@starfive:~# export LD_LIBRARY_PATH=/root/starfive/mylib_local/lib:$LD_LIBRARY_PATH
root@starfive:~# export PATH=/root/starfive/mylib_local/bin:$PATH

三、运行结果

运行命令：
root@starfive:~# ./gpio