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 <[email protected]> 8 * Varma Electronics Oy 9 * 10 * Copyright (C) 2008 Wolfgang Grandegger <[email protected]> 11 * 12 */ 13 14 #ifndef _CAN_DEV_H 15 #define _CAN_DEV_H 16 17 #include <linux/can.h> 18 #include <linux/can/error.h> 19 #include <linux/can/led.h> 20 #include <linux/can/netlink.h> 21 #include <linux/can/skb.h> 22 #include <linux/netdevice.h> 23 24 /* 25 * CAN mode 26 */ 27 enum can_mode { 28 CAN_MODE_STOP = 0, 29 CAN_MODE_START, 30 CAN_MODE_SLEEP 31 }; 32 33 /* 34 * CAN common private data 35 */ 36 struct can_priv { 37 struct net_device *dev; 38 struct can_device_stats can_stats; 39 40 struct can_bittiming bittiming, data_bittiming; 41 const struct can_bittiming_const *bittiming_const, 42 *data_bittiming_const; 43 const u16 *termination_const; 44 unsigned int termination_const_cnt; 45 u16 termination; 46 const u32 *bitrate_const; 47 unsigned int bitrate_const_cnt; 48 const u32 *data_bitrate_const; 49 unsigned int data_bitrate_const_cnt; 50 u32 bitrate_max; 51 struct can_clock clock; 52 53 enum can_state state; 54 55 /* CAN controller features - see include/uapi/linux/can/netlink.h */ 56 u32 ctrlmode; /* current options setting */ 57 u32 ctrlmode_supported; /* options that can be modified by netlink */ 58 u32 ctrlmode_static; /* static enabled options for driver/hardware */ 59 60 int restart_ms; 61 struct delayed_work restart_work; 62 63 int (*do_set_bittiming)(struct net_device *dev); 64 int (*do_set_data_bittiming)(struct net_device *dev); 65 int (*do_set_mode)(struct net_device *dev, enum can_mode mode); 66 int (*do_set_termination)(struct net_device *dev, u16 term); 67 int (*do_get_state)(const struct net_device *dev, 68 enum can_state *state); 69 int (*do_get_berr_counter)(const struct net_device *dev, 70 struct can_berr_counter *bec); 71 72 unsigned int echo_skb_max; 73 struct sk_buff **echo_skb; 74 75 #ifdef CONFIG_CAN_LEDS 76 struct led_trigger *tx_led_trig; 77 char tx_led_trig_name[CAN_LED_NAME_SZ]; 78 struct led_trigger *rx_led_trig; 79 char rx_led_trig_name[CAN_LED_NAME_SZ]; 80 struct led_trigger *rxtx_led_trig; 81 char rxtx_led_trig_name[CAN_LED_NAME_SZ]; 82 #endif 83 }; 84 85 #define CAN_SYNC_SEG 1 86 87 /* 88 * can_bit_time() - Duration of one bit 89 * 90 * Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for 91 * additional information. 92 * 93 * Return: the number of time quanta in one bit. 94 */ 95 static inline unsigned int can_bit_time(const struct can_bittiming *bt) 96 { 97 return CAN_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2; 98 } 99 100 /* 101 * get_can_dlc(value) - helper macro to cast a given data length code (dlc) 102 * to u8 and ensure the dlc value to be max. 8 bytes. 103 * 104 * To be used in the CAN netdriver receive path to ensure conformance with 105 * ISO 11898-1 Chapter 8.4.2.3 (DLC field) 106 */ 107 #define get_can_dlc(i) (min_t(u8, (i), CAN_MAX_DLC)) 108 #define get_canfd_dlc(i) (min_t(u8, (i), CANFD_MAX_DLC)) 109 110 /* Check for outgoing skbs that have not been created by the CAN subsystem */ 111 static inline bool can_skb_headroom_valid(struct net_device *dev, 112 struct sk_buff *skb) 113 { 114 /* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */ 115 if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv))) 116 return false; 117 118 /* af_packet does not apply CAN skb specific settings */ 119 if (skb->ip_summed == CHECKSUM_NONE) { 120 /* init headroom */ 121 can_skb_prv(skb)->ifindex = dev->ifindex; 122 can_skb_prv(skb)->skbcnt = 0; 123 124 skb->ip_summed = CHECKSUM_UNNECESSARY; 125 126 /* perform proper loopback on capable devices */ 127 if (dev->flags & IFF_ECHO) 128 skb->pkt_type = PACKET_LOOPBACK; 129 else 130 skb->pkt_type = PACKET_HOST; 131 132 skb_reset_mac_header(skb); 133 skb_reset_network_header(skb); 134 skb_reset_transport_header(skb); 135 } 136 137 return true; 138 } 139 140 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */ 141 static inline bool can_dropped_invalid_skb(struct net_device *dev, 142 struct sk_buff *skb) 143 { 144 const struct canfd_frame *cfd = (struct canfd_frame *)skb->data; 145 146 if (skb->protocol == htons(ETH_P_CAN)) { 147 if (unlikely(skb->len != CAN_MTU || 148 cfd->len > CAN_MAX_DLEN)) 149 goto inval_skb; 150 } else if (skb->protocol == htons(ETH_P_CANFD)) { 151 if (unlikely(skb->len != CANFD_MTU || 152 cfd->len > CANFD_MAX_DLEN)) 153 goto inval_skb; 154 } else 155 goto inval_skb; 156 157 if (!can_skb_headroom_valid(dev, skb)) 158 goto inval_skb; 159 160 return false; 161 162 inval_skb: 163 kfree_skb(skb); 164 dev->stats.tx_dropped++; 165 return true; 166 } 167 168 static inline bool can_is_canfd_skb(const struct sk_buff *skb) 169 { 170 /* the CAN specific type of skb is identified by its data length */ 171 return skb->len == CANFD_MTU; 172 } 173 174 /* helper to define static CAN controller features at device creation time */ 175 static inline void can_set_static_ctrlmode(struct net_device *dev, 176 u32 static_mode) 177 { 178 struct can_priv *priv = netdev_priv(dev); 179 180 /* alloc_candev() succeeded => netdev_priv() is valid at this point */ 181 priv->ctrlmode = static_mode; 182 priv->ctrlmode_static = static_mode; 183 184 /* override MTU which was set by default in can_setup()? */ 185 if (static_mode & CAN_CTRLMODE_FD) 186 dev->mtu = CANFD_MTU; 187 } 188 189 /* get data length from can_dlc with sanitized can_dlc */ 190 u8 can_dlc2len(u8 can_dlc); 191 192 /* map the sanitized data length to an appropriate data length code */ 193 u8 can_len2dlc(u8 len); 194 195 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max, 196 unsigned int txqs, unsigned int rxqs); 197 #define alloc_candev(sizeof_priv, echo_skb_max) \ 198 alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1) 199 #define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \ 200 alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count) 201 void free_candev(struct net_device *dev); 202 203 /* a candev safe wrapper around netdev_priv */ 204 struct can_priv *safe_candev_priv(struct net_device *dev); 205 206 int open_candev(struct net_device *dev); 207 void close_candev(struct net_device *dev); 208 int can_change_mtu(struct net_device *dev, int new_mtu); 209 210 int register_candev(struct net_device *dev); 211 void unregister_candev(struct net_device *dev); 212 213 int can_restart_now(struct net_device *dev); 214 void can_bus_off(struct net_device *dev); 215 216 void can_change_state(struct net_device *dev, struct can_frame *cf, 217 enum can_state tx_state, enum can_state rx_state); 218 219 int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 220 unsigned int idx); 221 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, 222 u8 *len_ptr); 223 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx); 224 void can_free_echo_skb(struct net_device *dev, unsigned int idx); 225 226 #ifdef CONFIG_OF 227 void of_can_transceiver(struct net_device *dev); 228 #else 229 static inline void of_can_transceiver(struct net_device *dev) { } 230 #endif 231 232 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf); 233 struct sk_buff *alloc_canfd_skb(struct net_device *dev, 234 struct canfd_frame **cfd); 235 struct sk_buff *alloc_can_err_skb(struct net_device *dev, 236 struct can_frame **cf); 237 238 #endif /* !_CAN_DEV_H */ 239