//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_DOWN
int 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--0
void * 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------------
",__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!
",p->name);
button_dev->event.code = p->code;
button_dev->event.value = 0;
}else{
//按下
printk("kenel:%s pressed!
",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------------
",__FUNCTION__);
return 0;
}
ssize_t button_read(struct file *filp , char __user *buf , size_t size, loff_t *flags)
{
int ret;
printk("--------^_^ %s------------
",__FUNCTION__);
//判读open时，有没有设置flags为NONBLOCK
if(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!
");
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------------
",__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------------
",__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!
");
}
return 0;
}
int button_mmap(struct file *filp, struct vm_area_struct *vma)
{
unsigned int addr;
printk("--------^_^ %s------------
",__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
",__func__);
return -EAGAIN;
}
return 0;
}
unsigned int button_poll(struct file *filp, struct poll_table_struct *pts)
{
unsigned int mask = 0;
printk("--------^_^ %s------------
",__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0
if(button_dev->have_data)
mask |= POLLIN;
return mask;
}
int button_close(struct inode *inode, struct file *filp)
{
printk("--------^_^ %s------------
",__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------------
",__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!
");
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!
");
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!
");
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!
");
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/button
button_dev->cls = class_create(THIS_MODULE,"button_cls");
if(IS_ERR(button_dev->cls)){
printk("class_create error!
");
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!
");
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!
");
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!
");
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------------
",__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_DOWN
int 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
",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!
");
else
printf("松开了上键!
");
break;
case KEY_DOWN:
if(event.value)
printf("按下了下键!
");
else
printf("松开了下键!
");
break;
case KEY_LEFT:
if(event.value)
printf("按下了左键!
");
else
printf("松开了左键!
");
break;
case KEY_RIGHT:
if(event.value)
printf("按下了右键!
");
else
printf("松开了右键!
");
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 = test
all:
#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) modules
arm-none-linux-gnueabi-gcc -o $(MYAPP) $(MYAPP).c
clean:
#删除上面编译生成的文件
make -C $(KERNEL_DIR) M=$(CUR_DIR) clean
rm -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
