驱动 day10 作业-编程知识

要求：platform驱动实现
在这里插入图片描述
现象：

test.c应用程序

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
int main(int argc, char const *argv[])
{int fd;char buf[10]={0};		fd = open("/dev/myplatform",O_RDWR);if(fd < 0){printf("打开设备文件失败\n");exit(-1);}  while(1){memset(buf,0,sizeof(buf));read(fd,buf,sizeof(buf));printf("buf[0]=%d\n",buf[0]);}  close(fd);return 0;
}

job.c驱动程序

#include <linux/init.h>
#include <linux/module.h>
#include<linux/fs.h>
#include<linux/device.h>
#include<linux/cdev.h>
#include<linux/slab.h>
#include <linux/io.h>
#include<linux/of.h>
#include<linux/gpio.h>
#include<linux/of_gpio.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/uaccess.h>
#include<linux/mod_devicetable.h>
#include<linux/platform_device.h>struct cdev *cdev;//字符设备驱动对象空间首地址
unsigned int major=200;//主设备号
unsigned int minor=0;//次设备号的起始值
dev_t devno;//设备号变量
char kbuf[128]={0};
struct class *cls;//存放向上提交目录的返回值
struct device *dev;//存放向上提交设备节点信息结构体
struct device_node *dnode;//设备数节点信息结构体
struct gpio_desc *gpiono;//GPIO信息结构体
char number = 0;
unsigned int irqno;//获取中断号
wait_queue_head_t wq_head;//定义一个等待队列头
unsigned int condition=0;
struct resource *res;//存放设备信息的数组首地址
unsigned int irqno;//软中断号
/*myplatform{compatible = "hqyj,myplatform";reg=<0X12345678 0X400>;interrupt-parent=<&gpiof>;interrupts=<9 0>;   //9表示引用中断父节点时的索引信息  0表示默认设置led1=<&gpioe 10 0>;
};*/
int mycdev_open(struct inode *inode, struct file *file)
{printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);return 0;
}
ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
{//size参数是用户期待读到的字节长度int ret;//把内核的数据再拷贝给进程if(size>sizeof(kbuf))size=sizeof(kbuf);kbuf[0] = number;if(file->f_flags & O_NONBLOCK){//非阻塞return -EINVAL;}else{//阻塞ret = wait_event_interruptible(wq_head,condition);if(ret < 0){printk("receive signal....\n");return ret;}}ret=copy_to_user(ubuf,kbuf,size);if(ret){printk("数据从内核向用户拷贝失败\n");return -EIO;}printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);condition = 0;return 0;
}
ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{   printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);return 0;
}// 定义操作方法结构体变量并赋值
struct file_operations fops =
{.read = mycdev_read,.open = mycdev_open,.write = mycdev_write,.release = mycdev_close,
};//中断处理函数
irqreturn_t myirq_handler(int irqno, void *dev_id)
{printk("key1 interrupt\n");number = !number;condition = 1;gpiod_set_value(gpiono,!gpiod_get_value(gpiono));wake_up_interruptible(&wq_head);return IRQ_HANDLED; 
}
//probe函数，匹配设备成功执行
int pdrv_probe(struct platform_device *pdev)
{int ret;//初始化等待队列头init_waitqueue_head(&wq_head);//1.分配字符设备驱动对象空间  cdev_alloccdev = cdev_alloc();if (!cdev) {printk(KERN_ALERT "cdev_alloc failed\n");return -ENOMEM;}printk("字符设备驱动对象空间申请成功\n");//2.字符设备驱动对象部分初始化  cdev_initcdev_init(cdev, &fops);//3.申请设备号  register_chrdev_region/alloc_chrdev_regionif(major>0)//静态申请设备号{ret=register_chrdev_region(MKDEV(major,minor),1,"myplatform");if(ret){printk("静态指定设备号失败\n");goto out2;}}else//动态申请设备号{ret=alloc_chrdev_region(&devno,minor,1,"myplatform");if(ret){printk("动态申请设备号失败\n");goto out2;}major=MAJOR(devno);//根据设备号得到主设备号minor=MINOR(devno);//根据设备号得到次设备号}printk("申请设备号成功\n");//4.注册字符设备驱动对象  cdev_add()ret=cdev_add(cdev,MKDEV(major,minor),1);if(ret){printk("注册字符设备驱动对象失败\n");goto out3;}printk("注册字符设备驱动对象成功\n");//5.向上提交目录cls=class_create(THIS_MODULE,"myplatform");if(IS_ERR(cls)){printk("向上提交目录失败\n");ret=-PTR_ERR(cls);goto out4;}printk("向上提交目录成功\n");//6.向上提交设备节点dev=device_create(cls,NULL,MKDEV(major,minor),NULL,"myplatform");if(IS_ERR(dev)){printk("向上提交节点信息失败\n");ret=-PTR_ERR(dev);goto out5;}printk("向上提交设备节点信息成功\n");/*res=platform_get_resource(pdev,IORESOURCE_MEM,0);if(res == NULL){printk("获取资源失败\n");return -ENXIO;}printk("获取资源信息成功%x\n",res->start);*/irqno = platform_get_irq(pdev,0);if(irqno < 0){printk("获取中断资源失败\n");return irqno;}printk("软中断号为%d\n",irqno);//pdev->dev.of_node  设备树匹配之后会把设备树节点结构体首地址赋值给dev的of_node成员gpiono=gpiod_get_from_of_node(pdev->dev.of_node,"led1",0,GPIOD_OUT_LOW,NULL);if(IS_ERR(gpiono)){printk("解析GPIO信息失败\n");return -PTR_ERR(gpiono);}//注册中断ret=request_irq(irqno,myirq_handler,IRQF_TRIGGER_FALLING,"myplatform",NULL);if(ret){printk("注册驱动失败\n");return ret;}printk("中断注册成功\n");return 0;
out5://销毁上面提交的设备信息device_destroy(cls,MKDEV(major,minor));class_destroy(cls);
out4:cdev_del(cdev);
out3:unregister_chrdev_region(MKDEV(major,minor),1);
out2:kfree(cdev);
out1:return ret;
}
//remove 设备和驱动分离时执行
int pdrv_remove(struct platform_device *pdev)
{//注销中断free_irq(irqno,NULL);//灭灯，注销gpio信息gpiod_set_value(gpiono,0);gpiod_put(gpiono);//1.销毁设备信息  device_destroydevice_destroy(cls,MKDEV(major,minor));//2.销毁目录  class_destroyclass_destroy(cls);//3.注销对象  cdev_del()cdev_del(cdev);//4.释放设备号   unregister_chrdev_region()unregister_chrdev_region(MKDEV(major,minor),1);//5.释放对象空间  kfree()kfree(cdev);return 0;
}
//用于通过设备树的形式匹配设备信息
struct of_device_id oftable[]={{.compatible="hqyj,myplatform",},{.compatible="hqyj,myplatform1",},{},
};//驱动端结构体
struct platform_driver pdrv={.probe=pdrv_probe,.remove=pdrv_remove,.driver={.name="11111",.of_match_table=oftable,},
};module_platform_driver(pdrv);
MODULE_LICENSE("GPL");