xref: /linux-6.15/include/linux/can/dev.h (revision 5d4a2e29)
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  * Send feedback to <[email protected]>
12  */
13 
14 #ifndef CAN_DEV_H
15 #define CAN_DEV_H
16 
17 #include <linux/can.h>
18 #include <linux/can/netlink.h>
19 #include <linux/can/error.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 	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 
58 /*
59  * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
60  * to __u8 and ensure the dlc value to be max. 8 bytes.
61  *
62  * To be used in the CAN netdriver receive path to ensure conformance with
63  * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
64  */
65 #define get_can_dlc(i)	(min_t(__u8, (i), 8))
66 
67 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */
68 static inline int can_dropped_invalid_skb(struct net_device *dev,
69 					  struct sk_buff *skb)
70 {
71 	const struct can_frame *cf = (struct can_frame *)skb->data;
72 
73 	if (unlikely(skb->len != sizeof(*cf) || cf->can_dlc > 8)) {
74 		kfree_skb(skb);
75 		dev->stats.tx_dropped++;
76 		return 1;
77 	}
78 
79 	return 0;
80 }
81 
82 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
83 void free_candev(struct net_device *dev);
84 
85 int open_candev(struct net_device *dev);
86 void close_candev(struct net_device *dev);
87 
88 int register_candev(struct net_device *dev);
89 void unregister_candev(struct net_device *dev);
90 
91 int can_restart_now(struct net_device *dev);
92 void can_bus_off(struct net_device *dev);
93 
94 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
95 		      unsigned int idx);
96 void can_get_echo_skb(struct net_device *dev, unsigned int idx);
97 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
98 
99 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
100 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
101 				  struct can_frame **cf);
102 
103 #endif /* CAN_DEV_H */
104