[sx1509] Extract clear_interrupt_ inline helper

Unmask per-pin interrupts and set both-edge sense detection when
interrupt_pin is configured. Clear interrupt source in loop() to
deassert INT line after servicing.

esphome/components/sx1509/__init__.py

@@ -5,6 +5,7 @@ import esphome.config_validation as cv
 from esphome.const import (
     CONF_ID,
     CONF_INPUT,
+    CONF_INTERRUPT_PIN,
     CONF_INVERTED,
     CONF_MODE,
     CONF_NUMBER,
@@ -75,6 +76,7 @@ CONFIG_SCHEMA = (
         {
             cv.GenerateID(): cv.declare_id(SX1509Component),
             cv.Optional(CONF_KEYPAD): cv.Schema(KEYPAD_SCHEMA),
+            cv.Optional(CONF_INTERRUPT_PIN): pins.internal_gpio_input_pin_schema,
         }
     )
     .extend(cv.COMPONENT_SCHEMA)
@@ -86,6 +88,8 @@ async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)
     await i2c.register_i2c_device(var, config)
+    if interrupt_pin := config.get(CONF_INTERRUPT_PIN):
+        cg.add(var.set_interrupt_pin(await cg.gpio_pin_expression(interrupt_pin)))
     if conf := config.get(CONF_KEYPAD):
         cg.add(var.set_rows_cols(conf[CONF_KEY_ROWS], conf[CONF_KEY_COLUMNS]))
         if (

esphome/components/sx1509/sx1509.cpp

@@ -28,10 +28,26 @@ void SX1509Component::setup() {
   delayMicroseconds(500);
   if (this->has_keypad_)
     this->setup_keypad_();
+
+  if (this->interrupt_pin_ != nullptr) {
+    this->interrupt_pin_->setup();
+    this->interrupt_pin_->attach_interrupt(&SX1509Component::gpio_intr, this, gpio::INTERRUPT_FALLING_EDGE);
+    this->set_invalidate_on_read_(false);
+  }
+  // Disable loop until an input pin is configured via pin_mode()
+  // or keypad is active. For interrupt-driven mode, loop is re-enabled by the ISR.
+  if (!this->has_keypad_) {
+    this->disable_loop();
+  }
 }
 
+void IRAM_ATTR SX1509Component::gpio_intr(SX1509Component *arg) {
+  arg->interrupt_pending_ = true;
+  arg->enable_loop_soon_any_context();
+}
 void SX1509Component::dump_config() {
   ESP_LOGCONFIG(TAG, "SX1509:");
+  LOG_PIN("  Interrupt Pin: ", this->interrupt_pin_);
   if (this->is_failed()) {
     ESP_LOGE(TAG, "Setting up SX1509 failed!");
   }
@@ -39,7 +55,17 @@ void SX1509Component::dump_config() {
 }
 
 void SX1509Component::loop() {
-  // Reset cache at the start of each loop
+  if (this->interrupt_pending_) {
+    this->interrupt_pending_ = false;
+    // Clear interrupt source before resetting cache to avoid losing
+    // pin changes that occur between cache reset and interrupt clear
+    this->clear_interrupt_();
+    this->reset_pin_cache_();
+    if (!this->has_keypad_) {
+      this->disable_loop();
+    }
+    return;
+  }
   this->reset_pin_cache_();
 
   if (this->has_keypad_) {
@@ -169,6 +195,11 @@ void SX1509Component::pin_mode(uint8_t pin, gpio::Flags flags) {
     // Set direction to input
     this->ddr_mask_ |= (1 << pin);
     this->write_byte_16(REG_DIR_B, this->ddr_mask_);
+    if (this->interrupt_pin_ != nullptr) {
+      this->enable_pin_interrupt_(pin);
+    } else {
+      this->enable_loop();
+    }
   }
 }
 
@@ -313,5 +344,23 @@ void SX1509Component::set_debounce_keypad_(uint8_t time, uint8_t num_rows, uint8
     set_debounce_pin_(i + 8);
 }
 
