1/*
2 * linux/can.h
3 *
4 * Definitions for CAN network layer (socket addr / CAN frame / CAN filter)
5 *
6 * Authors: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
7 *          Urs Thuermann   <urs.thuermann@volkswagen.de>
8 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
9 * All rights reserved.
10 *
11 */
12
13#ifndef CAN_H
14#define CAN_H
15
16#include <linux/types.h>
17#include <linux/socket.h>
18
19/* controller area network (CAN) kernel definitions */
20
21/* special address description flags for the CAN_ID */
22#define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */
23#define CAN_RTR_FLAG 0x40000000U /* remote transmission request */
24#define CAN_ERR_FLAG 0x20000000U /* error message frame */
25
26/* valid bits in CAN ID for frame formats */
27#define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
28#define CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */
29#define CAN_ERR_MASK 0x1FFFFFFFU /* omit EFF, RTR, ERR flags */
30
31/*
32 * Controller Area Network Identifier structure
33 *
34 * bit 0-28	: CAN identifier (11/29 bit)
35 * bit 29	: error message frame flag (0 = data frame, 1 = error message)
36 * bit 30	: remote transmission request flag (1 = rtr frame)
37 * bit 31	: frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
38 */
39typedef __u32 canid_t;
40
41#define CAN_SFF_ID_BITS		11
42#define CAN_EFF_ID_BITS		29
43
44/*
45 * Controller Area Network Error Message Frame Mask structure
46 *
47 * bit 0-28	: error class mask (see include/linux/can/error.h)
48 * bit 29-31	: set to zero
49 */
50typedef __u32 can_err_mask_t;
51
52/* CAN payload length and DLC definitions according to ISO 11898-1 */
53#define CAN_MAX_DLC 8
54#define CAN_MAX_DLEN 8
55
56/* CAN FD payload length and DLC definitions according to ISO 11898-7 */
57#define CANFD_MAX_DLC 15
58#define CANFD_MAX_DLEN 64
59
60/**
61 * struct can_frame - basic CAN frame structure
62 * @can_id:  CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
63 * @can_dlc: frame payload length in byte (0 .. 8) aka data length code
64 *           N.B. the DLC field from ISO 11898-1 Chapter 8.4.2.3 has a 1:1
65 *           mapping of the 'data length code' to the real payload length
66 * @data:    CAN frame payload (up to 8 byte)
67 */
68struct can_frame {
69	canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
70	__u8    can_dlc; /* frame payload length in byte (0 .. CAN_MAX_DLEN) */
71	__u8    data[CAN_MAX_DLEN] __attribute__((aligned(8)));
72};
73
74/*
75 * defined bits for canfd_frame.flags
76 *
77 * The use of struct canfd_frame implies the Extended Data Length (EDL) bit to
78 * be set in the CAN frame bitstream on the wire. The EDL bit switch turns
79 * the CAN controllers bitstream processor into the CAN FD mode which creates
80 * two new options within the CAN FD frame specification:
81 *
82 * Bit Rate Switch - to indicate a second bitrate is/was used for the payload
83 * Error State Indicator - represents the error state of the transmitting node
84 *
85 * As the CANFD_ESI bit is internally generated by the transmitting CAN
86 * controller only the CANFD_BRS bit is relevant for real CAN controllers when
87 * building a CAN FD frame for transmission. Setting the CANFD_ESI bit can make
88 * sense for virtual CAN interfaces to test applications with echoed frames.
89 */
90#define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */
91#define CANFD_ESI 0x02 /* error state indicator of the transmitting node */
92
93/**
94 * struct canfd_frame - CAN flexible data rate frame structure
95 * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
96 * @len:    frame payload length in byte (0 .. CANFD_MAX_DLEN)
97 * @flags:  additional flags for CAN FD
98 * @__res0: reserved / padding
99 * @__res1: reserved / padding
100 * @data:   CAN FD frame payload (up to CANFD_MAX_DLEN byte)
101 */
102struct canfd_frame {
103	canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
104	__u8    len;     /* frame payload length in byte */
105	__u8    flags;   /* additional flags for CAN FD */
106	__u8    __res0;  /* reserved / padding */
107	__u8    __res1;  /* reserved / padding */
108	__u8    data[CANFD_MAX_DLEN] __attribute__((aligned(8)));
109};
110
111#define CAN_MTU		(sizeof(struct can_frame))
112#define CANFD_MTU	(sizeof(struct canfd_frame))
113
114/* particular protocols of the protocol family PF_CAN */
115#define CAN_RAW		1 /* RAW sockets */
116#define CAN_BCM		2 /* Broadcast Manager */
117#define CAN_TP16	3 /* VAG Transport Protocol v1.6 */
118#define CAN_TP20	4 /* VAG Transport Protocol v2.0 */
119#define CAN_MCNET	5 /* Bosch MCNet */
120#define CAN_ISOTP	6 /* ISO 15765-2 Transport Protocol */
121#define CAN_NPROTO	7
122
123#define SOL_CAN_BASE 100
124
125/**
126 * struct sockaddr_can - the sockaddr structure for CAN sockets
127 * @can_family:  address family number AF_CAN.
128 * @can_ifindex: CAN network interface index.
129 * @can_addr:    protocol specific address information
130 */
131struct sockaddr_can {
132	__kernel_sa_family_t can_family;
133	int         can_ifindex;
134	union {
135		/* transport protocol class address information (e.g. ISOTP) */
136		struct { canid_t rx_id, tx_id; } tp;
137
138		/* reserved for future CAN protocols address information */
139	} can_addr;
140};
141
142/**
143 * struct can_filter - CAN ID based filter in can_register().
144 * @can_id:   relevant bits of CAN ID which are not masked out.
145 * @can_mask: CAN mask (see description)
146 *
147 * Description:
148 * A filter matches, when
149 *
150 *          <received_can_id> & mask == can_id & mask
151 *
152 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
153 * filter for error message frames (CAN_ERR_FLAG bit set in mask).
154 */
155struct can_filter {
156	canid_t can_id;
157	canid_t can_mask;
158};
159
160#define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */
161
162#endif /* CAN_H */
163