1/*
2 * linux/can/dev.h
3 *
4 * Definitions for the CAN network device driver interface
5 *
6 * Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
7 *               Varma Electronics Oy
8 *
9 * Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
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 */
24enum can_mode {
25	CAN_MODE_STOP = 0,
26	CAN_MODE_START,
27	CAN_MODE_SLEEP
28};
29
30/*
31 * CAN common private data
32 */
33struct 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
43	/* CAN controller features - see include/uapi/linux/can/netlink.h */
44	u32 ctrlmode;		/* current options setting */
45	u32 ctrlmode_supported;	/* options that can be modified by netlink */
46	u32 ctrlmode_static;	/* static enabled options for driver/hardware */
47
48	int restart_ms;
49	struct timer_list restart_timer;
50
51	int (*do_set_bittiming)(struct net_device *dev);
52	int (*do_set_data_bittiming)(struct net_device *dev);
53	int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
54	int (*do_get_state)(const struct net_device *dev,
55			    enum can_state *state);
56	int (*do_get_berr_counter)(const struct net_device *dev,
57				   struct can_berr_counter *bec);
58
59	unsigned int echo_skb_max;
60	struct sk_buff **echo_skb;
61
62#ifdef CONFIG_CAN_LEDS
63	struct led_trigger *tx_led_trig;
64	char tx_led_trig_name[CAN_LED_NAME_SZ];
65	struct led_trigger *rx_led_trig;
66	char rx_led_trig_name[CAN_LED_NAME_SZ];
67	struct led_trigger *rxtx_led_trig;
68	char rxtx_led_trig_name[CAN_LED_NAME_SZ];
69#endif
70};
71
72/*
73 * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
74 * to __u8 and ensure the dlc value to be max. 8 bytes.
75 *
76 * To be used in the CAN netdriver receive path to ensure conformance with
77 * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
78 */
79#define get_can_dlc(i)		(min_t(__u8, (i), CAN_MAX_DLC))
80#define get_canfd_dlc(i)	(min_t(__u8, (i), CANFD_MAX_DLC))
81
82/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
83static inline int can_dropped_invalid_skb(struct net_device *dev,
84					  struct sk_buff *skb)
85{
86	const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
87
88	if (skb->protocol == htons(ETH_P_CAN)) {
89		if (unlikely(skb->len != CAN_MTU ||
90			     cfd->len > CAN_MAX_DLEN))
91			goto inval_skb;
92	} else if (skb->protocol == htons(ETH_P_CANFD)) {
93		if (unlikely(skb->len != CANFD_MTU ||
94			     cfd->len > CANFD_MAX_DLEN))
95			goto inval_skb;
96	} else
97		goto inval_skb;
98
99	return 0;
100
101inval_skb:
102	kfree_skb(skb);
103	dev->stats.tx_dropped++;
104	return 1;
105}
106
107static inline bool can_is_canfd_skb(const struct sk_buff *skb)
108{
109	/* the CAN specific type of skb is identified by its data length */
110	return skb->len == CANFD_MTU;
111}
112
113/* helper to define static CAN controller features at device creation time */
114static inline void can_set_static_ctrlmode(struct net_device *dev,
115					   u32 static_mode)
116{
117	struct can_priv *priv = netdev_priv(dev);
118
119	/* alloc_candev() succeeded => netdev_priv() is valid at this point */
120	priv->ctrlmode = static_mode;
121	priv->ctrlmode_static = static_mode;
122
123	/* override MTU which was set by default in can_setup()? */
124	if (static_mode & CAN_CTRLMODE_FD)
125		dev->mtu = CANFD_MTU;
126}
127
128/* get data length from can_dlc with sanitized can_dlc */
129u8 can_dlc2len(u8 can_dlc);
130
131/* map the sanitized data length to an appropriate data length code */
132u8 can_len2dlc(u8 len);
133
134struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
135void free_candev(struct net_device *dev);
136
137/* a candev safe wrapper around netdev_priv */
138struct can_priv *safe_candev_priv(struct net_device *dev);
139
140int open_candev(struct net_device *dev);
141void close_candev(struct net_device *dev);
142int can_change_mtu(struct net_device *dev, int new_mtu);
143
144int register_candev(struct net_device *dev);
145void unregister_candev(struct net_device *dev);
146
147int can_restart_now(struct net_device *dev);
148void can_bus_off(struct net_device *dev);
149
150void can_change_state(struct net_device *dev, struct can_frame *cf,
151		      enum can_state tx_state, enum can_state rx_state);
152
153void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
154		      unsigned int idx);
155unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
156void can_free_echo_skb(struct net_device *dev, unsigned int idx);
157
158struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
159struct sk_buff *alloc_canfd_skb(struct net_device *dev,
160				struct canfd_frame **cfd);
161struct sk_buff *alloc_can_err_skb(struct net_device *dev,
162				  struct can_frame **cf);
163
164#endif /* !_CAN_DEV_H */
165