xref: /qemu/include/net/can_emu.h (revision ad0c6740)
1 /*
2  * CAN common CAN bus emulation support
3  *
4  * Copyright (c) 2013-2014 Jin Yang
5  * Copyright (c) 2014-2018 Pavel Pisa
6  *
7  * Initial development supported by Google GSoC 2013 from RTEMS project slot
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a copy
10  * of this software and associated documentation files (the "Software"), to deal
11  * in the Software without restriction, including without limitation the rights
12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13  * copies of the Software, and to permit persons to whom the Software is
14  * furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice shall be included in
17  * all copies or substantial portions of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25  * THE SOFTWARE.
26  */
27 
28 #ifndef NET_CAN_EMU_H
29 #define NET_CAN_EMU_H
30 
31 #include "qemu/queue.h"
32 #include "qom/object.h"
33 
34 /* NOTE: the following two structures is copied from <linux/can.h>. */
35 
36 /*
37  * Controller Area Network Identifier structure
38  *
39  * bit 0-28    : CAN identifier (11/29 bit)
40  * bit 29      : error frame flag (0 = data frame, 1 = error frame)
41  * bit 30      : remote transmission request flag (1 = rtr frame)
42  * bit 31      : frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
43  */
44 typedef uint32_t qemu_canid_t;
45 
46 typedef struct qemu_can_frame {
47     qemu_canid_t    can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
48     uint8_t         can_dlc; /* data length code: 0 .. 8 */
49     uint8_t         flags;
50     uint8_t         data[64] QEMU_ALIGNED(8);
51 } qemu_can_frame;
52 
53 /* Keep defines for QEMU separate from Linux ones for now */
54 
55 #define QEMU_CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */
56 #define QEMU_CAN_RTR_FLAG 0x40000000U /* remote transmission request */
57 #define QEMU_CAN_ERR_FLAG 0x20000000U /* error message frame */
58 
59 #define QEMU_CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
60 #define QEMU_CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */
61 
62 #define QEMU_CAN_FRMF_BRS     0x01 /* bit rate switch (2nd bitrate for data) */
63 #define QEMU_CAN_FRMF_ESI     0x02 /* error state ind. of transmitting node */
64 #define QEMU_CAN_FRMF_TYPE_FD 0x10 /* internal bit ind. of CAN FD frame */
65 
66 /**
67  * struct qemu_can_filter - CAN ID based filter in can_register().
68  * @can_id:   relevant bits of CAN ID which are not masked out.
69  * @can_mask: CAN mask (see description)
70  *
71  * Description:
72  * A filter matches, when
73  *
74  *          <received_can_id> & mask == can_id & mask
75  *
76  * The filter can be inverted (QEMU_CAN_INV_FILTER bit set in can_id) or it can
77  * filter for error message frames (QEMU_CAN_ERR_FLAG bit set in mask).
78  */
79 typedef struct qemu_can_filter {
80     qemu_canid_t    can_id;
81     qemu_canid_t    can_mask;
82 } qemu_can_filter;
83 
84 /* QEMU_CAN_INV_FILTER can be set in qemu_can_filter.can_id */
85 #define QEMU_CAN_INV_FILTER 0x20000000U
86 
87 typedef struct CanBusClientState CanBusClientState;
88 typedef struct CanBusState CanBusState;
89 
90 typedef struct CanBusClientInfo {
91     bool (*can_receive)(CanBusClientState *);
92     ssize_t (*receive)(CanBusClientState *,
93         const struct qemu_can_frame *frames, size_t frames_cnt);
94 } CanBusClientInfo;
95 
96 struct CanBusClientState {
97     CanBusClientInfo *info;
98     CanBusState *bus;
99     int link_down;
100     QTAILQ_ENTRY(CanBusClientState) next;
101     CanBusClientState *peer;
102     char *model;
103     char *name;
104     void (*destructor)(CanBusClientState *);
105     bool fd_mode;
106 };
107 
108 #define TYPE_CAN_BUS "can-bus"
109 OBJECT_DECLARE_SIMPLE_TYPE(CanBusState, CAN_BUS)
110 
111 int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id);
112 
113 int can_bus_insert_client(CanBusState *bus, CanBusClientState *client);
114 
115 int can_bus_remove_client(CanBusClientState *client);
116 
117 ssize_t can_bus_client_send(CanBusClientState *,
118                             const struct qemu_can_frame *frames,
119                             size_t frames_cnt);
120 
121 int can_bus_client_set_filters(CanBusClientState *,
122                                const struct qemu_can_filter *filters,
123                                size_t filters_cnt);
124 
125 uint8_t can_dlc2len(uint8_t can_dlc);
126 
127 uint8_t can_len2dlc(uint8_t len);
128 
129 #endif
130