7 files changed, 20 insertions, 1 deletions

diff --git a/minui/graphics.cpp b/minui/graphics.cpp
index b24c2b114..41a366112 100644
--- a/minui/graphics.cpp
+++ b/minui/graphics.cpp
@@ -502,3 +502,7 @@ void gr_fb_blank(bool blank, int index) {
 void gr_rotate(GRRotation rot) {
   rotation = rot;
 }
+
+bool gr_has_multiple_connectors() {
+  return gr_backend->HasMultipleConnectors();
+}
diff --git a/minui/graphics.h b/minui/graphics.h
index 5408c93e9..ff063ae23 100644
--- a/minui/graphics.h
+++ b/minui/graphics.h
@@ -40,8 +40,11 @@ class MinuiBackend {
   // Blank (or unblank) the specific screen.
   virtual void Blank(bool blank, DrmConnector index) = 0;
 
+  // Return true if the device supports multiple connectors.
+  virtual bool HasMultipleConnectors() = 0;
+
   // Device cleanup when drawing is done.
-  virtual ~MinuiBackend() {};
+  virtual ~MinuiBackend() = default;
 };
 
 #endif  // _GRAPHICS_H_
diff --git a/minui/graphics_drm.cpp b/minui/graphics_drm.cpp
index c55702276..6c3a5bdee 100644
--- a/minui/graphics_drm.cpp
+++ b/minui/graphics_drm.cpp
@@ -200,6 +200,10 @@ void MinuiBackendDrm::Blank(bool blank, DrmConnector index) {
   }
 }
 
+bool MinuiBackendDrm::HasMultipleConnectors() {
+  return (drm[DRM_SEC].GRSurfaceDrms[0] && drm[DRM_SEC].GRSurfaceDrms[1]);
+}
+
 static drmModeCrtc* find_crtc_for_connector(int fd, drmModeRes* resources,
                                             drmModeConnector* connector) {
   // Find the encoder. If we already have one, just use it.
diff --git a/minui/graphics_drm.h b/minui/graphics_drm.h
index fe3beaff9..a8c9886e5 100644
--- a/minui/graphics_drm.h
+++ b/minui/graphics_drm.h
@@ -60,6 +60,7 @@ class MinuiBackendDrm : public MinuiBackend {
   GRSurface* Flip() override;
   void Blank(bool) override;
   void Blank(bool blank, DrmConnector index) override;
+  bool HasMultipleConnectors() override;
 
  private:
   void DrmDisableCrtc(int drm_fd, drmModeCrtc* crtc);
diff --git a/minui/graphics_fbdev.cpp b/minui/graphics_fbdev.cpp
index 1cb0c0ab8..4a7d3252b 100644
--- a/minui/graphics_fbdev.cpp
+++ b/minui/graphics_fbdev.cpp
@@ -47,6 +47,11 @@ void MinuiBackendFbdev::Blank(bool blank, DrmConnector index) {
   fprintf(stderr, "Unsupported multiple connectors, blank = %d, index = %d\n", blank, index);
 }
 
+bool MinuiBackendFbdev::HasMultipleConnectors() {
+  fprintf(stderr, "Unsupported multiple connectors\n");
+  return false;
+}
+
 void MinuiBackendFbdev::SetDisplayedFramebuffer(size_t n) {
   if (n > 1 || !double_buffered) return;
 
diff --git a/minui/graphics_fbdev.h b/minui/graphics_fbdev.h
index 7e193c4ff..c772428dc 100644
--- a/minui/graphics_fbdev.h
+++ b/minui/graphics_fbdev.h
@@ -57,6 +57,7 @@ class MinuiBackendFbdev : public MinuiBackend {
   GRSurface* Flip() override;
   void Blank(bool) override;
   void Blank(bool blank, DrmConnector index) override;
+  bool HasMultipleConnectors() override;
 
  private:
   void SetDisplayedFramebuffer(size_t n);
diff --git a/minui/include/minui/minui.h b/minui/include/minui/minui.h
index f9be82f52..2353ed3b9 100644
--- a/minui/include/minui/minui.h
+++ b/minui/include/minui/minui.h
@@ -129,6 +129,7 @@ int gr_fb_height();
 void gr_flip();
 void gr_fb_blank(bool blank);
 void gr_fb_blank(bool blank, int index);
+bool gr_has_multiple_connectors();
 
 // Clears entire surface to current color.
 void gr_clear();