include/linux/can/dev.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * linux/can/dev.h
   4  *
   5  * Definitions for the CAN network device driver interface
   6  *
   7  * Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
   8  *               Varma Electronics Oy
   9  *
  10  * Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
  11  *
  12  */
  13
  14 #ifndef _CAN_DEV_H
  15 #define _CAN_DEV_H
  16
  17 #include <linux/can.h>
  18 #include <linux/can/bittiming.h>
  19 #include <linux/can/error.h>
  20 #include <linux/can/length.h>
  21 #include <linux/can/netlink.h>
  22 #include <linux/can/skb.h>
  23 #include <linux/ethtool.h>
  24 #include <linux/netdevice.h>
  25
  26 /*
  27  * CAN mode
  28  */
  29 enum can_mode {
  30         CAN_MODE_STOP = 0,
  31         CAN_MODE_START,
  32         CAN_MODE_SLEEP
  33 };
  34
  35 enum can_termination_gpio {
  36         CAN_TERMINATION_GPIO_DISABLED = 0,
  37         CAN_TERMINATION_GPIO_ENABLED,
  38         CAN_TERMINATION_GPIO_MAX,
  39 };
  40
  41 /*
  42  * CAN common private data
  43  */
  44 struct can_priv {
  45         struct net_device *dev;
  46         struct can_device_stats can_stats;
  47
  48         const struct can_bittiming_const *bittiming_const,
  49                 *data_bittiming_const;
  50         struct can_bittiming bittiming, data_bittiming;
  51         const struct can_tdc_const *tdc_const;
  52         struct can_tdc tdc;
  53
  54         unsigned int bitrate_const_cnt;
  55         const u32 *bitrate_const;
  56         const u32 *data_bitrate_const;
  57         unsigned int data_bitrate_const_cnt;
  58         u32 bitrate_max;
  59         struct can_clock clock;
  60
  61         unsigned int termination_const_cnt;
  62         const u16 *termination_const;
  63         u16 termination;
  64         struct gpio_desc *termination_gpio;
  65         u16 termination_gpio_ohms[CAN_TERMINATION_GPIO_MAX];
  66
  67         unsigned int echo_skb_max;
  68         struct sk_buff **echo_skb;
  69
  70         enum can_state state;
  71
  72         /* CAN controller features - see include/uapi/linux/can/netlink.h */
  73         u32 ctrlmode;           /* current options setting */
  74         u32 ctrlmode_supported; /* options that can be modified by netlink */
  75
  76         int restart_ms;
  77         struct delayed_work restart_work;
  78
  79         int (*do_set_bittiming)(struct net_device *dev);
  80         int (*do_set_data_bittiming)(struct net_device *dev);
  81         int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
  82         int (*do_set_termination)(struct net_device *dev, u16 term);
  83         int (*do_get_state)(const struct net_device *dev,
  84                             enum can_state *state);
  85         int (*do_get_berr_counter)(const struct net_device *dev,
  86                                    struct can_berr_counter *bec);
  87         int (*do_get_auto_tdcv)(const struct net_device *dev, u32 *tdcv);
  88 };
  89
  90 static inline bool can_tdc_is_enabled(const struct can_priv *priv)
  91 {
  92         return !!(priv->ctrlmode & CAN_CTRLMODE_TDC_MASK);
  93 }
  94
  95 /*
  96  * can_get_relative_tdco() - TDCO relative to the sample point
  97  *
  98  * struct can_tdc::tdco represents the absolute offset from TDCV. Some
  99  * controllers use instead an offset relative to the Sample Point (SP)
 100  * such that:
 101  *
 102  * SSP = TDCV + absolute TDCO
 103  *     = TDCV + SP + relative TDCO
 104  *
 105  * -+----------- one bit ----------+-- TX pin
 106  *  |<--- Sample Point --->|
 107  *
 108  *                         --+----------- one bit ----------+-- RX pin
 109  *  |<-------- TDCV -------->|
 110  *                           |<------------------------>| absolute TDCO
 111  *                           |<--- Sample Point --->|
 112  *                           |                      |<->| relative TDCO
 113  *  |<------------- Secondary Sample Point ------------>|
 114  */
 115 static inline s32 can_get_relative_tdco(const struct can_priv *priv)
 116 {
 117         const struct can_bittiming *dbt = &priv->data_bittiming;
