cached_gpio.h

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#pragma once
 
#include <array>
#include <cstdint>
#include "esphome/core/hal.h"
 
namespace esphome {
namespace gpio_expander {
 
template<typename T, T N> class CachedGpioExpander {
 public:
  bool digital_read(T pin) {
    uint8_t bank = pin / (sizeof(T) * BITS_PER_BYTE);
    if (this->read_cache_invalidated_[bank]) {
      this->read_cache_invalidated_[bank] = false;
      if (!this->digital_read_hw(pin))
        return false;
    }
    return this->digital_read_cache(pin);
  }
 
  void digital_write(T pin, bool value) { this->digital_write_hw(pin, value); }
 
 protected:
  virtual bool digital_read_hw(T pin) = 0;
  virtual bool digital_read_cache(T pin) = 0;
  virtual void digital_write_hw(T pin, bool value) = 0;
  const uint8_t cache_byte_size_ = N / (sizeof(T) * BITS_PER_BYTE);
 
  void reset_pin_cache_() {
    for (T i = 0; i < this->cache_byte_size_; i++) {
      this->read_cache_invalidated_[i] = true;
    }
  }
 
  static const uint8_t BITS_PER_BYTE = 8;
  std::array<bool, N / (sizeof(T) * BITS_PER_BYTE)> read_cache_invalidated_{};
};
 
}  // namespace gpio_expander
}  // namespace esphome