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References: <20220218145437.18563-1-granquet@baylibre.com> <20220218145437.18563-8-granquet@baylibre.com>
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From:   Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date:   Mon, 21 Feb 2022 10:32:32 +0800
Message-ID: <CAAOTY_-5g4fXVTOETDxbn2Cp3MVjFs-Sh9NT1NepfEXUhdJQEw@mail.gmail.com>
Subject: Re: [PATCH v8 07/19] drm/mediatek: dpi: implement a swap_input toggle
 in board config
To:     Guillaume Ranquet <granquet@baylibre.com>
Cc:     Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Chunfeng Yun <chunfeng.yun@mediatek.com>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Vinod Koul <vkoul@kernel.org>, deller@gmx.de,
        CK Hu <ck.hu@mediatek.com>, Jitao Shi <jitao.shi@mediatek.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        DTML <devicetree@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-phy@lists.infradead.org, linux-fbdev@vger.kernel.org
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Hi, Guillaume:

Guillaume Ranquet <granquet@baylibre.com> =E6=96=BC 2022=E5=B9=B42=E6=9C=88=
18=E6=97=A5 =E9=80=B1=E4=BA=94 =E4=B8=8B=E5=8D=8810:56=E5=AF=AB=E9=81=93=EF=
=BC=9A
>
> Adds a bit of flexibility to support boards without swap_input support
>
> Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediate=
k/mtk_dpi.c
> index 545a1337cc899..454f8563efae4 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -126,6 +126,7 @@ struct mtk_dpi_conf {
>         const u32 *output_fmts;
>         u32 num_output_fmts;
>         bool is_ck_de_pol;
> +       bool swap_input_support;
>         const struct mtk_dpi_yc_limit *limit;
>  };
>
> @@ -378,18 +379,21 @@ static void mtk_dpi_config_color_format(struct mtk_=
dpi *dpi,
>             (format =3D=3D MTK_DPI_COLOR_FORMAT_YCBCR_444_FULL)) {
>                 mtk_dpi_config_yuv422_enable(dpi, false);
>                 mtk_dpi_config_csc_enable(dpi, true);
> -               mtk_dpi_config_swap_input(dpi, false);
> +               if (dpi->conf->swap_input_support)
> +                       mtk_dpi_config_swap_input(dpi, false);
>                 mtk_dpi_config_channel_swap(dpi, MTK_DPI_OUT_CHANNEL_SWAP=
_BGR);
>         } else if ((format =3D=3D MTK_DPI_COLOR_FORMAT_YCBCR_422) ||
>                    (format =3D=3D MTK_DPI_COLOR_FORMAT_YCBCR_422_FULL)) {
>                 mtk_dpi_config_yuv422_enable(dpi, true);
>                 mtk_dpi_config_csc_enable(dpi, true);
> -               mtk_dpi_config_swap_input(dpi, true);
> +               if (dpi->conf->swap_input_support)
> +                       mtk_dpi_config_swap_input(dpi, true);

In MT8173, MT2701, MT8183, MT8192, YCBCR_444 would not swap but
YCBCR_422 would swap. But In MT8195, both YCBCR_444 and YCBCR_422
would not swap, So I think one of these format would be abnormal in
MT8195, right? Or would you provide more information about how this
swap work?

Regards,
Chun-Kuang.

>                 mtk_dpi_config_channel_swap(dpi, MTK_DPI_OUT_CHANNEL_SWAP=
_RGB);
>         } else {
>                 mtk_dpi_config_yuv422_enable(dpi, false);
>                 mtk_dpi_config_csc_enable(dpi, false);
> -               mtk_dpi_config_swap_input(dpi, false);
> +               if (dpi->conf->swap_input_support)
> +                       mtk_dpi_config_swap_input(dpi, false);
>                 mtk_dpi_config_channel_swap(dpi, MTK_DPI_OUT_CHANNEL_SWAP=
_RGB);
>         }
>  }
> @@ -808,6 +812,7 @@ static const struct mtk_dpi_conf mt8173_conf =3D {
>         .output_fmts =3D mt8173_output_fmts,
>         .num_output_fmts =3D ARRAY_SIZE(mt8173_output_fmts),
>         .is_ck_de_pol =3D true,
> +       .swap_input_support =3D true,
>         .limit =3D &mtk_dpi_limit,
>  };
>
> @@ -819,6 +824,7 @@ static const struct mtk_dpi_conf mt2701_conf =3D {
>         .output_fmts =3D mt8173_output_fmts,
>         .num_output_fmts =3D ARRAY_SIZE(mt8173_output_fmts),
>         .is_ck_de_pol =3D true,
> +       .swap_input_support =3D true,
>         .limit =3D &mtk_dpi_limit,
>  };
>
> @@ -829,6 +835,7 @@ static const struct mtk_dpi_conf mt8183_conf =3D {
>         .output_fmts =3D mt8183_output_fmts,
>         .num_output_fmts =3D ARRAY_SIZE(mt8183_output_fmts),
>         .is_ck_de_pol =3D true,
> +       .swap_input_support =3D true,
>         .limit =3D &mtk_dpi_limit,
>  };
>
> @@ -839,6 +846,7 @@ static const struct mtk_dpi_conf mt8192_conf =3D {
>         .output_fmts =3D mt8173_output_fmts,
>         .num_output_fmts =3D ARRAY_SIZE(mt8173_output_fmts),
>         .is_ck_de_pol =3D true,
> +       .swap_input_support =3D true,
>         .limit =3D &mtk_dpi_limit,
>  };
>
> --
> 2.34.1
>