xref: /linux-6.15/include/linux/can/dev.h (revision e756bc56)
1 /*
2  * linux/can/dev.h
3  *
4  * Definitions for the CAN network device driver interface
5  *
6  * Copyright (C) 2006 Andrey Volkov <[email protected]>
7  *               Varma Electronics Oy
8  *
9  * Copyright (C) 2008 Wolfgang Grandegger <[email protected]>
10  *
11  */
12 
13 #ifndef CAN_DEV_H
14 #define CAN_DEV_H
15 
16 #include <linux/can.h>
17 #include <linux/can/netlink.h>
18 #include <linux/can/error.h>
19 #include <linux/can/led.h>
20 
21 /*
22  * CAN mode
23  */
24 enum can_mode {
25 	CAN_MODE_STOP = 0,
26 	CAN_MODE_START,
27 	CAN_MODE_SLEEP
28 };
29 
30 /*
31  * CAN common private data
32  */
33 struct can_priv {
34 	struct can_device_stats can_stats;
35 
36 	struct can_bittiming bittiming;
37 	const struct can_bittiming_const *bittiming_const;
38 	struct can_clock clock;
39 
40 	enum can_state state;
41 	u32 ctrlmode;
42 	u32 ctrlmode_supported;
43 
44 	int restart_ms;
45 	struct timer_list restart_timer;
46 
47 	int (*do_set_bittiming)(struct net_device *dev);
48 	int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
49 	int (*do_get_state)(const struct net_device *dev,
50 			    enum can_state *state);
51 	int (*do_get_berr_counter)(const struct net_device *dev,
52 				   struct can_berr_counter *bec);
53 
54 	unsigned int echo_skb_max;
55 	struct sk_buff **echo_skb;
56 
57 #ifdef CONFIG_CAN_LEDS
58 	struct led_trigger *tx_led_trig;
59 	char tx_led_trig_name[CAN_LED_NAME_SZ];
60 	struct led_trigger *rx_led_trig;
61 	char rx_led_trig_name[CAN_LED_NAME_SZ];
62 #endif
63 };
64 
65 /*
66  * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
67  * to __u8 and ensure the dlc value to be max. 8 bytes.
68  *
69  * To be used in the CAN netdriver receive path to ensure conformance with
70  * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
71  */
72 #define get_can_dlc(i)		(min_t(__u8, (i), CAN_MAX_DLC))
73 #define get_canfd_dlc(i)	(min_t(__u8, (i), CANFD_MAX_DLC))
74 
75 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */
76 static inline int can_dropped_invalid_skb(struct net_device *dev,
77 					  struct sk_buff *skb)
78 {
79 	const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
80 
81 	if (skb->protocol == htons(ETH_P_CAN)) {
82 		if (unlikely(skb->len != CAN_MTU ||
83 			     cfd->len > CAN_MAX_DLEN))
84 			goto inval_skb;
85 	} else if (skb->protocol == htons(ETH_P_CANFD)) {
86 		if (unlikely(skb->len != CANFD_MTU ||
87 			     cfd->len > CANFD_MAX_DLEN))
88 			goto inval_skb;
89 	} else
90 		goto inval_skb;
91 
92 	return 0;
93 
94 inval_skb:
95 	kfree_skb(skb);
96 	dev->stats.tx_dropped++;
97 	return 1;
98 }
99 
100 /* get data length from can_dlc with sanitized can_dlc */
101 u8 can_dlc2len(u8 can_dlc);
102 
103 /* map the sanitized data length to an appropriate data length code */
104 u8 can_len2dlc(u8 len);
105 
106 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
107 void free_candev(struct net_device *dev);
108 
109 /* a candev safe wrapper around netdev_priv */
110 struct can_priv *safe_candev_priv(struct net_device *dev);
111 
112 int open_candev(struct net_device *dev);
113 void close_candev(struct net_device *dev);
114 
115 int register_candev(struct net_device *dev);
116 void unregister_candev(struct net_device *dev);
117 
118 int can_restart_now(struct net_device *dev);
119 void can_bus_off(struct net_device *dev);
120 
121 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
122 		      unsigned int idx);
123 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
124 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
125 
126 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
127 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
128 				  struct can_frame **cf);
129 
130 #endif /* CAN_DEV_H */
131