Add sn74hc165 input shift register (#4151)

esphome/components/sn74hc165/sn74hc165.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/core/hal.h"
+#include "esphome/core/helpers.h"
+
+#include <vector>
+
+namespace esphome {
+namespace sn74hc165 {
+
+class SN74HC165Component : public Component {
+ public:
+  SN74HC165Component() = default;
+
+  void setup() override;
+  void loop() override;
+  float get_setup_priority() const override;
+  void dump_config() override;
+
+  void set_data_pin(GPIOPin *pin) { this->data_pin_ = pin; }
+  void set_clock_pin(GPIOPin *pin) { this->clock_pin_ = pin; }
+  void set_load_pin(GPIOPin *pin) { this->load_pin_ = pin; }
+  void set_clock_inhibit_pin(GPIOPin *pin) { this->clock_inhibit_pin_ = pin; }
+  void set_sr_count(uint8_t count) {
+    this->sr_count_ = count;
+    this->input_bits_.resize(count * 8);
+  }
+
+ protected:
+  friend class SN74HC165GPIOPin;
+  bool digital_read_(uint16_t pin);
+  void read_gpio_();
+
+  GPIOPin *data_pin_;
+  GPIOPin *clock_pin_;
+  GPIOPin *load_pin_;
+  GPIOPin *clock_inhibit_pin_;
+  uint8_t sr_count_;
+  std::vector<bool> input_bits_;
+};
+
+/// Helper class to expose a SC74HC165 pin as an internal input GPIO pin.
+class SN74HC165GPIOPin : public GPIOPin, public Parented<SN74HC165Component> {
+ public:
+  void setup() override {}
+  void pin_mode(gpio::Flags flags) override {}
+  bool digital_read() override;
+  void digital_write(bool value) override{};
+  std::string dump_summary() const override;
+
+  void set_pin(uint16_t pin) { pin_ = pin; }
+  void set_inverted(bool inverted) { inverted_ = inverted; }
+
+ protected:
+  uint16_t pin_;
+  bool inverted_;
+};
+
+}  // namespace sn74hc165
+}  // namespace esphome