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/can/skb.h>
  22#include <linux/netdevice.h>
  23
  24/*
  25 * CAN mode
  26 */
  27enum can_mode {
  28        CAN_MODE_STOP = 0,
  29        CAN_MODE_START,
  30        CAN_MODE_SLEEP
  31};
  32
  33/*
  34 * CAN common private data
  35 */
  36struct can_priv {
  37        struct net_device *dev;
  38        struct can_device_stats can_stats;
  39
  40        struct can_bittiming bittiming, data_bittiming;
  41        const struct can_bittiming_const *bittiming_const,
  42                *data_bittiming_const;
  43        const u16 *termination_const;
  44        unsigned int termination_const_cnt;
  45        u16 termination;
  46        const u32 *bitrate_const;
  47        unsigned int bitrate_const_cnt;
  48        const u32 *data_bitrate_const;
  49        unsigned int data_bitrate_const_cnt;
  50        u32 bitrate_max;
  51        struct can_clock clock;
  52
  53        enum can_state state;
  54
  55        /* CAN controller features - see include/uapi/linux/can/netlink.h */
  56        u32 ctrlmode;           /* current options setting */
  57        u32 ctrlmode_supported; /* options that can be modified by netlink */
  58        u32 ctrlmode_static;    /* static enabled options for driver/hardware */
  59
  60        int restart_ms;
  61        struct delayed_work restart_work;
  62
  63        int (*do_set_bittiming)(struct net_device *dev);
  64        int (*do_set_data_bittiming)(struct net_device *dev);
  65        int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
  66        int (*do_set_termination)(struct net_device *dev, u16 term);
  67        int (*do_get_state)(const struct net_device *dev,
  68                            enum can_state *state);
  69        int (*do_get_berr_counter)(const struct net_device *dev,
  70                                   struct can_berr_counter *bec);
  71
  72        unsigned int echo_skb_max;
  73        struct sk_buff **echo_skb;
  74
  75#ifdef CONFIG_CAN_LEDS
  76        struct led_trigger *tx_led_trig;
  77        char tx_led_trig_name[CAN_LED_NAME_SZ];
  78        struct led_trigger *rx_led_trig;
  79        char rx_led_trig_name[CAN_LED_NAME_SZ];
  80        struct led_trigger *rxtx_led_trig;
  81        char rxtx_led_trig_name[CAN_LED_NAME_SZ];
  82#endif
  83};
  84
  85/*
  86 * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
  87 * to __u8 and ensure the dlc value to be max. 8 bytes.
  88 *
  89 * To be used in the CAN netdriver receive path to ensure conformance with
  90 * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
  91 */
  92#define get_can_dlc(i)          (min_t(__u8, (i), CAN_MAX_DLC))
  93#define get_canfd_dlc(i)        (min_t(__u8, (i), CANFD_MAX_DLC))
  94
  95/* Check for outgoing skbs that have not been created by the CAN subsystem */
  96static inline bool can_skb_headroom_valid(struct net_device *dev,
  97                                          struct sk_buff *skb)
  98{
  99        /* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */
 100        if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv)))
 101                return false;
 102
 103        /* af_packet does not apply CAN skb specific settings */
 104        if (skb->ip_summed == CHECKSUM_NONE) {
 105                /* init headroom */
 106                can_skb_prv(skb)->ifindex = dev->ifindex;
 107                can_skb_prv(skb)->skbcnt = 0;
 108
 109                skb->ip_summed = CHECKSUM_UNNECESSARY;
 110
 111                /* preform proper loopback on capable devices */
 112                if (dev->flags & IFF_ECHO)
 113                        skb->pkt_type = PACKET_LOOPBACK;
 114                else
 115                        skb->pkt_type = PACKET_HOST;
 116
 117                skb_reset_mac_header(skb);
 118                skb_reset_network_header(skb);
 119                skb_reset_transport_header(skb);
 120        }
 121
 122        return true;
 123}
 124
 125/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
 126static inline bool can_dropped_invalid_skb(struct net_device *dev,
 127                                          struct sk_buff *skb)
 128{
 129        const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 130
 131        if (skb->protocol == htons(ETH_P_CAN)) {
 132                if (unlikely(skb->len != CAN_MTU ||
 133                             cfd->len > CAN_MAX_DLEN))
 134                        goto inval_skb;
 135        } else if (skb->protocol == htons(ETH_P_CANFD)) {
 136                if (unlikely(skb->len != CANFD_MTU ||
 137                             cfd->len > CANFD_MAX_DLEN))
 138                        goto inval_skb;
 139        } else
 140                goto inval_skb;
 141
 142        if (!can_skb_headroom_valid(dev, skb))
 143                goto inval_skb;
 144
 145        return false;
 146
 147inval_skb:
 148        kfree_skb(skb);
 149        dev->stats.tx_dropped++;
 150        return true;
 151}
 152
 153static inline bool can_is_canfd_skb(const struct sk_buff *skb)
 154{
 155        /* the CAN specific type of skb is identified by its data length */
 156        return skb->len == CANFD_MTU;
 157}
 158
 159/* helper to define static CAN controller features at device creation time */
 160static inline void can_set_static_ctrlmode(struct net_device *dev,
 161                                           u32 static_mode)
 162{
 163        struct can_priv *priv = netdev_priv(dev);
 164
 165        /* alloc_candev() succeeded => netdev_priv() is valid at this point */
 166        priv->ctrlmode = static_mode;
 167        priv->ctrlmode_static = static_mode;
 168
 169        /* override MTU which was set by default in can_setup()? */
 170        if (static_mode & CAN_CTRLMODE_FD)
 171                dev->mtu = CANFD_MTU;
 172}
 173
 174/* get data length from can_dlc with sanitized can_dlc */
 175u8 can_dlc2len(u8 can_dlc);
 176
 177/* map the sanitized data length to an appropriate data length code */
 178u8 can_len2dlc(u8 len);
 179
 180struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 181                                    unsigned int txqs, unsigned int rxqs);
 182#define alloc_candev(sizeof_priv, echo_skb_max) \
 183        alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1)
 184#define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \
 185        alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count)
 186void free_candev(struct net_device *dev);
 187
 188/* a candev safe wrapper around netdev_priv */
 189struct can_priv *safe_candev_priv(struct net_device *dev);
 190
 191int open_candev(struct net_device *dev);
 192void close_candev(struct net_device *dev);
 193int can_change_mtu(struct net_device *dev, int new_mtu);
 194
 195int register_candev(struct net_device *dev);
 196void unregister_candev(struct net_device *dev);
 197
 198int can_restart_now(struct net_device *dev);
 199void can_bus_off(struct net_device *dev);
 200
 201void can_change_state(struct net_device *dev, struct can_frame *cf,
 202                      enum can_state tx_state, enum can_state rx_state);
 203
 204void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 205                      unsigned int idx);
 206struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
 207                                   u8 *len_ptr);
 208unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
 209void can_free_echo_skb(struct net_device *dev, unsigned int idx);
 210
 211#ifdef CONFIG_OF
 212void of_can_transceiver(struct net_device *dev);
 213#else
 214static inline void of_can_transceiver(struct net_device *dev) { }
 215#endif
 216
 217struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 218struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 219                                struct canfd_frame **cfd);
 220struct sk_buff *alloc_can_err_skb(struct net_device *dev,
 221                                  struct can_frame **cf);
 222
 223#endif /* !_CAN_DEV_H */
 224