//头文件
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/cdev.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/mm.h>#include <asm/io.h>
#include <asm/page.h>
#include <asm/string.h>
#include <asm/uaccess.h>
#include <asm-generic/ioctl.h>#define BUTTON_iOC_GET_DATA 0x4321
struct mem_data{char buf[128];
};//定义一个按键的数据包
struct button_event{int code;         //按键的名称---键值:KEY_DOWNint value;        //按键的状态---按下:1,松开:0
};//设计一个描述按键的结构体类型
struct buttons{char *name;        //名称unsigned int irqno;        //中断号int gpio;                //按键对应的gpio口int code;                //键值unsigned long flags;    //触发方式
};//定义一个数组来保存多个按键的数据
struct buttons buttons_set[] = {[0] = {.name = "key1_up",.irqno = IRQ_EINT(0),.gpio = S5PV210_GPH0(0),.code = KEY_UP,.flags = IRQF_TRIGGER_FALLING|IRQF_TRIGGER_RISING,},[1] = {.name = "key2_down",.irqno = IRQ_EINT(1),.gpio = S5PV210_GPH0(1),.code = KEY_DOWN,.flags = IRQF_TRIGGER_FALLING|IRQF_TRIGGER_RISING,},[2] = {.name = "key3_left",.irqno = IRQ_EINT(2),.gpio = S5PV210_GPH0(2),.code = KEY_LEFT,.flags = IRQF_TRIGGER_FALLING|IRQF_TRIGGER_RISING,},[3] = {.name = "key4_right",.irqno = IRQ_EINT(3),.gpio = S5PV210_GPH0(3),.code = KEY_RIGHT,.flags = IRQF_TRIGGER_FALLING|IRQF_TRIGGER_RISING,},
};//面向对象编程----设计设备的类型
struct s5pv210_button{//unsigned int major;
    dev_t  devno;struct class * cls;struct device * dev;struct cdev  *cdev;unsigned int irqno;struct button_event event;wait_queue_head_t wq_head;int have_data;        //表示当前是否有数据可读,可读--1，不可读--0void * virt_mem;
};
struct s5pv210_button *button_dev;//实现中断处理函数--------当触发中断时会被执行
irqreturn_t button_irq_svc(int irqno, void *dev)
{int value;struct buttons *p;printk("--------^_^ %s------------\n",__FUNCTION__);//获取当前触发中断的按键信息p = (struct buttons *)dev;//获取产生中断的gpio口的值value = gpio_get_value(p->gpio);//判断是按下还是松开if(value){//松开printk("kernel:%s up!\n",p->name);button_dev->event.code = p->code;button_dev->event.value = 0;}else{//按下printk("kenel:%s pressed!\n",p->name);button_dev->event.code = p->code;button_dev->event.value = 1;}//此时有数据可读button_dev->have_data = 1;//从等待队列中唤醒阻塞的进程wake_up_interruptible(&button_dev->wq_head);return IRQ_HANDLED;
}//实现设备操作接口
int button_open(struct inode *inode, struct file *filp)
{printk("--------^_^ %s------------\n",__FUNCTION__);return 0;
}
ssize_t button_read(struct file *filp , char __user *buf , size_t size, loff_t *flags)
{int ret;printk("--------^_^ %s------------\n",__FUNCTION__);//判读open时，有没有设置flags为NONBLOCKif(filp->f_flags & O_NONBLOCK && !button_dev->have_data)return -EAGAIN;//判断此时是否有数据可读wait_event_interruptible(button_dev->wq_head,button_dev->have_data);//将内核数据转换为用户空间数据ret = copy_to_user(buf,&button_dev->event,size);if(ret > 0){printk("copy_to_user error!\n");return -EFAULT;}//将数据返回给应用空间后，清空数据包,同时将hava_data置零memset(&button_dev->event,0,sizeof(button_dev->event));button_dev->have_data = 0;return size;
}ssize_t button_write(struct file *filp, const char __user *buf, size_t size, loff_t *flags)
{printk("--------^_^ %s------------\n",__FUNCTION__);return size;
}long button_ioctl(struct file *filp, unsigned int cmd , unsigned long args)
