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

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