/*  leddrv.c - Create an input/output character device */#include <linux/kernel.h>#include <linux/module.h>#include <linux/fs.h>#include <linux/errno.h> 	/* for -EBUSY */#include <linux/ioport.h>	/* for verify_area */#include <linux/init.h>		/* for module_init */#include <asm/uaccess.h>  	/* for get_user and put_user */#include <asm-arm/arch-s3c2410/S3C2410.h>#include <asm-arm/io.h>         //這個頭文件包含了io地址映射的函數#include "drv.h"#define 	DEVICE_NAME 	"char_dev"unsigned long *remapedadd;    //用來保存重新映射后的虛擬地址的起始地址/************************************************************************************///下面這段代碼是從ADT的LEDDEMO中拷貝過來的static int 	Device_Open = 0;#define U8 unsigned charunsigned char seg7table[16] = {    /* 0       1       2       3       4       5       6      7*/    0xc0,   0xf9,   0xa4,   0xb0,   0x99,   0x92,   0x82,   0xf8,    /* 8       9      A        B       C       D       E      F*/    0x80,   0x90,   0x88,   0x83,   0xc6,   0xa1,   0x86,   0x8e,};static void Test_Seg7(unsigned char i) {    		if((i>=0)&&(i<=15))          {	     *(remapedadd+2) = 0x00;			//outb(0x00,(remapedadd+2));		    	*remapedadd = seg7table[i];                   // outb(i,remapedadd);		 }}/*************************************************************************************/int 	device_ioctl(struct inode *,struct file *,unsigned int ,unsigned long ); 	/* This function is called whenever a process attempts  * to open the device file */static int device_open(struct inode *inode, struct file *file){  printk("Device Open\n");  /* We don't want to talk to two processes at the    * same time */  if (Device_Open) return -EBUSY;  Device_Open++;  MOD_INC_USE_COUNT;  return 0;}/* This function is called when a process closes the  * device file. It doesn't have a return value because  * it cannot fail. Regardless of what else happens, you  * should always be able to close a device (in 2.0, a 2.2 * device file could be impossible to close). */static int device_release(struct inode *inode, struct file *file){  printk(("device_release\n"));  /* We're now ready for our next caller */  Device_Open --;  MOD_DEC_USE_COUNT;  return 0;}//static int flags = 0xff;/* This function is called whenever a process which  * has already opened the device file attempts to  * read from it. */static ssize_t device_read(    struct file *file,    char *buffer, 		/* The buffer to fill with the data */       size_t length,     	/* The length of the buffer */    loff_t *offset) 	/* offset to the file */{    return 0;}/* This function is called when somebody tries to  * write into our device file. */ static ssize_t device_write(struct file *file, const char *buffer, size_t length, loff_t *offset){  char 	value;  int 	bytes_writes = 1;  char* data = (char*)buffer;  get_user(value, data);    Test_Seg7(value);  /* Again, return the number of input characters used */  return bytes_writes;};/* This function is called whenever a process tries to  * do an ioctl on our device file. We get two extra  * parameters (additional to the inode and file  * structures, which all device functions get): the number * of the ioctl called and the parameter given to the  * ioctl function. * * If the ioctl is write or read/write (meaning output  * is returned to the calling process), the ioctl call  * returns the output of this function. */int device_ioctl(    struct inode *inode,    struct file *file,    unsigned int ioctl_num,/* The number of the ioctl */    unsigned long ioctl_param) /* The parameter to it */{  return 0;};/* Module Declarations *************************** *//* This structure will hold the functions to be called  * when a process does something to the device we  * created. Since a pointer to this structure is kept in  * the devices table, it can't be local to * init_module. NULL is for unimplemented functions. */struct file_operations Fops = {	.read 		= device_read, 	.write 		= device_write,	.open 		= device_open,	.release 	= device_release,	.ioctl		= device_ioctl	};/* Initialize the module - Register the character device */static int __init led_module_init( void ){    	int ret_val;    /* Register the character device (atleast try) */  ret_val = register_chrdev(MAJOR_NUM, DEVICE_NAME, &Fops);  /* Negative values signify an error */  if (ret_val < 0) {    printk ("%s failed with %d\n",            "Sorry, registering the character device ",            ret_val);    return ret_val;  }    printk ("%s The major device number is %d.\n",          "Registeration is a success",           MAJOR_NUM);  remapedadd=ioremap(0x10000004,4);          printk ("If you want to talk to the device driver,\n");  printk ("you'll have to create a device file. \n");  printk ("We suggest you use:\n");  printk ("mknod /dev/%s c %d 0\n", DEVICE_FILE_NAME,MAJOR_NUM);  printk ("The device file name is important, because\n");  Test_Seg7(0) ;  return 0;};/* Cleanup - unregister the appropriate file from /proc */static void __exit led_module_cleanup(void){  int ret;//  release_region(LED_BASE, 12);  /* Unregister the device */  ret = unregister_chrdev(MAJOR_NUM, DEVICE_NAME);  /* If there's an error, report it */   if (ret < 0)    printk("Error in module_unregister_chrdev: %d\n", ret);  iounmap(remapedadd);};module_init(led_module_init);module_exit(led_module_cleanup);MODULE_LICENSE("GPL");MODULE_AUTHOR("gh");MODULE_DESCRIPTION("LED char driver");