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From:   Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date:   Sat, 10 Apr 2021 06:41:36 +0800
Message-ID: <CAAOTY_-gqN2HCLg6AABsXYzJoBxpN8FkMfjqWFu2q=6noiY1qg@mail.gmail.com>
Subject: Re: [PATCH] gpu/drm: mediatek: hdmi: check for valid modes on MT8167
To:     Neil Armstrong <narmstrong@baylibre.com>
Cc:     Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Fabien Parent <fparent@baylibre.com>
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Hi, Neil:

Neil Armstrong <narmstrong@baylibre.com> =E6=96=BC 2021=E5=B9=B44=E6=9C=889=
=E6=97=A5 =E9=80=B1=E4=BA=94 =E4=B8=8B=E5=8D=884:43=E5=AF=AB=E9=81=93=EF=BC=
=9A
>
> On MT8167, only CEA modes and anything using a clock below 148500 is
> supported for HDMI. This change adds some checks to make sure the
> video format is OK for MT8167.

I think this patch should be separated to 3 patches. check CEA mode,
check clock, add mt8167 hdmi support.

>
> Signed-off-by: Fabien Parent <fparent@baylibre.com>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_hdmi.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediat=
ek/mtk_hdmi.c
> index 8ee55f9e2954..991e2e935b93 100644
> --- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
> @@ -148,6 +148,8 @@ struct hdmi_audio_param {
>
>  struct mtk_hdmi_conf {
>         bool tz_disabled;
> +       unsigned long max_mode_clock;
> +       bool cea_modes_only;
>  };
>
>  struct mtk_hdmi {
> @@ -1259,6 +1261,13 @@ static int mtk_hdmi_conn_mode_valid(struct drm_con=
nector *conn,
>                         return MODE_BAD;
>         }
>
> +       if (hdmi->conf->cea_modes_only && !drm_match_cea_mode(mode))
> +               return MODE_BAD;
> +
> +       if (hdmi->conf->max_mode_clock &&
> +           mode->clock > hdmi->conf->max_mode_clock)
> +               return MODE_CLOCK_HIGH;
> +
>         if (mode->clock < 27000)
>                 return MODE_CLOCK_LOW;
>         if (mode->clock > 297000)
> @@ -1810,10 +1819,18 @@ static const struct mtk_hdmi_conf mtk_hdmi_conf_m=
t2701 =3D {
>         .tz_disabled =3D true,
>  };
>
> +static const struct mtk_hdmi_conf mtk_hdmi_conf_mt8167 =3D {
> +       .max_mode_clock =3D 148500,
> +       .cea_modes_only =3D true,
> +};
> +
>  static const struct of_device_id mtk_drm_hdmi_of_ids[] =3D {
>         { .compatible =3D "mediatek,mt2701-hdmi",
>           .data =3D &mtk_hdmi_conf_mt2701,
>         },
> +       { .compatible =3D "mediatek,mt8167-hdmi",

"mediatek,mt8167-hdmi" does not exist in binding document, so add this
to binding document first.
In addition, could you also transfer mediatek,hdmi.txt to yaml format?

Regards,
Chun-Kuang.

> +         .data =3D &mtk_hdmi_conf_mt8167,
> +       },
>         { .compatible =3D "mediatek,mt8173-hdmi",
>         },
>         {}
> --
> 2.25.1
>