CAN bus的状态

/*
 * CAN operational and error states
 */
enum can_state {
	CAN_STATE_ERROR_ACTIVE = 0,	/* RX/TX error count < 96 */
	CAN_STATE_ERROR_WARNING,	/* RX/TX error count < 128 */
	CAN_STATE_ERROR_PASSIVE,	/* RX/TX error count < 256 */
	CAN_STATE_BUS_OFF,		/* RX/TX error count >= 256 */
	CAN_STATE_STOPPED,		/* Device is stopped */
	CAN_STATE_SLEEPING,		/* Device is sleeping */
	CAN_STATE_MAX
};