xref: /openbmc/qemu/include/net/can_emu.h (revision 09a274d8)
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 "qom/object.h"
32 
33 /* NOTE: the following two structures is copied from <linux/can.h>. */
34 
35 /*
36  * Controller Area Network Identifier structure
37  *
38  * bit 0-28    : CAN identifier (11/29 bit)
39  * bit 29      : error frame flag (0 = data frame, 1 = error frame)
40  * bit 30      : remote transmission request flag (1 = rtr frame)
41  * bit 31      : frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
42  */
43 typedef uint32_t qemu_canid_t;
44 
45 typedef struct qemu_can_frame {
46     qemu_canid_t    can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
47     uint8_t         can_dlc; /* data length code: 0 .. 8 */
48     uint8_t         data[8] QEMU_ALIGNED(8);
49 } qemu_can_frame;
50 
51 /* Keep defines for QEMU separate from Linux ones for now */
52 
53 #define QEMU_CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */
54 #define QEMU_CAN_RTR_FLAG 0x40000000U /* remote transmission request */
55 #define QEMU_CAN_ERR_FLAG 0x20000000U /* error message frame */
56 
57 #define QEMU_CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
58 #define QEMU_CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */
59 
60 /**
61  * struct qemu_can_filter - CAN ID based filter in can_register().
62  * @can_id:   relevant bits of CAN ID which are not masked out.
63  * @can_mask: CAN mask (see description)
64  *
65  * Description:
66  * A filter matches, when
67  *
68  *          <received_can_id> & mask == can_id & mask
69  *
70  * The filter can be inverted (QEMU_CAN_INV_FILTER bit set in can_id) or it can
71  * filter for error message frames (QEMU_CAN_ERR_FLAG bit set in mask).
72  */
73 typedef struct qemu_can_filter {
74     qemu_canid_t    can_id;
75     qemu_canid_t    can_mask;
76 } qemu_can_filter;
77 
78 /* QEMU_CAN_INV_FILTER can be set in qemu_can_filter.can_id */
79 #define QEMU_CAN_INV_FILTER 0x20000000U
80 
81 typedef struct CanBusClientState CanBusClientState;
82 typedef struct CanBusState CanBusState;
83 
84 typedef struct CanBusClientInfo {
85     int (*can_receive)(CanBusClientState *);
86     ssize_t (*receive)(CanBusClientState *,
87         const struct qemu_can_frame *frames, size_t frames_cnt);
88 } CanBusClientInfo;
89 
90 struct CanBusClientState {
91     CanBusClientInfo *info;
92     CanBusState *bus;
93     int link_down;
94     QTAILQ_ENTRY(CanBusClientState) next;
95     CanBusClientState *peer;
96     char *model;
97     char *name;
98     void (*destructor)(CanBusClientState *);
99 };
100 
101 #define TYPE_CAN_BUS "can-bus"
102 #define CAN_BUS_CLASS(klass) \
103      OBJECT_CLASS_CHECK(CanBusClass, (klass), TYPE_CAN_BUS)
104 #define CAN_BUS_GET_CLASS(obj) \
105      OBJECT_GET_CLASS(CanBusClass, (obj), TYPE_CAN_BUS)
106 #define CAN_BUS(obj) \
107      OBJECT_CHECK(CanBusState, (obj), TYPE_CAN_BUS)
108 
109 int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id);
110 
111 int can_bus_insert_client(CanBusState *bus, CanBusClientState *client);
112 
113 int can_bus_remove_client(CanBusClientState *client);
114 
115 ssize_t can_bus_client_send(CanBusClientState *,
116                             const struct qemu_can_frame *frames,
117                             size_t frames_cnt);
118 
119 int can_bus_client_set_filters(CanBusClientState *,
120                                const struct qemu_can_filter *filters,
121                                size_t filters_cnt);
122 
123 #endif
124