[PATCH v3 11/17] drm/mediatek: drm/mediatek: Export OVL ignore pixel alpha function

[paul-pl.chen <paul-pl.chen@mediatek.com>]

From: Nancy Lin <nancy.lin@mediatek.com>

For the new BLENDER component, the OVL ignore pixel alpha logic
should be exported as a function and reused it.

Signed-off-by: Nancy Lin <nancy.lin@mediatek.com>
Signed-off-by: Paul-pl Chen <paul-pl.chen@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 24 ++++++++++++++++++++++--
 drivers/gpu/drm/mediatek/mtk_disp_ovl.h |  1 +
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
index a516b7c82b5a..747898a574da 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
@@ -211,6 +211,23 @@ void mtk_ovl_disable_vblank(struct device *dev)
 	writel_relaxed(0x0, ovl->regs + DISP_REG_OVL_INTEN);
 }
 
+bool mtk_ovl_is_ignore_pixel_alpha(struct mtk_plane_state *state, unsigned int blend_mode)
+{
+	if (!state->base.fb)
+		return false;
+	/*
+	 * Although the alpha channel can be ignored, CONST_BLD must be enabled
+	 * for XRGB format, otherwise OVL will still read the value from memory.
+	 * For RGB888 related formats, whether CONST_BLD is enabled or not won't
+	 * affect the result. Therefore we use !has_alpha as the condition.
+	 */
+
+	if (blend_mode == DRM_MODE_BLEND_PIXEL_NONE || !state->base.fb->format->has_alpha)
+		return true;
+
+	return false;
+}
+
 u32 mtk_ovl_get_blend_modes(struct device *dev)
 {
 	struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);
@@ -539,7 +556,7 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
 	unsigned int rotation = pending->rotation;
 	unsigned int offset = (pending->y << 16) | pending->x;
 	unsigned int src_size = (pending->height << 16) | pending->width;
-	unsigned int blend_mode = state->base.pixel_blend_mode;
+	unsigned int blend_mode = mtk_ovl_get_blend_mode(state, ovl->data->blend_modes);
 	unsigned int ignore_pixel_alpha = 0;
 	unsigned int con;
 
@@ -557,7 +574,7 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
 		 * For blend_modes supported SoCs, always enable alpha blending.
 		 * For blend_modes unsupported SoCs, enable alpha blending when has_alpha is set.
 		 */
-		if (blend_mode || state->base.fb->format->has_alpha)
+		if (state->base.pixel_blend_mode || state->base.fb->format->has_alpha)
 			con |= OVL_CON_AEN;
 	}
 
@@ -584,6 +601,9 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
 
 	mtk_ddp_write_relaxed(cmdq_pkt, con, &ovl->cmdq_reg, ovl->regs,
 			      DISP_REG_OVL_CON(idx));
+
+	if (mtk_ovl_is_ignore_pixel_alpha(state, blend_mode))
+		ignore_pixel_alpha = OVL_CONST_BLEND;
 	mtk_ddp_write_relaxed(cmdq_pkt, pitch_lsb | ignore_pixel_alpha,
 			      &ovl->cmdq_reg, ovl->regs, DISP_REG_OVL_PITCH(idx));
 	mtk_ddp_write_relaxed(cmdq_pkt, src_size, &ovl->cmdq_reg, ovl->regs,
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.h b/drivers/gpu/drm/mediatek/mtk_disp_ovl.h
index 3f7d7d54479d..431567538eb5 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.h
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.h
@@ -20,6 +20,7 @@ extern const u32 mt8195_ovl_formats[];
 extern const size_t mt8195_ovl_formats_len;
 
 bool mtk_ovl_is_10bit_rgb(unsigned int fmt);
+bool mtk_ovl_is_ignore_pixel_alpha(struct mtk_plane_state *state, unsigned int blend_mode);
 unsigned int mtk_ovl_get_blend_mode(struct mtk_plane_state *state, unsigned int blend_modes);
 unsigned int mtk_ovl_fmt_convert(unsigned int fmt, unsigned int blend_mode,
 				 bool fmt_rgb565_is_0, bool color_convert,
-- 
2.45.2