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

From: Nicolas Boichat <drinkcat@chromium.org>
To: Jitao Shi <jitao.shi@mediatek.com>
Cc: Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Devicetree List <devicetree@vger.kernel.org>,
	srv_heupstream <srv_heupstream@mediatek.com>,
	huijuan.xie@mediatek.com, stonea168@163.com,
	cawa cheng <cawa.cheng@mediatek.com>,
	shuijing.li@mediatek.com,
	"moderated list:ARM/Mediatek SoC support" 
	<linux-mediatek@lists.infradead.org>,
	Yingjoe Chen <yingjoe.chen@mediatek.com>,
	Eddie Huang <eddie.huang@mediatek.com>,
	linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] drm/mediatek: fine tune the data lane trail by project dts
Date: Wed, 3 Feb 2021 12:02:57 +0800	[thread overview]
Message-ID: <CANMq1KA4nXBuy50pANw1MKbOm0DKNBgBTcHTmMoPFEq-GskKxQ@mail.gmail.com> (raw)
In-Reply-To: <20210201034755.15793-1-jitao.shi@mediatek.com>

On Mon, Feb 1, 2021 at 11:48 AM Jitao Shi <jitao.shi@mediatek.com> wrote:
>
> Some panels or bridges require customized hs_da_trail time.
> So add a property in devicetree for this panels and bridges.

Since this changes the device tree, you also need to upload a binding
document change.

>
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> ---
>  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);
> +       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
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel