pca9505.cpp

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#include "pca9505.h"
#include "esphome/core/log.h"
 
namespace esphome::pca9505 {
 
// Each register block holds one byte per port. Add the port number to reach a single
// port, or set the auto-increment bit to transfer the whole block in one go.
static constexpr uint8_t INPUT_REG = 0x00;
static constexpr uint8_t OUTPUT_REG = 0x08;
static constexpr uint8_t INVERT_REG = 0x10;
static constexpr uint8_t CONFIG_REG = 0x18;
static constexpr uint8_t MASK_REG = 0x20;
static constexpr uint8_t AUTO_INCREMENT = 0x80;
 
ESPHOME_LOG_TAG(TAG, "pca9505");
 
void PCA9505Component::setup() {
  // Test to see if device exists
  if (!this->read_bank_(0)) {
    ESP_LOGE(TAG, "PCA9505 not detected at 0x%02X", this->address_);
    this->mark_failed(LOG_STR(ESP_LOG_MSG_COMM_FAIL));
    return;
  }
 
  // No polarity inversion
  this->write_all_banks_(INVERT_REG, 0x00);
  // All outputs low, before anything is switched to being an output
  this->write_all_banks_(OUTPUT_REG, 0x00);
  // All inputs at initialization. The part sees a 1 as an input, so this is the
  // inverse of config_, which is all zeroes here.
  this->write_all_banks_(CONFIG_REG, 0xFF);
 
  // Mask every interrupt. This must be written, not assumed: the chip keeps its
  // registers through an MCU reboot, so a previous run may have left pins unmasked.
  for (uint8_t &bank : this->mask_) {
    bank = 0xFF;
  }
  this->write_all_banks_(MASK_REG, 0xFF);
 
  if (this->interrupt_pin_ != nullptr) {
    this->interrupt_pin_->setup();
    this->interrupt_pin_->attach_interrupt(&PCA9505Component::gpio_intr, this, gpio::INTERRUPT_FALLING_EDGE);
    // Don't invalidate cache on read - only invalidate when interrupt fires
    this->set_invalidate_on_read_(false);
  }
 
  // Nothing to poll until pin_mode() registers an input pin.
  this->disable_loop();
}
 
void IRAM_ATTR PCA9505Component::gpio_intr(PCA9505Component *arg) { arg->enable_loop_soon_any_context(); }
 
void PCA9505Component::loop() {
  // Invalidate the cache so the next digital_read() triggers a fresh I2C read
  this->reset_pin_cache_();
  // Only disable the loop once INT has actually gone HIGH. Input transitions that straddle the
  // I2C read leave INT asserted without re-firing a falling edge, which would strand us with
  // stale state forever; keep looping until the line is released so we self-heal.
  if (this->interrupt_pin_ != nullptr && this->interrupt_pin_->digital_read()) {
    this->disable_loop();
  }
}
 
void PCA9505Component::dump_config() {
  ESP_LOGCONFIG(TAG, "PCA9505:");
  LOG_PIN("  Interrupt Pin: ", this->interrupt_pin_);
  LOG_I2C_DEVICE(this)
}
 
bool PCA9505Component::digital_read_hw(uint8_t pin) { return this->read_bank_(pin / 8); }
 
bool PCA9505Component::digital_read_cache(uint8_t pin) { return this->input_[pin / 8] & (1 << (pin % 8)); }
 
void PCA9505Component::digital_write_hw(uint8_t pin, bool value) {
  const uint8_t bank = pin / 8;
  const uint8_t mask = 1 << (pin % 8);
  if (value) {
    this->output_[bank] |= mask;
  } else {
    this->output_[bank] &= ~mask;
  }
  this->write_bank_(OUTPUT_REG, bank, this->output_[bank]);
}
 
void PCA9505Component::pin_mode(uint8_t pin, gpio::Flags flags) {
  const uint8_t bank = pin / 8;
  const uint8_t mask = 1 << (pin % 8);
  if (flags & gpio::FLAG_INPUT) {
    this->config_[bank] &= ~mask;
    // An input may raise INT; the polling loop is only needed when there is no interrupt pin.
    this->mask_[bank] &= ~mask;
    if (this->interrupt_pin_ == nullptr) {
      this->enable_loop();
    }
  } else if (flags & gpio::FLAG_OUTPUT) {
    this->config_[bank] |= mask;
    // An output must never raise INT.
    this->mask_[bank] |= mask;
  }
  // Invert as the part sees a 1 as an input
  this->write_bank_(CONFIG_REG, bank, ~this->config_[bank]);
  // Without an interrupt pin INT is unconnected, so the masks written at setup can stay
  if (this->interrupt_pin_ != nullptr) {
    this->write_bank_(MASK_REG, bank, this->mask_[bank]);
  }
}
 
bool PCA9505Component::read_bank_(uint8_t bank) {
  if (this->is_failed())
    return false;
 
  if (this->read_register(INPUT_REG + bank, &this->input_[bank], 1) != i2c::ERROR_OK) {
    this->status_set_warning(LOG_STR("Failed to read input register"));
    return false;
  }
  this->status_clear_warning();
  return true;
}
 
bool PCA9505Component::write_bank_(uint8_t reg, uint8_t bank, uint8_t value) {
  if (this->is_failed())
    return false;
 
  if (this->write_register(reg + bank, &value, 1) != i2c::ERROR_OK) {
    this->status_set_warning(LOG_STR("Failed to write register"));
    return false;
  }
  this->status_clear_warning();
  return true;
}
 
bool PCA9505Component::write_all_banks_(uint8_t reg, uint8_t value) {
  if (this->is_failed())
    return false;
 
  uint8_t values[BANK_COUNT];
  for (uint8_t &bank : values) {
    bank = value;
  }
  if (this->write_register(reg | AUTO_INCREMENT, values, sizeof(values)) != i2c::ERROR_OK) {
    this->status_set_warning(LOG_STR("Failed to write register"));
    return false;
  }
  this->status_clear_warning();
  return true;
}
 
float PCA9505Component::get_setup_priority() const { return setup_priority::IO; }
 
void PCA9505GPIOPin::setup() { this->pin_mode(this->flags_); }
 
void PCA9505GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this->pin_, flags); }
 
bool PCA9505GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
 
void PCA9505GPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value != this->inverted_); }
 
size_t PCA9505GPIOPin::dump_summary(char *buffer, size_t len) const {
  return buf_append_printf(buffer, len, 0, "%u via PCA9505", this->pin_);
}
 
}  // namespace esphome::pca9505