{void __user *argp;struct mem_data data;int ret;printk("--------^_^ %s------------\n",__FUNCTION__);argp = (void __user *)args;switch(cmd){case BUTTON_iOC_GET_DATA:memset(data.buf,0,sizeof(data.buf));memcpy(data.buf, button_dev->virt_mem,sizeof(data.buf));ret = copy_to_user(argp,&data,sizeof(data));if(ret > 0){return -EFAULT;}break;default:printk("unkown cmd!\n");}return 0;
}int button_mmap(struct file *filp, struct vm_area_struct *vma)
{unsigned int addr;printk("--------^_^ %s------------\n",__FUNCTION__);//1,获得一块物理内存空间-----将申请的虚拟空间转换为对应的物理空间addr = virt_to_phys(button_dev->virt_mem);    //2,将物理内存映射到虚拟空间---应用空间
    vma->vm_flags |= VM_IO;vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,PAGE_SIZE, vma->vm_page_prot)) {printk(KERN_ERR "%s: io_remap_pfn_range failed\n",__func__);return -EAGAIN;}return 0;
}unsigned int button_poll(struct file *filp, struct poll_table_struct *pts)
{unsigned int mask = 0;printk("--------^_^ %s------------\n",__FUNCTION__);//1,将等待队列头注册到系统中(VFS)poll_wait(filp,&button_dev->wq_head,pts);//2,如果产生按键中断-有数据可读，此时返回POLLIN，如果没有数据返回0if(button_dev->have_data)mask |= POLLIN;return mask;}int button_close(struct inode *inode, struct file *filp)
{printk("--------^_^ %s------------\n",__FUNCTION__);return 0;
}static struct file_operations fops = {.open = button_open,.read = button_read,.write = button_write,.poll = button_poll,.mmap = button_mmap,.unlocked_ioctl = button_ioctl,.release = button_close,
};//加载函数和卸载函数
static int __init button_init(void)   //加载函数-----在驱动被加载时执行
{int ret,i;printk("--------^_^ %s------------\n",__FUNCTION__);//0,实例化设备对象//参数1 ---- 要申请的空间的大小//参数2 ---- 申请的空间的标识button_dev = kzalloc(sizeof(struct s5pv210_button),GFP_KERNEL);if(IS_ERR(button_dev)){printk("kzalloc error!\n");ret = PTR_ERR(button_dev);return -ENOMEM;}//1,申请设备号-----新方法
#if 0//静态申请设备号button_dev->major = 256;ret = register_chrdev_region(MKDEV(button_dev->major,0),1,"button_drv");if(ret < 0){printk("register_chrdev_region error!\n");ret =  -EINVAL;goto err_kfree;}
#else//动态申请设备号ret = alloc_chrdev_region(&button_dev->devno,0,1,"button_drv");if(ret < 0){printk("register_chrdev_region error!\n");ret =  -EINVAL;goto err_kfree;}
#endif//创建cdev//申请cdev的空间button_dev->cdev = cdev_alloc();if(IS_ERR(button_dev->cdev)){        printk("button_dev->cdev error!\n");ret = PTR_ERR(button_dev->cdev);goto err_unregister;}//初始化cdev的成员cdev_init(button_dev->cdev,&fops);//将cdev加入到内核中----链表ret = cdev_add(button_dev->cdev,button_dev->devno,1);//2,创建设备文件-----/dev/buttonbutton_dev->cls = class_create(THIS_MODULE,"button_cls");if(IS_ERR(button_dev->cls)){printk("class_create error!\n");ret = PTR_ERR(button_dev->cls);goto err_cdev_del;}button_dev->dev = device_create(button_dev->cls,NULL,button_dev->devno,NULL,"button");if(IS_ERR(button_dev->dev)){printk("device_create error!\n");ret = PTR_ERR(button_dev->dev);goto err_class;}//3,硬件初始化---申请中断for(i = 0; i < ARRAY_SIZE(buttons_set);i++){ret = request_irq(buttons_set[i].irqno,button_irq_svc,buttons_set[i].flags,buttons_set[i].name,&buttons_set[i]);if(ret != 0){printk("request_irq error!\n");ret = -EBUSY;goto err_device;}}//初始化等待队列头init_waitqueue_head(&button_dev->wq_head);//获取一块虚拟的内存空间---内核中button_dev->virt_mem = kzalloc(PAGE_SIZE,GFP_KERNEL);if(IS_ERR(button_dev->virt_mem)){printk("kzalloc error!\n");ret = -EBUSY;goto err_free_irq;}return 0;