 118         s32 sample_point_in_tc = (CAN_SYNC_SEG + dbt->prop_seg +
 119                                   dbt->phase_seg1) * dbt->brp;
 120
 121         return (s32)priv->tdc.tdco - sample_point_in_tc;
 122 }
 123
 124 /* helper to define static CAN controller features at device creation time */
 125 static inline int __must_check can_set_static_ctrlmode(struct net_device *dev,
 126                                                        u32 static_mode)
 127 {
 128         struct can_priv *priv = netdev_priv(dev);
 129
 130         /* alloc_candev() succeeded => netdev_priv() is valid at this point */
 131         if (priv->ctrlmode_supported & static_mode) {
 132                 netdev_warn(dev,
 133                             "Controller features can not be supported and static at the same time\n");
 134                 return -EINVAL;
 135         }
 136         priv->ctrlmode = static_mode;
 137
 138         /* override MTU which was set by default in can_setup()? */
 139         if (static_mode & CAN_CTRLMODE_FD)
 140                 dev->mtu = CANFD_MTU;
 141
 142         return 0;
 143 }
 144
 145 static inline u32 can_get_static_ctrlmode(struct can_priv *priv)
 146 {
 147         return priv->ctrlmode & ~priv->ctrlmode_supported;
 148 }
 149
 150 static inline bool can_is_canxl_dev_mtu(unsigned int mtu)
 151 {
 152         return (mtu >= CANXL_MIN_MTU && mtu <= CANXL_MAX_MTU);
 153 }
 154
 155 /* drop skb if it does not contain a valid CAN frame for sending */
 156 static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *skb)
 157 {
 158         struct can_priv *priv = netdev_priv(dev);
 159
 160         if (priv->ctrlmode & CAN_CTRLMODE_LISTENONLY) {
 161                 netdev_info_once(dev,
 162                                  "interface in listen only mode, dropping skb\n");
 163                 kfree_skb(skb);
 164                 dev->stats.tx_dropped++;
 165                 return true;
 166         }
 167
 168         return can_dropped_invalid_skb(dev, skb);
 169 }
 170
 171 void can_setup(struct net_device *dev);
 172
 173 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 174                                     unsigned int txqs, unsigned int rxqs);
 175 #define alloc_candev(sizeof_priv, echo_skb_max) \
 176         alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1)
 177 #define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \
 178         alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count)
 179 void free_candev(struct net_device *dev);
 180
 181 /* a candev safe wrapper around netdev_priv */
 182 struct can_priv *safe_candev_priv(struct net_device *dev);
 183
 184 int open_candev(struct net_device *dev);
 185 void close_candev(struct net_device *dev);
 186 int can_change_mtu(struct net_device *dev, int new_mtu);
 187 int can_eth_ioctl_hwts(struct net_device *netdev, struct ifreq *ifr, int cmd);
 188 int can_ethtool_op_get_ts_info_hwts(struct net_device *dev,
 189                                     struct kernel_ethtool_ts_info *info);
 190
 191 int register_candev(struct net_device *dev);
 192 void unregister_candev(struct net_device *dev);
 193
 194 int can_restart_now(struct net_device *dev);
 195 void can_bus_off(struct net_device *dev);
 196
 197 const char *can_get_state_str(const enum can_state state);
 198 void can_state_get_by_berr_counter(const struct net_device *dev,
 199                                    const struct can_berr_counter *bec,
 200                                    enum can_state *tx_state,
 201                                    enum can_state *rx_state);
 202 void can_change_state(struct net_device *dev, struct can_frame *cf,
 203                       enum can_state tx_state, enum can_state rx_state);
 204
 205 #ifdef CONFIG_OF
 206 void of_can_transceiver(struct net_device *dev);
 207 #else
 208 static inline void of_can_transceiver(struct net_device *dev) { }
 209 #endif
 210
 211 extern struct rtnl_link_ops can_link_ops;
 212 int can_netlink_register(void);
 213 void can_netlink_unregister(void);
 214
 215 #endif /* !_CAN_DEV_H */