uart_component_rp2040.cpp

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#ifdef USE_RP2040
#include "uart_component_rp2040.h"
#include "esphome/core/application.h"
#include "esphome/core/defines.h"
#include "esphome/core/helpers.h"
#include "esphome/core/log.h"
 
#include <hardware/uart.h>
 
#ifdef USE_LOGGER
#include "esphome/components/logger/logger.h"
#endif
 
namespace esphome::uart {
 
static const char *const TAG = "uart.arduino_rp2040";
 
uint16_t RP2040UartComponent::get_config() {
  uint16_t config = 0;
 
  if (this->parity_ == UART_CONFIG_PARITY_NONE) {
    config |= UART_PARITY_NONE;
  } else if (this->parity_ == UART_CONFIG_PARITY_EVEN) {
    config |= UART_PARITY_EVEN;
  } else if (this->parity_ == UART_CONFIG_PARITY_ODD) {
    config |= UART_PARITY_ODD;
  }
 
  switch (this->data_bits_) {
    case 5:
      config |= SERIAL_DATA_5;
      break;
    case 6:
      config |= SERIAL_DATA_6;
      break;
    case 7:
      config |= SERIAL_DATA_7;
      break;
    case 8:
      config |= SERIAL_DATA_8;
      break;
  }
 
  if (this->stop_bits_ == 1) {
    config |= SERIAL_STOP_BIT_1;
  } else {
    config |= SERIAL_STOP_BIT_2;
  }
 
  return config;
}
 
void RP2040UartComponent::setup() {
  auto setup_pin_if_needed = [](InternalGPIOPin *pin) {
    if (!pin) {
      return;
    }
    const auto mask = gpio::Flags::FLAG_OPEN_DRAIN | gpio::Flags::FLAG_PULLUP | gpio::Flags::FLAG_PULLDOWN;
    if ((pin->get_flags() & mask) != gpio::Flags::FLAG_NONE) {
      pin->setup();
    }
  };
 
  setup_pin_if_needed(this->rx_pin_);
  if (this->rx_pin_ != this->tx_pin_) {
    setup_pin_if_needed(this->tx_pin_);
  }
 
  uint16_t config = get_config();
 
  constexpr uint32_t valid_tx_uart_0 = __bitset({0, 12, 16, 28});
  constexpr uint32_t valid_tx_uart_1 = __bitset({4, 8, 20, 24});
 
  constexpr uint32_t valid_rx_uart_0 = __bitset({1, 13, 17, 29});
  constexpr uint32_t valid_rx_uart_1 = __bitset({5, 9, 21, 25});
 
  int8_t tx_hw = -1;
  int8_t rx_hw = -1;
 
  if (this->tx_pin_ != nullptr) {
    if (this->tx_pin_->is_inverted()) {
      ESP_LOGD(TAG, "An inverted TX pin %u can only be used with SerialPIO", this->tx_pin_->get_pin());
    } else {
      if (((1 << this->tx_pin_->get_pin()) & valid_tx_uart_0) != 0) {
        tx_hw = 0;
      } else if (((1 << this->tx_pin_->get_pin()) & valid_tx_uart_1) != 0) {
        tx_hw = 1;
      } else {
        ESP_LOGD(TAG, "TX pin %u can only be used with SerialPIO", this->tx_pin_->get_pin());
      }
    }
  }
 
  if (this->rx_pin_ != nullptr) {
    if (this->rx_pin_->is_inverted()) {
      ESP_LOGD(TAG, "An inverted RX pin %u can only be used with SerialPIO", this->rx_pin_->get_pin());
    } else {
      if (((1 << this->rx_pin_->get_pin()) & valid_rx_uart_0) != 0) {
        rx_hw = 0;
      } else if (((1 << this->rx_pin_->get_pin()) & valid_rx_uart_1) != 0) {
        rx_hw = 1;
      } else {
        ESP_LOGD(TAG, "RX pin %u can only be used with SerialPIO", this->rx_pin_->get_pin());
      }
    }
  }
 
  // Determine which hardware UART to use. A pin that is not specified
  // should not prevent hardware UART selection — one-way UART is valid.
  // When both pins are configured, both must be HW-capable and agree on UART number.
  // When only one pin is configured (nullptr other), use that pin's HW UART.
  // If a pin is configured but not HW-capable (inverted/invalid), fall back to SerialPIO.
  int8_t hw_uart = -1;
  const bool tx_configured = (this->tx_pin_ != nullptr);
  const bool rx_configured = (this->rx_pin_ != nullptr);
 
  if (tx_configured && rx_configured) {
    // Both pins configured — both must map to the same hardware UART
    if (tx_hw != -1 && rx_hw != -1 && tx_hw == rx_hw) {
      hw_uart = tx_hw;
    }
  } else if (tx_configured) {
    hw_uart = tx_hw;
  } else if (rx_configured) {
    hw_uart = rx_hw;
  }
 
