From 1e9e5ca763a4802f3aa310bf788e8fbd2fa0dca1 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Sat, 4 Apr 2026 10:05:00 -1000
Subject: [PATCH] Fix pin_interrupt_mode overriding auto-enabled CHANGE
 interrupt

MCP23XXXGPIOPin::setup() calls pin_interrupt_mode(pin, NO_INTERRUPT)
after pin_mode() already auto-enabled CHANGE, undoing the auto-enable.
Skip the explicit pin_interrupt_mode call when interrupt_pin is
configured and the user didn't override the default.
---
 esphome/components/mcp23xxx_base/mcp23xxx_base.cpp | 7 ++++++-
 esphome/components/mcp23xxx_base/mcp23xxx_base.h   | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/esphome/components/mcp23xxx_base/mcp23xxx_base.cpp b/esphome/components/mcp23xxx_base/mcp23xxx_base.cpp
index 535119fc5c..4c1daac562 100644
--- a/esphome/components/mcp23xxx_base/mcp23xxx_base.cpp
+++ b/esphome/components/mcp23xxx_base/mcp23xxx_base.cpp
@@ -7,7 +7,12 @@ namespace mcp23xxx_base {
 
 template<uint8_t N> void MCP23XXXGPIOPin<N>::setup() {
   this->pin_mode(flags_);
-  this->parent_->pin_interrupt_mode(this->pin_, this->interrupt_mode_);
+  // When interrupt_pin is configured, pin_mode() already auto-enables CHANGE
+  // interrupt for input pins, so skip the explicit call if the user didn't
+  // override the default (NO_INTERRUPT)
+  if (this->interrupt_mode_ != MCP23XXX_NO_INTERRUPT || this->parent_->get_interrupt_pin() == nullptr) {
+    this->parent_->pin_interrupt_mode(this->pin_, this->interrupt_mode_);
+  }
 }
 template<uint8_t N> void MCP23XXXGPIOPin<N>::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this->pin_, flags); }
 template<uint8_t N> bool MCP23XXXGPIOPin<N>::digital_read() {
diff --git a/esphome/components/mcp23xxx_base/mcp23xxx_base.h b/esphome/components/mcp23xxx_base/mcp23xxx_base.h
index 7838e30127..5e2d9e9c68 100644
--- a/esphome/components/mcp23xxx_base/mcp23xxx_base.h
+++ b/esphome/components/mcp23xxx_base/mcp23xxx_base.h
@@ -16,6 +16,7 @@ template<uint8_t N> class MCP23XXXBase : public Component, public gpio_expander:
 
   void set_open_drain_ints(const bool value) { this->open_drain_ints_ = value; }
   void set_interrupt_pin(InternalGPIOPin *pin) { this->interrupt_pin_ = pin; }
+  InternalGPIOPin *get_interrupt_pin() const { return this->interrupt_pin_; }
   float get_setup_priority() const override { return setup_priority::IO; }
 
   void loop() override {