GPIO子系统点六盏灯

#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
struct device_node* node;
struct device_node* child_node1;
struct device_node* child_node2;
unsigned int gpionumb1[3];
unsigned int gpionumb2[3];
char *name[3]={"led1","led2","led3"};//字符指针数组
int i=0;
static int __init my_init(void)
{
    //解析设备树myled节点
    node=of_find_node_by_path("/myled");
    if(node==NULL)
    {
        printk("node error:");
        return -EIO;
    }
    child_node1 = of_get_child_by_name(node,"extend-led");
    if(child_node1==NULL)
    {
        printk("node error:");
        return -EIO;
    }
    child_node2 = of_get_child_by_name(node,"core-led");
    if(child_node2==NULL)
    {
        printk("node error:");
        return -EIO;
    }
    for(i=0;i<3;i++){
    //从设备树中读取gpio编号
        gpionumb1[i]=of_get_named_gpio(child_node1,name[i],0);
        if(gpionumb1[i]<0)
        {
            printk("of get name gpio is error:");
            return -EIO;
        }

        //申请gpio编号
        gpio_request(gpionumb1[i],NULL);
        //设置gpio编号输出高电平
        gpio_direction_output(gpionumb1[i],1);
    

   
        //从设备树中读取gpio编号
        gpionumb2[i]=of_get_named_gpio(child_node2,"led",i);
        if(gpionumb2[i]<0)
        {
            printk("of get name gpio is error:");
            return -EIO;
        }

        //申请gpio编号
        gpio_request(gpionumb2[i],NULL);
        //设置gpio编号输出高电平
        gpio_direction_output(gpionumb2[i],1);
    }

    return 0;
} 

static void __exit my_exit(void)
{
    for(i=0;i<3;i++){
        //设置gpio编号输出低电平
        gpio_direction_output(gpionumb1[i],0);
        //释放gpio编号
        gpio_free(gpionumb1[i]);
        //设置gpio编号输出低电平
        gpio_direction_output(gpionumb2[i],0);
        //释放gpio编号
        gpio_free(gpionumb2[i]);
    }
}
module_init(my_init);
module_exit(my_exit);
MODULE_LICENSE("GPL");

GPIOD子系统点六盏灯

#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
struct device_node* node;
struct device_node* child_node1_expend;
struct device_node* child_node2_core;
unsigned int gpionumb1[3];
unsigned int gpionumb2[3];
struct gpio_desc* edesc[3];
struct gpio_desc* cdesc[3];
char *name[3]={"led1","led2","led3"};//字符指针数组
int i=0;
/*
myled{ //添加基于gpio子系统设备树节点
    core-led{ //核心板子节点
        led = <&gpioz 5 0>,<&gpioz 6 0>,<&gpioz 7 0>;
    };
    extend-led{ //扩展板子节点
        led1 = <&gpioe 10 0>; //led1 PE10
        led2 = <&gpiof 10 0>; //led2 PF10
        led3 = <&gpioe 8 0>; //led3 PE8
    };
};  
*/
static int __init my_init(void)
{
    //解析设备树myled节点
    node=of_find_node_by_path("/myled");
    if(node==NULL)
    {
        printk("node error:");
        return -EIO;
    }
    //扩展板LED子节点
    child_node1_expend = of_get_child_by_name(node,"extend-led");
    if(child_node1_expend==NULL)
    {
        printk("node error:");
        return -EIO;
    }
    //核心板LED子节点
    child_node2_core = of_get_child_by_name(node,"core-led");
    if(child_node2_core==NULL)
    {
        printk("node error:");
        return -EIO;
    }
    for(i=0;i<3;i++){
        //直接从设备中获取struct gpio_desc*结构体指针
        edesc[i]=gpiod_get_from_of_node(child_node1_expend,name[i],0,GPIOD_OUT_LOW,NULL);
        if(IS_ERR(edesc[i])){//判断地址是否在4K空间内
            printk("gpiod get from node is error\n");
            return PTR_ERR(edesc[i]);//将地址转换成错误码
        }
        gpiod_direction_output(edesc[i],1);//设置gpio引脚输出高电平

        cdesc[i]=gpiod_get_from_of_node(child_node2_core,"led",i,GPIOD_OUT_LOW,NULL);
        if(IS_ERR(cdesc[i])){//判断地址是否在4K空间内
            printk("gpiod get from node is error\n");
            return PTR_ERR(cdesc[i]);//将地址转换成错误码
        }
        gpiod_direction_output(cdesc[i],1);//设置gpio引脚输出高电平

    }

    return 0;
} 

static void __exit my_exit(void)
{
    for(i=0;i<3;i++){
        //设置gpio编号输出低电平
        gpiod_set_value(edesc[i],0);
        //释放gpio编号
        gpiod_put(edesc[i]);
        //设置gpio编号输出低电平
        gpiod_set_value(cdesc[i],0);
        //释放gpio编号
        gpiod_put(cdesc[i]);
  
    }
}
module_init(my_init);
module_exit(my_exit);
MODULE_LICENSE("GPL");