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From:   Guillaume Ranquet <granquet@baylibre.com>
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 <812a5de2-dbe3-2f0d-492c-16ea004c996a@collabora.com>
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Date:   Tue, 27 Sep 2022 06:34:34 -0700
Message-ID: <CABnWg9sSbtXYLpcCoEts73CAsciKMEeMMRwfcfGng8H-rGYvkA@mail.gmail.com>
Subject: Re: [PATCH v1 16/17] drm/mediatek: dpi: Add mt8195 hdmi to DPI driver
To:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Vinod Koul <vkoul@kernel.org>, Stephen Boyd <sboyd@kernel.org>,
        David Airlie <airlied@linux.ie>,
        Rob Herring <robh+dt@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        Chunfeng Yun <chunfeng.yun@mediatek.com>,
        CK Hu <ck.hu@mediatek.com>, Jitao shi <jitao.shi@mediatek.com>,
        Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Kishon Vijay Abraham I <kishon@ti.com>
Cc:     linux-mediatek@lists.infradead.org,
        dri-devel@lists.freedesktop.org,
        Pablo Sun <pablo.sun@mediatek.com>, linux-clk@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Mattijs Korpershoek <mkorpershoek@baylibre.com>,
        linux-arm-kernel@lists.infradead.org,
        linux-phy@lists.infradead.org, devicetree@vger.kernel.org
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On Tue, 20 Sep 2022 14:22, AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com> wrote:
>Il 19/09/22 18:56, Guillaume Ranquet ha scritto:
>> Add the DPI1 hdmi path support in mtk dpi driver
>>
>> Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
>> index 630a4e301ef6..91212b7610e8 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
>> @@ -15,7 +15,10 @@
>>   #include <linux/of_graph.h>
>>   #include <linux/pinctrl/consumer.h>
>>   #include <linux/platform_device.h>
>> +#include <linux/reset.h>
>>   #include <linux/types.h>
>> +#include <linux/regmap.h>
>> +#include <linux/mfd/syscon.h>
>>
>>   #include <video/videomode.h>
>>
>> @@ -66,10 +69,14 @@ struct mtk_dpi {
>>   	struct drm_bridge *next_bridge;
>>   	struct drm_connector *connector;
>>   	void __iomem *regs;
>> +	struct reset_control *reset_ctl;
>>   	struct device *dev;
>>   	struct clk *engine_clk;
>> +	struct clk *dpi_ck_cg;
>>   	struct clk *pixel_clk;
>> +	struct clk *dpi_sel_clk;
>>   	struct clk *tvd_clk;
>> +	struct clk *hdmi_cg;
>
>
>You're adding new clocks and then you're making *all clocks*, including the
>already existing ones... optional.
>
>That looks seriously odd.... can you please give a devicetree example for
>MT8195 in the next version, perhaps in the cover letter?
>
>Would also make it easier to test this entire big series.
>
>Regards,
>Angelo
>

The clock names are different for MT8195 HDMI than for the legacy DP.
Making everything optional might not have been a smart move.
I'll try to think of something else to make it look less odd.

The device tree I'm using to test things is rather "hackish" and has a bunch of
changes from what is found on linux-next.
I think Jason and Nancy are due to upstream those patches.

I'll try to include something minimal for you to test.
Otherwise would a public branch containing everything work for you?

Thx,
Guillaume.