drm_hwcomposer: Add support for Arm Framebuffer Compression (AFBC) modifiers.

One needs to translate the Gralloc buffer flags for AFBC (eg
MALI_GRALLOC_INTFMT_AFBC_BASIC) to the corresponding linux kernel drm modifiers.
This gets passed to libdrm via drmModeAddFB2WithModifiers.

Changes from v1:-
- Moved ConvertGrallocFormatToDrmModifiers() and IsDrmFormatRgb() from 'DrmGenericImporter'
to 'HisiImporter' as suggested by Sean paul
- Check if the format is rgb and set AFBC_FORMAT_MOD_YTR only if any of the AFBC related
Gralloc flags are set.

Changes from v2:-
- Changed ConvertGrallocFormatToDrmModifiers() and IsDrmFormatRgb() from 'public' to 'private'
(suggested by Sean Paul)

Changes from v3:-
- Reordered the members of 'class HisiImporter'. Functions should go above member variables.
(suggested by Sean Paul)

Changes from v4:-
- Rebased and some style changes (as suggested by gitlab-ci-checkcommit.sh)

Signed-off-by: Ayan Kumar Halder <ayan.halder@arm.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>

/-- Note for reviewer
I was able to get this working for hikey960 with aosp/master for kernel 4.14. The libdrm
headers need to be updated as the AFBC modifiers are missing in the aosp/master's external/libdrm.
--/

Change-Id: I66abaa08d19ce88169cc40522b167dfe5efc7036

2 files changed, 58 insertions, 2 deletions

diff --git a/platformhisi.cpp b/platformhisi.cpp
index 76fe1e7..9413457 100644
--- a/platformhisi.cpp
+++ b/platformhisi.cpp
@@ -70,7 +70,52 @@ int HisiImporter::Init() {
   return 0;
 }
 
+uint64_t HisiImporter::ConvertGrallocFormatToDrmModifiers(uint64_t flags,
+                                                          bool is_rgb) {
+  uint64_t features = 0UL;
+
+  if (flags & MALI_GRALLOC_INTFMT_AFBC_BASIC)
+    features |= AFBC_FORMAT_MOD_BLOCK_SIZE_16x16;
+
+  if (flags & MALI_GRALLOC_INTFMT_AFBC_SPLITBLK)
+    features |= (AFBC_FORMAT_MOD_SPLIT | AFBC_FORMAT_MOD_SPARSE);
+
+  if (flags & MALI_GRALLOC_INTFMT_AFBC_WIDEBLK)
+    features |= AFBC_FORMAT_MOD_BLOCK_SIZE_32x8;
+
+  if (flags & MALI_GRALLOC_INTFMT_AFBC_TILED_HEADERS)
+    features |= AFBC_FORMAT_MOD_TILED;
+
+  if (features) {
+    if (is_rgb)
+      features |= AFBC_FORMAT_MOD_YTR;
+
+    return DRM_FORMAT_MOD_ARM_AFBC(features);
+  }
+
+  return 0;
+}
+
+bool HisiImporter::IsDrmFormatRgb(uint32_t drm_format) {
+  switch (drm_format) {
+    case DRM_FORMAT_ARGB8888:
+    case DRM_FORMAT_XBGR8888:
+    case DRM_FORMAT_ABGR8888:
+    case DRM_FORMAT_BGR888:
+    case DRM_FORMAT_BGR565:
+      return true;
+    case DRM_FORMAT_YVU420:
+      return false;
+    default:
+      ALOGE("Unsupported format %u assuming rgb?", drm_format);
+      return true;
+  }
+}
+
 int HisiImporter::ImportBuffer(buffer_handle_t handle, hwc_drm_bo_t *bo) {
+  bool is_rgb;
+  uint64_t modifiers[4] = {0};
+
   memset(bo, 0, sizeof(hwc_drm_bo_t));
 
   private_handle_t const *hnd = reinterpret_cast<private_handle_t const *>(
@@ -94,6 +139,10 @@ int HisiImporter::ImportBuffer(buffer_handle_t handle, hwc_drm_bo_t *bo) {
   if (fmt < 0)
     return fmt;
 
+  is_rgb = IsDrmFormatRgb(fmt);
+  modifiers[0] = ConvertGrallocFormatToDrmModifiers(hnd->internal_format,
+                                                    is_rgb);
+
   bo->width = hnd->width;
   bo->height = hnd->height;
   bo->hal_format = hnd->req_format;
@@ -129,8 +178,11 @@ int HisiImporter::ImportBuffer(buffer_handle_t handle, hwc_drm_bo_t *bo) {
       break;
   }
 
-  ret = drmModeAddFB2(drm_->fd(), bo->width, bo->height, bo->format,
-                      bo->gem_handles, bo->pitches, bo->offsets, &bo->fb_id, 0);
+  ret = drmModeAddFB2WithModifiers(drm_->fd(), bo->width, bo->height,
+                                   bo->format, bo->gem_handles, bo->pitches,
+                                   bo->offsets, modifiers, &bo->fb_id,
+                                   modifiers[0] ? DRM_MODE_FB_MODIFIERS : 0);
+
   if (ret) {
     ALOGE("could not create drm fb %d", ret);
     return ret;
diff --git a/platformhisi.h b/platformhisi.h
index 927da17..14a58b9 100644
--- a/platformhisi.h
+++ b/platformhisi.h
@@ -39,6 +39,10 @@ class HisiImporter : public DrmGenericImporter {
   bool CanImportBuffer(buffer_handle_t handle) override;
 
  private:
+  uint64_t ConvertGrallocFormatToDrmModifiers(uint64_t flags, bool is_rgb);
+
+  bool IsDrmFormatRgb(uint32_t drm_format);
+
   DrmDevice *drm_;
 
   const gralloc_module_t *gralloc_;