#ifdef USE_LOGGER
  if (hw_uart != -1 && logger::global_logger->get_uart() == hw_uart) {
    ESP_LOGD(TAG, "Using SerialPIO as UART%d is taken by the logger", hw_uart);
    hw_uart = -1;
  }
#endif
 
  if (hw_uart == -1) {
    ESP_LOGV(TAG, "Using SerialPIO");
    pin_size_t tx = this->tx_pin_ == nullptr ? NOPIN : this->tx_pin_->get_pin();
    pin_size_t rx = this->rx_pin_ == nullptr ? NOPIN : this->rx_pin_->get_pin();
    auto *serial = new SerialPIO(tx, rx, this->rx_buffer_size_);  // NOLINT(cppcoreguidelines-owning-memory)
    serial->begin(this->baud_rate_, config);
    if (this->tx_pin_ != nullptr && this->tx_pin_->is_inverted())
      gpio_set_outover(tx, GPIO_OVERRIDE_INVERT);
    if (this->rx_pin_ != nullptr && this->rx_pin_->is_inverted())
      gpio_set_inover(rx, GPIO_OVERRIDE_INVERT);
    this->serial_ = serial;
  } else {
    ESP_LOGV(TAG, "Using Hardware Serial");
    SerialUART *serial;
    if (hw_uart == 0) {
      serial = &Serial1;
    } else {
      serial = &Serial2;
    }
    if (this->tx_pin_ != nullptr)
      serial->setTX(this->tx_pin_->get_pin());
    if (this->rx_pin_ != nullptr)
      serial->setRX(this->rx_pin_->get_pin());
    serial->setFIFOSize(this->rx_buffer_size_);
    serial->begin(this->baud_rate_, config);
    this->serial_ = serial;
    this->hw_serial_ = true;
  }
}
 
void RP2040UartComponent::dump_config() {
  ESP_LOGCONFIG(TAG, "UART Bus:");
  LOG_PIN("  TX Pin: ", tx_pin_);
  LOG_PIN("  RX Pin: ", rx_pin_);
  if (this->rx_pin_ != nullptr) {
    ESP_LOGCONFIG(TAG, "  RX Buffer Size: %u", this->rx_buffer_size_);
  }
  ESP_LOGCONFIG(TAG,
                "  Baud Rate: %u baud\n"
                "  Data Bits: %u\n"
                "  Parity: %s\n"
                "  Stop bits: %u",
                this->baud_rate_, this->data_bits_, LOG_STR_ARG(parity_to_str(this->parity_)), this->stop_bits_);
  if (this->hw_serial_) {
    ESP_LOGCONFIG(TAG, "  Using hardware serial");
  } else {
    ESP_LOGCONFIG(TAG, "  Using SerialPIO");
  }
}
 
void RP2040UartComponent::write_array(const uint8_t *data, size_t len) {
  this->serial_->write(data, len);
#ifdef USE_UART_DEBUGGER
  for (size_t i = 0; i < len; i++) {
    this->debug_callback_.call(UART_DIRECTION_TX, data[i]);
  }
#endif
}
bool RP2040UartComponent::peek_byte(uint8_t *data) {
  if (!this->check_read_timeout_())
    return false;
  *data = this->serial_->peek();
  return true;
}
bool RP2040UartComponent::read_array(uint8_t *data, size_t len) {
  if (!this->check_read_timeout_(len))
    return false;
  this->serial_->readBytes(data, len);
#ifdef USE_UART_DEBUGGER
  for (size_t i = 0; i < len; i++) {
    this->debug_callback_.call(UART_DIRECTION_RX, data[i]);
  }
#endif
  return true;
}
size_t RP2040UartComponent::available() { return this->serial_->available(); }
UARTFlushResult RP2040UartComponent::flush() {
  ESP_LOGVV(TAG, "    Flushing");
  this->serial_->flush();
  return UARTFlushResult::UART_FLUSH_RESULT_ASSUMED_SUCCESS;
}
 
}  // namespace esphome::uart
#endif  // USE_RP2040