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        const u16 *termination_const;
  42        unsigned int termination_const_cnt;
  43        u16 termination;
  44        const u32 *bitrate_const;
  45        unsigned int bitrate_const_cnt;
  46        const u32 *data_bitrate_const;
  47        unsigned int data_bitrate_const_cnt;
  48        struct can_clock clock;
  49
  50        enum can_state state;
  51
  52        /* CAN controller features - see include/uapi/linux/can/netlink.h */
  53        u32 ctrlmode;           /* current options setting */
  54        u32 ctrlmode_supported; /* options that can be modified by netlink */
  55        u32 ctrlmode_static;    /* static enabled options for driver/hardware */
  56
  57        int restart_ms;
  58        struct delayed_work restart_work;
  59
  60        int (*do_set_bittiming)(struct net_device *dev);
  61        int (*do_set_data_bittiming)(struct net_device *dev);
  62        int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
  63        int (*do_set_termination)(struct net_device *dev, u16 term);
  64        int (*do_get_state)(const struct net_device *dev,
  65                            enum can_state *state);
  66        int (*do_get_berr_counter)(const struct net_device *dev,
  67                                   struct can_berr_counter *bec);
  68
  69        unsigned int echo_skb_max;
  70        struct sk_buff **echo_skb;
  71
  72#ifdef CONFIG_CAN_LEDS
  73        struct led_trigger *tx_led_trig;
  74        char tx_led_trig_name[CAN_LED_NAME_SZ];
  75        struct led_trigger *rx_led_trig;
  76        char rx_led_trig_name[CAN_LED_NAME_SZ];
  77        struct led_trigger *rxtx_led_trig;
  78        char rxtx_led_trig_name[CAN_LED_NAME_SZ];
  79#endif
  80};
  81
  82/*
  83 * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
  84 * to __u8 and ensure the dlc value to be max. 8 bytes.
  85 *
  86 * To be used in the CAN netdriver receive path to ensure conformance with
  87 * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
  88 */
  89#define get_can_dlc(i)          (min_t(__u8, (i), CAN_MAX_DLC))
  90#define get_canfd_dlc(i)        (min_t(__u8, (i), CANFD_MAX_DLC))
  91
  92/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
  93static inline bool can_dropped_invalid_skb(struct net_device *dev,
  94                                          struct sk_buff *skb)
  95{
  96        const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
  97
  98        if (skb->protocol == htons(ETH_P_CAN)) {
  99                if (unlikely(skb->len != CAN_MTU ||
 100                             cfd->len > CAN_MAX_DLEN))
 101                        goto inval_skb;
 102        } else if (skb->protocol == htons(ETH_P_CANFD)) {
 103                if (unlikely(skb->len != CANFD_MTU ||
 104                             cfd->len > CANFD_MAX_DLEN))
 105                        goto inval_skb;
 106        } else
 107                goto inval_skb;
 108
 109        return false;
 110
 111inval_skb:
 112        kfree_skb(skb);
 113        dev->stats.tx_dropped++;
 114        return true;
 115}
 116
 117static inline bool can_is_canfd_skb(const struct sk_buff *skb)
 118{
 119        /* the CAN specific type of skb is identified by its data length */
 120        return skb->len == CANFD_MTU;
 121}
 122
 123/* helper to define static CAN controller features at device creation time */
 124static inline void can_set_static_ctrlmode(struct net_device *dev,
 125                                           u32 static_mode)
 126{
 127        struct can_priv *priv = netdev_priv(dev);
 128
 129        /* alloc_candev() succeeded => netdev_priv() is valid at this point */
 130        priv->ctrlmode = static_mode;
 131        priv->ctrlmode_static = static_mode;
 132
 133        /* override MTU which was set by default in can_setup()? */
 134        if (static_mode & CAN_CTRLMODE_FD)
 135                dev->mtu = CANFD_MTU;
 136}
 137
 138/* get data length from can_dlc with sanitized can_dlc */
 139u8 can_dlc2len(u8 can_dlc);
 140
 141/* map the sanitized data length to an appropriate data length code */
 142u8 can_len2dlc(u8 len);
 143
 144struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
 145void free_candev(struct net_device *dev);
 146
 147/* a candev safe wrapper around netdev_priv */
 148struct can_priv *safe_candev_priv(struct net_device *dev);
 149
 150int open_candev(struct net_device *dev);
 151void close_candev(struct net_device *dev);
 152int can_change_mtu(struct net_device *dev, int new_mtu);
 153
 154int register_candev(struct net_device *dev);
 155void unregister_candev(struct net_device *dev);
 156
 157int can_restart_now(struct net_device *dev);
 158void can_bus_off(struct net_device *dev);
 159
 160void can_change_state(struct net_device *dev, struct can_frame *cf,
 161                      enum can_state tx_state, enum can_state rx_state);
 162
 163void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 164                      unsigned int idx);
 165unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
 166void can_free_echo_skb(struct net_device *dev, unsigned int idx);
 167
 168struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 169struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 170                                struct canfd_frame **cfd);
 171struct sk_buff *alloc_can_err_skb(struct net_device *dev,
 172                                  struct can_frame **cf);
 173
 174#endif /* !_CAN_DEV_H */
 175