LXR linux/include/linux/can/dev.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * linux/can/dev.h
   4 *
   5 * Definitions for the CAN network device driver interface
   6 *
   7 * Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
   8 *               Varma Electronics Oy
   9 *
  10 * Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
  11 *
  12 */
  13
  14#ifndef _CAN_DEV_H
  15#define _CAN_DEV_H
  16
  17#include <linux/can.h>
  18#include <linux/can/error.h>
  19#include <linux/can/led.h>
  20#include <linux/can/netlink.h>
  21#include <linux/netdevice.h>
  22
  23/*
  24 * CAN mode
  25 */
  26enum can_mode {
  27        CAN_MODE_STOP = 0,
  28        CAN_MODE_START,
  29        CAN_MODE_SLEEP
  30};
  31
  32/*
  33 * CAN common private data
  34 */
  35struct can_priv {
  36        struct net_device *dev;
  37        struct can_device_stats can_stats;
  38
  39        struct can_bittiming bittiming, data_bittiming;
  40        const struct can_bittiming_const *bittiming_const,
  41                *data_bittiming_const;
  42        const u16 *termination_const;
  43        unsigned int termination_const_cnt;
  44        u16 termination;
  45        const u32 *bitrate_const;
  46        unsigned int bitrate_const_cnt;
  47        const u32 *data_bitrate_const;
  48        unsigned int data_bitrate_const_cnt;
  49        u32 bitrate_max;
  50        struct can_clock clock;
  51
  52        enum can_state state;
  53
  54        /* CAN controller features - see include/uapi/linux/can/netlink.h */
  55        u32 ctrlmode;           /* current options setting */
  56        u32 ctrlmode_supported; /* options that can be modified by netlink */
  57        u32 ctrlmode_static;    /* static enabled options for driver/hardware */
  58
  59        int restart_ms;
  60        struct delayed_work restart_work;
  61
  62        int (*do_set_bittiming)(struct net_device *dev);
  63        int (*do_set_data_bittiming)(struct net_device *dev);
  64        int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
  65        int (*do_set_termination)(struct net_device *dev, u16 term);
  66        int (*do_get_state)(const struct net_device *dev,
  67                            enum can_state *state);
  68        int (*do_get_berr_counter)(const struct net_device *dev,
  69                                   struct can_berr_counter *bec);
  70
  71        unsigned int echo_skb_max;
  72        struct sk_buff **echo_skb;
  73
  74#ifdef CONFIG_CAN_LEDS
  75        struct led_trigger *tx_led_trig;
  76        char tx_led_trig_name[CAN_LED_NAME_SZ];
  77        struct led_trigger *rx_led_trig;
  78        char rx_led_trig_name[CAN_LED_NAME_SZ];
  79        struct led_trigger *rxtx_led_trig;
  80        char rxtx_led_trig_name[CAN_LED_NAME_SZ];
  81#endif
  82};
  83
  84/*
  85 * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
  86 * to __u8 and ensure the dlc value to be max. 8 bytes.
  87 *
  88 * To be used in the CAN netdriver receive path to ensure conformance with
  89 * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
  90 */
  91#define get_can_dlc(i)          (min_t(__u8, (i), CAN_MAX_DLC))
  92#define get_canfd_dlc(i)        (min_t(__u8, (i), CANFD_MAX_DLC))
  93
  94/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
  95static inline bool can_dropped_invalid_skb(struct net_device *dev,
  96                                          struct sk_buff *skb)
  97{
  98        const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
  99
 100        if (skb->protocol == htons(ETH_P_CAN)) {
 101                if (unlikely(skb->len != CAN_MTU ||
 102                             cfd->len > CAN_MAX_DLEN))
 103                        goto inval_skb;
 104        } else if (skb->protocol == htons(ETH_P_CANFD)) {
 105                if (unlikely(skb->len != CANFD_MTU ||
 106                             cfd->len > CANFD_MAX_DLEN))
 107                        goto inval_skb;
 108        } else
 109                goto inval_skb;
 110
 111        return false;
 112
 113inval_skb:
 114        kfree_skb(skb);
 115        dev->stats.tx_dropped++;
 116        return true;
 117}
 118
 119static inline bool can_is_canfd_skb(const struct sk_buff *skb)
 120{
 121        /* the CAN specific type of skb is identified by its data length */
 122        return skb->len == CANFD_MTU;
 123}
 124
 125/* helper to define static CAN controller features at device creation time */
 126static inline void can_set_static_ctrlmode(struct net_device *dev,
 127                                           u32 static_mode)
 128{
 129        struct can_priv *priv = netdev_priv(dev);
 130
 131        /* alloc_candev() succeeded => netdev_priv() is valid at this point */
 132        priv->ctrlmode = static_mode;
 133        priv->ctrlmode_static = static_mode;
 134
 135        /* override MTU which was set by default in can_setup()? */
 136        if (static_mode & CAN_CTRLMODE_FD)
 137                dev->mtu = CANFD_MTU;
 138}
 139
 140/* get data length from can_dlc with sanitized can_dlc */
 141u8 can_dlc2len(u8 can_dlc);
 142
 143/* map the sanitized data length to an appropriate data length code */
 144u8 can_len2dlc(u8 len);
 145
 146struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 147                                    unsigned int txqs, unsigned int rxqs);
 148#define alloc_candev(sizeof_priv, echo_skb_max) \
 149        alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1)
 150#define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \
 151        alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count)
 152void free_candev(struct net_device *dev);
 153
 154/* a candev safe wrapper around netdev_priv */
 155struct can_priv *safe_candev_priv(struct net_device *dev);
 156
 157int open_candev(struct net_device *dev);
 158void close_candev(struct net_device *dev);
 159int can_change_mtu(struct net_device *dev, int new_mtu);
 160
 161int register_candev(struct net_device *dev);
 162void unregister_candev(struct net_device *dev);
 163
 164int can_restart_now(struct net_device *dev);
 165void can_bus_off(struct net_device *dev);
 166
 167void can_change_state(struct net_device *dev, struct can_frame *cf,
 168                      enum can_state tx_state, enum can_state rx_state);
 169
 170void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 171                      unsigned int idx);
 172struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
 173                                   u8 *len_ptr);
 174unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
 175void can_free_echo_skb(struct net_device *dev, unsigned int idx);
 176
 177#ifdef CONFIG_OF
 178void of_can_transceiver(struct net_device *dev);
 179#else
 180static inline void of_can_transceiver(struct net_device *dev) { }
 181#endif
 182
 183struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 184struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 185                                struct canfd_frame **cfd);
 186struct sk_buff *alloc_can_err_skb(struct net_device *dev,
 187                                  struct can_frame **cf);
 188
 189#endif /* !_CAN_DEV_H */
 190