| 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 | /* CAN DLC to real data length conversion helpers */ |
| 37 | |
| 38 | static const uint8_t dlc2len[] = { |
| 39 | 0, 1, 2, 3, 4, 5, 6, 7, |
| 40 | 8, 12, 16, 20, 24, 32, 48, 64 |
| 41 | }; |
| 42 | |
| 43 | /* get data length from can_dlc with sanitized can_dlc */ |
| 44 | uint8_t can_dlc2len(uint8_t can_dlc) |
| 45 | { |
| 46 | return dlc2len[can_dlc & 0x0F]; |
| 47 | } |
| 48 | |
| 49 | static const uint8_t len2dlc[] = { |
| 50 | 0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */ |
| 51 | 9, 9, 9, 9, /* 9 - 12 */ |
| 52 | 10, 10, 10, 10, /* 13 - 16 */ |
| 53 | 11, 11, 11, 11, /* 17 - 20 */ |
| 54 | 12, 12, 12, 12, /* 21 - 24 */ |
| 55 | 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */ |
| 56 | 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */ |
| 57 | 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */ |
| 58 | 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */ |
| 59 | 15, 15, 15, 15, 15, 15, 15, 15 /* 57 - 64 */ |
| 60 | }; |
| 61 | |
| 62 | /* map the sanitized data length to an appropriate data length code */ |
| 63 | uint8_t can_len2dlc(uint8_t len) |
| 64 | { |
| 65 | if (unlikely(len > 64)) { |
| 66 | return 0xF; |
| 67 | } |
| 68 | |
| 69 | return len2dlc[len]; |
| 70 | } |
| 71 | |
| 72 | struct CanBusState { |
| 73 | Object object; |
| 74 | |
| 75 | QTAILQ_HEAD(, CanBusClientState) clients; |
| 76 | }; |
| 77 | |
| 78 | static void can_bus_instance_init(Object *object) |
| 79 | { |
| 80 | CanBusState *bus = (CanBusState *)object; |
| 81 | |
| 82 | QTAILQ_INIT(&bus->clients); |
| 83 | } |
| 84 | |
| 85 | int can_bus_insert_client(CanBusState *bus, CanBusClientState *client) |
| 86 | { |
| 87 | client->bus = bus; |
| 88 | QTAILQ_INSERT_TAIL(&bus->clients, client, next); |
| 89 | return 0; |
| 90 | } |
| 91 | |
| 92 | int can_bus_remove_client(CanBusClientState *client) |
| 93 | { |
| 94 | CanBusState *bus = client->bus; |
| 95 | if (bus == NULL) { |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | QTAILQ_REMOVE(&bus->clients, client, next); |
| 100 | client->bus = NULL; |
| 101 | return 1; |
| 102 | } |
| 103 | |
| 104 | ssize_t can_bus_client_send(CanBusClientState *client, |
| 105 | const struct qemu_can_frame *frames, size_t frames_cnt) |
| 106 | { |
| 107 | int ret = 0; |
| 108 | CanBusState *bus = client->bus; |
| 109 | CanBusClientState *peer; |
| 110 | if (bus == NULL) { |
| 111 | return -1; |
| 112 | } |
| 113 | |
| 114 | QTAILQ_FOREACH(peer, &bus->clients, next) { |
| 115 | if (peer->info->can_receive(peer)) { |
| 116 | if (peer == client) { |
| 117 | /* No loopback support for now */ |
| 118 | continue; |
| 119 | } |
| 120 | if (peer->info->receive(peer, frames, frames_cnt) > 0) { |
| 121 | ret = 1; |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | return ret; |
| 127 | } |
| 128 | |
| 129 | int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id) |
| 130 | { |
| 131 | int m; |
| 132 | if (((can_id | filter->can_mask) & QEMU_CAN_ERR_FLAG)) { |
| 133 | return (filter->can_mask & QEMU_CAN_ERR_FLAG) != 0; |
| 134 | } |
| 135 | m = (can_id & filter->can_mask) == (filter->can_id & filter->can_mask); |
| 136 | return filter->can_id & QEMU_CAN_INV_FILTER ? !m : m; |
| 137 | } |
| 138 | |
| 139 | int can_bus_client_set_filters(CanBusClientState *client, |
| 140 | const struct qemu_can_filter *filters, size_t filters_cnt) |
| 141 | { |
| 142 | return 0; |
| 143 | } |
| 144 | |
| 145 | |
| 146 | static bool can_bus_prepare_delete(UserCreatable *uc, Error **errp) |
| 147 | { |
| 148 | error_setg(errp, "Deleting CAN bus device '%s' is not supported", |
| 149 | object_get_canonical_path_component(OBJECT(uc))); |
| 150 | return false; |
| 151 | } |
| 152 | |
| 153 | static void can_bus_class_init(ObjectClass *klass, |
| 154 | const void *class_data G_GNUC_UNUSED) |
| 155 | { |
| 156 | UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass); |
| 157 | |
| 158 | uc_klass->prepare_delete = can_bus_prepare_delete; |
| 159 | } |
| 160 | |
| 161 | static const TypeInfo can_bus_info = { |
| 162 | .parent = TYPE_OBJECT, |
| 163 | .name = TYPE_CAN_BUS, |
| 164 | .instance_size = sizeof(CanBusState), |
| 165 | .instance_init = can_bus_instance_init, |
| 166 | .class_init = can_bus_class_init, |
| 167 | .interfaces = (const InterfaceInfo[]) { |
| 168 | { TYPE_USER_CREATABLE }, |
| 169 | { } |
| 170 | } |
| 171 | }; |
| 172 | |
| 173 | static void can_bus_register_types(void) |
| 174 | { |
| 175 | type_register_static(&can_bus_info); |
| 176 | } |
| 177 | |
| 178 | type_init(can_bus_register_types); |