xref: /linux/include/linux/can/dev.h (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
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  */
29 enum can_mode {
30 	CAN_MODE_STOP = 0,
31 	CAN_MODE_START,
32 	CAN_MODE_SLEEP
33 };
34 
35 enum 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  */
44 struct 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 
can_tdc_is_enabled(const struct can_priv * priv)90 static 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  */
can_get_relative_tdco(const struct can_priv * priv)115 static 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 */
can_set_static_ctrlmode(struct net_device * dev,u32 static_mode)125 static 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 
can_get_static_ctrlmode(struct can_priv * priv)145 static inline u32 can_get_static_ctrlmode(struct can_priv *priv)
146 {
147 	return priv->ctrlmode & ~priv->ctrlmode_supported;
148 }
149 
can_is_canxl_dev_mtu(unsigned int mtu)150 static 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 */
can_dev_dropped_skb(struct net_device * dev,struct sk_buff * skb)156 static 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 
171 void can_setup(struct net_device *dev);
172 
173 struct 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)
179 void free_candev(struct net_device *dev);
180 
181 /* a candev safe wrapper around netdev_priv */
182 struct can_priv *safe_candev_priv(struct net_device *dev);
183 
184 int open_candev(struct net_device *dev);
185 void close_candev(struct net_device *dev);
186 int can_change_mtu(struct net_device *dev, int new_mtu);
187 int can_eth_ioctl_hwts(struct net_device *netdev, struct ifreq *ifr, int cmd);
188 int can_ethtool_op_get_ts_info_hwts(struct net_device *dev,
189 				    struct kernel_ethtool_ts_info *info);
190 
191 int register_candev(struct net_device *dev);
192 void unregister_candev(struct net_device *dev);
193 
194 int can_restart_now(struct net_device *dev);
195 void can_bus_off(struct net_device *dev);
196 
197 const char *can_get_state_str(const enum can_state state);
198 void 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);
202 void 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
206 void of_can_transceiver(struct net_device *dev);
207 #else
of_can_transceiver(struct net_device * dev)208 static inline void of_can_transceiver(struct net_device *dev) { }
209 #endif
210 
211 extern struct rtnl_link_ops can_link_ops;
212 int can_netlink_register(void);
213 void can_netlink_unregister(void);
214 
215 #endif /* !_CAN_DEV_H */
216