2023.08.01 驱动开发day8-Toy模板网

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2023.08.01 驱动开发day8,驱动开发

驱动层

#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>

#define LED_ON  _IO('l', 1)
#define LED_OFF _IO('l', 0)

struct class *cls;
struct device *dev;
struct device_node *dev_irq, *dev_led;
unsigned int major;
unsigned int irqno1, irqno2, irqno3;
struct gpio_desc *gpiono1, *gpiono2, *gpiono3;

//中断处理函数
irqreturn_t myirq_handler(int irq, void *dev)
{
    if(irq == irqno1) {
		gpiod_set_value(gpiono1, !gpiod_get_value(gpiono1));
	}
	else if(irq == irqno2) {
		gpiod_set_value(gpiono2, !gpiod_get_value(gpiono2));
	}
	else if(irq == irqno3) {
		gpiod_set_value(gpiono3, !gpiod_get_value(gpiono3));
	}
    return IRQ_HANDLED;
}

int mycdev_open(struct inode *inode, struct file *file)
{
    int a = inode->i_rdev;  //获取当前设备文件对应的设备号
    file->private_data = (void *)MINOR(a);  //将次设备号保存到当前文件的file结构中
    return 0;
}

long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    unsigned int a = (unsigned int)file->private_data;
    switch(a)
    {
        case 0:
            switch(cmd)
            {
                case LED_ON:
                    gpiod_set_value(gpiono1, 1);
                    break;
                case LED_OFF:
                    gpiod_set_value(gpiono1, 0);
                    break;
            }
            break;   
        case 1:
            switch(cmd)
            {
                case LED_ON:
                    gpiod_set_value(gpiono2, 1);
                    break;
                case LED_OFF:
                    gpiod_set_value(gpiono2, 0);
                    break;
            }
            break; 
        case 2:
            switch(cmd)
            {
                case LED_ON:
                    gpiod_set_value(gpiono3, 1);
                    break;
                case LED_OFF:
                    gpiod_set_value(gpiono3, 0);
                    break;
            }
            break;                          
    }
    return 0;
}

struct file_operations fops = {
    .open = mycdev_open,
    .unlocked_ioctl = mycdev_ioctl,
};

static int __init mycdev_init(void)
{
    // 注册字符设备驱动
    major = register_chrdev(0, "mychrdev", &fops);
    if (major < 0)
    {
        printk("注册字符设备驱动失败\n");
        return major;
    }
    printk("注册字符设备驱动成功major=%d\n", major);

    // 向上提交目录
    cls = class_create(THIS_MODULE, "myled");
    if (IS_ERR(cls))
    {
        printk("向上提交目录失败\n");
        return -PTR_ERR(cls);
    }
    printk("向上提交目录信息成功\n");
    
    // 向上提交设备节点信息
    int i;
    for (i = 0; i < 3; i++)
    {
        dev = device_create(cls, NULL, MKDEV(major, i), NULL, "myled%d", i);
        if (IS_ERR(dev))
        {
            printk("向上提交设备节点信息失败\n");
            return -PTR_ERR(dev);
        }
    }
    printk("向上提交设备节点成功\n");
	
	int ret;
    //解析设备树节点
    dev_irq = of_find_node_by_path("/myirq");
    if(dev_irq == NULL)
    {
        printk("解析irq设备树节点失败\n");
        return -EFAULT;
    }
	dev_led = of_find_node_by_path("/leds");
    if(dev_led == NULL)
	{
        printk("解析led设备树节点失败\n");
        return -EIO;
    }
    printk("解析设备树节点成功\n");

    // 申请gpio_desc对象并设置输出为低电平
    gpiono1 = gpiod_get_from_of_node(dev_led, "led1-gpios", 0, GPIOD_OUT_LOW, NULL);
    if(IS_ERR(gpiono1))
    {
        printk("申请gpio对象失败\n");
        return -PTR_ERR(gpiono1);
    }
	gpiono2 = gpiod_get_from_of_node(dev_led, "led2-gpios", 0, GPIOD_OUT_LOW, NULL);
    if(IS_ERR(gpiono1))
    {
        printk("申请gpio对象失败\n");
        return -PTR_ERR(gpiono1);
    }
	gpiono3 = gpiod_get_from_of_node(dev_led, "led3-gpios", 0, GPIOD_OUT_LOW, NULL);
    if(IS_ERR(gpiono1))
    {
        printk("申请gpio对象失败\n");
        return -PTR_ERR(gpiono1);
    }
    printk("申请gpio对象成功\n");

