int (*txdata)(struct device *dev, struct sk_buff *skb);
int (*txctl)(struct device *dev, unsigned char *msg, uint len);
int (*rxctl)(struct device *dev, unsigned char *msg, uint len);
int (*txdata)(struct device *dev, struct sk_buff *skb);
int (*txctl)(struct device *dev, unsigned char *msg, uint len);
int (*rxctl)(struct device *dev, unsigned char *msg, uint len);