控制IO端口 s3c2410_gpio_setpin()的使用

本文基于FL2440 ARM开发板

Linux内核版本 2.6.28.7

arm-linux-gcc 3.4.1

转载请标明出处http://blog.csdn.net/yming0221

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/interrupt.h>/*设置中断方式*/
#include <linux/wait.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
//设备名
#define IO_DEVICE_NAME "my_io"
//主设备号
#define IO_DEVICE_MAJOR 240
//次设备号
#define IO_DEVICE_SECONDARY 32
//返回一个数x的第y位
#define MYBIT(x,y) ((x>>y)%2)
#ifndef _LINUX_IRQRETURN_H
#define _LINUX_IRQRETURN_H
typedef int irqreturn_t;
#define IRQ_EINT0	0
#define IRQ_EINT2	2
#define IRQ_EINT3	3
#define IRQ_EINT4	32
#define IRQ_NONE       (0)
#define IRQ_HANDLED       (1)
#define IRQ_RETVAL(x)      ((x) != 0)
#endif
/*
 * S3C2410 GPIO edge detection for IRQs:
 * IRQs are generated on Falling-Edge, Rising-Edge, both, low level or higg level.
 * This must be called *before* the corresponding IRQ is registered.
 */
#define EXT_LOWLEVEL		0
#define EXT_HIGHLEVEL		1
#define EXT_FALLING_EDGE	2
#define EXT_RISING_EDGE		4
#define EXT_BOTH_EDGES		6
static int flag_0,flag_2;//中断转换标志
static int cnt;
DECLARE_WAIT_QUEUE_HEAD(io_wait);//声明等待队列
void io_con_set();
static irqreturn_t io_interrupt_0(int irq,void * dev_id,struct pt_regs *regs)
{
	printk("**********the interrupt 0 works**********/n");
	if(flag_0==0)
	{
		cnt=(cnt+1)%2;
		flag_0=1;
		if(cnt==0)
		{
			printk("IN/n");
			s3c2410_gpio_setpin(S3C2410_GPB5,0);
			s3c2410_gpio_setpin(S3C2410_GPB6,1);
		}
		wake_up_interruptible(&io_wait);
	}
	return IRQ_HANDLED;
}
static irqreturn_t io_interrupt_2(int irq,void * dev_id,struct pt_regs *regs)
{
	printk("**********the interrupt 2 works**********/n");
	if(flag_2==0)
	{
		cnt=(cnt+1)%2;
		flag_2=1;
		if(cnt==0)
		{
			printk("OUT/n");
			s3c2410_gpio_setpin(S3C2410_GPB5,1);
			s3c2410_gpio_setpin(S3C2410_GPB6,0);
		}
		wake_up_interruptible(&io_wait);
	}
	return IRQ_HANDLED;
}
static int io_open(struct inode * inode,struct file * file)//打开设备函数
{
	int ret;
	set_irq_type(IRQ_EINT0,EXT_FALLING_EDGE);//设置中断0 触发方式
	set_irq_type(IRQ_EINT2,EXT_FALLING_EDGE);//设置中断2 触发方式
	// EXT_LOWLEVEL
	// EXT_HIGHLEVEL
	// EXT_FALLING_EDGE
	// EXT_RISING_EDGE
	// EXT_BOTH_EDGES
	disable_irq(IRQ_EINT0);
	disable_irq(IRQ_EINT2);
	enable_irq(IRQ_EINT0);
	enable_irq(IRQ_EINT2);
	ret=request_irq(IRQ_EINT0,io_interrupt_0,IRQF_SHARED,IO_DEVICE_NAME,1);//注册中断0
	if(ret<0)
	{
		printk("IRQ %d can not request/n",IRQ_EINT0);
		return ret;
	}
	ret=request_irq(IRQ_EINT2,io_interrupt_2,IRQF_SHARED,IO_DEVICE_NAME,1);//注册中断2
	if(ret<0)
	{
		printk("IRQ %d can not request/n",IRQ_EINT2);
		return ret;
	}
	printk("the device is opened/n");
	io_con_set();
	cnt=0;
	return 0;
}
void io_con_set()//IO端口控制寄存器初始化
{
	 s3c2410_gpio_cfgpin(S3C2410_GPF0,S3C2410_GPF0_EINT0);
	 s3c2410_gpio_cfgpin(S3C2410_GPF2,S3C2410_GPF2_EINT2);
	 s3c2410_gpio_cfgpin(S3C2410_GPB5,S3C2410_GPB5_OUTP);
	 s3c2410_gpio_cfgpin(S3C2410_GPB6,S3C2410_GPB6_OUTP);
}
static int io_close(struct inode * inode,struct file * file)//设备关闭函数
{
	free_irq(IRQ_EINT0,1);//释放中断
	free_irq(IRQ_EINT2,1);//释放中断
	printk("the device is closed/n");
	return 0;
}
static ssize_t io_read(struct file * filp,char  * buff,size_t count,loff_t  * f_ops)//读取IO端口
{
	wait_event_interruptible(io_wait,flag_0);
	wait_event_interruptible(io_wait,flag_0);
	flag_0=0;
	flag_2=0;
	//printk("the value is %d/n",io_data);
	copy_to_user(buff,(char *)&cnt,sizeof(cnt));
}
static struct file_operations io_device_fops = 
{
	.owner=THIS_MODULE,
	.read=io_read,
	.open=io_open,
	.release=io_close,
};
static int __init io_init(void)//insmod加载驱动时执行
{
	int ret;
	ret=register_chrdev(IO_DEVICE_MAJOR,IO_DEVICE_NAME,&io_device_fops);
	if(ret<0)
	{
		printk("Fail to regist the device/n");
		return ret;
	}
	return 0;
}
static int __exit io_exit(void)//rmmod卸载驱动时执行
{
	unregister_chrdev(IO_DEVICE_MAJOR,IO_DEVICE_NAME);
	printk("the device has been unregisted/n");
}
module_init(io_init);
module_exit(io_exit);
MODULE_LICENSE("GPL");  

