Thread (3 messages) flat view 3 messages, 3 authors, 2021-03-18

Re: [PATCH] drm/mediatek: fine tune the data lane trail by project dts

From: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date: 2021-03-18 00:32:06
Also in: dri-devel, linux-devicetree, linux-mediatek, lkml

Hi, Jitao:

Jitao Shi [off-list ref] 於 2021年2月1日 週一 上午11:48寫道:
quoted hunk ↗ jump to hunk
Some panels or bridges require customized hs_da_trail time.
So add a property in devicetree for this panels and bridges.

Signed-off-by: Jitao Shi <redacted>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 8c70ec39bfe1..6e7092fa2fee 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -194,6 +194,7 @@ struct mtk_dsi {
        struct clk *hs_clk;

        u32 data_rate;
+       u32 da_trail_delta;

        unsigned long mode_flags;
        enum mipi_dsi_pixel_format format;
@@ -234,7 +235,7 @@ static void mtk_dsi_phy_timconfig(struct mtk_dsi *dsi)
        timing->da_hs_prepare = (80 * data_rate_mhz + 4 * 1000) / 8000;
        timing->da_hs_zero = (170 * data_rate_mhz + 10 * 1000) / 8000 + 1 -
                             timing->da_hs_prepare;
-       timing->da_hs_trail = timing->da_hs_prepare + 1;
+       timing->da_hs_trail = timing->da_hs_prepare + 1 + dsi->da_trail_delta;

        timing->ta_go = 4 * timing->lpx - 2;
        timing->ta_sure = timing->lpx + 2;
@@ -1094,6 +1095,13 @@ static int mtk_dsi_probe(struct platform_device *pdev)
                goto err_unregister_host;
        }

+       ret = of_property_read_u32_index(dev->of_node, "da_trail_delta", 0,
+                                        &dsi->da_trail_delta);
This value depends on panel, so I think we should get some value from
panel's device node to calculate this value.

Regards,
Chun-Kuang.
+       if (ret) {
+               dev_info(dev, "Can't get da_trail_delta, keep it as 0: %d\n", ret);
+               dsi->da_trail_delta = 0;
+       }
+
        comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DSI);
        if (comp_id < 0) {
                dev_err(dev, "Failed to identify by alias: %d\n", comp_id);
--
2.12.5
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