[max6956] Migrate to CachedGpioExpander to reduce I2C bus usage

esphome/components/max6956/__init__.py

@@ -15,6 +15,7 @@ from esphome.const import (
 CODEOWNERS = ["@looping40"]
 
 DEPENDENCIES = ["i2c"]
+AUTO_LOAD = ["gpio_expander"]
 MULTI_CONF = True
 
 CONF_BRIGHTNESS_MODE = "brightness_mode"

esphome/components/max6956/max6956.cpp

@@ -40,14 +40,55 @@ void MAX6956::setup() {
   ESP_LOGD(TAG, "setup reg[0x%.2X]=0x%.2X", MAX6956_CONFIGURATION, configuration);
 }
 
-bool MAX6956::digital_read(uint8_t pin) {
-  uint8_t reg_addr = MAX6956_1PORT_VALUE_START + pin;
-  uint8_t value = 0;
-  this->read_reg_(reg_addr, &value);
-  return (value & MASK_1PORT_VALUE);
+void MAX6956::loop() {
+  // Invalidate cache at the start of each loop
+  this->reset_pin_cache_();
 }
 
-void MAX6956::digital_write(uint8_t pin, bool value) {
+bool MAX6956::digital_read_hw(uint8_t pin) {
+  // MAX6956 pins start at MAX6956_MIN
+  if (pin < MAX6956_MIN || pin > MAX6956_MAX) {
+    return false;
+  }
+
+  // Calculate bank index
+  uint8_t bank_index = (pin - MAX6956_MIN) / MAX6956_BANK_SIZE;
+
+  // Register addresses for each bank
+  static const uint8_t bank_regs[4] = {
+      MAX6956_8PORTS_VALUE_START,  // 0x44 - ports 4-11
+      MAX6956_8PORTS_12_19,        // 0x4C - ports 12-19
+      MAX6956_8PORTS_20_27,        // 0x54 - ports 20-27
+      MAX6956_8PORTS_24_31         // 0x58 - ports 24-31
+  };
+
+  // Read the 8-port bank register
+  uint8_t bank_value = 0;
+  if (!this->read_reg_(bank_regs[bank_index], &bank_value)) {
+    return false;
+  }
+
+  // Store the bank value in our cache
+  this->input_banks_[bank_index] = bank_value;
+
+  return true;
+}
+
+bool MAX6956::digital_read_cache(uint8_t pin) {
+  // MAX6956 pins start at MAX6956_MIN
+  if (pin < MAX6956_MIN || pin > MAX6956_MAX) {
+    return false;
+  }
+
+  // Calculate bank index and bit position
+  uint8_t adjusted_pin = pin - MAX6956_MIN;
+  uint8_t bank_index = adjusted_pin / MAX6956_BANK_SIZE;
+  uint8_t bit_position = adjusted_pin % MAX6956_BANK_SIZE;
+
+  return (this->input_banks_[bank_index] & (1 << bit_position)) != 0;
+}
+
+void MAX6956::digital_write_hw(uint8_t pin, bool value) {
   uint8_t reg_addr = MAX6956_1PORT_VALUE_START + pin;
   this->write_reg_(reg_addr, value);
 }
@@ -159,8 +200,8 @@ void MAX6956::dump_config() {
  **************************************/
 void MAX6956GPIOPin::setup() { pin_mode(flags_); }
 void MAX6956GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this->pin_, flags); }
-bool MAX6956GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; }
-void MAX6956GPIOPin::digital_write(bool value) { this->parent_->digital_write(this->pin_, value != this->inverted_); }
+bool MAX6956GPIOPin::digital_read() { return this->parent_->read_pin_cached(this->pin_) != this->inverted_; }
+void MAX6956GPIOPin::digital_write(bool value) { this->parent_->write_pin(this->pin_, value != this->inverted_); }
 std::string MAX6956GPIOPin::dump_summary() const {
   char buffer[32];
   snprintf(buffer, sizeof(buffer), "%u via Max6956", pin_);

esphome/components/max6956/max6956.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 max6956 {
@@ -21,6 +22,9 @@ enum MAX6956GPIORange : uint8_t {
   MAX6956_MAX = 31,
 };
 
+/// Bank configuration for MAX6956
+static constexpr uint8_t MAX6956_BANK_SIZE = 8;
+
 enum MAX6956GPIORegisters {
   MAX6956_GLOBAL_CURRENT = 0x02,
   MAX6956_CONFIGURATION = 0x04,
@@ -30,20 +34,23 @@ enum MAX6956GPIORegisters {
   MAX6956_CURRENT_START = 0x12,       // Current054
   MAX6956_1PORT_VALUE_START = 0x20,   // Port 0 only (virtual port, no action)
   MAX6956_8PORTS_VALUE_START = 0x44,  // 8 ports 4-11 (data bits D0-D7)
+  // Additional 8-port bulk read registers
+  MAX6956_8PORTS_12_19 = 0x4C,  // 8 ports 12-19
+  MAX6956_8PORTS_20_27 = 0x54,  // 8 ports 20-27
+  MAX6956_8PORTS_24_31 = 0x58,  // 8 ports 24-31
 };
 
 enum MAX6956GPIOFlag { FLAG_LED = 0x20 };
 
 enum MAX6956CURRENTMODE { GLOBAL = 0x00, SEGMENT = 0x01 };
 
-class MAX6956 : public Component, public i2c::I2CDevice {
+class MAX6956 : public Component, public i2c::I2CDevice, public gpio_expander::CachedGpioExpander<uint8_t, 28> {
  public:
   MAX6956() = default;
 
   void setup() override;
+  void loop() override;
 
-  bool digital_read(uint8_t pin);
-  void digital_write(uint8_t pin, bool value);
   void pin_mode(uint8_t pin, gpio::Flags flags);
   void pin_mode(uint8_t pin, max6956::MAX6956GPIOFlag flags);
 
@@ -58,6 +65,11 @@ class MAX6956 : public Component, public i2c::I2CDevice {
   void write_brightness_global();
   void write_brightness_mode();
 
+  // CachedGpioExpander implementation
+  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;
+
  protected:
   // read a given register
   bool read_reg_(uint8_t reg, uint8_t *value);
@@ -66,6 +78,10 @@ class MAX6956 : public Component, public i2c::I2CDevice {
   max6956::MAX6956CURRENTMODE brightness_mode_;
   uint8_t global_brightness_;
 
+  // Cache for the 4 banks of 8 pins each
+  // Bank 0: pins 4-11, Bank 1: pins 12-19, Bank 2: pins 20-27, Bank 3: pins 24-31
+  uint8_t input_banks_[4] = {0, 0, 0, 0};
+
  private:
   int8_t prev_bright_[28] = {0};
 };