Makefile同上一篇的Makefile

obj-m := my_io.o

KERNELDIR ?= /arm/linux-2.6.28.7-2440

PWD := $(shell pwd)

default:

$(MAKE) -C $(KERNELDIR) M=$(PWD) modules

clean:

rm -f *.o *.ko *.order *.symvers

这次本人修改了下内核头文件的目录，将目录./arch/arm/include下asm文件夹复制到./include

将目录./arch/arm/mach-s3c2410/include下mach文件夹复制到./include下

驱动修改版

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/interrupt.h>/*设置中断方式*/
#include <linux/wait.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
//设备名
#define IO_DEVICE_NAME "my_io"
//主设备号
#define IO_DEVICE_MAJOR 240
//次设备号
#define IO_DEVICE_SECONDARY 32
//返回一个数x的第y位
#define MYBIT(x,y) ((x>>y)%2)
#ifndef _LINUX_IRQRETURN_H
#define _LINUX_IRQRETURN_H
typedef int irqreturn_t;
#define IRQ_EINT0	0
#define IRQ_EINT2	2
#define IRQ_EINT3	3
#define IRQ_EINT4	32
#define IRQ_NONE       (0)
#define IRQ_HANDLED       (1)
#define IRQ_RETVAL(x)      ((x) != 0)
#endif
/*
 * S3C2410 GPIO edge detection for IRQs:
 * IRQs are generated on Falling-Edge, Rising-Edge, both, low level or higg level.
 * This must be called *before* the corresponding IRQ is registered.
 */
#define EXT_LOWLEVEL		0
#define EXT_HIGHLEVEL		1
#define EXT_FALLING_EDGE	2
#define EXT_RISING_EDGE		4
#define EXT_BOTH_EDGES		6
static int flag_0,flag_2;//中断转换标志
static int cnt;
DECLARE_WAIT_QUEUE_HEAD(io_wait);//声明等待队列
void io_con_set();
static irqreturn_t io_interrupt_0(int irq,void * dev_id,struct pt_regs *regs)
{
	if(flag_0==0)
	{
		printk("**********the interrupt 0 works**********/n");
		cnt=(cnt+1)%2;
		flag_0=1;
		if(cnt==0)
		{
			printk("IN/n");
			s3c2410_gpio_setpin(S3C2410_GPB5,0);
			s3c2410_gpio_setpin(S3C2410_GPB6,1);
		}
		wake_up_interruptible(&io_wait);
	}
	return IRQ_HANDLED;
}
static irqreturn_t io_interrupt_2(int irq,void * dev_id,struct pt_regs *regs)
{
	if(flag_2==0)
	{
		printk("**********the interrupt 2 works**********/n");
		cnt=(cnt+1)%2;
		flag_2=1;
		if(cnt==0)
		{
			printk("OUT/n");
			s3c2410_gpio_setpin(S3C2410_GPB5,1);
			s3c2410_gpio_setpin(S3C2410_GPB6,0);
		}
		wake_up_interruptible(&io_wait);
	}
	return IRQ_HANDLED;
}
