From 93da52c4d294561fed5b82bf7d36340b62be098d Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 7 Sep 2025 18:26:11 -0500
Subject: [PATCH 1/4] [pca9554] Migrate to CachedGpioExpander to reduce I2C bus
 usage (#10571)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
---
 CODEOWNERS                             |  2 +-
 esphome/components/pca9554/__init__.py |  3 ++-
 esphome/components/pca9554/pca9554.cpp | 30 +++++++++++---------------
 esphome/components/pca9554/pca9554.h   | 19 ++++++++--------
 4 files changed, 25 insertions(+), 29 deletions(-)

diff --git a/CODEOWNERS b/CODEOWNERS
index 116f35f3b6..c34774fce6 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -342,7 +342,7 @@ esphome/components/ota/* @esphome/core
 esphome/components/output/* @esphome/core
 esphome/components/packet_transport/* @clydebarrow
 esphome/components/pca6416a/* @Mat931
-esphome/components/pca9554/* @clydebarrow @hwstar
+esphome/components/pca9554/* @bdraco @clydebarrow @hwstar
 esphome/components/pcf85063/* @brogon
 esphome/components/pcf8563/* @KoenBreeman
 esphome/components/pi4ioe5v6408/* @jesserockz
diff --git a/esphome/components/pca9554/__init__.py b/esphome/components/pca9554/__init__.py
index 05713cccda..626b08a378 100644
--- a/esphome/components/pca9554/__init__.py
+++ b/esphome/components/pca9554/__init__.py
@@ -11,7 +11,8 @@ from esphome.const import (
     CONF_OUTPUT,
 )
 
-CODEOWNERS = ["@hwstar", "@clydebarrow"]
+CODEOWNERS = ["@hwstar", "@clydebarrow", "@bdraco"]
+AUTO_LOAD = ["gpio_expander"]
 DEPENDENCIES = ["i2c"]
 MULTI_CONF = True
 CONF_PIN_COUNT = "pin_count"
diff --git a/esphome/components/pca9554/pca9554.cpp b/esphome/components/pca9554/pca9554.cpp
index 1166cc1a09..e8d49f66e2 100644
--- a/esphome/components/pca9554/pca9554.cpp
+++ b/esphome/components/pca9554/pca9554.cpp
@@ -37,10 +37,9 @@ void PCA9554Component::setup() {
 }
 
 void PCA9554Component::loop() {
-  // The read_inputs_() method will cache the input values from the chip.
-  this->read_inputs_();
-  // Clear all the previously read flags.
-  this->was_previously_read_ = 0x00;
+  // Invalidate the cache at the start of each loop.
+  // The actual read will happen on demand when digital_read() is called
+  this->reset_pin_cache_();
 }
 
 void PCA9554Component::dump_config() {
@@ -54,21 +53,17 @@ void PCA9554Component::dump_config() {
   }
 }
 
-bool PCA9554Component::digital_read(uint8_t pin) {
-  // Note: We want to try and avoid doing any I2C bus read transactions here
-  // to conserve I2C bus bandwidth. So what we do is check to see if we
-  // have seen a read during the time esphome is running this loop. If we have,
-  // we do an I2C bus transaction to get the latest value. If we haven't
-  // we return a cached value which was read at the time loop() was called.
-  if (this->was_previously_read_ & (1 << pin))
-    this->read_inputs_();  // Force a read of a new value
-  // Indicate we saw a read request for this pin in case a
-  // read happens later in the same loop.
-  this->was_previously_read_ |= (1 << pin);
+bool PCA9554Component::digital_read_hw(uint8_t pin) {
+  // Read all pins from hardware into input_mask_
+  return this->read_inputs_();  // Return true if I2C read succeeded, false on error
+}
+
+bool PCA9554Component::digital_read_cache(uint8_t pin) {
+  // Return the cached pin state from input_mask_
   return this->input_mask_ & (1 << pin);
 }
 
-void PCA9554Component::digital_write(uint8_t pin, bool value) {
+void PCA9554Component::digital_write_hw(uint8_t pin, bool value) {
   if (value) {
     this->output_mask_ |= (1 << pin);
   } else {
@@ -127,8 +122,7 @@ bool PCA9554Component::write_register_(uint8_t reg, uint16_t value) {
 
 float PCA9554Component::get_setup_priority() const { return setup_priority::IO; }
 
