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/* SPDX-License-Identifier: GPL-2.0 */
* linux/can/dev.h
* Definitions for the CAN network device driver interface
* Copyright (C) 2006 Andrey Volkov <>
* Varma Electronics Oy
* Copyright (C) 2008 Wolfgang Grandegger <>
#ifndef _CAN_DEV_H
#define _CAN_DEV_H
#include <linux/can.h>
#include <linux/can/error.h>
#include <linux/can/led.h>
#include <linux/can/netlink.h>
#include <linux/netdevice.h>
* CAN mode
enum can_mode {
* CAN common private data
struct can_priv {
struct net_device *dev;
struct can_device_stats can_stats;
struct can_bittiming bittiming, data_bittiming;
const struct can_bittiming_const *bittiming_const,
const u16 *termination_const;
unsigned int termination_const_cnt;
u16 termination;
const u32 *bitrate_const;
unsigned int bitrate_const_cnt;
const u32 *data_bitrate_const;
unsigned int data_bitrate_const_cnt;
struct can_clock clock;
enum can_state state;
/* CAN controller features - see include/uapi/linux/can/netlink.h */
u32 ctrlmode; /* current options setting */
u32 ctrlmode_supported; /* options that can be modified by netlink */
u32 ctrlmode_static; /* static enabled options for driver/hardware */
int restart_ms;
struct delayed_work restart_work;
int (*do_set_bittiming)(struct net_device *dev);
int (*do_set_data_bittiming)(struct net_device *dev);
int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
int (*do_set_termination)(struct net_device *dev, u16 term);
int (*do_get_state)(const struct net_device *dev,
enum can_state *state);
int (*do_get_berr_counter)(const struct net_device *dev,
struct can_berr_counter *bec);
unsigned int echo_skb_max;
struct sk_buff **echo_skb;
struct led_trigger *tx_led_trig;
char tx_led_trig_name[CAN_LED_NAME_SZ];
struct led_trigger *rx_led_trig;
char rx_led_trig_name[CAN_LED_NAME_SZ];
struct led_trigger *rxtx_led_trig;
char rxtx_led_trig_name[CAN_LED_NAME_SZ];
* get_can_dlc(value) - helper macro to cast a given data length code (dlc)
* to __u8 and ensure the dlc value to be max. 8 bytes.
* To be used in the CAN netdriver receive path to ensure conformance with
* ISO 11898-1 Chapter (DLC field)
#define get_can_dlc(i) (min_t(__u8, (i), CAN_MAX_DLC))
#define get_canfd_dlc(i) (min_t(__u8, (i), CANFD_MAX_DLC))
/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
static inline bool can_dropped_invalid_skb(struct net_device *dev,
struct sk_buff *skb)
const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
if (skb->protocol == htons(ETH_P_CAN)) {
if (unlikely(skb->len != CAN_MTU ||
cfd->len > CAN_MAX_DLEN))
goto inval_skb;
} else if (skb->protocol == htons(ETH_P_CANFD)) {
if (unlikely(skb->len != CANFD_MTU ||
cfd->len > CANFD_MAX_DLEN))
goto inval_skb;
} else
goto inval_skb;
return false;
return true;
static inline bool can_is_canfd_skb(const struct sk_buff *skb)
/* the CAN specific type of skb is identified by its data length */
return skb->len == CANFD_MTU;
/* helper to define static CAN controller features at device creation time */
static inline void can_set_static_ctrlmode(struct net_device *dev,
u32 static_mode)
struct can_priv *priv = netdev_priv(dev);
/* alloc_candev() succeeded => netdev_priv() is valid at this point */
priv->ctrlmode = static_mode;
priv->ctrlmode_static = static_mode;
/* override MTU which was set by default in can_setup()? */
if (static_mode & CAN_CTRLMODE_FD)
dev->mtu = CANFD_MTU;
/* get data length from can_dlc with sanitized can_dlc */
u8 can_dlc2len(u8 can_dlc);
/* map the sanitized data length to an appropriate data length code */
u8 can_len2dlc(u8 len);
struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
void free_candev(struct net_device *dev);
/* a candev safe wrapper around netdev_priv */
struct can_priv *safe_candev_priv(struct net_device *dev);
int open_candev(struct net_device *dev);
void close_candev(struct net_device *dev);
int can_change_mtu(struct net_device *dev, int new_mtu);
int register_candev(struct net_device *dev);
void unregister_candev(struct net_device *dev);
int can_restart_now(struct net_device *dev);
void can_bus_off(struct net_device *dev);
void can_change_state(struct net_device *dev, struct can_frame *cf,
enum can_state tx_state, enum can_state rx_state);
void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
unsigned int idx);
unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
void can_free_echo_skb(struct net_device *dev, unsigned int idx);
struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
struct sk_buff *alloc_canfd_skb(struct net_device *dev,
struct canfd_frame **cfd);
struct sk_buff *alloc_can_err_skb(struct net_device *dev,
struct can_frame **cf);
#endif /* !_CAN_DEV_H */