esp32_can.cpp

Go to the documentation of this file.

#ifdef USE_ESP32
#include "esp32_can.h"
#include "esphome/core/log.h"
 
#include <driver/twai.h>
 
// WORKAROUND, because CAN_IO_UNUSED is just defined as (-1) in this version
// of the framework which does not work with -fpermissive
#undef CAN_IO_UNUSED
#define CAN_IO_UNUSED ((gpio_num_t) -1)
 
namespace esphome {
namespace esp32_can {
 
static const char *const TAG = "esp32_can";
 
static bool get_bitrate(canbus::CanSpeed bitrate, twai_timing_config_t *t_config) {
  switch (bitrate) {
#if defined(USE_ESP32_VARIANT_ESP32C3) || defined(USE_ESP32_VARIANT_ESP32C6) || defined(USE_ESP32_VARIANT_ESP32C61) || \
    defined(USE_ESP32_VARIANT_ESP32H2) || defined(USE_ESP32_VARIANT_ESP32P4) || defined(USE_ESP32_VARIANT_ESP32S2) || \
    defined(USE_ESP32_VARIANT_ESP32S3)
    case canbus::CAN_1KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_1KBITS();
      return true;
    case canbus::CAN_5KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_5KBITS();
      return true;
    case canbus::CAN_10KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_10KBITS();
      return true;
    case canbus::CAN_12K5BPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_12_5KBITS();
      return true;
    case canbus::CAN_16KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_16KBITS();
      return true;
    case canbus::CAN_20KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_20KBITS();
      return true;
#endif
    case canbus::CAN_25KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_25KBITS();
      return true;
    case canbus::CAN_50KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_50KBITS();
      return true;
    case canbus::CAN_100KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_100KBITS();
      return true;
    case canbus::CAN_125KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_125KBITS();
      return true;
    case canbus::CAN_250KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_250KBITS();
      return true;
    case canbus::CAN_500KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_500KBITS();
      return true;
    case canbus::CAN_800KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_800KBITS();
      return true;
    case canbus::CAN_1000KBPS:
      *t_config = (twai_timing_config_t) TWAI_TIMING_CONFIG_1MBITS();
      return true;
    default:
      return false;
  }
}
 
bool ESP32Can::setup_internal() {
  static int next_twai_ctrl_num = 0;
  if (static_cast<unsigned>(next_twai_ctrl_num) >= SOC_TWAI_CONTROLLER_NUM) {
    ESP_LOGW(TAG, "Maximum number of esp32_can components created already");
    this->mark_failed();
    return false;
  }
 
  // Select TWAI mode based on configuration
  twai_mode_t twai_mode = (this->mode_ == CAN_MODE_LISTEN_ONLY) ? TWAI_MODE_LISTEN_ONLY : TWAI_MODE_NORMAL;
 
  if (this->mode_ == CAN_MODE_LISTEN_ONLY) {
    ESP_LOGI(TAG, "CAN bus configured in LISTEN_ONLY mode (passive, no ACKs)");
  }
 
  twai_general_config_t g_config =
      TWAI_GENERAL_CONFIG_DEFAULT((gpio_num_t) this->tx_, (gpio_num_t) this->rx_, twai_mode);
  g_config.controller_id = next_twai_ctrl_num++;
  if (this->tx_queue_len_.has_value()) {
    g_config.tx_queue_len = this->tx_queue_len_.value();
  }
  if (this->rx_queue_len_.has_value()) {
    g_config.rx_queue_len = this->rx_queue_len_.value();
  }
 
  twai_filter_config_t f_config = TWAI_FILTER_CONFIG_ACCEPT_ALL();
  twai_timing_config_t t_config;
 
  if (!get_bitrate(this->bit_rate_, &t_config)) {
    // invalid bit rate
    this->mark_failed();
    return false;
  }
 
  // Install TWAI driver
  if (twai_driver_install_v2(&g_config, &t_config, &f_config, &(this->twai_handle_)) != ESP_OK) {
    // Failed to install driver
    this->mark_failed();
    return false;
  }
 
  // Start TWAI driver
  if (twai_start_v2(this->twai_handle_) != ESP_OK) {
    // Failed to start driver
    this->mark_failed();
    return false;
  }
  return true;
}
 
canbus::Error ESP32Can::send_message(struct canbus::CanFrame *frame) {
  // In listen-only mode, we cannot transmit
  if (this->mode_ == CAN_MODE_LISTEN_ONLY) {
    ESP_LOGW(TAG, "Cannot send messages in LISTEN_ONLY mode");
    return canbus::ERROR_FAIL;
  }
 
  if (this->twai_handle_ == nullptr) {
    // not setup yet or setup failed
    return canbus::ERROR_FAIL;
  }
 
  if (frame->can_data_length_code > canbus::CAN_MAX_DATA_LENGTH) {
    return canbus::ERROR_FAILTX;
  }
 
  uint32_t flags = TWAI_MSG_FLAG_NONE;
  if (frame->use_extended_id) {
    flags |= TWAI_MSG_FLAG_EXTD;
  }
  if (frame->remote_transmission_request) {
    flags |= TWAI_MSG_FLAG_RTR;
  }
 
  twai_message_t message = {
      .flags = flags,
      .identifier = frame->can_id,
      .data_length_code = frame->can_data_length_code,
      .data = {},  // to suppress warning, data is initialized properly below
  };
  if (!frame->remote_transmission_request) {
    memcpy(message.data, frame->data, frame->can_data_length_code);
  }
 
  if (twai_transmit_v2(this->twai_handle_, &message, this->tx_enqueue_timeout_ticks_) == ESP_OK) {
    return canbus::ERROR_OK;
  } else {
    return canbus::ERROR_ALLTXBUSY;
  }
}
 
canbus::Error ESP32Can::read_message(struct canbus::CanFrame *frame) {
  if (this->twai_handle_ == nullptr) {
    // not setup yet or setup failed
    return canbus::ERROR_FAIL;
  }
 
  twai_message_t message;
 
  if (twai_receive_v2(this->twai_handle_, &message, 0) != ESP_OK) {
    return canbus::ERROR_NOMSG;
  }
 
  frame->can_id = message.identifier;
  frame->use_extended_id = message.flags & TWAI_MSG_FLAG_EXTD;
  frame->remote_transmission_request = message.flags & TWAI_MSG_FLAG_RTR;
  frame->can_data_length_code = message.data_length_code;
 
  if (!frame->remote_transmission_request) {
    size_t dlc =
        message.data_length_code < canbus::CAN_MAX_DATA_LENGTH ? message.data_length_code : canbus::CAN_MAX_DATA_LENGTH;
    memcpy(frame->data, message.data, dlc);
  }
 
  return canbus::ERROR_OK;
}
 
}  // namespace esp32_can
}  // namespace esphome
 
#endif