-// Run our loop() method very early in the loop, so that we cache read values before
-// before other components call our digital_read() method.
+// Run our loop() method early to invalidate cache before any other components access the pins
 float PCA9554Component::get_loop_priority() const { return 9.0f; }  // Just after WIFI
 
 void PCA9554GPIOPin::setup() { pin_mode(flags_); }
diff --git a/esphome/components/pca9554/pca9554.h b/esphome/components/pca9554/pca9554.h
index efeec4d306..7b356b4068 100644
--- a/esphome/components/pca9554/pca9554.h
+++ b/esphome/components/pca9554/pca9554.h
@@ -3,22 +3,21 @@
 #include "esphome/core/component.h"
 #include "esphome/core/hal.h"
 #include "esphome/components/i2c/i2c.h"
+#include "esphome/components/gpio_expander/cached_gpio.h"
 
 namespace esphome {
 namespace pca9554 {
 
-class PCA9554Component : public Component, public i2c::I2CDevice {
+class PCA9554Component : public Component,
+                         public i2c::I2CDevice,
+                         public gpio_expander::CachedGpioExpander<uint16_t, 16> {
  public:
   PCA9554Component() = default;
 
   /// Check i2c availability and setup masks
   void setup() override;
-  /// Poll for input changes periodically
+  /// Invalidate cache at start of each loop
   void loop() override;
-  /// Helper function to read the value of a pin.
-  bool digital_read(uint8_t pin);
-  /// Helper function to write the value of a pin.
-  void digital_write(uint8_t pin, bool value);
   /// Helper function to set the pin mode of a pin.
   void pin_mode(uint8_t pin, gpio::Flags flags);
 
@@ -32,9 +31,13 @@ class PCA9554Component : public Component, public i2c::I2CDevice {
 
  protected:
   bool read_inputs_();
-
   bool write_register_(uint8_t reg, uint16_t value);
 
+  // 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;
+
   /// number of bits the expander has
   size_t pin_count_{8};
   /// width of registers
@@ -45,8 +48,6 @@ class PCA9554Component : public Component, public i2c::I2CDevice {
   uint16_t output_mask_{0x00};
   /// The state of the actual input pin states - 1 means HIGH, 0 means LOW
   uint16_t input_mask_{0x00};
-  /// Flags to check if read previously during this loop
-  uint16_t was_previously_read_ = {0x00};
   /// Storage for last I2C error seen
   esphome::i2c::ErrorCode last_error_;
 };

From afa191ae41365918a1a085139d5ea6bb144c5652 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 7 Sep 2025 18:26:22 -0500
Subject: [PATCH 2/4] [pcf8574] Migrate to CachedGpioExpander to reduce I2C bus
 usage (#10573)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
---
 esphome/components/pcf8574/__init__.py |  1 +
 esphome/components/pcf8574/pcf8574.cpp | 19 ++++++++++++++-----
 esphome/components/pcf8574/pcf8574.h   | 19 +++++++++++++------
 3 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/esphome/components/pcf8574/__init__.py b/esphome/components/pcf8574/__init__.py
index ff7c314bcd..f387d0a610 100644
--- a/esphome/components/pcf8574/__init__.py
+++ b/esphome/components/pcf8574/__init__.py
@@ -11,6 +11,7 @@ from esphome.const import (
     CONF_OUTPUT,
 )
 
+AUTO_LOAD = ["gpio_expander"]
 DEPENDENCIES = ["i2c"]
 MULTI_CONF = True
 
diff --git a/esphome/components/pcf8574/pcf8574.cpp b/esphome/components/pcf8574/pcf8574.cpp
index 848fbed484..72d8865d7f 100644
--- a/esphome/components/pcf8574/pcf8574.cpp
+++ b/esphome/components/pcf8574/pcf8574.cpp
@@ -16,6 +16,10 @@ void PCF8574Component::setup() {
   this->write_gpio_();
   this->read_gpio_();
 }
+void PCF8574Component::loop() {
+  // Invalidate the cache at the start of each loop
+  this->reset_pin_cache_();
+}
 void PCF8574Component::dump_config() {
   ESP_LOGCONFIG(TAG, "PCF8574:");
   LOG_I2C_DEVICE(this)
@@ -24,17 +28,19 @@ void PCF8574Component::dump_config() {
     ESP_LOGE(TAG, ESP_LOG_MSG_COMM_FAIL);
   }
 }
-bool PCF8574Component::digital_read(uint8_t pin) {
-  this->read_gpio_();
-  return this->input_mask_ & (1 << pin);
+bool PCF8574Component::digital_read_hw(uint8_t pin) {
+  // Read all pins from hardware into input_mask_
+  return this->read_gpio_();  // Return true if I2C read succeeded, false on error
 }
-void PCF8574Component::digital_write(uint8_t pin, bool value) {
+
+bool PCF8574Component::digital_read_cache(uint8_t pin) { return this->input_mask_ & (1 << pin); }
+
+void PCF8574Component::digital_write_hw(uint8_t pin, bool value) {
   if (value) {
     this->output_mask_ |= (1 << pin);
   } else {
     this->output_mask_ &= ~(1 << pin);
   }
-
   this->write_gpio_();
 }
 void PCF8574Component::pin_mode(uint8_t pin, gpio::Flags flags) {
@@ -91,6 +97,9 @@ bool PCF8574Component::write_gpio_() {
 }
 float PCF8574Component::get_setup_priority() const { return setup_priority::IO; }
 
