xref: /openbmc/qemu/net/can/can_core.c (revision f363d039)
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 #include "qemu/osdep.h"
29 #include "chardev/char.h"
30 #include "qemu/module.h"
31 #include "qemu/sockets.h"
32 #include "qapi/error.h"
33 #include "net/can_emu.h"
34 #include "qom/object_interfaces.h"
35 
36 struct CanBusState {
37     Object object;
38 
39     QTAILQ_HEAD(, CanBusClientState) clients;
40 };
41 
42 static void can_bus_instance_init(Object *object)
43 {
44     CanBusState *bus = (CanBusState *)object;
45 
46     QTAILQ_INIT(&bus->clients);
47 }
48 
49 int can_bus_insert_client(CanBusState *bus, CanBusClientState *client)
50 {
51     client->bus = bus;
52     QTAILQ_INSERT_TAIL(&bus->clients, client, next);
53     return 0;
54 }
55 
56 int can_bus_remove_client(CanBusClientState *client)
57 {
58     CanBusState *bus = client->bus;
59     if (bus == NULL) {
60         return 0;
61     }
62 
63     QTAILQ_REMOVE(&bus->clients, client, next);
64     client->bus = NULL;
65     return 1;
66 }
67 
68 ssize_t can_bus_client_send(CanBusClientState *client,
69              const struct qemu_can_frame *frames, size_t frames_cnt)
70 {
71     int ret = 0;
72     CanBusState *bus = client->bus;
73     CanBusClientState *peer;
74     if (bus == NULL) {
75         return -1;
76     }
77 
78     QTAILQ_FOREACH(peer, &bus->clients, next) {
79         if (peer->info->can_receive(peer)) {
80             if (peer == client) {
81                 /* No loopback support for now */
82                 continue;
83             }
84             if (peer->info->receive(peer, frames, frames_cnt) > 0) {
85                 ret = 1;
86             }
87         }
88     }
89 
90     return ret;
91 }
92 
93 int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id)
94 {
95     int m;
96     if (((can_id | filter->can_mask) & QEMU_CAN_ERR_FLAG)) {
97         return (filter->can_mask & QEMU_CAN_ERR_FLAG) != 0;
98     }
99     m = (can_id & filter->can_mask) == (filter->can_id & filter->can_mask);
100     return filter->can_id & QEMU_CAN_INV_FILTER ? !m : m;
101 }
102 
103 int can_bus_client_set_filters(CanBusClientState *client,
104              const struct qemu_can_filter *filters, size_t filters_cnt)
105 {
106     return 0;
107 }
108 
109 
110 static bool can_bus_can_be_deleted(UserCreatable *uc)
111 {
112     return false;
113 }
114 
115 static void can_bus_class_init(ObjectClass *klass,
116                                 void *class_data G_GNUC_UNUSED)
117 {
118     UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass);
119 
120     uc_klass->can_be_deleted = can_bus_can_be_deleted;
121 }
122 
123 static const TypeInfo can_bus_info = {
124     .parent = TYPE_OBJECT,
125     .name = TYPE_CAN_BUS,
126     .instance_size = sizeof(CanBusState),
127     .instance_init = can_bus_instance_init,
128     .class_init = can_bus_class_init,
129     .interfaces = (InterfaceInfo[]) {
130         { TYPE_USER_CREATABLE },
131         { }
132     }
133 };
134 
135 static void can_bus_register_types(void)
136 {
137     type_register_static(&can_bus_info);
138 }
139 
140 type_init(can_bus_register_types);
141