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  */
  25 enum can_mode {
  26         CAN_MODE_STOP = 0,
  27         CAN_MODE_START,
  28         CAN_MODE_SLEEP
  29 };
  30
  31 /*
  32  * CAN common private data
  33  */
  34 struct 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. */
  84 static 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
 102 inval_skb:
 103         kfree_skb(skb);
 104         dev->stats.tx_dropped++;
 105         return true;
 106 }
 107
 108 static 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 */
 115 static 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 */
 130 u8 can_dlc2len(u8 can_dlc);
 131
 132 /* map the sanitized data length to an appropriate data length code */
 133 u8 can_len2dlc(u8 len);
 134
 135 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
 136 void free_candev(struct net_device *dev);
 137
 138 /* a candev safe wrapper around netdev_priv */
 139 struct can_priv *safe_candev_priv(struct net_device *dev);
 140
 141 int open_candev(struct net_device *dev);
 142 void close_candev(struct net_device *dev);
 143 int can_change_mtu(struct net_device *dev, int new_mtu);
 144
 145 int register_candev(struct net_device *dev);
 146 void unregister_candev(struct net_device *dev);
 147
 148 int can_restart_now(struct net_device *dev);
 149 void can_bus_off(struct net_device *dev);
 150
 151 void can_change_state(struct net_device *dev, struct can_frame *cf,
 152                       enum can_state tx_state, enum can_state rx_state);
 153
 154 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 155                       unsigned int idx);
 156 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
 157 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
 158
 159 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 160 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 161                                 struct canfd_frame **cfd);
 162 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
 163                                   struct can_frame **cf);
 164
 165 #endif /* !_CAN_DEV_H */