[PATCH v8 12/16] drm/mediatek: Support "Pre-multiplied" blending in Mixer

[Shawn Sung]

From: Hsiao Chien Sung <shawn.s...@mediatek.com>

Support "Pre-multiplied" alpha blending mode in Mixer.
Before this patch, only the coverage mode is supported.

Signed-off-by: Hsiao Chien Sung <shawn.s...@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_ethdr.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_ethdr.c 
b/drivers/gpu/drm/mediatek/mtk_ethdr.c
index bcced62e455d..d01f65819816 100644
--- a/drivers/gpu/drm/mediatek/mtk_ethdr.c
+++ b/drivers/gpu/drm/mediatek/mtk_ethdr.c
@@ -6,6 +6,7 @@
 #include <drm/drm_blend.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
+#include <drm/drm_blend.h>
 #include <linux/clk.h>
 #include <linux/component.h>
 #include <linux/of.h>
@@ -36,6 +37,7 @@
 #define MIX_SRC_L0_EN                          BIT(0)
 #define MIX_L_SRC_CON(n)               (0x28 + 0x18 * (n))
 #define NON_PREMULTI_SOURCE                    (2 << 12)
+#define PREMULTI_SOURCE                                (3 << 12)
 #define MIX_L_SRC_SIZE(n)              (0x30 + 0x18 * (n))
 #define MIX_L_SRC_OFFSET(n)            (0x34 + 0x18 * (n))
 #define MIX_FUNC_DCM0                  0x120
@@ -172,8 +174,12 @@ void mtk_ethdr_layer_config(struct device *dev, unsigned 
int idx,
                return;
        }
 
-       if (state->base.fb && state->base.fb->format->has_alpha)
-               alpha_con = MIXER_ALPHA_AEN | MIXER_ALPHA;
+       alpha_con |= MIXER_ALPHA_AEN | (state->base.alpha & MIXER_ALPHA);
+
+       if (state->base.pixel_blend_mode != DRM_MODE_BLEND_COVERAGE)
+               alpha_con |= PREMULTI_SOURCE;
+       else
+               alpha_con |= NON_PREMULTI_SOURCE;
 
        if (state->base.pixel_blend_mode == DRM_MODE_BLEND_PIXEL_NONE ||
            (state->base.fb && !state->base.fb->format->has_alpha)) {
@@ -191,8 +197,7 @@ void mtk_ethdr_layer_config(struct device *dev, unsigned 
int idx,
        mtk_ddp_write(cmdq_pkt, pending->height << 16 | align_width, 
&mixer->cmdq_base,
                      mixer->regs, MIX_L_SRC_SIZE(idx));
        mtk_ddp_write(cmdq_pkt, offset, &mixer->cmdq_base, mixer->regs, 
MIX_L_SRC_OFFSET(idx));
-       mtk_ddp_write_mask(cmdq_pkt, alpha_con, &mixer->cmdq_base, mixer->regs, 
MIX_L_SRC_CON(idx),
-                          0x1ff);
+       mtk_ddp_write(cmdq_pkt, alpha_con, &mixer->cmdq_base, mixer->regs, 
MIX_L_SRC_CON(idx));
        mtk_ddp_write_mask(cmdq_pkt, BIT(idx), &mixer->cmdq_base, mixer->regs, 
MIX_SRC_CON,
                           BIT(idx));
 }
-- 
2.18.0