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         u32 ctrlmode;
  44         u32 ctrlmode_supported;
  45
  46         int restart_ms;
  47         struct timer_list restart_timer;
  48
  49         int (*do_set_bittiming)(struct net_device *dev);
  50         int (*do_set_data_bittiming)(struct net_device *dev);
  51         int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
  52         int (*do_get_state)(const struct net_device *dev,
  53                             enum can_state *state);
  54         int (*do_get_berr_counter)(const struct net_device *dev,
  55                                    struct can_berr_counter *bec);
  56
  57         unsigned int echo_skb_max;
  58         struct sk_buff **echo_skb;
  59
  60 #ifdef CONFIG_CAN_LEDS
  61         struct led_trigger *tx_led_trig;
  62         char tx_led_trig_name[CAN_LED_NAME_SZ];
  63         struct led_trigger *rx_led_trig;
  64         char rx_led_trig_name[CAN_LED_NAME_SZ];
  65         struct led_trigger *rxtx_led_trig;
  66         char rxtx_led_trig_name[CAN_LED_NAME_SZ];
  67 #endif
  68 };
  69
  70 /*
  71  * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
  72  * to __u8 and ensure the dlc value to be max. 8 bytes.
  73  *
  74  * To be used in the CAN netdriver receive path to ensure conformance with
  75  * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
  76  */
  77 #define get_can_dlc(i)          (min_t(__u8, (i), CAN_MAX_DLC))
  78 #define get_canfd_dlc(i)        (min_t(__u8, (i), CANFD_MAX_DLC))
  79
  80 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */
  81 static inline bool can_dropped_invalid_skb(struct net_device *dev,
  82                                           struct sk_buff *skb)
  83 {
  84         const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
  85
  86         if (skb->protocol == htons(ETH_P_CAN)) {
  87                 if (unlikely(skb->len != CAN_MTU ||
  88                              cfd->len > CAN_MAX_DLEN))
  89                         goto inval_skb;
  90         } else if (skb->protocol == htons(ETH_P_CANFD)) {
  91                 if (unlikely(skb->len != CANFD_MTU ||
  92                              cfd->len > CANFD_MAX_DLEN))
  93                         goto inval_skb;
  94         } else
  95                 goto inval_skb;
  96
  97         return false;
  98
  99 inval_skb:
 100         kfree_skb(skb);
 101         dev->stats.tx_dropped++;
 102         return true;
 103 }
 104
 105 static inline bool can_is_canfd_skb(const struct sk_buff *skb)
 106 {
 107         /* the CAN specific type of skb is identified by its data length */
 108         return skb->len == CANFD_MTU;
 109 }
 110
 111 /* get data length from can_dlc with sanitized can_dlc */
 112 u8 can_dlc2len(u8 can_dlc);
 113
 114 /* map the sanitized data length to an appropriate data length code */
 115 u8 can_len2dlc(u8 len);
 116
 117 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
 118 void free_candev(struct net_device *dev);
 119
 120 /* a candev safe wrapper around netdev_priv */
 121 struct can_priv *safe_candev_priv(struct net_device *dev);
 122
 123 int open_candev(struct net_device *dev);
 124 void close_candev(struct net_device *dev);
 125 int can_change_mtu(struct net_device *dev, int new_mtu);
 126
 127 int register_candev(struct net_device *dev);
 128 void unregister_candev(struct net_device *dev);
 129
 130 int can_restart_now(struct net_device *dev);
 131 void can_bus_off(struct net_device *dev);
 132
 133 void can_change_state(struct net_device *dev, struct can_frame *cf,
 134                       enum can_state tx_state, enum can_state rx_state);
 135
 136 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 137                       unsigned int idx);
 138 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
 139 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
 140
 141 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 142 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 143                                 struct canfd_frame **cfd);
 144 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
 145                                   struct can_frame **cf);
 146
 147 #endif /* !_CAN_DEV_H */