1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * linux/can/dev.h
4 *
5 * Definitions for the CAN network device driver interface
6 *
7 * Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
8 *               Varma Electronics Oy
9 *
10 * Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
11 *
12 */
13
14#ifndef _CAN_DEV_H
15#define _CAN_DEV_H
16
17#include <linux/can.h>
18#include <linux/can/bittiming.h>
19#include <linux/can/error.h>
20#include <linux/can/length.h>
21#include <linux/can/netlink.h>
22#include <linux/can/skb.h>
23#include <linux/ethtool.h>
24#include <linux/netdevice.h>
25
26/*
27 * CAN mode
28 */
29enum can_mode {
30	CAN_MODE_STOP = 0,
31	CAN_MODE_START,
32	CAN_MODE_SLEEP
33};
34
35enum can_termination_gpio {
36	CAN_TERMINATION_GPIO_DISABLED = 0,
37	CAN_TERMINATION_GPIO_ENABLED,
38	CAN_TERMINATION_GPIO_MAX,
39};
40
41/*
42 * CAN common private data
43 */
44struct can_priv {
45	struct net_device *dev;
46	struct can_device_stats can_stats;
47
48	const struct can_bittiming_const *bittiming_const,
49		*data_bittiming_const;
50	struct can_bittiming bittiming, data_bittiming;
51	const struct can_tdc_const *tdc_const;
52	struct can_tdc tdc;
53
54	unsigned int bitrate_const_cnt;
55	const u32 *bitrate_const;
56	const u32 *data_bitrate_const;
57	unsigned int data_bitrate_const_cnt;
58	u32 bitrate_max;
59	struct can_clock clock;
60
61	unsigned int termination_const_cnt;
62	const u16 *termination_const;
63	u16 termination;
64	struct gpio_desc *termination_gpio;
65	u16 termination_gpio_ohms[CAN_TERMINATION_GPIO_MAX];
66
67	unsigned int echo_skb_max;
68	struct sk_buff **echo_skb;
69
70	enum can_state state;
71
72	/* CAN controller features - see include/uapi/linux/can/netlink.h */
73	u32 ctrlmode;		/* current options setting */
74	u32 ctrlmode_supported;	/* options that can be modified by netlink */
75
76	int restart_ms;
77	struct delayed_work restart_work;
78
79	int (*do_set_bittiming)(struct net_device *dev);
80	int (*do_set_data_bittiming)(struct net_device *dev);
81	int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
82	int (*do_set_termination)(struct net_device *dev, u16 term);
83	int (*do_get_state)(const struct net_device *dev,
84			    enum can_state *state);
85	int (*do_get_berr_counter)(const struct net_device *dev,
86				   struct can_berr_counter *bec);
87	int (*do_get_auto_tdcv)(const struct net_device *dev, u32 *tdcv);
88};
89
90static inline bool can_tdc_is_enabled(const struct can_priv *priv)
91{
92	return !!(priv->ctrlmode & CAN_CTRLMODE_TDC_MASK);
93}
94
95/*
96 * can_get_relative_tdco() - TDCO relative to the sample point
97 *
98 * struct can_tdc::tdco represents the absolute offset from TDCV. Some
99 * controllers use instead an offset relative to the Sample Point (SP)
100 * such that:
101 *
102 * SSP = TDCV + absolute TDCO
103 *     = TDCV + SP + relative TDCO
104 *
105 * -+----------- one bit ----------+-- TX pin
106 *  |<--- Sample Point --->|
107 *
108 *                         --+----------- one bit ----------+-- RX pin
109 *  |<-------- TDCV -------->|
110 *                           |<------------------------>| absolute TDCO
111 *                           |<--- Sample Point --->|
112 *                           |                      |<->| relative TDCO
113 *  |<------------- Secondary Sample Point ------------>|
114 */
115static inline s32 can_get_relative_tdco(const struct can_priv *priv)
116{
117	const struct can_bittiming *dbt = &priv->data_bittiming;
118	s32 sample_point_in_tc = (CAN_SYNC_SEG + dbt->prop_seg +
119				  dbt->phase_seg1) * dbt->brp;
120
121	return (s32)priv->tdc.tdco - sample_point_in_tc;
122}
123
124/* helper to define static CAN controller features at device creation time */
125static inline int __must_check can_set_static_ctrlmode(struct net_device *dev,
126						       u32 static_mode)
127{
128	struct can_priv *priv = netdev_priv(dev);
129
130	/* alloc_candev() succeeded => netdev_priv() is valid at this point */
131	if (priv->ctrlmode_supported & static_mode) {
132		netdev_warn(dev,
133			    "Controller features can not be supported and static at the same time\n");
134		return -EINVAL;
135	}
136	priv->ctrlmode = static_mode;
137
138	/* override MTU which was set by default in can_setup()? */
139	if (static_mode & CAN_CTRLMODE_FD)
140		dev->mtu = CANFD_MTU;
141
142	return 0;
143}
144
145static inline u32 can_get_static_ctrlmode(struct can_priv *priv)
146{
147	return priv->ctrlmode & ~priv->ctrlmode_supported;
148}
149
150static inline bool can_is_canxl_dev_mtu(unsigned int mtu)
151{
152	return (mtu >= CANXL_MIN_MTU && mtu <= CANXL_MAX_MTU);
153}
154
155/* drop skb if it does not contain a valid CAN frame for sending */
156static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *skb)
157{
158	struct can_priv *priv = netdev_priv(dev);
159
160	if (priv->ctrlmode & CAN_CTRLMODE_LISTENONLY) {
161		netdev_info_once(dev,
162				 "interface in listen only mode, dropping skb\n");
163		kfree_skb(skb);
164		dev->stats.tx_dropped++;
165		return true;
166	}
167
168	return can_dropped_invalid_skb(dev, skb);
169}
170
171void can_setup(struct net_device *dev);
172
173struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
174				    unsigned int txqs, unsigned int rxqs);
175#define alloc_candev(sizeof_priv, echo_skb_max) \
176	alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1)
177#define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \
178	alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count)
179void free_candev(struct net_device *dev);
180
181/* a candev safe wrapper around netdev_priv */
182struct can_priv *safe_candev_priv(struct net_device *dev);
183
184int open_candev(struct net_device *dev);
185void close_candev(struct net_device *dev);
186int can_change_mtu(struct net_device *dev, int new_mtu);
187int can_eth_ioctl_hwts(struct net_device *netdev, struct ifreq *ifr, int cmd);
188int can_ethtool_op_get_ts_info_hwts(struct net_device *dev,
189				    struct ethtool_ts_info *info);
190
191int register_candev(struct net_device *dev);
192void unregister_candev(struct net_device *dev);
193
194int can_restart_now(struct net_device *dev);
195void can_bus_off(struct net_device *dev);
196
197const char *can_get_state_str(const enum can_state state);
198void can_state_get_by_berr_counter(const struct net_device *dev,
199				   const struct can_berr_counter *bec,
200				   enum can_state *tx_state,
201				   enum can_state *rx_state);
202void can_change_state(struct net_device *dev, struct can_frame *cf,
203		      enum can_state tx_state, enum can_state rx_state);
204
205#ifdef CONFIG_OF
206void of_can_transceiver(struct net_device *dev);
207#else
208static inline void of_can_transceiver(struct net_device *dev) { }
209#endif
210
211extern struct rtnl_link_ops can_link_ops;
212int can_netlink_register(void);
213void can_netlink_unregister(void);
214
215#endif /* !_CAN_DEV_H */
216