xref: /linux-6.15/include/linux/can/dev.h (revision dec102aa)
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, data_bittiming;
37 	const struct can_bittiming_const *bittiming_const,
38 		*data_bittiming_const;
39 	struct can_clock clock;
40 
41 	enum can_state state;
42 	u32 ctrlmode;
43 	u32 ctrlmode_supported;
44 
45 	int restart_ms;
46 	struct timer_list restart_timer;
47 
48 	int (*do_set_bittiming)(struct net_device *dev);
49 	int (*do_set_data_bittiming)(struct net_device *dev);
50 	int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
51 	int (*do_get_state)(const struct net_device *dev,
52 			    enum can_state *state);
53 	int (*do_get_berr_counter)(const struct net_device *dev,
54 				   struct can_berr_counter *bec);
55 
56 	unsigned int echo_skb_max;
57 	struct sk_buff **echo_skb;
58 
59 #ifdef CONFIG_CAN_LEDS
60 	struct led_trigger *tx_led_trig;
61 	char tx_led_trig_name[CAN_LED_NAME_SZ];
62 	struct led_trigger *rx_led_trig;
63 	char rx_led_trig_name[CAN_LED_NAME_SZ];
64 #endif
65 };
66 
67 /*
68  * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
69  * to __u8 and ensure the dlc value to be max. 8 bytes.
70  *
71  * To be used in the CAN netdriver receive path to ensure conformance with
72  * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
73  */
74 #define get_can_dlc(i)		(min_t(__u8, (i), CAN_MAX_DLC))
75 #define get_canfd_dlc(i)	(min_t(__u8, (i), CANFD_MAX_DLC))
76 
77 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */
78 static inline int can_dropped_invalid_skb(struct net_device *dev,
79 					  struct sk_buff *skb)
80 {
81 	const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
82 
83 	if (skb->protocol == htons(ETH_P_CAN)) {
84 		if (unlikely(skb->len != CAN_MTU ||
85 			     cfd->len > CAN_MAX_DLEN))
86 			goto inval_skb;
87 	} else if (skb->protocol == htons(ETH_P_CANFD)) {
88 		if (unlikely(skb->len != CANFD_MTU ||
89 			     cfd->len > CANFD_MAX_DLEN))
90 			goto inval_skb;
91 	} else
92 		goto inval_skb;
93 
94 	return 0;
95 
96 inval_skb:
97 	kfree_skb(skb);
98 	dev->stats.tx_dropped++;
99 	return 1;
100 }
101 
102 /* get data length from can_dlc with sanitized can_dlc */
103 u8 can_dlc2len(u8 can_dlc);
104 
105 /* map the sanitized data length to an appropriate data length code */
106 u8 can_len2dlc(u8 len);
107 
108 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
109 void free_candev(struct net_device *dev);
110 
111 /* a candev safe wrapper around netdev_priv */
112 struct can_priv *safe_candev_priv(struct net_device *dev);
113 
114 int open_candev(struct net_device *dev);
115 void close_candev(struct net_device *dev);
116 int can_change_mtu(struct net_device *dev, int new_mtu);
117 
118 int register_candev(struct net_device *dev);
119 void unregister_candev(struct net_device *dev);
120 
121 int can_restart_now(struct net_device *dev);
122 void can_bus_off(struct net_device *dev);
123 
124 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
125 		      unsigned int idx);
126 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
127 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
128 
129 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
130 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
131 				struct canfd_frame **cfd);
132 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
133 				  struct can_frame **cf);
134 
135 #endif /* CAN_DEV_H */
136