+// Run our loop() method early to invalidate cache before any other components access the pins
+float PCF8574Component::get_loop_priority() const { return 9.0f; }  // Just after WIFI
+
 void PCF8574GPIOPin::setup() { pin_mode(flags_); }
 void PCF8574GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this->pin_, flags); }
 bool PCF8574GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
diff --git a/esphome/components/pcf8574/pcf8574.h b/esphome/components/pcf8574/pcf8574.h
index 6edc67fc96..fd1ea8af63 100644
--- a/esphome/components/pcf8574/pcf8574.h
+++ b/esphome/components/pcf8574/pcf8574.h
@@ -3,11 +3,16 @@
 #include "esphome/core/component.h"
 #include "esphome/core/hal.h"
 #include "esphome/components/i2c/i2c.h"
+#include "esphome/components/gpio_expander/cached_gpio.h"
 
 namespace esphome {
 namespace pcf8574 {
 
-class PCF8574Component : public Component, public i2c::I2CDevice {
+// PCF8574(8 pins)/PCF8575(16 pins) always read/write all pins in a single I2C transaction
+// so we use uint16_t as bank type to ensure all pins are in one bank and cached together
+class PCF8574Component : public Component,
+                         public i2c::I2CDevice,
+                         public gpio_expander::CachedGpioExpander<uint16_t, 16> {
  public:
   PCF8574Component() = default;
 
@@ -15,20 +20,22 @@ class PCF8574Component : public Component, public i2c::I2CDevice {
 
   /// Check i2c availability and setup masks
   void setup() override;
-  /// Helper function to read the value of a pin.
-  bool digital_read(uint8_t pin);
-  /// Helper function to write the value of a pin.
-  void digital_write(uint8_t pin, bool value);
+  /// Invalidate cache at start of each loop
+  void loop() override;
   /// Helper function to set the pin mode of a pin.
   void pin_mode(uint8_t pin, gpio::Flags flags);
 
   float get_setup_priority() const override;
+  float get_loop_priority() const override;
 
   void dump_config() override;
 
  protected:
-  bool read_gpio_();
+  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;
 
+  bool read_gpio_();
   bool write_gpio_();
 
   /// Mask for the pin mode - 1 means output, 0 means input

From 6e2bcabbc9ae8d654e47d587c5ae47cfe41a4e6f Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 7 Sep 2025 18:26:33 -0500
Subject: [PATCH 3/4] [sx1509] Migrate to CachedGpioExpander to reduce I2C bus
 usage (#10588)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
---
 esphome/components/sx1509/__init__.py |  2 +-
 esphome/components/sx1509/sx1509.cpp  | 19 ++++++++++++-------
 esphome/components/sx1509/sx1509.h    | 15 +++++++++++----
 3 files changed, 24 insertions(+), 12 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..746ec9cda3 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 +76,20 @@ void SX1509Component::loop() {
   }
 }
 
-bool SX1509Component::digital_read(uint8_t pin) {
+bool SX1509Component::digital_read_hw(uint8_t pin) {
+  // Always read all pins when any input pin is accessed
+  return this->read_byte_16(REG_DATA_B, &this->input_mask_);
+}
+
+bool SX1509Component::digital_read_cache(uint8_t pin) {
+  // Return cached value for input pins, false for output pins
   if (this->ddr_mask_ & (1 << pin)) {
-    uint16_t temp_reg_data;
-    if (!this->read_byte_16(REG_DATA_B, &temp_reg_data))
-      return false;
-    if (temp_reg_data & (1 << pin))
-      return true;
+    return (this->input_mask_ & (1 << pin)) != 0;
   }
   return false;
 }
 
-void SX1509Component::digital_write(uint8_t pin, bool bit_value) {
+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;

