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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/error.h>
18#include <linux/can/led.h>
19#include <linux/can/netlink.h>
20#include <linux/netdevice.h>
21
22/*
23 * CAN mode
24 */
25enum can_mode {
26 CAN_MODE_STOP = 0,
27 CAN_MODE_START,
28 CAN_MODE_SLEEP
29};
30
31/*
32 * CAN common private data
33 */
34struct can_priv {
35 struct net_device *dev;
36 struct can_device_stats can_stats;
37
38 struct can_bittiming bittiming, data_bittiming;
39 const struct can_bittiming_const *bittiming_const,
40 *data_bittiming_const;
41 const u16 *termination_const;
42 unsigned int termination_const_cnt;
43 u16 termination;
44 const u32 *bitrate_const;
45 unsigned int bitrate_const_cnt;
46 const u32 *data_bitrate_const;
47 unsigned int data_bitrate_const_cnt;
48 struct can_clock clock;
49
50 enum can_state state;
51
52 /* CAN controller features - see include/uapi/linux/can/netlink.h */
53 u32 ctrlmode; /* current options setting */
54 u32 ctrlmode_supported; /* options that can be modified by netlink */
55 u32 ctrlmode_static; /* static enabled options for driver/hardware */
56
57 int restart_ms;
58 struct delayed_work restart_work;
59
60 int (*do_set_bittiming)(struct net_device *dev);
61 int (*do_set_data_bittiming)(struct net_device *dev);
62 int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
63 int (*do_set_termination)(struct net_device *dev, u16 term);
64 int (*do_get_state)(const struct net_device *dev,
65 enum can_state *state);
66 int (*do_get_berr_counter)(const struct net_device *dev,
67 struct can_berr_counter *bec);
68
69 unsigned int echo_skb_max;
70 struct sk_buff **echo_skb;
71
72#ifdef CONFIG_CAN_LEDS
73 struct led_trigger *tx_led_trig;
74 char tx_led_trig_name[CAN_LED_NAME_SZ];
75 struct led_trigger *rx_led_trig;
76 char rx_led_trig_name[CAN_LED_NAME_SZ];
77 struct led_trigger *rxtx_led_trig;
78 char rxtx_led_trig_name[CAN_LED_NAME_SZ];
79#endif
80};
81
82/*
83 * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
84 * to __u8 and ensure the dlc value to be max. 8 bytes.
85 *
86 * To be used in the CAN netdriver receive path to ensure conformance with
87 * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
88 */
89#define get_can_dlc(i) (min_t(__u8, (i), CAN_MAX_DLC))
90#define get_canfd_dlc(i) (min_t(__u8, (i), CANFD_MAX_DLC))
91
92/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
93static inline bool can_dropped_invalid_skb(struct net_device *dev,
94 struct sk_buff *skb)
95{
96 const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
97
98 if (skb->protocol == htons(ETH_P_CAN)) {
99 if (unlikely(skb->len != CAN_MTU ||
100 cfd->len > CAN_MAX_DLEN))
101 goto inval_skb;
102 } else if (skb->protocol == htons(ETH_P_CANFD)) {
103 if (unlikely(skb->len != CANFD_MTU ||
104 cfd->len > CANFD_MAX_DLEN))
105 goto inval_skb;
106 } else
107 goto inval_skb;
108
109 return false;
110
111inval_skb:
112 kfree_skb(skb);
113 dev->stats.tx_dropped++;
114 return true;
115}
116
117static inline bool can_is_canfd_skb(const struct sk_buff *skb)
118{
119 /* the CAN specific type of skb is identified by its data length */
120 return skb->len == CANFD_MTU;
121}
122
123/* helper to define static CAN controller features at device creation time */
124static inline void can_set_static_ctrlmode(struct net_device *dev,
125 u32 static_mode)
126{
127 struct can_priv *priv = netdev_priv(dev);
128
129 /* alloc_candev() succeeded => netdev_priv() is valid at this point */
130 priv->ctrlmode = static_mode;
131 priv->ctrlmode_static = static_mode;
132
133 /* override MTU which was set by default in can_setup()? */
134 if (static_mode & CAN_CTRLMODE_FD)
135 dev->mtu = CANFD_MTU;
136}
137
138/* get data length from can_dlc with sanitized can_dlc */
139u8 can_dlc2len(u8 can_dlc);
140
141/* map the sanitized data length to an appropriate data length code */
142u8 can_len2dlc(u8 len);
143
144struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
145void free_candev(struct net_device *dev);
146
147/* a candev safe wrapper around netdev_priv */
148struct can_priv *safe_candev_priv(struct net_device *dev);
149
150int open_candev(struct net_device *dev);
151void close_candev(struct net_device *dev);
152int can_change_mtu(struct net_device *dev, int new_mtu);
153
154int register_candev(struct net_device *dev);
155void unregister_candev(struct net_device *dev);
156
157int can_restart_now(struct net_device *dev);
158void can_bus_off(struct net_device *dev);
159
160void can_change_state(struct net_device *dev, struct can_frame *cf,
161 enum can_state tx_state, enum can_state rx_state);
162
163void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
164 unsigned int idx);
165unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
166void can_free_echo_skb(struct net_device *dev, unsigned int idx);
167
168struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
169struct sk_buff *alloc_canfd_skb(struct net_device *dev,
170 struct canfd_frame **cfd);
171struct sk_buff *alloc_can_err_skb(struct net_device *dev,
172 struct can_frame **cf);
173
174#endif /* !_CAN_DEV_H */