[PATCH v3 6/7] drm/meson: overlay: setup overlay for Amlogic FBC Memory Saving mode

[Neil Armstrong]

Setup the Amlogic FBC decoder for the VD1 video overlay plane to use
a different superblock size for the Memory Saving mode.

Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
 drivers/gpu/drm/meson/meson_overlay.c | 14 ++++++++++++--
 include/uapi/drm/drm_fourcc.h         | 16 +++++++++++++++-
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_overlay.c b/drivers/gpu/drm/meson/meson_overlay.c
index 51fa038ad5d7..8b9d4984b2a7 100644
--- a/drivers/gpu/drm/meson/meson_overlay.c
+++ b/drivers/gpu/drm/meson/meson_overlay.c
@@ -487,6 +487,9 @@ static void meson_overlay_atomic_update(struct drm_plane *plane,
 					  AFBC_HOLD_LINE_NUM(8) |
 					  AFBC_BURST_LEN(2);
 
+		if (fb->modifier & DRM_FORMAT_MOD_AMLOGIC_FBC_MEM_SAVING)
+			priv->viu.vd1_afbc_mode |= AFBC_BLK_MEM_MODE;
+
 		priv->viu.vd1_afbc_en = 0x1600 | AFBC_DEC_ENABLE;
 
 		priv->viu.vd1_afbc_conv_ctrl = AFBC_CONV_LBUF_LEN(256);
@@ -672,12 +675,17 @@ static void meson_overlay_atomic_update(struct drm_plane *plane,
 	}
 
 	if (priv->viu.vd1_afbc) {
+		/* Default mode is 4k per superblock */
+		unsigned long block_size = 4096;
 		unsigned long body_size;
 
-		/* Default mode is 4k per superblock */
+		/* 8bit mem saving mode is 3072bytes per superblock */
+		if (priv->viu.vd1_afbc_mode & AFBC_BLK_MEM_MODE)
+			block_size = 3072;
+
 		body_size = (ALIGN(priv->viu.vd1_stride0, 64) / 64) *
 			    (ALIGN(priv->viu.vd1_height0, 32) / 32) *
-			    4096;
+			    block_size;
 
 		priv->viu.vd1_afbc_body_addr = priv->viu.vd1_addr0 >> 4;
 
@@ -763,6 +771,8 @@ static const uint32_t supported_drm_formats[] = {
 };
 
 static const uint64_t format_modifiers[] = {
+	DRM_FORMAT_MOD_AMLOGIC_FBC(DRM_FORMAT_MOD_AMLOGIC_FBC_LAYOUT_BASIC |
+				   DRM_FORMAT_MOD_AMLOGIC_FBC_MEM_SAVING),
 	DRM_FORMAT_MOD_AMLOGIC_FBC(DRM_FORMAT_MOD_AMLOGIC_FBC_LAYOUT_BASIC),
 	DRM_FORMAT_MOD_LINEAR,
 	DRM_FORMAT_MOD_INVALID,
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 84edc5d69613..b49f1d45e1b4 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -840,6 +840,19 @@ extern "C" {
  */
 #define DRM_FORMAT_MOD_AMLOGIC_FBC_LAYOUT_BASIC		(1ULL << 0)
 
+/*
+ * Amlogic FBC Scatter Memory layout
+ *
+ * Indicates the header contains IOMMU references to the compressed
+ * frames content to optimize memory access and layout.
+ *
+ * In this mode, only the header memory address is needed, thus the
+ * content memory organization is tied to the current producer
+ * execution and cannot be saved/dumped neither transferrable between
+ * Amlogic SoCs supporting this modifier.
+ */
+#define DRM_FORMAT_MOD_AMLOGIC_FBC_LAYOUT_SCATTER	(2ULL << 0)
+
 /*
  * Amlogic FBC Layout Options
  */
@@ -852,7 +865,8 @@ extern "C" {
  * memory.
  *
  * This mode reduces body layout to 3072 bytes per 64x32 superblock with
- * the basic layout.
+ * the basic layout and 3200 bytes per 64x32 superblock combined with
+ * the scatter layout.
  */
 #define DRM_FORMAT_MOD_AMLOGIC_FBC_MEM_SAVING	(1ULL << 8)
 
-- 
2.22.0