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![Vincent Mailhol](/assets/img/avatar_default.png)
Rename macro CAN_CALC_SYNC_SEG to CAN_SYNC_SEG and make it available through include/linux/can/dev.h Add an helper function can_bit_time() which returns the duration (in time quanta) of one CAN bit. Rationale for this patch: the sync segment and the bit time are two concepts which are defined in the CAN ISO standard. Device drivers for CAN might need those. Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for additional information. Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20201002154219.4887-6-mailhol.vincent@wanadoo.fr [mkl: Let can_bit_time() return an unsinged int, make argument const] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
238 lines
6.8 KiB
C
238 lines
6.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* linux/can/dev.h
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*
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* Definitions for the CAN network device driver interface
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*
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* Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
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* Varma Electronics Oy
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*
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* Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
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*
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*/
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#ifndef _CAN_DEV_H
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#define _CAN_DEV_H
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#include <linux/can.h>
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#include <linux/can/error.h>
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#include <linux/can/led.h>
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#include <linux/can/netlink.h>
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#include <linux/can/skb.h>
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#include <linux/netdevice.h>
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/*
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* CAN mode
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*/
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enum can_mode {
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CAN_MODE_STOP = 0,
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CAN_MODE_START,
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CAN_MODE_SLEEP
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};
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/*
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* CAN common private data
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*/
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struct can_priv {
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struct net_device *dev;
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struct can_device_stats can_stats;
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struct can_bittiming bittiming, data_bittiming;
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const struct can_bittiming_const *bittiming_const,
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*data_bittiming_const;
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const u16 *termination_const;
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unsigned int termination_const_cnt;
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u16 termination;
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const u32 *bitrate_const;
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unsigned int bitrate_const_cnt;
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const u32 *data_bitrate_const;
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unsigned int data_bitrate_const_cnt;
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u32 bitrate_max;
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struct can_clock clock;
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enum can_state state;
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/* CAN controller features - see include/uapi/linux/can/netlink.h */
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u32 ctrlmode; /* current options setting */
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u32 ctrlmode_supported; /* options that can be modified by netlink */
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u32 ctrlmode_static; /* static enabled options for driver/hardware */
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int restart_ms;
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struct delayed_work restart_work;
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int (*do_set_bittiming)(struct net_device *dev);
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int (*do_set_data_bittiming)(struct net_device *dev);
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int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
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int (*do_set_termination)(struct net_device *dev, u16 term);
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int (*do_get_state)(const struct net_device *dev,
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enum can_state *state);
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int (*do_get_berr_counter)(const struct net_device *dev,
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struct can_berr_counter *bec);
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unsigned int echo_skb_max;
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struct sk_buff **echo_skb;
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#ifdef CONFIG_CAN_LEDS
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struct led_trigger *tx_led_trig;
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char tx_led_trig_name[CAN_LED_NAME_SZ];
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struct led_trigger *rx_led_trig;
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char rx_led_trig_name[CAN_LED_NAME_SZ];
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struct led_trigger *rxtx_led_trig;
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char rxtx_led_trig_name[CAN_LED_NAME_SZ];
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#endif
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};
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#define CAN_SYNC_SEG 1
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/*
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* can_bit_time() - Duration of one bit
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*
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* Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for
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* additional information.
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*
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* Return: the number of time quanta in one bit.
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*/
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static inline unsigned int can_bit_time(const struct can_bittiming *bt)
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{
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return CAN_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2;
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}
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/*
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* get_can_dlc(value) - helper macro to cast a given data length code (dlc)
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* to u8 and ensure the dlc value to be max. 8 bytes.
