From d9ded6b87ef65bb96916801a7ac99b171943ee3f Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Thu, 4 Sep 2025 14:35:34 -0500
Subject: [PATCH] [sx1509] Migrate to CachedGpioExpander to reduce I2C bus
 usage

---
 esphome/components/sx1509/__init__.py |  2 +-
 esphome/components/sx1509/sx1509.cpp  | 20 ++++++++++++++------
 esphome/components/sx1509/sx1509.h    | 15 +++++++++++----
 3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/esphome/components/sx1509/__init__.py b/esphome/components/sx1509/__init__.py
index 67dc924903..b61b92fd1e 100644
--- a/esphome/components/sx1509/__init__.py
+++ b/esphome/components/sx1509/__init__.py
@@ -25,7 +25,7 @@ CONF_SCAN_TIME = "scan_time"
 CONF_DEBOUNCE_TIME = "debounce_time"
 CONF_SX1509_ID = "sx1509_id"
 
-AUTO_LOAD = ["key_provider"]
+AUTO_LOAD = ["key_provider", "gpio_expander"]
 DEPENDENCIES = ["i2c"]
 MULTI_CONF = True
 
diff --git a/esphome/components/sx1509/sx1509.cpp b/esphome/components/sx1509/sx1509.cpp
index 2bf6701dd2..ea3d5a6adb 100644
--- a/esphome/components/sx1509/sx1509.cpp
+++ b/esphome/components/sx1509/sx1509.cpp
@@ -39,6 +39,9 @@ void SX1509Component::dump_config() {
 }
 
 void SX1509Component::loop() {
+  // Reset cache at the start of each loop
+  this->reset_pin_cache_();
+
   if (this->has_keypad_) {
     if (millis() - this->last_loop_timestamp_ < min_loop_period_)
       return;
@@ -73,18 +76,23 @@ void SX1509Component::loop() {
   }
 }
 
-bool SX1509Component::digital_read(uint8_t pin) {
+bool SX1509Component::digital_read_hw(uint8_t pin) {
   if (this->ddr_mask_ & (1 << pin)) {
-    uint16_t temp_reg_data;
-    if (!this->read_byte_16(REG_DATA_B, &temp_reg_data))
+    if (!this->read_byte_16(REG_DATA_B, &this->input_mask_))
       return false;
-    if (temp_reg_data & (1 << pin))
-      return true;
+    return true;
   }
   return false;
 }
 
-void SX1509Component::digital_write(uint8_t pin, bool bit_value) {
+bool SX1509Component::digital_read_cache(uint8_t pin) {
+  if (this->ddr_mask_ & (1 << pin)) {
+    return this->input_mask_ & (1 << pin);
+  }
+  return false;
+}
+
+void SX1509Component::digital_write_hw(uint8_t pin, bool bit_value) {
   if ((~this->ddr_mask_) & (1 << pin)) {
     // If the pin is an output, write high/low
     uint16_t temp_reg_data = 0;
diff --git a/esphome/components/sx1509/sx1509.h b/esphome/components/sx1509/sx1509.h
index c0e86aa8a1..2afd0d0e4e 100644
--- a/esphome/components/sx1509/sx1509.h
+++ b/esphome/components/sx1509/sx1509.h
@@ -2,6 +2,7 @@
 
 #include "esphome/components/i2c/i2c.h"
 #include "esphome/components/key_provider/key_provider.h"
+#include "esphome/components/gpio_expander/cached_gpio.h"
 #include "esphome/core/component.h"
 #include "esphome/core/hal.h"
 #include "sx1509_gpio_pin.h"
@@ -30,7 +31,10 @@ class SX1509Processor {
 
 class SX1509KeyTrigger : public Trigger<uint8_t> {};
 
-class SX1509Component : public Component, public i2c::I2CDevice, public key_provider::KeyProvider {
+class SX1509Component : public Component,
+                        public i2c::I2CDevice,
+                        public gpio_expander::CachedGpioExpander<uint16_t, 16>,
+                        public key_provider::KeyProvider {
  public:
   SX1509Component() = default;
 
@@ -39,11 +43,9 @@ class SX1509Component : public Component, public i2c::I2CDevice, public key_prov
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
   void loop() override;
 
-  bool digital_read(uint8_t pin);
   uint16_t read_key_data();
   void set_pin_value(uint8_t pin, uint8_t i_on) { this->write_byte(REG_I_ON[pin], i_on); };
   void pin_mode(uint8_t pin, gpio::Flags flags);
-  void digital_write(uint8_t pin, bool bit_value);
   uint32_t get_clock() { return this->clk_x_; };
   void set_rows_cols(uint8_t rows, uint8_t cols) {
     this->rows_ = rows;
@@ -61,10 +63,15 @@ class SX1509Component : public Component, public i2c::I2CDevice, public key_prov
   void setup_led_driver(uint8_t pin);
 
  protected:
+  // Virtual methods from CachedGpioExpander
+  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;
+
   uint32_t clk_x_ = 2000000;
   uint8_t frequency_ = 0;
   uint16_t ddr_mask_ = 0x00;
-  uint16_t input_mask_ = 0x00;
+  uint16_t input_mask_ = 0x00;  // Cache for input values (16-bit for all pins)
   uint16_t port_mask_ = 0x00;
   uint16_t output_state_ = 0x00;
   bool has_keypad_ = false;