From 0ff08bbc090bd02cab8d3658d9cd0d8b843c656f Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 7 Sep 2025 18:26:49 -0500
Subject: [PATCH 4/4] [mcp23016] Migrate to CachedGpioExpander to reduce I2C
 bus usage (#10581)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
---
 esphome/components/mcp23016/__init__.py  |  1 +
 esphome/components/mcp23016/mcp23016.cpp | 25 +++++++++++++++++++-----
 esphome/components/mcp23016/mcp23016.h   | 14 +++++++++----
 3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/esphome/components/mcp23016/__init__.py b/esphome/components/mcp23016/__init__.py
index 3333e46c97..5a1f011617 100644
--- a/esphome/components/mcp23016/__init__.py
+++ b/esphome/components/mcp23016/__init__.py
@@ -11,6 +11,7 @@ from esphome.const import (
     CONF_OUTPUT,
 )
 
+AUTO_LOAD = ["gpio_expander"]
 DEPENDENCIES = ["i2c"]
 MULTI_CONF = True
 
diff --git a/esphome/components/mcp23016/mcp23016.cpp b/esphome/components/mcp23016/mcp23016.cpp
index 9d8d6e4dae..be86cb2256 100644
--- a/esphome/components/mcp23016/mcp23016.cpp
+++ b/esphome/components/mcp23016/mcp23016.cpp
@@ -22,14 +22,29 @@ void MCP23016::setup() {
   this->write_reg_(MCP23016_IODIR0, 0xFF);
   this->write_reg_(MCP23016_IODIR1, 0xFF);
 }
-bool MCP23016::digital_read(uint8_t pin) {
-  uint8_t bit = pin % 8;
+
+void MCP23016::loop() {
+  // Invalidate cache at the start of each loop
+  this->reset_pin_cache_();
+}
+bool MCP23016::digital_read_hw(uint8_t pin) {
   uint8_t reg_addr = pin < 8 ? MCP23016_GP0 : MCP23016_GP1;
   uint8_t value = 0;
-  this->read_reg_(reg_addr, &value);
-  return value & (1 << bit);
+  if (!this->read_reg_(reg_addr, &value)) {
+    return false;
+  }
+
+  // Update the appropriate part of input_mask_
+  if (pin < 8) {
+    this->input_mask_ = (this->input_mask_ & 0xFF00) | value;
+  } else {
+    this->input_mask_ = (this->input_mask_ & 0x00FF) | (uint16_t(value) << 8);
+  }
+  return true;
 }
-void MCP23016::digital_write(uint8_t pin, bool value) {
+
+bool MCP23016::digital_read_cache(uint8_t pin) { return this->input_mask_ & (1 << pin); }
+void MCP23016::digital_write_hw(uint8_t pin, bool value) {
   uint8_t reg_addr = pin < 8 ? MCP23016_OLAT0 : MCP23016_OLAT1;
   this->update_reg_(pin, value, reg_addr);
 }
diff --git a/esphome/components/mcp23016/mcp23016.h b/esphome/components/mcp23016/mcp23016.h
index e4ed47a3b2..781c207de0 100644
--- a/esphome/components/mcp23016/mcp23016.h
+++ b/esphome/components/mcp23016/mcp23016.h
@@ -3,6 +3,7 @@
 #include "esphome/core/component.h"
 #include "esphome/core/hal.h"
 #include "esphome/components/i2c/i2c.h"
+#include "esphome/components/gpio_expander/cached_gpio.h"
 
 namespace esphome {
 namespace mcp23016 {
@@ -24,19 +25,22 @@ enum MCP23016GPIORegisters {
   MCP23016_IOCON1 = 0x0B,
 };
 
-class MCP23016 : public Component, public i2c::I2CDevice {
+class MCP23016 : public Component, public i2c::I2CDevice, public gpio_expander::CachedGpioExpander<uint8_t, 16> {
  public:
   MCP23016() = default;
 
   void setup() override;
-
-  bool digital_read(uint8_t pin);
-  void digital_write(uint8_t pin, bool value);
+  void loop() override;
   void pin_mode(uint8_t pin, gpio::Flags flags);
 
   float get_setup_priority() const override;
 
  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;
+
   // read a given register
   bool read_reg_(uint8_t reg, uint8_t *value);
   // write a value to a given register
@@ -46,6 +50,8 @@ class MCP23016 : public Component, public i2c::I2CDevice {
 
   uint8_t olat_0_{0x00};
   uint8_t olat_1_{0x00};
+  // Cache for input values (16-bit combined for both banks)
+  uint16_t input_mask_{0x00};
 };
 
 class MCP23016GPIOPin : public GPIOPin {