[it8951] Hold display enable pins off during deep-sleep (#20471)

esphome/components/it8951/display.py

@@ -145,8 +145,8 @@ IT8951Model(
     reset_pin=12,
     cs_pin=10,
     # Board power-enable rails: 1.8V logic supply (GPIO21) and the EPD supply
-    # (GPIO11). Driven high during setup so no separate power_supply is needed.
-    enable_pin=[21, 11],
+    # (GPIO11). Driven high during setup so no separate power_supply is needed, and held low during deep_sleep.
+    enable_pin=[{"number": 21, "hold_state": True}, {"number": 11, "hold_state": True}],
     vcom=1400,
     # reTerminal E1003 panel firmware only accepts the 0x0002 VCOM SET
     # selector; using the default 0x0001 leaves VCOM unchanged and breaks

esphome/components/it8951/it8951.cpp

@@ -351,6 +351,12 @@ void IT8951Display::on_safe_shutdown() {
   this->spi_cmd_(TCON_SLEEP);
 }
 
+void IT8951Display::on_powerdown() {
+  for (auto *pin : this->enable_pins_) {
+    pin->digital_write(false);
+  }
+}
+
 // --- Init op enqueuers -------------------------------------------------------
 
 void IT8951Display::enqueue_init_reset_() {

esphome/components/it8951/it8951.h

@@ -150,6 +150,7 @@ class IT8951Display : public Display,
   void loop() override;
   void dump_config() override;
   void on_safe_shutdown() override;
+  void on_powerdown() override;
   float get_setup_priority() const override { return setup_priority::PROCESSOR; }
 
   // --- Config setters (called from generated code) ---

tests/component_tests/it8951/test_init.py

@@ -0,0 +1,28 @@
+"""Tests for it8951 configuration validation."""
+
+from collections.abc import Callable
+from typing import Any
+
+from esphome.components.const import CONF_HOLD_STATE
+from esphome.components.esp32 import KEY_BOARD, KEY_VARIANT, VARIANT_ESP32S3
+from esphome.components.it8951.display import CONFIG_SCHEMA
+from esphome.const import CONF_ENABLE_PIN, CONF_NUMBER, PlatformFramework
+from tests.component_tests.types import SetCoreConfigCallable
+
+
+def test_reterminal_e1003_enable_pins_hold_state(
+    set_core_config: SetCoreConfigCallable,
+    set_component_config: Callable[[str, Any], None],
+) -> None:
+    """The reTerminal E1003 enable pins must hold their state during deep sleep."""
+    set_core_config(
+        PlatformFramework.ESP32_IDF,
+        platform_data={KEY_BOARD: "esp32-s3-devkitc-1", KEY_VARIANT: VARIANT_ESP32S3},
+    )
+    set_component_config("spi", {"id": "spi_bus", "clk_pin": 7, "mosi_pin": 9})
+
+    config = CONFIG_SCHEMA({"id": "test_display", "model": "seeed-reterminal-e1003"})
+
+    enable_pins = config[CONF_ENABLE_PIN]
+    assert [pin[CONF_NUMBER] for pin in enable_pins] == [21, 11]
+    assert all(pin[CONF_HOLD_STATE] for pin in enable_pins)