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/bittiming.h> 19 #include <linux/can/error.h> 20 #include <linux/can/led.h> 21 #include <linux/can/netlink.h> 22 #include <linux/can/skb.h> 23 #include <linux/netdevice.h> 24 25 /* 26 * CAN mode 27 */ 28 enum can_mode { 29 CAN_MODE_STOP = 0, 30 CAN_MODE_START, 31 CAN_MODE_SLEEP 32 }; 33 34 /* 35 * CAN common private data 36 */ 37 struct can_priv { 38 struct net_device *dev; 39 struct can_device_stats can_stats; 40 41 struct can_bittiming bittiming, data_bittiming; 42 const struct can_bittiming_const *bittiming_const, 43 *data_bittiming_const; 44 const u16 *termination_const; 45 unsigned int termination_const_cnt; 46 u16 termination; 47 const u32 *bitrate_const; 48 unsigned int bitrate_const_cnt; 49 const u32 *data_bitrate_const; 50 unsigned int data_bitrate_const_cnt; 51 u32 bitrate_max; 52 struct can_clock clock; 53 54 enum can_state state; 55 56 /* CAN controller features - see include/uapi/linux/can/netlink.h */ 57 u32 ctrlmode; /* current options setting */ 58 u32 ctrlmode_supported; /* options that can be modified by netlink */ 59 u32 ctrlmode_static; /* static enabled options for driver/hardware */ 60 61 int restart_ms; 62 struct delayed_work restart_work; 63 64 int (*do_set_bittiming)(struct net_device *dev); 65 int (*do_set_data_bittiming)(struct net_device *dev); 66 int (*do_set_mode)(struct net_device *dev, enum can_mode mode); 67 int (*do_set_termination)(struct net_device *dev, u16 term); 68 int (*do_get_state)(const struct net_device *dev, 69 enum can_state *state); 70 int (*do_get_berr_counter)(const struct net_device *dev, 71 struct can_berr_counter *bec); 72 73 unsigned int echo_skb_max; 74 struct sk_buff **echo_skb; 75 76 #ifdef CONFIG_CAN_LEDS 77 struct led_trigger *tx_led_trig; 78 char tx_led_trig_name[CAN_LED_NAME_SZ]; 79 struct led_trigger *rx_led_trig; 80 char rx_led_trig_name[CAN_LED_NAME_SZ]; 81 struct led_trigger *rxtx_led_trig; 82 char rxtx_led_trig_name[CAN_LED_NAME_SZ]; 83 #endif 84 }; 85 86 /* 87 * can_cc_dlc2len(value) - convert a given data length code (dlc) of a 88 * Classical CAN frame into a valid data length of max. 8 bytes. 89 * 90 * To be used in the CAN netdriver receive path to ensure conformance with 91 * ISO 11898-1 Chapter 8.4.2.3 (DLC field) 92 */ 93 #define can_cc_dlc2len(dlc) (min_t(u8, (dlc), CAN_MAX_DLEN)) 94 95 /* Check for outgoing skbs that have not been created by the CAN subsystem */ 96 static inline bool can_skb_headroom_valid(struct net_device *dev, 97 struct sk_buff *skb) 98 { 99 /* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */ 100 if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv))) 101 return false; 102 103 /* af_packet does not apply CAN skb specific settings */ 104 if (skb->ip_summed == CHECKSUM_NONE) { 105 /* init headroom */ 106 can_skb_prv(skb)->ifindex = dev->ifindex; 107 can_skb_prv(skb)->skbcnt = 0; 108 109 skb->ip_summed = CHECKSUM_UNNECESSARY; 110 111 /* perform proper loopback on capable devices */ 112 if (dev->flags & IFF_ECHO) 113 skb->pkt_type = PACKET_LOOPBACK; 114 else 115 skb->pkt_type = PACKET_HOST; 116 117 skb_reset_mac_header(skb); 118 skb_reset_network_header(skb); 119 skb_reset_transport_header(skb); 120 } 121 122 return true; 123 } 124 125 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */ 126 static inline bool can_dropped_invalid_skb(struct net_device *dev, 127 struct sk_buff *skb) 128 { 129 const struct canfd_frame *cfd = (struct canfd_frame *)skb->data; 130 131 if (skb->protocol == htons(ETH_P_CAN)) { 132 if (unlikely(skb->len != CAN_MTU || 133 cfd->len > CAN_MAX_DLEN)) 134 goto inval_skb; 135 } else if (skb->protocol == htons(ETH_P_CANFD)) { 136 if (unlikely(skb->len != CANFD_MTU || 137 cfd->len > CANFD_MAX_DLEN)) 138 goto inval_skb; 139 } else 140 goto inval_skb; 141 142 if (!can_skb_headroom_valid(dev, skb)) 