LED定时闪烁的driver

1. 平台：
   操作系统：linux-2.6.34
   硬件平台：s3c2440
   编译器版本：arm-none-eabi-gcc 4.4.1
2. 实现功能：2个LED不断闪烁，间隔2s
   
3. 电路图
   
   
   图1 两个上拉的LED
   

   
   图2 接到S3C2440的GPB10和GPB7
4. 一个公共的头文件ypublic.h
   

   //ypublic.h

   #ifndef __Y_PUBLIC__
#define __Y_PUBLIC__

#include <linux/ioport.h>
#include <linux/timer.h>

#include <asm/io.h>

//#define MS(n) (HZ*(n)/1000)

#define PI 3.1415927
#define uint unsigned int
#define uchar unsigned char
#define ulong unsigned long
#define byte uchar

static void* yioremap(ulong start,ulong n,char name[])
{
    if(request_mem_region(start,n,name)==NULL)return NULL;
    return ioremap(start,n);
}

static void yiounmap(ulong start,ulong n)
{
    iounmap(start);
    release_mem_region(start,n);
}

static ulong fortimems(ulong ms)
{
    return (jiffies+HZ*ms/1000);
}

#define MS(n) fortimems(n)
#endif

   
   
5. LED驱动程序：yled.c
   

   //yled.c


   #include <linux/module.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/ioport.h>
#include <linux/fs.h>
#include <linux/slab.h>

#include <asm/io.h>
#include "ypublic.h"

MODULE_LICENSE("Dual BSD/GPL");
#define YMAJOR 100
#define YMINOR 1
#define YDEVICENAME "uartdriver"
#define YBUFSIZE 10
#define UBRDIVn(baud) ()
#define SETB(n) (1<<(n))
#define CLRB(n) (~ SETB(n))
#define SETN(v,n) (v<<n)
#define SETNB(v,d,n,w)\
    ({\
    ulong rs;\
    rs=0xffffffff;\
    rs=rs<<(32-n-w);\
    rs=rs>>(32-w);\
    rs=~(rs<<n);\
    rs=n&rs|(v<<n);\
    rs;\
    })
#if 0
#define uint unsigned int
#define uchar unsigned char
#define ulong unsigned long
#endif


//io

#define UARTBASE(n) (0x50000000+(0x00004000<<(n)))
#define UARTREGNUM 3
#define YUART0 UARTBASE(0)
#define YUART1 UARTBASE(1)
#define YUART2 UARTBASE(2)
#define YINFRARED_MODE SETB(6)
#define YNOPARITY 0
#define Y2STOPBIT SETB(2)
#define Y8BITS SETN(3,0)


typedef struct {
    struct cdev dev;
    uchar inbuf[YBUFSIZE];
    uchar outbuf[YBUFSIZE];
}ycdev;

ycdev *_pdev;
static int _major=YMAJOR;
static struct timer_list _tm;

//io regs

#define GPBBASE 0x56000010
ulong rgpbcon,rgpbdat,rgpbup;


static void* initio(void)
{
    if(request_mem_region(UARTBASE(0),sizeof(YRUart),"UART")==NULL)
        return NULL;
    _uart=(YRUart *)ioremap(UARTBASE(0),sizeof(YRUart));
    return (void*)_uart;
}

void releaseio(void)
{
    if(_uart!=NULL){
        iounmap((void*)UARTBASE(0));
        release_mem_region(UARTBASE(0),sizeof(YRUart));
    }
}
irqreturn_t onIrq(int irq,void *dev_id)
{
    _tm.expires=MS(2000);
    add_timer(&_tm);
    
    return IRQ_HANDLED;
}

void initUart(void)
{
    iowrite32(Y8BITS,&_uart->ULCON);
}

static void onTime(ulong arg)
{

    uint dat;
    dat=ioread32(rgpbdat);
    if(dat&SETB(10)){
        iowrite32((~(SETB(7)|SETB(10)))&dat,rgpbdat);
        }
    else{
        iowrite32(SETB(7)|SETB(10)|dat,rgpbdat);
        }
  
    _tm.expires=MS(2000);
    printk(KERN_INFO "on time:%u\n",dat);
    add_timer(&_tm);
}

int yopen(struct inode *pinode,struct file *pfile)
{
    return 0;
}

int yrelease(struct inode *pinode,struct file *pfile)
{
    return 0;
}

static struct file_operations _fops={
    .open=yopen,
    .release=yrelease,
};

int __init yinit(void)
{
    dev_t devno=MKDEV(YMAJOR,YMINOR);
    int rs;
    uint tmp;
    if(_major){
            rs=register_chrdev_region(devno,1,YDEVICENAME);
        }
    else{
        rs=alloc_chrdev_region(&devno,YMINOR,1,YDEVICENAME);
        _major=MAJOR(devno);
        }
    if(rs<0)return rs;
    _pdev=kmalloc(sizeof(ycdev),GFP_KERNEL);
    if(!_pdev){
        
        rs= -ENOMEM;
        goto fail1;
        }
    cdev_init(&_pdev->dev,&_fops);
    _pdev->dev.owner=THIS_MODULE;
    rs=cdev_add(&_pdev->dev,MKDEV(_major,YMINOR),0);
    if(rs){
        rs=-EBUSY;
        goto fail2;
        }
#if 0
    if(initio()==NULL)
        printk(KERN_ERR"ioremap failed\n");
    else printk(KERN_ERR"ioremap success\n");
#endif
    rgpbcon=yioremap(GPBBASE,12,"gpbreg");
    rgpgcon=yioremap(GPBGASE,12,"gpgreg");
    if(rgpbcon==NULL||rgpgcon==NULL)goto fail2;
    else{
        rgpbdat=rgpbcon+4;
        rgpbup=rgpbcon+8;
        iowrite32(SETN(1,14)|SETN(1,20)|ioread32(rgpbcon),rgpbcon);
        iowrite32(SETB(7)|SETB(10)|ioread32(rgpbup),rgpbup);
        iowrite32(SETB(7)|SETB(10)|ioread32(rgpbdat),rgpbdat);
        if(rs)printk(KERN_INFO"irq failed");
        }
    setup_timer(&_tm,onTime,1);
    
    printk(KERN_INFO "driver ok\n");
    return 0;
fail2:
    kfree(_pdev);
fail1:
    unregister_chrdev_region(devno,1);
    return -EBUSY;
}

void __exit yexit(void)
{
    del_timer(&_tm);
    yiounmap(GPBBASE,12);
    cdev_del(&_pdev->dev);
    kfree(_pdev);
    unregister_chrdev_region(MKDEV(_major,YMINOR),1);
}

MODULE_AUTHOR("MrY");
module_init(yinit);
module_exit(yexit);