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_can_be_deleted(UserCreatable *uc) 147 { 148 return false; 149 } 150 151 static void can_bus_class_init(ObjectClass *klass, 152 void *class_data G_GNUC_UNUSED) 153 { 154 UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass); 155 156 uc_klass->can_be_deleted = can_bus_can_be_deleted; 157 } 158 159 static const TypeInfo can_bus_info = { 160 .parent = TYPE_OBJECT, 161 .name = TYPE_CAN_BUS, 162 .instance_size = sizeof(CanBusState), 163 .instance_init = can_bus_instance_init, 164 .class_init = can_bus_class_init, 165 .interfaces = (InterfaceInfo[]) { 166 { TYPE_USER_CREATABLE }, 167 { } 168 } 169 }; 170 171 static void can_bus_register_types(void) 172 { 173 type_register_static(&can_bus_info); 174 } 175 176 type_init(can_bus_register_types); 177