+void SX1509Component::enable_pin_interrupt_(uint8_t pin) {
+  // Unmask this pin's interrupt (clear bit = enabled)
+  uint16_t mask = 0;
+  this->read_byte_16(REG_INTERRUPT_MASK_B, &mask);
+  mask &= ~(1 << pin);
+  this->write_byte_16(REG_INTERRUPT_MASK_B, mask);
+
+  // Configure sense to trigger on both edges
+  uint8_t sense_reg = SENSE_REGS[pin / 4];
+  uint8_t sense_val = 0;
+  this->read_byte(sense_reg, &sense_val);
+  // 2-bit field position within the sense register (4 pins per register, 2 bits each)
+  uint8_t shift = (pin % 4) * 2;
+  sense_val &= ~(SENSE_BOTH_EDGES << shift);
+  sense_val |= (SENSE_BOTH_EDGES << shift);
+  this->write_byte(sense_reg, sense_val);
+}
+
 }  // namespace sx1509
 }  // namespace esphome

esphome/components/sx1509/sx1509.h

@@ -46,6 +46,7 @@ class SX1509Component : public Component,
   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 set_interrupt_pin(InternalGPIOPin *pin) { this->interrupt_pin_ = pin; }
   uint32_t get_clock() { return this->clk_x_; };
   void set_rows_cols(uint8_t rows, uint8_t cols) {
     this->rows_ = rows;
@@ -63,6 +64,8 @@ class SX1509Component : public Component,
   void setup_led_driver(uint8_t pin);
 
  protected:
+  static void IRAM_ATTR gpio_intr(SX1509Component *arg);
+
   // Virtual methods from CachedGpioExpander
   bool digital_read_hw(uint8_t pin) override;
   bool digital_read_cache(uint8_t pin) override;
@@ -75,6 +78,7 @@ class SX1509Component : public Component,
   uint16_t port_mask_ = 0x00;
   uint16_t output_state_ = 0x00;
   bool has_keypad_ = false;
+  volatile bool interrupt_pending_{false};
   uint8_t rows_ = 0;
   uint8_t cols_ = 0;
   std::string keys_;
@@ -85,9 +89,15 @@ class SX1509Component : public Component,
   std::vector<SX1509Processor *> keypad_binary_sensors_;
   std::vector<SX1509KeyTrigger *> key_triggers_;
 
+  InternalGPIOPin *interrupt_pin_{nullptr};
   uint32_t last_loop_timestamp_ = 0;
   const uint32_t min_loop_period_ = 15;  // ms
 
+  void enable_pin_interrupt_(uint8_t pin);
+  void clear_interrupt_() {
+    uint16_t interrupt_source = 0;
+    this->read_byte_16(REG_INTERRUPT_SOURCE_B, &interrupt_source);
+  }
   void setup_keypad_();
   void set_debounce_config_(uint8_t config_value);
   void set_debounce_time_(uint8_t time);

esphome/components/sx1509/sx1509_registers.h

@@ -57,6 +57,10 @@ const uint8_t REG_SENSE_HIGH_B = 0x14;  //    RegSenseHighB Sense register for I
 const uint8_t REG_SENSE_LOW_B = 0x15;   //    RegSenseLowB Sense register for I/O[11:8] 0000 0000
 const uint8_t REG_SENSE_HIGH_A = 0x16;  //    RegSenseHighA Sense register for I/O[7:4] 0000 0000
 const uint8_t REG_SENSE_LOW_A = 0x17;   //    RegSenseLowA Sense register for I/O[3:0] 0000 0000
+// Sense register values (2 bits per pin): 00=None, 01=Rising, 10=Falling, 11=Both
+const uint8_t SENSE_BOTH_EDGES = 0x03;
+// Sense register lookup: each register covers 4 pins (pins 0-3, 4-7, 8-11, 12-15)
+const uint8_t SENSE_REGS[] = {REG_SENSE_LOW_A, REG_SENSE_HIGH_A, REG_SENSE_LOW_B, REG_SENSE_HIGH_B};
 const uint8_t REG_INTERRUPT_SOURCE_B =
     0x18;  //    RegInterruptSourceB Interrupt source register _ I/O[15_8] (Bank B) 0000 0000
 const uint8_t REG_INTERRUPT_SOURCE_A =

tests/components/sx1509/common.yaml

@@ -2,6 +2,7 @@ sx1509:
   - id: sx1509_hub
     i2c_id: i2c_bus
     address: 0x3E
+    interrupt_pin: ${interrupt_pin}
     keypad:
       key_rows: 2
       key_columns: 2

tests/components/sx1509/test.esp32-idf.yaml

@@ -1,3 +1,6 @@
+substitutions:
+  interrupt_pin: GPIO15
+
 packages:
   i2c: !include ../../test_build_components/common/i2c/esp32-idf.yaml
 

tests/components/sx1509/test.esp8266-ard.yaml

@@ -1,3 +1,6 @@
+substitutions:
+  interrupt_pin: GPIO15
+
 packages:
   i2c: !include ../../test_build_components/common/i2c/esp8266-ard.yaml
 

tests/components/sx1509/test.rp2040-ard.yaml

@@ -1,3 +1,6 @@
+substitutions:
+  interrupt_pin: GPIO2
+
 packages:
   i2c: !include ../../test_build_components/common/i2c/rp2040-ard.yaml