static int io_open(struct inode * inode,struct file * file)//打开设备函数
{
	int ret;
	set_irq_type(IRQ_EINT0,EXT_FALLING_EDGE);//设置中断0 触发方式
	set_irq_type(IRQ_EINT2,EXT_FALLING_EDGE);//设置中断2 触发方式
	// EXT_LOWLEVEL
	// EXT_HIGHLEVEL
	// EXT_FALLING_EDGE
	// EXT_RISING_EDGE
	// EXT_BOTH_EDGES
	disable_irq(IRQ_EINT0);
	disable_irq(IRQ_EINT2);
	enable_irq(IRQ_EINT0);
	enable_irq(IRQ_EINT2);
	ret=request_irq(IRQ_EINT0,io_interrupt_0,IRQF_SHARED,IO_DEVICE_NAME,1);//注册中断0
	if(ret<0)
	{
		printk("IRQ %d can not request/n",IRQ_EINT0);
		return ret;
	}
	ret=request_irq(IRQ_EINT2,io_interrupt_2,IRQF_SHARED,IO_DEVICE_NAME,1);//注册中断2
	if(ret<0)
	{
		printk("IRQ %d can not request/n",IRQ_EINT2);
		return ret;
	}
	printk("the device is opened/n");
	io_con_set();
	cnt=0;
	return 0;
}
void io_con_set()//IO端口控制寄存器初始化
{
	 s3c2410_gpio_cfgpin(S3C2410_GPF0,S3C2410_GPF0_EINT0);
	 s3c2410_gpio_cfgpin(S3C2410_GPF2,S3C2410_GPF2_EINT2);
	 s3c2410_gpio_cfgpin(S3C2410_GPB5,S3C2410_GPB5_OUTP);
	 s3c2410_gpio_cfgpin(S3C2410_GPB6,S3C2410_GPB6_OUTP);
}
static int io_close(struct inode * inode,struct file * file)//设备关闭函数
{
	free_irq(IRQ_EINT0,1);//释放中断
	free_irq(IRQ_EINT2,1);//释放中断
	printk("the device is closed/n");
	return 0;
}
static ssize_t io_read(struct file * filp,char  * buff,size_t count,loff_t  * f_ops)//读取IO端口
{
	wait_event_interruptible(io_wait,flag_0&flag_2);
	flag_0=0;
	flag_2=0;
	//printk("the value is %d/n",io_data);
	copy_to_user(buff,(char *)&cnt,sizeof(cnt));
}
static struct file_operations io_device_fops = 
{
	.owner=THIS_MODULE,
	.read=io_read,
	.open=io_open,
	.release=io_close,
};
static int __init io_init(void)//insmod加载驱动时执行
{
	int ret;
	ret=register_chrdev(IO_DEVICE_MAJOR,IO_DEVICE_NAME,&io_device_fops);
	if(ret<0)
	{
		printk("Fail to regist the device/n");
		return ret;
	}
	return 0;
}
static int __exit io_exit(void)//rmmod卸载驱动时执行
{
	unregister_chrdev(IO_DEVICE_MAJOR,IO_DEVICE_NAME);
	printk("the device has been unregisted/n");
}
module_init(io_init);
module_exit(io_exit);
MODULE_LICENSE("GPL");  

这个驱动实际上是通过红外传感器检测电平变化，来实现人数的统计，改进后能够实现正确的通过中断先后来识别方向，还排除了单一中断的

抖动干扰。