《精通Linux設備驅動開發》——i2c協議（代碼1）

/* 代碼清單8-2 */
/* 初始化EEPROM驅動程序 */
/* Driver entry points */
static struct file_operation eep_fops = {
	.owner    = THIS_MODULE,
	.llseek   = eep_llseek,
	.read     = eep_read,
	.ioctl    = eep_ioctl,
	.open     = eep_open,
	.release  = eep_release,
	.write    = eep_write,
};

static dev_t dev_number;		/* Allotted Device Number */
static struct class *eep_class;		/* Device class */

/* Per-device client data structure for each memory bank supported by the driver */

struct eep_bank{
	struct i2c_client *client;	/* i2c client for this bank */
	unsigned int addr;		/* Slave address of this bank */
	unsigned short current_pointer;	/* File pointer */
	int bank_number;		/* Actual memory bank number */
	/* ... */
};

#define NUM_BANKS    2			/* Two supported banks */
#define BANK_SIZE    2048		/* Size of each bank */

struct eep_bank *ee_bank_list;		/* List of private data structures,one per bank */

/* Device Initialization */
int __init eep_init(void)
{
	int err, i;	
	/* Allocate the per-device data structure ,ee_bank */
	ee_bank_list = kmalloc(sizeof(struct ee_bank) * NUM_BANKS, GFP_KERNEL);
	memset(ee_bank_list, 0, sizeof(struct ee_bank) * NUM_BANKS);
	/* Register and create the /dev interfaces to access the EEPROM banks.
	 * Refer back to Chapter 5,"Character Drivers" for more details
	 */
	if( alloc_chrdev_region(&dev_numbers, 0, NUM_BANKS, "eep") < 0 ){
		printk(KERN_DEBUG "Can't register device\n");
		return -1;
	}

	eep_class = class_create(THIS_MODULE, DEVICE_NAME);
	for( i = 0; i < NUM_BANKS, i++ ){
		/* Connect the file operations with cdev */
		cdev_init(&ee_bank[i].cdev, &eep_fops);

		/* Connect the major/minor number to the cdev */
		if( cdev_add(&ee_bank[i].cdev, (dev_number + i), 1) ){
			printk("Bad kmalloc\n");
			return 1;
		}
		device_create(eep_class, NULL, MKDEV(MAJOR) (dev_number), i),
		    "eeprom%d", i );
	}
     /* Inform the i2c core about out existence.See the section 
      "Probing the Device" for the definition of eep_driver */
       
        err = i2c_add_driver(&eep_driver);
	
	if( err ){
	    printk("Registering I2C driver failed, errno is %d\n", err);
	    return err;
	 }

	printk("EEPROM Driver Initialized.\n");
	return 0;
}