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/netdevice.h>
24 
25 /*
26  * CAN mode
27  */
28 enum can_mode {
29 	CAN_MODE_STOP = 0,
30 	CAN_MODE_START,
31 	CAN_MODE_SLEEP
32 };
33 
34 enum can_termination_gpio {
35 	CAN_TERMINATION_GPIO_DISABLED = 0,
36 	CAN_TERMINATION_GPIO_ENABLED,
37 	CAN_TERMINATION_GPIO_MAX,
38 };
39 
40 /*
41  * CAN common private data
42  */
43 struct can_priv {
44 	struct net_device *dev;
45 	struct can_device_stats can_stats;
46 
47 	const struct can_bittiming_const *bittiming_const,
48 		*data_bittiming_const;
49 	struct can_bittiming bittiming, data_bittiming;
50 	const struct can_tdc_const *tdc_const;
51 	struct can_tdc tdc;
52 
53 	unsigned int bitrate_const_cnt;
54 	const u32 *bitrate_const;
55 	const u32 *data_bitrate_const;
56 	unsigned int data_bitrate_const_cnt;
57 	u32 bitrate_max;
58 	struct can_clock clock;
59 
60 	unsigned int termination_const_cnt;
61 	const u16 *termination_const;
62 	u16 termination;
63 	struct gpio_desc *termination_gpio;
64 	u16 termination_gpio_ohms[CAN_TERMINATION_GPIO_MAX];
65 
66 	unsigned int echo_skb_max;
67 	struct sk_buff **echo_skb;
68 
69 	enum can_state state;
70 
71 	/* CAN controller features - see include/uapi/linux/can/netlink.h */
72 	u32 ctrlmode;		/* current options setting */
73 	u32 ctrlmode_supported;	/* options that can be modified by netlink */
74 
75 	int restart_ms;
76 	struct delayed_work restart_work;
77 
78 	int (*do_set_bittiming)(struct net_device *dev);
79 	int (*do_set_data_bittiming)(struct net_device *dev);
80 	int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
81 	int (*do_set_termination)(struct net_device *dev, u16 term);
82 	int (*do_get_state)(const struct net_device *dev,
83 			    enum can_state *state);
84 	int (*do_get_berr_counter)(const struct net_device *dev,
85 				   struct can_berr_counter *bec);
86 	int (*do_get_auto_tdcv)(const struct net_device *dev, u32 *tdcv);
87 };
88 
can_tdc_is_enabled(const struct can_priv * priv)89 static inline bool can_tdc_is_enabled(const struct can_priv *priv)
90 {
91 	return !!(priv->ctrlmode & CAN_CTRLMODE_TDC_MASK);
92 }
93 
94 /*
95  * can_get_relative_tdco() - TDCO relative to the sample point
96  *
97  * struct can_tdc::tdco represents the absolute offset from TDCV. Some
98  * controllers use instead an offset relative to the Sample Point (SP)
99  * such that:
100  *
101  * SSP = TDCV + absolute TDCO
102  *     = TDCV + SP + relative TDCO
103  *
104  * -+----------- one bit ----------+-- TX pin
105  *  |<--- Sample Point --->|
106  *
107  *                         --+----------- one bit ----------+-- RX pin
108  *  |<-------- TDCV -------->|
109  *                           |<------------------------>| absolute TDCO
110  *                           |<--- Sample Point --->|
111  *                           |                      |<->| relative TDCO
112  *  |<------------- Secondary Sample Point ------------>|
113  */
can_get_relative_tdco(const struct can_priv * priv)114 static inline s32 can_get_relative_tdco(const struct can_priv *priv)
115 {
116 	const struct can_bittiming *dbt = &priv->data_bittiming;
117 	s32 sample_point_in_tc = (CAN_SYNC_SEG + dbt->prop_seg +
118 				  dbt->phase_seg1) * dbt->brp;
119 
120 	return (s32)priv->tdc.tdco - sample_point_in_tc;
121 }
122 
123 /* helper to define static CAN controller features at device creation time */
can_set_static_ctrlmode(struct net_device * dev,u32 static_mode)124 static inline int __must_check 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 	if (priv->ctrlmode_supported & static_mode) {
131 		netdev_warn(dev,
132 			    "Controller features can not be supported and static at the same time\n");
133 		return -EINVAL;
134 	}
135 	priv->ctrlmode = static_mode;
136 
137 	/* override MTU which was set by default in can_setup()? */
138 	if (static_mode & CAN_CTRLMODE_FD)
139 		dev->mtu = CANFD_MTU;
140 
141 	return 0;
142 }
143 
can_get_static_ctrlmode(struct can_priv * priv)144 static inline u32 can_get_static_ctrlmode(struct can_priv *priv)
145 {
146 	return priv->ctrlmode & ~priv->ctrlmode_supported;
147 }
148 
149 void can_setup(struct net_device *dev);
150 
151 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
152 				    unsigned int txqs, unsigned int rxqs);
153 #define alloc_candev(sizeof_priv, echo_skb_max) \
154 	alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1)
155 #define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \
156 	alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count)
157 void free_candev(struct net_device *dev);
158 
159 /* a candev safe wrapper around netdev_priv */
160 struct can_priv *safe_candev_priv(struct net_device *dev);
161 
162 int open_candev(struct net_device *dev);
163 void close_candev(struct net_device *dev);
164 int can_change_mtu(struct net_device *dev, int new_mtu);
165 
166 int register_candev(struct net_device *dev);
167 void unregister_candev(struct net_device *dev);
168 
169 int can_restart_now(struct net_device *dev);
170 void can_bus_off(struct net_device *dev);
171 
172 const char *can_get_state_str(const enum can_state state);
173 void can_change_state(struct net_device *dev, struct can_frame *cf,
174 		      enum can_state tx_state, enum can_state rx_state);
175 
176 #ifdef CONFIG_OF
177 void of_can_transceiver(struct net_device *dev);
178 #else
of_can_transceiver(struct net_device * dev)179 static inline void of_can_transceiver(struct net_device *dev) { }
180 #endif
181 
182 extern struct rtnl_link_ops can_link_ops;
183 int can_netlink_register(void);
184 void can_netlink_unregister(void);
185 
186 #endif /* !_CAN_DEV_H */
187