Linux 驱动——Button驱动4(fasync)异步通知
button_drv.c驱动文件:
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <asm/io.h> //含有iomap函数iounmap函数
#include <asm/uaccess.h> //含有copy_from_user函数
#include <linux/device.h> //含有类相关的处理函数
#include <asm/arch/regs-gpio.h> //含有S3C2410_GPF0等相关的
#include <linux/irq.h> //含有IRQ_HANDLED\IRQ_TYPE_EDGE_RISING
#include <asm-arm/irq.h> //含有IRQT_BOTHEDGE触发类型
#include <linux/interrupt.h> //含有request_irq、free_irq函数
#include <linux/delay.h>
#include <asm/hardware.h>
#include <linux/poll.h>
#define DRIVER_NAME "button_drv"
#define DEVICE_NAME "button_dev"
int major;
volatile unsigned long *gpfcon;
volatile unsigned long *gpfdat;
volatile unsigned long *gpgcon;
volatile unsigned long *gpgdat;
struct class *button_class;
struct class_device *button_class_device;
unsigned char ev_press;
DECLARE_WAIT_QUEUE_HEAD(button_waitq); //注册等待队列
struct fasync_struct *button_fasync; //定义fasync_struct结构体
unsigned char keyVal;
struct pin_desc{
unsigned int pin;
unsigned int key_val;
};
struct pin_desc pins_desc[4] = {
{S3C2410_GPF0, 0x01},
{S3C2410_GPF2, 0x02},
{S3C2410_GPG3, 0x03},
{S3C2410_GPG11, 0x04},
};
irqreturn_t buttons_irq(int irq, void *dev_id)
{
unsigned int pin_val;
struct pin_desc *pin_desc = (struct pin_desc *)dev_id;
pin_val = s3c2410_gpio_getpin(pin_desc->pin);
if(pin_val)
{
keyVal = 0x80 | pin_desc->key_val;
}
else
{
keyVal = pin_desc->key_val;
}
wake_up_interruptible(&button_waitq);
ev_press = 1;
kill_fasync(&button_fasync, SIGIO, POLL_IN); //发送信号给进程
return IRQ_HANDLED;
}
int button_drv_open(struct inode *inode, struct file *file)
{
int ret;
ret = request_irq(IRQ_EINT0, buttons_irq, IRQT_BOTHEDGE, "S1", &pins_desc[0]); //注册中断S1, 并将IRQ_EINT0这个引脚配
//置为中断模式, 双边沿触发
if(ret<0)
{
printk("failed 1 button_drv_open");
}
ret = request_irq(IRQ_EINT2, buttons_irq, IRQT_BOTHEDGE, "S2", &pins_desc[1]);
if(ret<0)
{
printk("failed 2 button_drv_open");
}
ret = request_irq(IRQ_EINT11, buttons_irq, IRQT_BOTHEDGE, "S3", &pins_desc[2]);
if(ret<0)
{
printk("failed 3 button_drv_open");
}
ret = request_irq(IRQ_EINT19, buttons_irq, IRQT_BOTHEDGE, "S4", &pins_desc[3]);
if(ret<0)
{
printk("failed 4 button_drv_open");
}
return 0;
}
ssize_t button_drv_read(struct file *file, char __user *userbuf, size_t count, loff_t *off)
{
int ret;
ret = copy_to_user(userbuf, &keyVal, 1);
if(ret<0)
{
printk("failed 1 button_drv_read \n");
return -1;
}
ev_press = 0;
return 1;
}
int button_drv_close(struct inode *inode, struct file *file)
{
free_irq(IRQ_EINT0, &pins_desc[0]); //释放中断
free_irq(IRQ_EINT2, &pins_desc[1]);
free_irq(IRQ_EINT11, &pins_desc[2]);
free_irq(IRQ_EINT19, &pins_desc[3]);
return 0;
}
unsigned int button_drv_poll(struct file *file, poll_table *wait)
{
unsigned int mask = 0;
poll_wait(file, &button_waitq, wait);
if(ev_press)
{
mask |= POLLIN | POLLRDNORM;
}
return mask;
}
int button_drv_fasync(int fd, struct file *file, int on)
{
int ret;
ret = fasync_helper(fd, file, on, &button_fasync);
if(ret<0)
{
printk("failed 1 button_drv_fasync \n");
return ret;
}
return 0;
}
struct file_operations button_drv_fops = {
.owner = THIS_MODULE,
.open = button_drv_open,
.read = button_drv_read,
.release = button_drv_close,
.poll = button_drv_poll,
.fasync = button_drv_fasync,
};
int __init button_drv_init(void)
{
major = register_chrdev(0, DRIVER_NAME, &button_drv_fops);
if(major<0)
{
printk("failed 1 button_drv_init \n");
}
