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/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 * can_cc_dlc2len(value) - convert a given data length code (dlc) of a 102 * Classical CAN frame into a valid data length of 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 can_cc_dlc2len(dlc) (min_t(u8, (dlc), CAN_MAX_DLEN)) 108 109 /* Check for outgoing skbs that have not been created by the CAN subsystem */ 110 static inline bool can_skb_headroom_valid(struct net_device *dev, 111 struct sk_buff *skb) 112 { 113 /* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */ 114 if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv))) 115 return false; 116 117 /* af_packet does not apply CAN skb specific settings */ 118 if (skb->ip_summed == CHECKSUM_NONE) { 119 /* init headroom */ 120 can_skb_prv(skb)->ifindex = dev->ifindex; 121 can_skb_prv(skb)->skbcnt = 0; 122 123 skb->ip_summed = CHECKSUM_UNNECESSARY; 124 125 /* perform proper loopback on capable devices */ 126 if (dev->flags & IFF_ECHO) 127 skb->pkt_type = PACKET_LOOPBACK; 128 else 129 skb->pkt_type = PACKET_HOST; 130 131 skb_reset_mac_header(skb); 132 skb_reset_network_header(skb); 133 skb_reset_transport_header(skb); 134 } 135 136 return true; 137 } 138 139 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */ 140 static inline bool can_dropped_invalid_skb(struct net_device *dev, 141 struct sk_buff *skb) 142 { 143 const struct canfd_frame *cfd = (struct canfd_frame *)skb->data; 144 145 if (skb->protocol == htons(ETH_P_CAN)) { 146 if (unlikely(skb->len != CAN_MTU || 147 cfd->len > CAN_MAX_DLEN)) 148 goto inval_skb; 149 } else if (skb->protocol == htons(ETH_P_CANFD)) { 150 if (unlikely(skb->len != CANFD_MTU || 151 cfd->len > CANFD_MAX_DLEN)) 152 goto inval_skb; 153 } else 154 goto inval_skb; 155 156 if (!can_skb_headroom_valid(dev, skb)) 157 goto inval_skb; 158 159 return false; 160 161 inval_skb: 162 kfree_skb(skb); 163 dev->stats.tx_dropped++; 164 return true; 165 } 166 167 static inline bool can_is_canfd_skb(const struct sk_buff *skb) 168 { 169 /* the CAN specific type of skb is identified by its data length */ 170 return skb->len == CANFD_MTU; 171 } 172 173 /* helper to get the data length code (DLC) for Classical CAN raw DLC access */ 174 static inline u8 can_get_cc_dlc(const struct can_frame *cf, const u32 ctrlmode) 175 { 176 /* return len8_dlc as dlc value only if all conditions apply */ 177 if ((ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC) && 178 (cf->len == CAN_MAX_DLEN) && 179 (cf->len8_dlc > CAN_MAX_DLEN && cf->len8_dlc <= CAN_MAX_RAW_DLC)) 180 return cf->len8_dlc; 181 182 /* return the payload length as dlc value */ 183 return cf->len; 184 } 185 186 /* helper to set len and len8_dlc value for Classical CAN raw DLC access */ 187 static inline void can_frame_set_cc_len(struct can_frame *cf, const u8 dlc, 188 const u32 ctrlmode) 189 { 190 /* the caller already ensured that dlc is a value from 0 .. 15 */ 191 if (ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC && dlc > CAN_MAX_DLEN) 192 cf->len8_dlc = dlc; 193 194 /* limit the payload length 'len' to CAN_MAX_DLEN */ 195 cf->len = can_cc_dlc2len(dlc); 196 } 197 198 /* helper to define static CAN controller features at device creation time */ 199 static inline void can_set_static_ctrlmode(struct net_device *dev, 200 u32 static_mode) 201 { 202 struct can_priv *priv = netdev_priv(dev); 203 204 /* alloc_candev() succeeded => netdev_priv() is valid at this point */ 205 priv->ctrlmode = static_mode; 206 priv->ctrlmode_static = static_mode; 207 208 /* override MTU which was set by default in can_setup()? */ 209 if (static_mode & CAN_CTRLMODE_FD) 210 dev->mtu = CANFD_MTU; 211 } 212 213 /* get data length from raw data length code (DLC) */ 214 u8 can_fd_dlc2len(u8 dlc); 215 216 /* map the sanitized data length to an appropriate data length code */ 217 u8 can_fd_len2dlc(u8 len); 218 219 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max, 220 unsigned int txqs, unsigned int rxqs); 221 #define alloc_candev(sizeof_priv, echo_skb_max) \ 222 alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1) 223 #define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \ 224 alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count) 225 void free_candev(struct net_device *dev); 226 227 /* a candev safe wrapper around netdev_priv */ 228 struct can_priv *safe_candev_priv(struct net_device *dev); 229 230 int open_candev(struct net_device *dev); 231 void close_candev(struct net_device *dev); 232 int can_change_mtu(struct net_device *dev, int new_mtu); 233 234 int register_candev(struct net_device *dev); 235 void unregister_candev(struct net_device *dev); 236 237 int can_restart_now(struct net_device *dev); 238 void can_bus_off(struct net_device *dev); 239 240 void can_change_state(struct net_device *dev, struct can_frame *cf, 241 enum can_state tx_state, enum can_state rx_state); 242 243 int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 244 unsigned int idx); 245 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, 246 u8 *len_ptr); 247 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx); 248 void can_free_echo_skb(struct net_device *dev, unsigned int idx); 249 250 #ifdef CONFIG_OF 251 void of_can_transceiver(struct net_device *dev); 252 #else 253 static inline void of_can_transceiver(struct net_device *dev) { } 254 #endif 255 256 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf); 257 struct sk_buff *alloc_canfd_skb(struct net_device *dev, 258 struct canfd_frame **cfd); 259 struct sk_buff *alloc_can_err_skb(struct net_device *dev, 260 struct can_frame **cf); 261 262 #endif /* !_CAN_DEV_H */ 263