tca8418.h

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#pragma once
 
#include "esphome/components/key_provider/key_provider.h"
#include "esphome/components/i2c/i2c.h"
#include "esphome/core/component.h"
#include "esphome/core/hal.h"
#include "esphome/core/helpers.h"
 
namespace esphome::tca8418 {
 
//  Register map (see TI datasheet SCPS231)
static constexpr uint8_t TCA8418_REG_CFG = 0x01;
static constexpr uint8_t TCA8418_REG_INT_STAT = 0x02;
static constexpr uint8_t TCA8418_REG_KEY_LCK_EC = 0x03;
static constexpr uint8_t TCA8418_REG_KEY_EVENT_A = 0x04;  // top of the event FIFO
static constexpr uint8_t TCA8418_REG_GPIO_INT_EN1 = 0x1A;
static constexpr uint8_t TCA8418_REG_KP_GPIO1 = 0x1D;
static constexpr uint8_t TCA8418_REG_GPI_EM1 = 0x20;
static constexpr uint8_t TCA8418_REG_GPIO_PULL1 = 0x2C;
 
//  CFG
static constexpr uint8_t TCA8418_CFG_KEY_INT_EN = 0x01;  // interrupt on key events
static constexpr uint8_t TCA8418_CFG_INT_CFG = 0x10;     // re-assert INT while events remain
//  INT_STAT
static constexpr uint8_t TCA8418_INT_STAT_ALL = 0x1F;  // every interrupt flag
//  KEY_LCK_EC: the low nibble is the number of queued events
static constexpr uint8_t TCA8418_EVENT_COUNT_MASK = 0x0F;
//  Key events: bit 7 set = pressed, clear = released; bits 6-0 are the key number
static constexpr uint8_t TCA8418_KEY_PRESSED = 0x80;
static constexpr uint8_t TCA8418_KEY_CODE_MASK = 0x7F;
//  The event queue holds ten entries, which bounds how many can be read at once.
static constexpr uint8_t TCA8418_FIFO_DEPTH = 10;
 
class TCA8418Listener {
 public:
  virtual void key_pressed(uint8_t key) {}
  virtual void key_released(uint8_t key) {}
};
 
class TCA8418Component : public key_provider::KeyProvider, public Component, public i2c::I2CDevice {
 public:
  void setup() override;
  void loop() override;
  void dump_config() override;
 
  void set_rows(uint8_t rows) { this->rows_ = rows; }
  void set_columns(uint8_t columns) { this->columns_ = columns; }
  void set_gpi_events(bool gpi_events) { this->gpi_events_ = gpi_events; }
  void set_keys(const uint8_t *keys, uint8_t size) {
    this->keys_ = keys;
    this->keys_size_ = size;
  }
  void set_interrupt_pin(InternalGPIOPin *pin) { this->interrupt_pin_ = pin; }
 
#ifdef TCA8418_LISTENER_COUNT
  void register_listener(TCA8418Listener *listener) { this->listeners_.push_back(listener); }
#endif
 
  static void IRAM_ATTR interrupt_handler(TCA8418Component *arg);
 
 protected:
  bool configure_pins_();
  bool drain_events_(bool dispatch);
  void dispatch_(uint8_t key, bool pressed);
  uint8_t key_char_(uint8_t key) const;
 
  const uint8_t *keys_{nullptr};  // PROGMEM, indexed by key number - 1
  InternalGPIOPin *interrupt_pin_{nullptr};
  uint32_t last_poll_{0};
#ifdef TCA8418_LISTENER_COUNT
  StaticVector<TCA8418Listener *, TCA8418_LISTENER_COUNT> listeners_;
#endif
  uint8_t rows_{0};
  uint8_t columns_{0};
  uint8_t keys_size_{0};
  bool gpi_events_{true};
};
 
}  // namespace esphome::tca8418