MCP23XXX Refactor (#1560)

* Refactor MCP23XXX classes to consolidate shared code

* Update test mcp23xxx pin schemas

esphome/components/mcp23xxx_base/mcp23xxx_base.h

@@ -0,0 +1,55 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/core/esphal.h"
+
+namespace esphome {
+namespace mcp23xxx_base {
+
+enum MCP23XXXInterruptMode : uint8_t { MCP23XXX_NO_INTERRUPT = 0, MCP23XXX_CHANGE, MCP23XXX_RISING, MCP23XXX_FALLING };
+
+/// Modes for MCP23XXX pins
+enum MCP23XXXGPIOMode : uint8_t {
+  MCP23XXX_INPUT = INPUT,                // 0x00
+  MCP23XXX_INPUT_PULLUP = INPUT_PULLUP,  // 0x02
+  MCP23XXX_OUTPUT = OUTPUT               // 0x01
+};
+
+class MCP23XXXBase : public Component {
+ public:
+  virtual bool digital_read(uint8_t pin);
+  virtual void digital_write(uint8_t pin, bool value);
+  virtual void pin_mode(uint8_t pin, uint8_t mode);
+  virtual void pin_interrupt_mode(uint8_t pin, MCP23XXXInterruptMode interrupt_mode);
+
+  void set_open_drain_ints(const bool value) { this->open_drain_ints_ = value; }
+  float get_setup_priority() const override;
+
+ protected:
+  // read a given register
+  virtual bool read_reg(uint8_t reg, uint8_t *value);
+  // write a value to a given register
+  virtual bool write_reg(uint8_t reg, uint8_t value);
+  // update registers with given pin value.
+  virtual void update_reg(uint8_t pin, bool pin_value, uint8_t reg_a);
+
+  bool open_drain_ints_;
+};
+
+class MCP23XXXGPIOPin : public GPIOPin {
+ public:
+  MCP23XXXGPIOPin(MCP23XXXBase *parent, uint8_t pin, uint8_t mode, bool inverted = false,
+                  MCP23XXXInterruptMode interrupt_mode = MCP23XXX_NO_INTERRUPT);
+
+  void setup() override;
+  void pin_mode(uint8_t mode) override;
+  bool digital_read() override;
+  void digital_write(bool value) override;
+
+ protected:
+  MCP23XXXBase *parent_;
+  MCP23XXXInterruptMode interrupt_mode_;
+};
+
+}  // namespace mcp23xxx_base
+}  // namespace esphome