xref: /openbmc/qemu/include/net/can_emu.h (revision a68694cd)
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         data[8] QEMU_ALIGNED(8);
50 } qemu_can_frame;
51 
52 /* Keep defines for QEMU separate from Linux ones for now */
53 
54 #define QEMU_CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */
55 #define QEMU_CAN_RTR_FLAG 0x40000000U /* remote transmission request */
56 #define QEMU_CAN_ERR_FLAG 0x20000000U /* error message frame */
57 
58 #define QEMU_CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
59 #define QEMU_CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */
60 
61 /**
62  * struct qemu_can_filter - CAN ID based filter in can_register().
63  * @can_id:   relevant bits of CAN ID which are not masked out.
64  * @can_mask: CAN mask (see description)
65  *
66  * Description:
67  * A filter matches, when
68  *
69  *          <received_can_id> & mask == can_id & mask
70  *
71  * The filter can be inverted (QEMU_CAN_INV_FILTER bit set in can_id) or it can
72  * filter for error message frames (QEMU_CAN_ERR_FLAG bit set in mask).
73  */
74 typedef struct qemu_can_filter {
75     qemu_canid_t    can_id;
76     qemu_canid_t    can_mask;
77 } qemu_can_filter;
78 
79 /* QEMU_CAN_INV_FILTER can be set in qemu_can_filter.can_id */
80 #define QEMU_CAN_INV_FILTER 0x20000000U
81 
82 typedef struct CanBusClientState CanBusClientState;
83 typedef struct CanBusState CanBusState;
84 
85 typedef struct CanBusClientInfo {
86     bool (*can_receive)(CanBusClientState *);
87     ssize_t (*receive)(CanBusClientState *,
88         const struct qemu_can_frame *frames, size_t frames_cnt);
89 } CanBusClientInfo;
90 
91 struct CanBusClientState {
92     CanBusClientInfo *info;
93     CanBusState *bus;
94     int link_down;
95     QTAILQ_ENTRY(CanBusClientState) next;
96     CanBusClientState *peer;
97     char *model;
98     char *name;
99     void (*destructor)(CanBusClientState *);
100 };
101 
102 #define TYPE_CAN_BUS "can-bus"
103 DECLARE_INSTANCE_CHECKER(CanBusState, CAN_BUS,
104                          TYPE_CAN_BUS)
105 
106 int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id);
107 
108 int can_bus_insert_client(CanBusState *bus, CanBusClientState *client);
109 
110 int can_bus_remove_client(CanBusClientState *client);
111 
112 ssize_t can_bus_client_send(CanBusClientState *,
113                             const struct qemu_can_frame *frames,
114                             size_t frames_cnt);
115 
116 int can_bus_client_set_filters(CanBusClientState *,
117                                const struct qemu_can_filter *filters,
118                                size_t filters_cnt);
119 
120 #endif
121