Commit 7c941636 authored by Oliver Hartkopp's avatar Oliver Hartkopp Committed by Marc Kleine-Budde
Browse files

canfd: add new data structures and constants 



- add new struct canfd_frame
- check identical element offsets in struct can_frame and struct canfd_frame
- new ETH_P_CANFD definition to tag CAN FD skbs correctly
- add CAN_MTU and CANFD_MTU definitions for easy frame and mode detection
- add CAN[FD]_MAX_[DLC|DLEN] helper constants to remove hard coded values
- update existing struct can_frame with helper constants and comments

Signed-off-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 5b92da04

include/linux/can.h

+54 −5
Original line number Diff line number Diff line
@@ -46,18 +46,67 @@ typedef __u32 canid_t; 
 */

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

 *

 * As the default for CAN FD should be to support the high data rate in the

 * payload section of the frame (HDR) and to support up to 64 byte in the

 * data section (EDL) the bits are only set in the non-default case.

 * Btw. as long as there's no real implementation for CAN FD network driver

 * these bits are only preliminary.

 *

 * RX: NOHDR/NOEDL - info about received CAN FD frame

 *     ESI         - bit from originating CAN controller

 * TX: NOHDR/NOEDL - control per-frame settings if supported by CAN controller

 *     ESI         - bit is set by local CAN controller

 */

#define CANFD_NOHDR 0x01 /* frame without high data rate */

#define CANFD_NOEDL 0x02 /* frame without extended data length */

#define CANFD_ESI   0x04 /* error state indicator */



/**

 * 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 */

include/linux/if_ether.h

+2 −1
Original line number Diff line number Diff line
@@ -105,7 +105,8 @@ 
#define ETH_P_WAN_PPP   0x0007          /* Dummy type for WAN PPP frames*/

#define ETH_P_PPP_MP    0x0008          /* Dummy type for PPP MP frames */

#define ETH_P_LOCALTALK 0x0009		/* Localtalk pseudo type 	*/

#define ETH_P_CAN	0x000C		/* Controller Area Network      */

#define ETH_P_CAN	0x000C		/* CAN: Controller Area Network */

#define ETH_P_CANFD	0x000D		/* CANFD: CAN flexible data rate*/

#define ETH_P_PPPTALK	0x0010		/* Dummy type for Atalk over PPP*/

#define ETH_P_TR_802_2	0x0011		/* 802.2 frames 		*/

#define ETH_P_MOBITEX	0x0015		/* Mobitex (kaz@cafe.net)	*/

net/can/af_can.c

+7 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 
 */



#include <linux/module.h>

#include <linux/stddef.h>

#include <linux/init.h>

#include <linux/kmod.h>

#include <linux/slab.h>
@@ -824,6 +825,12 @@ static struct notifier_block can_netdev_notifier __read_mostly = { 


static __init int can_init(void)

{

	/* check for correct padding to be able to use the structs similarly */

	BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=

		     offsetof(struct canfd_frame, len) ||

		     offsetof(struct can_frame, data) !=

		     offsetof(struct canfd_frame, data));



	printk(banner);



	memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));

CRA Git | Maintained and supported by SUSTech CRA and CCSE