src/can/can-message.cpp

   1 /*
   2  * Copyright (C) 2015, 2016 "IoT.bzh"
   3  * Author "Romain Forlot" <romain.forlot@iot.bzh>
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *       http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include "can/can-message.hpp"
  19
  20 #include <cstring>
  21
  22 #include "low-can-binding.hpp"
  23
  24 /********************************************************************************
  25 *
  26 *               CanMessage method implementation
  27 *
  28 *********************************************************************************/
  29 /**
  30 * @brief Class constructor
  31 *
  32 * Constructor about can_message_t class.
  33 */
  34 can_message_t::can_message_t()
  35         : maxdlen_{0}, id_{0}, length_{0}, format_{can_message_format_t::ERROR}, rtr_flag_{false}, flags_{0}
  36 {}
  37
  38 can_message_t::can_message_t(uint8_t maxdlen, uint32_t id, uint8_t length, can_message_format_t format, bool rtr_flag_, uint8_t flags, std::vector<uint8_t> data)
  39         :  maxdlen_{0}, id_{0}, length_{0}, format_{can_message_format_t::ERROR}, rtr_flag_{false}, flags_{0}, data_{data}
  40 {}
  41
  42 /**
  43 * @brief Retrieve id_ member value.
  44 *
  45 * @return id_ class member
  46 */
  47 uint32_t can_message_t::get_id() const
  48 {
  49         return id_;
  50 }
  51
  52 /**
  53 * @brief Retrieve RTR flag member.
  54 *
  55 * @return rtr_flags_ class member
  56 */
  57 bool can_message_t::get_rtr_flag_() const
  58 {
  59         return rtr_flag_;
  60 }
  61
  62 /**
  63 * @brief Retrieve format_ member value.
  64 *
  65 * @return format_ class member
  66 */
  67 can_message_format_t can_message_t::get_format() const
  68 {
  69         if (format_ != can_message_format_t::STANDARD || format_ != can_message_format_t::EXTENDED)
  70                 return can_message_format_t::ERROR;
  71         return format_;
  72 }
  73
  74 /**
  75 * @brief Retrieve flags_ member value.
  76 *
  77 * @return flags_ class member
  78 */
  79 uint8_t can_message_t::get_flags() const
  80 {
  81         return flags_;
  82 }
  83
  84 /**
  85 * @brief Retrieve data_ member value.
  86 *
  87 * @return pointer to the first element
  88 *  of class member data_
  89 */
  90 const uint8_t* can_message_t::get_data() const
  91 {
  92         return data_.data();
  93 }
  94
  95 /**
  96 * @brief Retrieve length_ member value.
  97 *
  98 * @return length_ class member
  99 */
 100 uint8_t can_message_t::get_length() const
 101 {
 102         return length_;
 103 }
 104
 105 /**
 106 * @brief Control whether the object is correctly initialized
 107 *  to be sent over the CAN bus
 108 *
 109 * @return true if object correctly initialized and false if not.
 110 */
 111 bool can_message_t::is_correct_to_send()
 112 {
 113         if (id_ != 0 && length_ != 0 && format_ != can_message_format_t::ERROR)
 114         {
 115                 int i;
 116                 for(i=0;i<CAN_MESSAGE_SIZE;i++)
 117                         if(data_[i] != 0)
 118                                 return true;
 119         }
 120         return false;
 121 }
 122
 123 /**
 124 * @brief Set format_ member value.
 125 *
 126 * Preferred way to initialize these members by using
 127 * convert_from_canfd_frame method.
 128 *
 129 * @param[in] new_format - class member
 130 */
 131 void can_message_t::set_format(const can_message_format_t new_format)
 132 {
 133         if(new_format == can_message_format_t::STANDARD || new_format == can_message_format_t::EXTENDED || new_format == can_message_format_t::ERROR)
 134                 format_ = new_format;
 135         else
 136                 ERROR(binder_interface, "ERROR: Can set format, wrong format chosen");
 137 }
 138
 139 /**
 140 * @brief Take a canfd_frame struct to initialize class members
 141 *
 142 * This is the preferred way to initialize class members.
 143 *
 144 * @param[in] args - struct read from can bus device.
