Linux I2C驱动注册详解

#define i2c_add_driver(driver) \
       i2c_register_driver(THIS_MODULE, driver)

int i2c_register_driver(struct module *owner, struct i2c_driver *driver)

static int __devinit zsl_i2c_drv_probe(struct i2c_client *client, const struct i2c_device_id *id)
{	
	struct property *pp = NULL;
	uint8_t buf[4];
	struct i2c_msg msgs[2] = {{0}, {0}};
	int len = sizeof(msgs) / sizeof(msgs[0]);

	printk(KERN_INFO "%s: %x\n",__func__,client->addr);

	pp = of_find_property(client->dev.of_node, "testdata", NULL);
	if (pp)
		printk(KERN_INFO "%s: %d:%s \n",__func__,pp->length,(char *)pp->value);
	
	dump_stack();

	if (client->adapter)
	{
		buf[0] = 0;
		buf[1] = 4;
		buf[2] = 0;
		buf[3] = 0;
		memset(msgs,0,sizeof(struct i2c_msg)*2);
		msgs[0].addr  = client->addr;
		msgs[0].flags = 0x0;
		msgs[0].len   = 2;
		msgs[0].buf   = buf;
		
		msgs[1].addr  = client->addr;
		msgs[1].flags = I2C_M_RD;
		msgs[1].len   = 4;
		msgs[1].buf   = buf;

		if (i2c_transfer(client->adapter, msgs,	len) == len)
			printk(KERN_INFO "zsl i2c_transfer r: %d:%x %x %x %x\n",len,buf[0],buf[1],buf[2],buf[3]);
		
		buf[0] = 0;
		buf[1] = 4;
		buf[2] = 7;
		buf[3] = 8;

		memset(msgs,0,sizeof(struct i2c_msg)*2);
		msgs[0].addr = client->addr;
		msgs[0].flags = 0;
		msgs[0].len = 4;
		msgs[0].buf = buf;
		
		if (i2c_transfer(client->adapter, msgs,	1) == 1)
			printk(KERN_INFO "zsl i2c_transfer w: %d:%x %x %x %x\n",1,buf[0],buf[1],buf[2],buf[3]);

		buf[0] = 0;
		buf[1] = 4;
		buf[2] = 0;
		buf[3] = 0;
		memset(msgs,0,sizeof(struct i2c_msg)*2);
		msgs[0].addr  = client->addr;
		msgs[0].flags = 0x0;
		msgs[0].len   = 2;
		msgs[0].buf   = buf;
		
		msgs[1].addr  = client->addr;
		msgs[1].flags = I2C_M_RD;
		msgs[1].len   = 4;
		msgs[1].buf   = buf;
		msleep(100);
		len = i2c_transfer(client->adapter, msgs, len);
		if (2 == len)
			printk(KERN_INFO "zsl i2c_transfer r: %d:%x %x %x %x\n",len,buf[0],buf[1],buf[2],buf[3]);				
	}
	
    return 0;
}
 
static void __devexit zsl_i2c_drv_remove(struct i2c_client *client)
{
	printk(KERN_INFO "%s: \n",__func__);
}
 
static const struct i2c_device_id zsl_dev_id_table[] = {
    { "zsl_i2c_dev", 0 },
    {}
};//这里的名字很重要，驱动第一种匹配设备的方式要用到
 
static const struct of_device_id zsl_of_match_ids[] = {
	{ .compatible = "i2c_name,zsl",		.data = NULL },
	{ /* END OF LIST */ } //最后一项为空，用于判断数组遍历完成
};

static struct i2c_driver zsl_i2c_driver = {
    .driver        = {
        .name        = "zsl_i2c",
        .owner        = THIS_MODULE,
        .of_match_table = zsl_of_match_ids,//设备树匹配用
    },
    .probe		= zsl_i2c_drv_probe,
    .remove		= __devexit_p(zsl_i2c_drv_remove),
    .id_table	= zsl_dev_id_table,  //设备树不需要，i2c_register_board_info匹配使用
};

void zsl_i2c_drv_init(void)
{
    i2c_add_driver(&zsl_i2c_driver);
}

static struct i2c_board_info zsl_i2c_dev = {
    I2C_BOARD_INFO("zsl_i2c_dev", 0x50),//这个名字很重要，用于匹配 I2C 驱动
};

static struct i2c_client *zsl_i2c_client;

void zsl_i2c_dev_init(void)
{
       i2c_register_board_info(4, &zsl_i2c_dev, 1);
}

&i2c4 {
       zsli2c0: zsli2c@50 {
              compatible = "i2c_name,zsl";
              status = "okay";
              testdata = "asdfg";
              reg = <0x50>;
       };
};