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*
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* To be used in the CAN netdriver receive path to ensure conformance with
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* ISO 11898-1 Chapter 8.4.2.3 (DLC field)
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*/
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#define get_can_dlc(i) (min_t(u8, (i), CAN_MAX_DLC))
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#define get_canfd_dlc(i) (min_t(u8, (i), CANFD_MAX_DLC))
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/* Check for outgoing skbs that have not been created by the CAN subsystem */
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static inline bool can_skb_headroom_valid(struct net_device *dev,
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struct sk_buff *skb)
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{
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/* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */
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if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv)))
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return false;
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/* af_packet does not apply CAN skb specific settings */
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if (skb->ip_summed == CHECKSUM_NONE) {
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/* init headroom */
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can_skb_prv(skb)->ifindex = dev->ifindex;
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can_skb_prv(skb)->skbcnt = 0;
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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/* perform proper loopback on capable devices */
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if (dev->flags & IFF_ECHO)
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skb->pkt_type = PACKET_LOOPBACK;
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else
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skb->pkt_type = PACKET_HOST;
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skb_reset_mac_header(skb);
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skb_reset_network_header(skb);
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skb_reset_transport_header(skb);
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}
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return true;
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}
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/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
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static inline bool can_dropped_invalid_skb(struct net_device *dev,
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struct sk_buff *skb)
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{
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const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
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if (skb->protocol == htons(ETH_P_CAN)) {
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if (unlikely(skb->len != CAN_MTU ||
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cfd->len > CAN_MAX_DLEN))
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goto inval_skb;
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} else if (skb->protocol == htons(ETH_P_CANFD)) {
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if (unlikely(skb->len != CANFD_MTU ||
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cfd->len > CANFD_MAX_DLEN))
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goto inval_skb;
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} else
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goto inval_skb;
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if (!can_skb_headroom_valid(dev, skb))
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goto inval_skb;
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return false;
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inval_skb:
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kfree_skb(skb);
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dev->stats.tx_dropped++;
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return true;
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}
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static inline bool can_is_canfd_skb(const struct sk_buff *skb)
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{
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/* the CAN specific type of skb is identified by its data length */
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return skb->len == CANFD_MTU;
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}
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/* helper to define static CAN controller features at device creation time */
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static inline void can_set_static_ctrlmode(struct net_device *dev,
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u32 static_mode)
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{
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struct can_priv *priv = netdev_priv(dev);
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/* alloc_candev() succeeded => netdev_priv() is valid at this point */
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priv->ctrlmode = static_mode;
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priv->ctrlmode_static = static_mode;
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/* override MTU which was set by default in can_setup()? */
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if (static_mode & CAN_CTRLMODE_FD)
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dev->mtu = CANFD_MTU;
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}
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/* get data length from can_dlc with sanitized can_dlc */
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u8 can_dlc2len(u8 can_dlc);
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/* map the sanitized data length to an appropriate data length code */
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u8 can_len2dlc(u8 len);
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struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
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unsigned int txqs, unsigned int rxqs);
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#define alloc_candev(sizeof_priv, echo_skb_max) \
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alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1)
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#define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \
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alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count)
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void free_candev(struct net_device *dev);
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/* a candev safe wrapper around netdev_priv */
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struct can_priv *safe_candev_priv(struct net_device *dev);
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int open_candev(struct net_device *dev);
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void close_candev(struct net_device *dev);
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int can_change_mtu(struct net_device *dev, int new_mtu);
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int register_candev(struct net_device *dev);
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void unregister_candev(struct net_device *dev);
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int can_restart_now(struct net_device *dev);
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void can_bus_off(struct net_device *dev);
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void can_change_state(struct net_device *dev, struct can_frame *cf,
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enum can_state tx_state, enum can_state rx_state);
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int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
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unsigned int idx);
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struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
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u8 *len_ptr);
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unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
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void can_free_echo_skb(struct net_device *dev, unsigned int idx);
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#ifdef CONFIG_OF
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void of_can_transceiver(struct net_device *dev);
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#else
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static inline void of_can_transceiver(struct net_device *dev) { }
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#endif
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struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
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struct sk_buff *alloc_canfd_skb(struct net_device *dev,
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struct canfd_frame **cfd);
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struct sk_buff *alloc_can_err_skb(struct net_device *dev,
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struct can_frame **cf);
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#endif /* !_CAN_DEV_H */
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