143 goto inval_skb; 144 145 return false; 146 147 inval_skb: 148 kfree_skb(skb); 149 dev->stats.tx_dropped++; 150 return true; 151 } 152 153 static inline bool can_is_canfd_skb(const struct sk_buff *skb) 154 { 155 /* the CAN specific type of skb is identified by its data length */ 156 return skb->len == CANFD_MTU; 157 } 158 159 /* helper to get the data length code (DLC) for Classical CAN raw DLC access */ 160 static inline u8 can_get_cc_dlc(const struct can_frame *cf, const u32 ctrlmode) 161 { 162 /* return len8_dlc as dlc value only if all conditions apply */ 163 if ((ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC) && 164 (cf->len == CAN_MAX_DLEN) && 165 (cf->len8_dlc > CAN_MAX_DLEN && cf->len8_dlc <= CAN_MAX_RAW_DLC)) 166 return cf->len8_dlc; 167 168 /* return the payload length as dlc value */ 169 return cf->len; 170 } 171 172 /* helper to set len and len8_dlc value for Classical CAN raw DLC access */ 173 static inline void can_frame_set_cc_len(struct can_frame *cf, const u8 dlc, 174 const u32 ctrlmode) 175 { 176 /* the caller already ensured that dlc is a value from 0 .. 15 */ 177 if (ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC && dlc > CAN_MAX_DLEN) 178 cf->len8_dlc = dlc; 179 180 /* limit the payload length 'len' to CAN_MAX_DLEN */ 181 cf->len = can_cc_dlc2len(dlc); 182 } 183 184 /* helper to define static CAN controller features at device creation time */ 185 static inline void can_set_static_ctrlmode(struct net_device *dev, 186 u32 static_mode) 187 { 188 struct can_priv *priv = netdev_priv(dev); 189 190 /* alloc_candev() succeeded => netdev_priv() is valid at this point */ 191 priv->ctrlmode = static_mode; 192 priv->ctrlmode_static = static_mode; 193 194 /* override MTU which was set by default in can_setup()? */ 195 if (static_mode & CAN_CTRLMODE_FD) 196 dev->mtu = CANFD_MTU; 197 } 198 199 /* get data length from raw data length code (DLC) */ 200 u8 can_fd_dlc2len(u8 dlc); 201 202 /* map the sanitized data length to an appropriate data length code */ 203 u8 can_fd_len2dlc(u8 len); 204 205 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max, 206 unsigned int txqs, unsigned int rxqs); 207 #define alloc_candev(sizeof_priv, echo_skb_max) \ 208 alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1) 209 #define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \ 210 alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count) 211 void free_candev(struct net_device *dev); 212 213 /* a candev safe wrapper around netdev_priv */ 214 struct can_priv *safe_candev_priv(struct net_device *dev); 215 216 int open_candev(struct net_device *dev); 217 void close_candev(struct net_device *dev); 218 int can_change_mtu(struct net_device *dev, int new_mtu); 219 220 int register_candev(struct net_device *dev); 221 void unregister_candev(struct net_device *dev); 222 223 int can_restart_now(struct net_device *dev); 224 void can_bus_off(struct net_device *dev); 225 226 void can_change_state(struct net_device *dev, struct can_frame *cf, 227 enum can_state tx_state, enum can_state rx_state); 228 229 int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 230 unsigned int idx); 231 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, 232 u8 *len_ptr); 233 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx); 234 void can_free_echo_skb(struct net_device *dev, unsigned int idx); 235 236 #ifdef CONFIG_OF 237 void of_can_transceiver(struct net_device *dev); 238 #else 239 static inline void of_can_transceiver(struct net_device *dev) { } 240 #endif 241 242 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf); 243 struct sk_buff *alloc_canfd_skb(struct net_device *dev, 244 struct canfd_frame **cfd); 245 struct sk_buff *alloc_can_err_skb(struct net_device *dev, 246 struct can_frame **cf); 247 248 #endif /* !_CAN_DEV_H */ 249