commit 364f957f3eefafd0963f140b68bec314cc05f07a
author Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com> Wed Mar 21 11:40:01 2018 +0000
committer Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com> Fri Jul 13 15:36:57 2018 +0100
tree 14ce23329c3a79625fe2babaa5badd8035323613
parent 62e2d2c8a6cf240ccc44c847d8e20f56e4b12492

drm_hwcomposer: Add writeback connector support

Writeback connector is a special case of connector, which can be
linked to a CRTC in order to get the result of the composition back to
a memory buffer. This had not been merged to the mainline kernel yet,
latest version of the kernel patches could be found here [1].

[1] https://lists.freedesktop.org/archives/dri-devel/2018-February/167703.html

Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com>
Reviewed-by: Sean Paul <seanpaul at chromium.org>

drmconnector.cpp

diff --git a/drmconnector.cpp b/drmconnector.cpp
index 83d4161..bdf4811 100644
--- a/drmconnector.cpp
+++ b/drmconnector.cpp
@@ -52,6 +52,26 @@
     ALOGE("Could not get CRTC_ID property\n");
     return ret;
   }
+  if (writeback()) {
+    ret = drm_->GetConnectorProperty(*this, "WRITEBACK_PIXEL_FORMATS",
+                                     &writeback_pixel_formats_);
+    if (ret) {
+      ALOGE("Could not get WRITEBACK_PIXEL_FORMATS connector_id = %d\n", id_);
+      return ret;
+    }
+    ret = drm_->GetConnectorProperty(*this, "WRITEBACK_FB_ID",
+                                     &writeback_fb_id_);
+    if (ret) {
+      ALOGE("Could not get WRITEBACK_FB_ID connector_id = %d\n", id_);
+      return ret;
+    }
+    ret = drm_->GetConnectorProperty(*this, "WRITEBACK_OUT_FENCE_PTR",
+                                     &writeback_out_fence_);
+    if (ret) {
+      ALOGE("Could not get WRITEBACK_OUT_FENCE_PTR connector_id = %d\n", id_);
+      return ret;
+    }
+  }
   return 0;
 }
 
@@ -78,8 +98,16 @@
          type_ == DRM_MODE_CONNECTOR_VGA;
 }
 
+bool DrmConnector::writeback() const {
+#ifdef DRM_MODE_CONNECTOR_WRITEBACK
+  return type_ == DRM_MODE_CONNECTOR_WRITEBACK;
+#else
+  return false;
+#endif
+}
+
 bool DrmConnector::valid_type() const {
-  return internal() || external();
+  return internal() || external() || writeback();
 }
 
 int DrmConnector::UpdateModes() {
@@ -130,6 +158,18 @@
   return crtc_id_property_;
 }
 
+const DrmProperty &DrmConnector::writeback_pixel_formats() const {
+  return writeback_pixel_formats_;
+}
+
+const DrmProperty &DrmConnector::writeback_fb_id() const {
+  return writeback_fb_id_;
+}
+
+const DrmProperty &DrmConnector::writeback_out_fence() const {
+  return writeback_out_fence_;
+}
+
 DrmEncoder *DrmConnector::encoder() const {
   return encoder_;
 }