diff options
Diffstat (limited to 'include/linux/can.h')
| -rw-r--r-- | include/linux/can.h | 71 |
1 files changed, 62 insertions, 9 deletions
diff --git a/include/linux/can.h b/include/linux/can.h index 9a19bcb3eeaf..e52958d7c2d1 100644 --- a/include/linux/can.h +++ b/include/linux/can.h @@ -21,7 +21,7 @@ /* 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 frame */ +#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) */ @@ -32,32 +32,85 @@ * Controller Area Network Identifier structure * * bit 0-28 : CAN identifier (11/29 bit) - * bit 29 : error frame flag (0 = data frame, 1 = error frame) + * 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 Frame Mask structure + * 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: the CAN ID of the frame and CAN_*_FLAG flags, see above. - * @can_dlc: the data length field of the CAN frame - * @data: the CAN frame payload. + * @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; /* data length code: 0 .. 8 */ - __u8 data[8] __attribute__((aligned(8))); + __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 */ @@ -97,7 +150,7 @@ struct sockaddr_can { * <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 frames (CAN_ERR_FLAG bit set in mask). + * filter for error message frames (CAN_ERR_FLAG bit set in mask). */ struct can_filter { canid_t can_id; |