/*
   * linux/can.h
   *
   * Definitions for CAN network layer (socket addr / CAN frame / CAN filter)
   *
   * Authors: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
   *          Urs Thuermann   <urs.thuermann@volkswagen.de>
   * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
   * All rights reserved.
   *
   */
  
  #ifndef CAN_H
  #define CAN_H
  
  #include <linux/types.h>
  #include <linux/socket.h>
  
  /* controller area network (CAN) kernel definitions */
  
  /* special address description flags for the CAN_ID */
  #define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */
  #define CAN_RTR_FLAG 0x40000000U /* remote transmission request */
  #define CAN_ERR_FLAG 0x20000000U /* error message frame */
  
  /* valid bits in CAN ID for frame formats */
  #define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
  #define CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */
  #define CAN_ERR_MASK 0x1FFFFFFFU /* omit EFF, RTR, ERR flags */
  
  /*
   * Controller Area Network Identifier structure
   *
   * bit 0-28	: CAN identifier (11/29 bit)
   * bit 29	: error message frame flag (0 = data frame, 1 = error message)
   * bit 30	: remote transmission request flag (1 = rtr frame)
   * bit 31	: frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
   */
  typedef __u32 canid_t;
  
  #define CAN_SFF_ID_BITS		11
  #define CAN_EFF_ID_BITS		29
  
  /*
   * Controller Area Network Error Message Frame Mask structure
   *
   * bit 0-28	: error class mask (see include/linux/can/error.h)
   * bit 29-31	: set to zero
   */
  typedef __u32 can_err_mask_t;
  
  /* CAN payload length and DLC definitions according to ISO 11898-1 */
  #define CAN_MAX_DLC 8
  #define CAN_MAX_DLEN 8
  
  /* CAN FD payload length and DLC definitions according to ISO 11898-7 */
  #define CANFD_MAX_DLC 15
  #define CANFD_MAX_DLEN 64
  
  /**
   * struct can_frame - basic CAN frame structure
   * @can_id:  CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
   * @can_dlc: frame payload length in byte (0 .. 8) aka data length code
   *           N.B. the DLC field from ISO 11898-1 Chapter 8.4.2.3 has a 1:1
   *           mapping of the 'data length code' to the real payload length
   * @data:    CAN frame payload (up to 8 byte)
   */
  struct can_frame {
  	canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
  	__u8    can_dlc; /* frame payload length in byte (0 .. CAN_MAX_DLEN) */
  	__u8    data[CAN_MAX_DLEN] __attribute__((aligned(8)));
  };
  
  /*
   * defined bits for canfd_frame.flags
   *
   * The use of struct canfd_frame implies the Extended Data Length (EDL) bit to
   * be set in the CAN frame bitstream on the wire. The EDL bit switch turns
   * the CAN controllers bitstream processor into the CAN FD mode which creates
   * two new options within the CAN FD frame specification:
   *
   * Bit Rate Switch - to indicate a second bitrate is/was used for the payload
   * Error State Indicator - represents the error state of the transmitting node
   *
   * As the CANFD_ESI bit is internally generated by the transmitting CAN
   * controller only the CANFD_BRS bit is relevant for real CAN controllers when
   * building a CAN FD frame for transmission. Setting the CANFD_ESI bit can make
   * sense for virtual CAN interfaces to test applications with echoed frames.
   */
  #define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */
  #define CANFD_ESI 0x02 /* error state indicator of the transmitting node */
  
  /**
   * struct canfd_frame - CAN flexible data rate frame structure
   * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
   * @len:    frame payload length in byte (0 .. CANFD_MAX_DLEN)
   * @flags:  additional flags for CAN FD
   * @__res0: reserved / padding
   * @__res1: reserved / padding
   * @data:   CAN FD frame payload (up to CANFD_MAX_DLEN byte)
   */
  struct canfd_frame {
  	canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
  	__u8    len;     /* frame payload length in byte */
  	__u8    flags;   /* additional flags for CAN FD */
  	__u8    __res0;  /* reserved / padding */
  	__u8    __res1;  /* reserved / padding */
  	__u8    data[CANFD_MAX_DLEN] __attribute__((aligned(8)));
  };
  
  #define CAN_MTU		(sizeof(struct can_frame))
  #define CANFD_MTU	(sizeof(struct canfd_frame))
  
  /* particular protocols of the protocol family PF_CAN */
  #define CAN_RAW		1 /* RAW sockets */
  #define CAN_BCM		2 /* Broadcast Manager */
  #define CAN_TP16	3 /* VAG Transport Protocol v1.6 */
  #define CAN_TP20	4 /* VAG Transport Protocol v2.0 */
  #define CAN_MCNET	5 /* Bosch MCNet */
  #define CAN_ISOTP	6 /* ISO 15765-2 Transport Protocol */
  #define CAN_NPROTO	7
  
  #define SOL_CAN_BASE 100
  
  /**
   * struct sockaddr_can - the sockaddr structure for CAN sockets
   * @can_family:  address family number AF_CAN.
   * @can_ifindex: CAN network interface index.
   * @can_addr:    protocol specific address information
   */
  struct sockaddr_can {
  	__kernel_sa_family_t can_family;
  	int         can_ifindex;
  	union {
  		/* transport protocol class address information (e.g. ISOTP) */
  		struct { canid_t rx_id, tx_id; } tp;
  
  		/* reserved for future CAN protocols address information */
  	} can_addr;
  };
  
  /**
   * struct can_filter - CAN ID based filter in can_register().
   * @can_id:   relevant bits of CAN ID which are not masked out.
   * @can_mask: CAN mask (see description)
   *
   * Description:
   * A filter matches, when
   *
   *          <received_can_id> & mask == can_id & mask
   *
   * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
   * filter for error message frames (CAN_ERR_FLAG bit set in mask).
   */
  struct can_filter {
  	canid_t can_id;
  	canid_t can_mask;
  };
  
  #define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */
  
  #endif /* CAN_H */