 145 */
 146 can_message_t can_message_t::convert_to_canfd_frame(const struct canfd_frame& frame, size_t nbytes)
 147 {
 148         uint8_t maxdlen, length, flags = (uint8_t)NULL;
 149         uint32_t id;
 150         can_message_format_t format;
 151         bool rtr_flag;
 152         std::vector<uint8_t> data;
 153
 154         switch(nbytes)
 155         {
 156                 case CANFD_MTU:
 157                         DEBUG(binder_interface, "set_max_data_length: Got an CAN FD frame");
 158                         maxdlen = CANFD_MAX_DLEN;
 159                         break;
 160                 case CAN_MTU:
 161                         DEBUG(binder_interface, "set_max_data_length: Got a legacy CAN frame");
 162                         maxdlen = CAN_MAX_DLEN;
 163                         break;
 164                 default:
 165                         ERROR(binder_interface, "set_max_data_length: unsupported CAN frame");
 166                         break;
 167         }
 168
 169         if(rtr_flag)
 170                 length = frame.len& 0xF;
 171         else
 172                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 173
 174         if (frame.can_id & CAN_ERR_FLAG)
 175                 format = can_message_format_t::ERROR;
 176         else if (frame.can_id & CAN_EFF_FLAG)
 177                 format = can_message_format_t::EXTENDED;
 178         else
 179                 format = can_message_format_t::STANDARD;
 180
 181         switch(format)
 182         {
 183                 case can_message_format_t::STANDARD:
 184                         id = frame.can_id & CAN_SFF_MASK;
 185                         break;
 186                 case can_message_format_t::EXTENDED:
 187                         id = frame.can_id & CAN_EFF_MASK;
 188                         break;
 189                 case can_message_format_t::ERROR:
 190                         id = frame.can_id & (CAN_ERR_MASK|CAN_ERR_FLAG);
 191                         break;
 192                 default:
 193                         ERROR(binder_interface, "ERROR: Can set id, not a compatible format or format not set prior to set id.");
 194                         break;
 195         }
 196
 197         /* Overwrite length_ if RTR flags is detected.
 198          * standard CAN frames may have RTR enabled. There are no ERR frames with RTR */
 199         if (frame.can_id & CAN_RTR_FLAG)
 200         {
 201                 rtr_flag = true;
 202                 if(frame.len && frame.len <= CAN_MAX_DLC)
 203                 {
 204                         if(rtr_flag)
 205                                 length = frame.len& 0xF;
 206                         else
 207                         {
 208                                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 209                         }
 210                 }
 211         }
 212         else
 213         {
 214                 /* Flags field only present for CAN FD frames*/
 215                 if(maxdlen == CANFD_MAX_DLEN)
 216                                 flags = frame.flags & 0xF;
 217
 218                 if (data.capacity() < maxdlen)
 219                         data.reserve(maxdlen);
 220                                 int i;
 221
 222                         data.clear();
 223                         /* maxdlen_ is now set at CAN_MAX_DLEN or CANFD_MAX_DLEN, respectively 8 and 64 bytes*/
 224                         for(i=0;i<maxdlen;i++)
 225                         {
 226                                 data.push_back(frame.data[i]);
 227                         };
 228
 229                 DEBUG(binder_interface, "convert_from_canfd_frame: Found id: %X, format: %X, length: %X, data %02X%02X%02X%02X%02X%02X%02X%02X",
 230                                                                 id, format, length, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);
 231         }
 232
 233         return can_message_t(maxdlen, id, length, format, rtr_flag, flags, data);
 234 }
 235
 236 /**
 237 * @brief Take all initialized class's members and build an
 238 * canfd_frame struct that can be use to send a CAN message over
 239 * the bus.
 240 *
 241 * @return canfd_frame struct built from class members.
 242 */
 243 canfd_frame can_message_t::convert_to_canfd_frame()
 244 {
 245         canfd_frame frame;
 246
 247         if(is_correct_to_send())
 248         {
 249                 frame.can_id = get_id();
 250                 frame.len = get_length();
 251                 ::memcpy(frame.data, get_data(), length_);
 252         }
 253         else
 254                 ERROR(binder_interface, "can_message_t not correctly initialized to be sent");
 255
 256         return frame;
 257 }
 258
 259 /********************************************************************************
 260 *
 261 *               can_message_definition_t method implementation
 262 *
 263 *********************************************************************************/
 264
 265 can_message_definition_t::can_message_definition_t()
 266         : last_value_(CAN_MESSAGE_SIZE)
 267 {}
 268
 269 uint32_t can_message_definition_t::get_id() const
 270 {
 271         return id_;
 272 }