[epaper_spi] Fix deep sleep command (#15544)

esphome/components/epaper_spi/epaper_spi.h

@@ -110,12 +110,14 @@ class EPaperBase : public Display,
     this->fill(COLOR_ON);
   }
 
- protected:
-  int get_height_internal() override { return this->height_; };
-  int get_width_internal() override { return this->width_; };
   int get_width() override { return this->effective_transform_ & SWAP_XY ? this->height_ : this->width_; }
   int get_height() override { return this->effective_transform_ & SWAP_XY ? this->width_ : this->height_; }
   void draw_pixel_at(int x, int y, Color color) override;
+
+ protected:
+  int get_height_internal() override { return this->height_; };
+  int get_width_internal() override { return this->width_; };
+  bool is_using_partial_update_() const { return this->full_update_every_ > 1; }
   void process_state_();
 
   const char *epaper_state_to_string_();

esphome/components/epaper_spi/epaper_spi_mono.cpp

@@ -15,7 +15,11 @@ void EPaperMono::refresh_screen(bool partial) {
 
 void EPaperMono::deep_sleep() {
   ESP_LOGV(TAG, "Deep sleep");
-  this->command(0x10);
+  if (this->is_using_partial_update_()) {
+    this->cmd_data(0x10, {0x00});  // sleep in power on mode
+  } else {
+    this->cmd_data(0x10, {0x03});  // deep sleep
+  }
 }
 
 bool EPaperMono::reset() {
@@ -27,6 +31,14 @@ bool EPaperMono::reset() {
 }
 
 void EPaperMono::set_window() {
+  // if not using partial update, the display will go into deep sleep, so must rewrite entire
+  // buffer since the display RAM will not retain contents
+  if (!this->is_using_partial_update_()) {
+    this->x_low_ = 0;
+    this->x_high_ = this->width_;
+    this->y_low_ = 0;
+    this->y_high_ = this->height_;
+  }
   // round x-coordinates to byte boundaries
   this->x_low_ &= ~7;
   this->x_high_ += 7;

tests/components/epaper_spi/test.esp32-s3-idf.yaml

@@ -78,6 +78,7 @@ display:
     model: seeed-reterminal-e1002
   - platform: epaper_spi
     model: seeed-ee04-mono-4.26
+    full_update_every: 10
     # Override pins to avoid conflict with other display configs
     busy_pin: 43
     dc_pin: 42