[PATCH v11 7/9] drm/mediatek: enable dither function

Hsin-Yi Wang
2021-01-28T07:29:25Z

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

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

Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 44 ++++++++++++++++++++-
1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
index 8173f709272be..e85625704d611 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
@@ -53,7 +53,9 @@
#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 DITHER_REG(idx) (0x100 + (idx) * 4)

#define LUT_10BIT_MASK 0x03ff

@@ -313,8 +315,48 @@ static void mtk_dither_config(struct device *dev, unsigned int w,
{
struct mtk_ddp_comp_dev *priv = dev_get_drvdata(dev);

+ bool enable = false;
+
+ /* default value for dither reg 5 to 14 */
+ const u32 dither_setting[] = {
+ 0x00000000, /* 5 */
+ 0x00003002, /* 6 */
+ 0x00000000, /* 7 */
+ 0x00000000, /* 8 */
+ 0x00000000, /* 9 */
+ 0x00000000, /* 10 */
+ 0x00000000, /* 11 */
+ 0x00000011, /* 12 */
+ 0x00000000, /* 13 */
+ 0x00000000, /* 14 */
+ };
+
+ if (bpc == 5 || bpc == 6) {
+ enable = true;
+ mtk_ddp_write(cmdq_pkt,
+ DITHER_LSB_ERR_SHIFT_R(MTK_MAX_BPC - bpc) |
+ DITHER_ADD_LSHIFT_R(MTK_MAX_BPC - bpc) |
+ DITHER_NEW_BIT_MODE,
+ &priv->cmdq_reg, priv->regs, DITHER_REG(15));
+ mtk_ddp_write(cmdq_pkt,
+ DITHER_LSB_ERR_SHIFT_B(MTK_MAX_BPC - bpc) |
+ DITHER_ADD_LSHIFT_B(MTK_MAX_BPC - bpc) |
+ DITHER_LSB_ERR_SHIFT_G(MTK_MAX_BPC - bpc) |
+ DITHER_ADD_LSHIFT_G(MTK_MAX_BPC - bpc),
+ &priv->cmdq_reg, priv->regs, DITHER_REG(16));
+ }
+
+
+ if (enable) {
+ u32 idx;
+
+ for (idx = 0; idx < ARRAY_SIZE(dither_setting); idx++)
+ mtk_ddp_write(cmdq_pkt, dither_setting[idx], &priv->cmdq_reg, priv->regs,
+ DITHER_REG(idx + 5));
+ }
+
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);
+ mtk_ddp_write(cmdq_pkt, enable ? DITHER_ENGINE_EN : DITHER_RELAY_MODE, &priv->cmdq_reg, priv->regs, DISP_DITHER_CFG);
}

static void mtk_dither_start(struct device *dev)
--
2.30.0.280.ga3ce27912f-goog