button_class = class_create(THIS_MODULE, DEVICE_NAME);
if(button_class<0)
{
printk("failed 2 button_drv_init \n");
}
button_class_device = class_device_create(button_class, NULL, MKDEV(major, 0), NULL, DEVICE_NAME);
if(button_class_device<0)
{
printk("failed 3 button_drv_init \n");
}
gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
gpfdat = gpfcon + 1;
gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
gpgdat = gpgcon + 1;
return 0;
}
void __exit button_drv_exit(void)
{
unregister_chrdev(major, DEVICE_NAME);
class_device_unregister(button_class_device);
class_destroy(button_class);
iounmap(gpfcon);
iounmap(gpgcon);
}
module_init(button_drv_init);
module_exit(button_drv_exit);
MODULE_LICENSE("GPL");
Makefile文件:
obj-m += timer_drv.o
KERN_DIR = /work/system/linux-2.6.22.6
all:
make -C $(KERN_DIR) M=`pwd` modules
clean:
rm -rf *.o *.ko *.order *.symvers *.mod.c
button_app.c文件:
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <poll.h>
#include <signal.h>
static int fd;
void button_signal(int signum)
{
unsigned char keyVal;
printf("signal = %d \n", signum);
read(fd, &keyVal, 1);
printf("keyVal = 0x%x \n", keyVal);
}
int main(int argc, char **argv)
{
int oflags;
char *filename;
filename = argv[1];
fd = open(filename, O_RDWR);
if(fd<0)
{
printf("can not open \n");
}
signal(SIGIO, button_signal); //注册一个信号, 启动信号驱动机制
fcntl(fd, F_SETOWN, getpid()); //将本应用程序的进程号告诉给内核,最终使得驱动程序可以成功发送信号给应用程序
oflags = fcntl(fd, F_GETFL); //取得当前的状态
fcntl(fd, F_SETFL, oflags|FASYNC); //改变fasync标记, 最终会调用到驱动的fasync->fasync_helper
while(1)
{
sleep(1000);
}
return 0;
}
编译生成button_drv.ko和button_app文件,运行./button_app /dev/button_dev
- 【腾讯云的1001种玩法】十分钟搞定云架构 · 什么是Bucket、什么是Object
- 【腾讯云的1001种玩法】十分钟轻松搞定云架构 · 负载均衡的最佳实践
- 【黑客浅析】像黑客一样思考
- 【腾讯云的1001种玩法】 十分钟轻松搞定云架构 · 负载均衡的几种均衡模式
- ASP.NET Web API的Controller是如何被创建的?
- 【腾讯云的1001种玩法】十分钟轻松搞定云架构:COS的两种上传模式
- 物流行业迎变革,云计算是基础,大数据是关键
- Socket学习总结系列(二) -- CocoaAsyncSocket
- 比特币勒索病毒肆虐,腾讯云安全专家给你支招
- HTML5 直播协议之 WebSocket 和 MSE
- IoC在ASP.NET Web API中的应用
- 跟鹅厂老司机学技术之一:“遇见” Kotlin
- 简单的 H5 视频推流解决方案
- 来腾讯云开发者实验室学习.NET
- JavaScript 教程
- JavaScript 编辑工具
- JavaScript 与HTML
- JavaScript 与Java
- JavaScript 数据结构
- JavaScript 基本数据类型
- JavaScript 特殊数据类型
- JavaScript 运算符
- JavaScript typeof 运算符
- JavaScript 表达式
- JavaScript 类型转换
- JavaScript 基本语法
- JavaScript 注释
- Javascript 基本处理流程
- Javascript 选择结构
- Javascript if 语句
- Javascript if 语句的嵌套
- Javascript switch 语句
- Javascript 循环结构
- Javascript 循环结构实例
- Javascript 跳转语句
- Javascript 控制语句总结
- Javascript 函数介绍
- Javascript 函数的定义
- Javascript 函数调用
- Javascript 几种特殊的函数
- JavaScript 内置函数简介
- Javascript eval() 函数
- Javascript isFinite() 函数
- Javascript isNaN() 函数
- parseInt() 与 parseFloat()
- escape() 与 unescape()
- Javascript 字符串介绍
- Javascript length属性
- javascript 字符串函数
- Javascript 日期对象简介
- Javascript 日期对象用途
- Date 对象属性和方法
- Javascript 数组是什么
- Javascript 创建数组
- Javascript 数组赋值与取值
- Javascript 数组属性和方法
- JavaWeb - Servlet:重定向和转发,状态管理
- 设计模式(12)[JS版]--JavaScript必会设计模式之外观模式(Façade Pattern)
- JavaWeb - JSP:概述和语法,内置对象,JavaBean 组件,MVC 设计模式
- kill -9 导致 Kakfa 重启失败的惨痛经历!
- 图解 DataX 核心设计原理
- 不会吧不会吧,你不会还不知道这些提高JS代码质量的骚操作吧?
- Flask架站基础篇(一)--环境配置
- Flask架站基础篇(三)--Flask生成文件内容和文件夹详解
- Flask架站基础篇(四)--URL
- Flask架站基础篇(六)--mysql-python 安装
- Flask架站基础篇(五)----Jinja2模板
- Flask架站基础篇(七)--SQLAlchemy(1)
- JavaScript 进阶教程(1)--面向对象编程
- Flask架站基础篇(八)--SQLAlchemy(2)
- JavaWeb - EL and JSTL