    //根据设备树节点解析出软中断号s
    irqno1 = irq_of_parse_and_map(dev_irq, 0); //按键1索引号为0
    if(!irqno1)
    {
        printk("解析软中断号失败\n");
        return -ENXIO;
    }
	irqno2 = irq_of_parse_and_map(dev_irq, 1);
    if(!irqno2)
    {
        printk("解析软中断号失败\n");
        return -ENXIO;
    }
	irqno3 = irq_of_parse_and_map(dev_irq, 2);
    if(!irqno3)
    {
        printk("解析软中断号失败\n");
        return -ENXIO;
    }
    printk("解析软中断号成功 irqno123=%d,%d,%d\n",irqno1,irqno2,irqno3);

    //注册中断
    ret = request_irq(irqno1, myirq_handler, IRQF_TRIGGER_FALLING, "key1", NULL);
    if(ret)
    {
        printk("注册中断失败\n");
        return ret;
    }
	ret = request_irq(irqno2, myirq_handler, IRQF_TRIGGER_FALLING, "key2", NULL);
    if(ret)
    {
        printk("注册中断失败\n");
        return ret;
    }
	ret = request_irq(irqno3, myirq_handler, IRQF_TRIGGER_FALLING, "key3", NULL);
    if(ret)
    {
        printk("注册中断失败\n");
        return ret;
    }
    printk("注册中断成功\n");
    return 0;
}

static void __exit mycdev_exit(void)
{
    //注销中断
    free_irq(irqno1, NULL);
	free_irq(irqno2, NULL);
	free_irq(irqno3, NULL);
	//灭灯
	gpiod_set_value(gpiono1, 0);
	gpiod_set_value(gpiono2, 0);
	gpiod_set_value(gpiono3, 0);
	//释放gpio编号
	gpiod_put(gpiono1);
	gpiod_put(gpiono2);
	gpiod_put(gpiono3);
	//销毁节点信息
	int i;
	for (i = 0; i < 3; i++)
	{
		device_destroy(cls, MKDEV(major, i));
	}
	//销毁目录信息
	class_destroy(cls);
	//注销字符设备驱动
	unregister_chrdev(major, "mycdev");
}

module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

应用层文章来源地址https://www.toymoban.com/news/detail-627722.html

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>

#define LED_ON  _IO('l', 1)
#define LED_OFF _IO('l', 0)

int main(int argc,const char * argv[])
{
    int sel;
    int fd1 = open("/dev/myled0", O_RDWR);
    if(fd1 < 0)
    {
        perror("open");
        printf("%s : %s : %d\n", __FILE__, __func__, __LINE__);
        return -1;
    }
    int fd2 = open("/dev/myled1", O_RDWR);
    if(fd2 < 0)
    {
        perror("open");
        printf("%s : %s : %d\n", __FILE__, __func__, __LINE__);
        return -1;
    }
    int fd3 = open("/dev/myled2", O_RDWR);
    if(fd3 < 0)
    {
        perror("open");
        printf("%s : %s : %d\n", __FILE__, __func__, __LINE__);
        return -1;
    }

    while(1)
    {
        printf("1> LED1 ON\n");
        printf("2> LED1 OFF\n");
        printf("3> LED2 ON\n");
        printf("4> LED2 OFF\n");
        printf("5> LED3 ON\n");
        printf("6> LED3 OFF\n");
        printf("请选择功能>>>");
        scanf("%d", &sel);
        getchar();
        switch(sel)
        {
            case 1:
                ioctl(fd1, LED_ON); 
                break;
            case 2:
                ioctl(fd1, LED_OFF);
                break;
            case 3:
                ioctl(fd2, LED_ON); 
                break;
            case 4:
                ioctl(fd2, LED_OFF);
                break;
            case 5:
                ioctl(fd3, LED_ON); 
                break;
            case 6:
                ioctl(fd3, LED_OFF);
                break;
        }
    }
    close(fd1);
    close(fd2);
    close(fd3);
    return 0;
}

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