TCA6408 in lowercase

components/tca6408/tca6408.h

@@ -0,0 +1,74 @@
+#pragma once
+
+#include "esphome/components/gpio_expander/cached_gpio.h"
+#include "esphome/components/i2c/i2c.h"
+#include "esphome/core/component.h"
+#include "esphome/core/hal.h"
+
+namespace esphome {
+namespace tca6408 {
+
+/**
+ * TCA6408 8-bit I²C I/O Expander
+ *
+ * Supports:
+ * - 8 bidirectional pins
+ * - Hardware polarity inversion for inputs
+ * - Interrupt-driven inputs (active-low open-drain INT)
+ * - Efficient cached access
+ */
+class TCA6408Component : public Component,
+                         public i2c::I2CDevice,
+                         public gpio_expander::CachedGpioExpander<uint8_t, 8> {
+ public:
+  void setup() override;
+  void loop() override;
+  void dump_config() override;
+  float get_setup_priority() const override { return setup_priority::IO; }
+
+  void set_address(uint8_t address) { this->address_ = address; }
+  void set_interrupt_pin(InternalGPIOPin *pin) { this->interrupt_pin_ = pin; }
+
+  void set_polarity_inversion(uint8_t pin, bool inverted);
+
+ protected:
+  static void IRAM_ATTR gpio_intr(TCA6408Component *arg);
+
+  bool digital_read_hw(uint8_t pin) override;
+  bool digital_read_cache(uint8_t pin) override;
+  void digital_write_hw(uint8_t pin, bool value) override;
+  void pin_mode(uint8_t pin, gpio::Flags flags) override;
+
+  uint8_t mode_mask_{0xFF};      // 1 = input, 0 = output
+  uint8_t output_mask_{0x00};
+  uint8_t input_mask_{0x00};
+  uint8_t polarity_mask_{0x00};  // Hardware polarity inversion
+
+  InternalGPIOPin *interrupt_pin_{nullptr};
+  bool interrupt_triggered_{false};
+
+ private:
+  bool read_gpio_outputs_();
+};
+
+class TCA6408GPIOPin : public gpio::GPIOPin, public Parented<TCA6408Component> {
+ public:
+  void setup() override;
+  void pin_mode(gpio::Flags flags) override;
+  bool digital_read() override;
+  void digital_write(bool value) override;
+  size_t dump_summary(char *buffer, size_t len) const override;
+
+  void set_pin(uint8_t pin) { pin_ = pin; }
+  void set_inverted(bool inverted);
+  void set_flags(gpio::Flags flags) { flags_ = flags; }
+  gpio::Flags get_flags() const override { return flags_; }
+
+ protected:
+  uint8_t pin_{0};
+  bool inverted_{false};
+  gpio::Flags flags_{0};
+};
+
+}  // namespace tca6408
+}  // namespace esphome