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分类: LINUX

2010-08-18 16:34:02

【飞凌】platform_device + miscdevice 模式的LED驱动程序

本文转引自 飞凌嵌入式 Linux技术交流区

感谢作者朋友的分享精神!

这是我最近学习Linux驱动模型的成果,发出来大家共同学习一下,该程序还有很多缺陷,希望高手能不吝赐教
#include

MODULE_AUTHOR("YUZIQIANG");
MODULE_DESCRIPTION("LEDS DRIVE");
MODULE_VERSION("0.1");
MODULE_LICENSE("GPL");
#define DEV_NAME        "FL2440LED"

#define LED_MAGIC        'L'
#define LED_ON                _IOW(LED_MAGIC,0,int)
#define LED_OFF                _IOW(LED_MAGIC,1,int)
#define LED_MINOR        125
#define LED_MAJOR        10       
#define LED_CON                0
#define LED_DAT                4
#define LED_UP                8


int major;
dev_t devNu;
struct cdev ledCdev ;
void   *ledbase;


ssize_t  led_read(struct file *filp,char __user *buffer,size_t size,loff_t *offset);
ssize_t  led_write(struct file *filp,const char __user *buffer,size_t size,loff_t *offset);
int led_open(struct inode *inode,struct file *filp);
int led_release(struct inode *inode,struct file *filp);
int led_ioctl(struct inode *inode,struct file *filp,unsigned int cmd,unsigned long arg);
static int led_probe(struct platform_device *pdev);
static int led_remove(struct platform_device *pdev);

 

struct resource        s3c_led_resource[]        ={
        [0]={
                .start        =        0x56000010,
                .end                =        0x5600001b,
                .flags        =        IORESOURCE_MEM,
                }
        };
       
               
struct file_operations led_opt ={
        .owner                =        THIS_MODULE,
        .ioctl                =        led_ioctl,
        .open                =        led_open,
        .read                =        led_read,
        .write                =        led_write,
        .release        =        led_release,
};

static struct miscdevice misc_led ={
        .minor        =        LED_MINOR,
        .name        =        "led",
        .fops        =        &led_opt,
};

struct platform_device  ledDevice= {
        .name        =        "led",
        .id                =        -1,//why
        .num_resources        =        ARRAY_SIZE(s3c_led_resource),
        .resource        =        s3c_led_resource,
        .dev                        =        {
                .release        =        led_release,
        }
        };


struct platform_driver         ledDriver ={
        .probe        =        led_probe,
        .remove        =        led_remove,
        .driver        =        {
                .owner        =        THIS_MODULE,
                .name        =        "led",
                }
        };
       
       
int led_open(struct inode *inode,struct file *filp)
{
       
        //GPBCON        =        0x55555555;
        writel(0x55555555,ledbase+LED_CON);
        //GPBUP        =        0xffffffff;
        writel(0,ledbase+LED_UP);
        writel(0,ledbase+LED_DAT);
        //GPBDAT        =        0x00000000;
        printk("\nopen success \n");
        return 0;
}

ssize_t  led_read(struct file *filp,char __user *buffer,size_t size,loff_t *offset)
{
        return 0;
}

ssize_t  led_write(struct file *filp,const char __user *buffer,size_t size,loff_t *offset)
{
        return 0;
}

int led_release(struct inode *inode,struct file *filp)
{

        return 0;
}

int led_ioctl(struct inode *inode,struct file *filp,unsigned int cmd,unsigned long arg)
{

        unsigned long tmp;
        int pin=0;
///check the command is in the right form
        if(arg>4||arg<1)
                return -1;
        if(_IOC_NR(cmd)>1||_IOC_NR(cmd)<0)
                return -1;
if(arg==1)
        pin=5;
else if(arg==2)
        pin = 6;
else if(arg==3)
        pin=8;
else if(arg==4)
        pin=10;
        else pin= 0;
                do {
                        if(cmd==LED_ON)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp &=(~(1<
                                writel(tmp,ledbase +LED_DAT);
                                }
                        else if(cmd==LED_OFF)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp |=(1<
                                writel(tmp,ledbase +LED_DAT);
                                }
                        else
                                printk("command error");
                        break;
                        }
                        while(0);
///command switch
/*
        switch (arg) {
                case 1:
                        if(cmd==LED_ON)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp &=(~(1<<5));
                                writel(tmp,ledbase +LED_DAT);
                                }

