feat(emu): add LED to emulator

- if USE_RGB_LED is set, emulator has the capability to display_rgb_led

core/SConscript.unix

@@ -21,7 +21,7 @@ if BENCHMARK and PYOPT != '0':
   print("BENCHMARK=1 works only with PYOPT=0.")
   exit(1)
 
-FEATURES_WANTED = ["input", "sd_card", "dma2d", "optiga"]
+FEATURES_WANTED = ["input", "rgb_led", "sd_card", "dma2d", "optiga"]
 
 if not models.has_emulator(TREZOR_MODEL):
     # skip unix build

core/embed/io/display/inc/io/display.h

@@ -159,4 +159,10 @@ void display_copy_mono1p(const gfx_bitblt_t *bb);
 // The function is available only on the emulator.
 const char *display_save(const char *prefix);
 void display_clear_save(void);
+
+#ifdef USE_RGB_LED
+// Display a color on the LED.
+// The function is available only on the emulator.
+void display_rgb_led(uint32_t color);
+#endif
 #endif

core/embed/io/display/unix/display_driver.c

@@ -74,6 +74,9 @@ typedef struct {
   // and we have to simulate it
   uint8_t mono_framebuf[DISPLAY_RESX * DISPLAY_RESY];
 #endif
+#ifdef USE_RGB_LED
+  uint32_t led_color;
+#endif
 
 } display_driver_t;
 
@@ -319,6 +322,46 @@ static void copy_mono_framebuf(display_driver_t *drv) {
 }
 #endif
 
+#ifdef USE_RGB_LED
+void draw_rgb_led(uint32_t color) {
+  display_driver_t *drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return;
+  }
+  // Extract RGB components
+  uint32_t r = (color >> 16) & 0xFF;
+  uint32_t g = (color >> 8) & 0xFF;
+  uint32_t b = color & 0xFF;
+
+  // Define LED circle properties
+  const int radius = 5;
+  int center_x = DISPLAY_RESX / 2;
+  int center_y = 0;
+
+  // Position based on background
+  if (drv->background) {
+    center_x += TOUCH_OFFSET_X;
+    center_y = TOUCH_OFFSET_Y / 2;
+  } else {
+    center_x += EMULATOR_BORDER;
+    center_y = EMULATOR_BORDER / 2;
+  }
+
+  // Draw the LED
+  SDL_SetRenderDrawColor(drv->renderer, r, g, b, 255);
+  for (int y = -radius; y <= radius; y++) {
+    for (int x = -radius; x <= radius; x++) {
+      if (x * x + y * y <= radius * radius) {
+        SDL_RenderDrawPoint(drv->renderer, center_x + x, center_y + y);
+      }
+    }
+  }
+  SDL_SetRenderDrawColor(drv->renderer, 0, 0, 0, 255);
+  SDL_RenderPresent(drv->renderer);
+}
+#endif
+
 void display_refresh(void) {
   display_driver_t *drv = &g_display_driver;
 
@@ -353,6 +396,10 @@ void display_refresh(void) {
     SDL_RenderCopyEx(drv->renderer, drv->texture, NULL, &r,
                      drv->orientation_angle, NULL, 0);
   }
+  // Show the LED
+#ifdef USE_RGB_LED
+  draw_rgb_led(drv->led_color);
+#endif
   SDL_RenderPresent(drv->renderer);
 }
 
@@ -493,3 +540,14 @@ void display_clear_save(void) {
   SDL_FreeSurface(drv->prev_saved);
   drv->prev_saved = NULL;
 }
+
+#ifdef USE_RGB_LED
+void display_rgb_led(uint32_t color) {
+  display_driver_t *drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return;
+  }
+  drv->led_color = color;
+}
+#endif

core/embed/io/rgb_led/unix/rgb_led.c

@@ -0,0 +1,23 @@
+/*
+ * This file is part of the Trezor project, https://trezor.io/
+ *
+ * Copyright (c) SatoshiLabs
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <io/display.h>
+#include <io/rgb_led.h>
+
+void rgb_led_set_color(uint32_t color) { display_rgb_led(color); }

core/site_scons/models/T3W1/emulator.py

@@ -45,6 +45,12 @@ def configure(
         paths += ["embed/io/sbu/inc"]
         defines += [("USE_SBU", "1")]
 
+    if "rgb_led" in features_wanted:
+        sources += ["embed/io/rgb_led/unix/rgb_led.c"]
+        paths += ["embed/io/rgb_led/inc"]
+        features_available.append("rgb_led")
+        defines += [("USE_RGB_LED", "1")]
+
     if "optiga" in features_wanted:
         sources += ["embed/sec/optiga/unix/optiga_hal.c"]
         sources += ["embed/sec/optiga/unix/optiga.c"]