#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <asm/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <asm/unistd.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <linux/ioport.h>

#include "bcm2835.h"

// Blinks on RPi Plug P1 pin 11 (which is GPIO pin 17)
#define PIN RPI_GPIO_P1_11

int open_state = 0;         //檔案開啟狀態

static int leds_open(struct inode *inode, struct file *filp)
{
    if(open_state == 0)  
    {  
        open_state =  1;  
        printk("Open file suc!\n");  
        return 0;  
    }  
    else  
    {  
        printk("The file has opened!\n");  
        return -1;  
    }  
}

static int leds_ioctl(struct file*filp, unsigned int cmd, unsigned long arg)
{
    switch(cmd)  
    {  
        case 0:  
            bcm2835_gpio_clr(PIN);
            printk("LED OFF!\n");
            break;  
        case 1:  
            bcm2835_gpio_set(PIN);
            printk("LED ON!\n");
            break;  

        default:  
            return-EINVAL;  
    }  

    return 0;
}

static int leds_release(struct inode *inode, struct file *filp)
{
    if(open_state == 1)  
    {  
        open_state =  0;  
        printk("close file suc!\n");  
        return 0;  
    }  
    else  
    {  
        printk("The file has closed!\n");  
        return -1;  
    }  
}

static const struct file_operations leds_fops = {
    .owner = THIS_MODULE,
    .open = leds_open,
    .unlocked_ioctl = leds_ioctl,
    .release = leds_release,
};

static struct miscdevice misc = {
    .minor =MISC_DYNAMIC_MINOR,
    .name ="my_leds",
    .fops =&leds_fops,
};


static int __init leds_init(void)
{
    int ret;

    //註冊混雜裝置
    ret =misc_register(&misc);

    //配置功能選擇暫存器為輸出
    bcm2835_gpio_fsel(PIN, BCM2835_GPIO_FSEL_OUTP);

    //設定輸出電平為高電平，LED亮
    bcm2835_gpio_set(PIN);

    printk("ledsinit.\n");
    return ret;
}

static void leds_exit(void)
{
    //LED滅
    bcm2835_gpio_clr(PIN);

    misc_deregister(&misc);        

    printk("leds_exit\n");
}

module_init(leds_init);
module_exit(leds_exit);

MODULE_AUTHOR("Hu Chunxu");
MODULE_LICENSE("GPL");