       else if(cmd==LED_OFF)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp |=(1<<5);
                                writel(tmp,ledbase +LED_DAT);
                                }
                        else
                                printk("command error");
                        break;
                case 2:
                        if(cmd==LED_ON)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp &=(~(1<<6));
                                writel(tmp,ledbase +LED_DAT);
                                }
                        else if(cmd==LED_OFF)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp |=(1<<6);
                                writel(tmp,ledbase +LED_DAT);
                                }
                        else
                                printk("command error");
                        break;
                case 3:
                        if(cmd==LED_ON)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp &=(~(1<<8));
                                writel(tmp,ledbase +LED_DAT);
                                }
                        else if(cmd==LED_OFF)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp |=(1<<8);
                                writel(tmp,ledbase +LED_DAT);
                                }
                        else
                                printk("command error");
                        break;
                case 4:
                        if(cmd==LED_ON)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp &=(~(1<<10));
                                writel(tmp,ledbase +LED_DAT);
                                }
                        else if(cmd==LED_OFF)
                        {
                                tmp        =        readl(ledbase+LED_DAT);
                                tmp |=(1<<10);
                                writel(tmp,ledbase +LED_DAT);
                                }
                        else
                                printk("command error");
                        break;
                default :
                        printk("error");
                                break;
                }
                */
        return 0;
}

static int led_probe(struct platform_device *pdev)
{
        struct resource *res;
        struct device *dev;
        int size;
        int ret;
        dev=&pdev->dev;
        printk("\nMatch success");
        res=        platform_get_resource(pdev,IORESOURCE_MEM,0);
        if(res==NULL)
        {
                dev_err(dev,"no memory resource specified\n");
                return -ENOENT;
                }
        size        =        res->end-res->start +1;

        ledbase        =        ioremap(res->start,size);
        if(ledbase==NULL)
        {
        dev_err(dev,"fail to ioremap() region\n");
        ret=-EINVAL;
        goto err_req;
        }
        ret=misc_register(&misc_led);
        if(ret)
        {
                dev_err(dev,"cannot register led  miscdev ");
                goto err_misc;
                }

        err_misc:
                iounmap(ledbase);
        err_req:


        return ret;
        }


static int led_remove(struct platform_device *pdev)
{
        //iounmap(ledbase);这一句有问题,加上就会出现oops
        misc_deregister(&misc_led);
        return 0;
        }
       
int __init ledInit(void)
{
        //int ret;
         //struct class *ledClass = class_create(THIS_MODULE,"ledClass");
        //alloc_chrdev_region(&devNu,0,1,DEV_NAME);
        major = LED_MAJOR;
        printk("\nMAJOR is %d\n",major);
        devNu        =        MKDEV(LED_MAJOR,LED_MINOR);
        //regist miscdevice
        //misc_register(&misc_led);
        //cdev_init(&ledCdev,&led_opt);
        //ledCdev.owner = THIS_MODULE;
        //ledCdev.ops = &led_opt;
        //cdev_add(&ledCdev,devNu,1);
        //AUTOMATIC CREATE DEVICE FILE IN /dev
        platform_device_register(&ledDevice);
        platform_driver_register(&ledDriver);
        //device_create(ledClass,NULL,devNu,NULL,"led");
        //在platform_device的总线中注册设备时,会自动在/dev/下面生成设备文件,
        //所以在这里若果在调用device_create就会出错
        //在platform_device_register中会创建/dev/下面的设备文件
        //并且在调用platform_device_unregister的时候也会自动删除/dev/下面创建的设备文件。
        return 0;
}

void __exit ledExit(void)
{
        //cdev_del(&ledCdev);
        //unregister_chrdev_region(devNu,1);
       
        //misc_deregister(&misc_led);
        platform_driver_unregister(&ledDriver);
        platform_device_unregister(&ledDevice);
       
}
module_init(ledInit);
module_exit(ledExit);

PS:

虽然有点大材小用,但是用来熟悉platform——device还是不错的。



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