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/netlink.h>
  18 #include <linux/can/error.h>
  19 #include <linux/can/led.h>
  20
  21 /*
  22  * CAN mode
  23  */
  24 enum can_mode {
  25         CAN_MODE_STOP = 0,
  26         CAN_MODE_START,
  27         CAN_MODE_SLEEP
  28 };
  29
  30 /*
  31  * CAN common private data
  32  */
  33 struct can_priv {
  34         struct can_device_stats can_stats;
  35
  36         struct can_bittiming bittiming, data_bittiming;
  37         const struct can_bittiming_const *bittiming_const,
  38                 *data_bittiming_const;
  39         struct can_clock clock;
  40
  41         enum can_state state;
  42         u32 ctrlmode;
  43         u32 ctrlmode_supported;
  44
  45         int restart_ms;
  46         struct timer_list restart_timer;
  47
  48         int (*do_set_bittiming)(struct net_device *dev);
  49         int (*do_set_data_bittiming)(struct net_device *dev);
  50         int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
  51         int (*do_get_state)(const struct net_device *dev,
  52                             enum can_state *state);
  53         int (*do_get_berr_counter)(const struct net_device *dev,
  54                                    struct can_berr_counter *bec);
  55
  56         unsigned int echo_skb_max;
  57         struct sk_buff **echo_skb;
  58
  59 #ifdef CONFIG_CAN_LEDS
  60         struct led_trigger *tx_led_trig;
  61         char tx_led_trig_name[CAN_LED_NAME_SZ];
  62         struct led_trigger *rx_led_trig;
  63         char rx_led_trig_name[CAN_LED_NAME_SZ];
  64 #endif
  65 };
  66
  67 /*
  68  * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
  69  * to __u8 and ensure the dlc value to be max. 8 bytes.
  70  *
  71  * To be used in the CAN netdriver receive path to ensure conformance with
  72  * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
  73  */
  74 #define get_can_dlc(i)          (min_t(__u8, (i), CAN_MAX_DLC))
  75 #define get_canfd_dlc(i)        (min_t(__u8, (i), CANFD_MAX_DLC))
  76
  77 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */
  78 static inline int can_dropped_invalid_skb(struct net_device *dev,
  79                                           struct sk_buff *skb)
  80 {
  81         const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
  82
  83         if (skb->protocol == htons(ETH_P_CAN)) {
  84                 if (unlikely(skb->len != CAN_MTU ||
  85                              cfd->len > CAN_MAX_DLEN))
  86                         goto inval_skb;
  87         } else if (skb->protocol == htons(ETH_P_CANFD)) {
  88                 if (unlikely(skb->len != CANFD_MTU ||
  89                              cfd->len > CANFD_MAX_DLEN))
  90                         goto inval_skb;
  91         } else
  92                 goto inval_skb;
  93
  94         return 0;
  95
  96 inval_skb:
  97         kfree_skb(skb);
  98         dev->stats.tx_dropped++;
  99         return 1;
 100 }
 101
 102 static inline bool can_is_canfd_skb(const struct sk_buff *skb)
 103 {
 104         /* the CAN specific type of skb is identified by its data length */
 105         return skb->len == CANFD_MTU;
 106 }
 107
 108 /* get data length from can_dlc with sanitized can_dlc */
 109 u8 can_dlc2len(u8 can_dlc);
 110
 111 /* map the sanitized data length to an appropriate data length code */
 112 u8 can_len2dlc(u8 len);
 113
 114 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
 115 void free_candev(struct net_device *dev);
 116
 117 /* a candev safe wrapper around netdev_priv */
 118 struct can_priv *safe_candev_priv(struct net_device *dev);
 119
 120 int open_candev(struct net_device *dev);
 121 void close_candev(struct net_device *dev);
 122 int can_change_mtu(struct net_device *dev, int new_mtu);
 123
 124 int register_candev(struct net_device *dev);
 125 void unregister_candev(struct net_device *dev);
 126
 127 int can_restart_now(struct net_device *dev);
 128 void can_bus_off(struct net_device *dev);
 129
 130 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 131                       unsigned int idx);
 132 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
 133 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
 134
 135 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 136 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 137                                 struct canfd_frame **cfd);
 138 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
 139                                   struct can_frame **cf);
 140
 141 #endif /* !_CAN_DEV_H */