[PATCH v4 1/8] drm/fourcc: Add modifier definitions for describing Amlogic Video Framebuffer Compression

[Neil Armstrong]

Amlogic uses a proprietary lossless image compression protocol and format
for their hardware video codec accelerators, either video decoders or
video input encoders.

It considerably reduces memory bandwidth while writing and reading
frames in memory.

The underlying storage is considered to be 3 components, 8bit or 10-bit
per component, YCbCr 420, single plane :
- DRM_FORMAT_YUV420_8BIT
- DRM_FORMAT_YUV420_10BIT

This modifier will be notably added to DMA-BUF frames imported from the V4L2
Amlogic VDEC decoder.

This introduces the basic layout composed of:
- a body content organized in 64x32 superblocks with 4096 bytes per
  superblock in default mode.
- a 32 bytes per 128x64 header block

This layout is tranferrable between Amlogic SoCs supporting this modifier.

Tested-by: Kevin Hilman <khilman@xxxxxxxxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
 include/uapi/drm/drm_fourcc.h | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 8bc0b31597d8..6564813d2f7a 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -309,6 +309,7 @@ extern "C" {
 #define DRM_FORMAT_MOD_VENDOR_BROADCOM 0x07
 #define DRM_FORMAT_MOD_VENDOR_ARM     0x08
 #define DRM_FORMAT_MOD_VENDOR_ALLWINNER 0x09
+#define DRM_FORMAT_MOD_VENDOR_AMLOGIC 0x0a
 
 /* add more to the end as needed */
 
@@ -804,6 +805,35 @@ extern "C" {
  */
 #define DRM_FORMAT_MOD_ALLWINNER_TILED fourcc_mod_code(ALLWINNER, 1)
 
+/*
+ * Amlogic Video Framebuffer Compression modifiers
+ *
+ * Amlogic uses a proprietary lossless image compression protocol and format
+ * for their hardware video codec accelerators, either video decoders or
+ * video input encoders.
+ *
+ * It considerably reduces memory bandwidth while writing and reading
+ * frames in memory.
+ *
+ * The underlying storage is considered to be 3 components, 8bit or 10-bit
+ * per component YCbCr 420, single plane :
+ * - DRM_FORMAT_YUV420_8BIT
+ * - DRM_FORMAT_YUV420_10BIT
+ */
+#define DRM_FORMAT_MOD_AMLOGIC_FBC(__modes) fourcc_mod_code(AMLOGIC, __modes)
+
+/*
+ * Amlogic FBC Basic Layout
+ *
+ * The basic layout is composed of:
+ * - a body content organized in 64x32 superblocks with 4096 bytes per
+ *   superblock in default mode.
+ * - a 32 bytes per 128x64 header block
+ *
+ * This layout is transferrable between Amlogic SoCs supporting this modifier.
+ */
+#define DRM_FORMAT_MOD_AMLOGIC_FBC_LAYOUT_BASIC		(1ULL << 0)
+
 #if defined(__cplusplus)
 }
 #endif
-- 
2.22.0