/* 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 #include #include #include #include #include /* * CAN mode */ enum can_mode { CAN_MODE_STOP = 0, CAN_MODE_START, CAN_MODE_SLEEP }; /* * 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, *data_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; #ifdef CONFIG_CAN_LEDS 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]; #endif }; /* * 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 8.4.2.3 (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)) /* Check for outgoing skbs that have not been created by the CAN subsystem */ static inline bool can_skb_headroom_valid(struct net_device *dev, struct sk_buff *skb) { /* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */ if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv))) return false; /* af_packet does not apply CAN skb specific settings */ if (skb->ip_summed == CHECKSUM_NONE) { /* init headroom */ can_skb_prv(skb)->ifindex = dev->ifindex; can_skb_prv(skb)->skbcnt = 0; skb->ip_summed = CHECKSUM_UNNECESSARY; /* preform proper loopback on capable devices */ if (dev->flags & IFF_ECHO) skb->pkt_type = PACKET_LOOPBACK; else skb->pkt_type = PACKET_HOST; skb_reset_mac_header(skb); skb_reset_network_header(skb); skb_reset_transport_header(skb); } return true; } /* 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; if (!can_skb_headroom_valid(dev, skb)) goto inval_skb; return false; inval_skb: kfree_skb(skb); dev->stats.tx_dropped++; 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); struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr); 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 */