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