err_free_irq:for(i = 0; i < ARRAY_SIZE(buttons_set);i++){free_irq(buttons_set[i].irqno,&buttons_set[i]);}
err_device:device_destroy(button_dev->cls,button_dev->devno);
err_class:class_destroy(button_dev->cls);err_cdev_del:cdev_del(button_dev->cdev);err_unregister:unregister_chrdev_region(button_dev->devno,1);err_kfree:kfree(button_dev);return ret;}static void __exit button_exit(void)   //卸载函数-----在驱动被卸载时执行
{int i;printk("--------^_^ %s------------\n",__FUNCTION__);kfree(button_dev->virt_mem);    for(i = 0; i < ARRAY_SIZE(buttons_set);i++){free_irq(buttons_set[i].irqno,&buttons_set[i]);}device_destroy(button_dev->cls,button_dev->devno);class_destroy(button_dev->cls);cdev_del(button_dev->cdev);unregister_chrdev_region(button_dev->devno,1);kfree(button_dev);
}//声明和认证
module_init(button_init);
module_exit(button_exit);
MODULE_LICENSE("GPL");

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <poll.h>
#include <sys/mman.h>
#include <linux/input.h>//定义一个按键的数据包
struct button_event{int code;    //按键的名称---键值:KEY_DOWNint value;        //按键的状态---按下:1,松开:0
};#define BUTTON_iOC_GET_DATA 0x4321
#define PAGE_SIZE 1UL<<12
struct mem_data{char buf[128];
};
int main(void)
{int fd;int ret;struct button_event event;struct pollfd pfds[2];char buf[128];char *str = "hello kernel";struct mem_data data;fd = open("/dev/button",O_RDWR);if(fd < 0){perror("open");exit(1);}//测试mmap的功能char *addr = mmap(NULL,PAGE_SIZE,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);if(addr == NULL){perror("mmap");exit(1);}//向映射的物理空间中写数据
    strcpy(addr,str);sleep(1);//验证数据是否写入到映射的物理空间----通过ioctl读取数据ret = ioctl(fd,BUTTON_iOC_GET_DATA,&data);if(ret < 0){perror("ioctl");exit(1);}printf("data.buf = %s\n",data.buf); //将读到的数据打印出来sleep(1);pfds[0].fd = 0;        //标准输入文件描述符pfds[0].events = POLLIN;    //是否可读
pfds[1].fd = fd;        //开发板中的键盘pfds[1].events = POLLIN;    //按键是否触发中断while(1){ret = poll(pfds,2,-1);if(ret < 0){perror("poll");exit(1);}if(ret > 0){//标准输入可读if(pfds[0].revents & POLLIN){fgets(buf,sizeof(buf),stdin);printf("%s",buf);}//开发板中的按键触发了中断 if(pfds[1].revents & POLLIN){bzero(&event,sizeof(event));ret = read(fd,&event,sizeof(event));if(ret < 0){perror("read");exit(1);}switch(event.code){case KEY_UP:if(event.value)printf("按下了上键!\n");elseprintf("松开了上键!\n");break;case KEY_DOWN:if(event.value)printf("按下了下键!\n");elseprintf("松开了下键!\n");break;case KEY_LEFT:if(event.value)printf("按下了左键!\n");elseprintf("松开了左键!\n");break;case KEY_RIGHT:if(event.value)printf("按下了右键!\n");elseprintf("松开了右键!\n");break;}}}}close(fd);return 0;
}

#指定内核源码路径
KERNEL_DIR = /home/farsight/s5pv210/kernel/linux-3.0.8
CUR_DIR = $(shell pwd)
MYAPP = testall:#让make进入内核源码编译，同时将当前目录中的c程序作为内核模块一起编译make -C $(KERNEL_DIR) M=$(CUR_DIR) modulesarm-none-linux-gnueabi-gcc -o $(MYAPP) $(MYAPP).cclean:#删除上面编译生成的文件make -C $(KERNEL_DIR) M=$(CUR_DIR) cleanrm -rf $(MYAPP)install:cp *.ko $(MYAPP) /opt/rootfs/drv_module#指定当前目录下哪个文件作为内核模块编
obj-m = button_drv.o