LXR qemu/net/can/can

   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
  38static 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 */
  44uint8_t can_dlc2len(uint8_t can_dlc)
  45{
  46    return dlc2len[can_dlc & 0x0F];
  47}
  48
  49static 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 */
  63uint8_t can_len2dlc(uint8_t len)
  64{
  65    if (unlikely(len > 64)) {
  66        return 0xF;
  67    }
  68
  69    return len2dlc[len];
  70}
  71
  72struct CanBusState {
  73    Object object;
  74
  75    QTAILQ_HEAD(, CanBusClientState) clients;
  76};
  77
  78static void can_bus_instance_init(Object *object)
  79{
  80    CanBusState *bus = (CanBusState *)object;
  81
  82    QTAILQ_INIT(&bus->clients);
  83}
  84
  85int 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
  92int 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
 104ssize_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
 129int 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
 139int 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
 146static bool can_bus_can_be_deleted(UserCreatable *uc)
 147{
 148    return false;
 149}
 150
 151static 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
 159static 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
 171static void can_bus_register_types(void)
 172{
 173    type_register_static(&can_bus_info);
 174}
 175
 176type_init(can_bus_register_types);
 177