[PATCH v12 6/8] drm/mediatek: enable dither function

[Hsin-Yi Wang]

From: Yongqiang Niu <yongqiang....@mediatek.com>

for 5 or 6 bpc panel, we need enable dither function
to improve the display quality

Signed-off-by: Yongqiang Niu <yongqiang....@mediatek.com>
Signed-off-by: Hsin-Yi Wang <hsi...@chromium.org>
---
 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c 
b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
index ac2cb25620357..6c8f246380a74 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
@@ -53,6 +53,7 @@
 #define DITHER_EN                              BIT(0)
 #define DISP_DITHER_CFG                                0x0020
 #define DITHER_RELAY_MODE                      BIT(0)
+#define DITHER_ENGINE_EN                       BIT(1)
 #define DISP_DITHER_SIZE                       0x0030
 
 #define LUT_10BIT_MASK                         0x03ff
@@ -314,9 +315,19 @@ static void mtk_dither_config(struct device *dev, unsigned 
int w,
                              unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
 {
        struct mtk_ddp_comp_dev *priv = dev_get_drvdata(dev);
+       bool enable = (bpc == 5 || bpc == 6);
 
-       mtk_ddp_write(cmdq_pkt, h << 16 | w, &priv->cmdq_reg, priv->regs, 
DISP_DITHER_SIZE);
-       mtk_ddp_write(cmdq_pkt, DITHER_RELAY_MODE, &priv->cmdq_reg, priv->regs, 
DISP_DITHER_CFG);
+       if (enable) {
+               mtk_dither_set_common(priv->regs, &priv->cmdq_reg, bpc,
+                                     DISP_DITHER_CFG, DITHER_ENGINE_EN,
+                                     cmdq_pkt);
+       } else {
+               mtk_ddp_write(cmdq_pkt, DITHER_RELAY_MODE, &priv->cmdq_reg,
+                             priv->regs, DISP_DITHER_CFG);
+       }
+
+       mtk_ddp_write(cmdq_pkt, h << 16 | w, &priv->cmdq_reg, priv->regs,
+                     DISP_DITHER_SIZE);
 }
 
 static void mtk_dither_start(struct device *dev)
-- 
2.30.0.280.ga3ce27912f-goog