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Subject: Re: [RFC PATCH 2/9] drm: bridge: Add Samsung SEC MIPI DSIM bridge
 driver
To:     Jagan Teki <jagan@amarulasolutions.com>
Cc:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Fabio Estevam <festevam@gmail.com>,
        Michael Tretter <m.tretter@pengutronix.de>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>, Peng Fan <peng.fan@nxp.com>,
        Francis Laniel <francis.laniel@amarulasolutions.com>,
        Matteo Lisi <matteo.lisi@engicam.com>,
        Neil Armstrong <narmstrong@baylibre.com>,
        linux-amarula <linux-amarula@amarulasolutions.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Robert Foss <robert.foss@linaro.org>,
        Andrzej Hajda <a.hajda@samsung.com>,
        DRI mailing list <dri-devel@lists.freedesktop.org>,
        Milco Pratesi <milco.pratesi@engicam.com>,
        Anthony Brandon <anthony@amarulasolutions.com>,
        linux-phy@lists.infradead.org, Fancy Fang <chen.fang@nxp.com>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>,
        NXP Linux Team <linux-imx@nxp.com>
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 <fdd446c6-c8ce-9dae-f7ac-e06241f76250@canonical.com>
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From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Message-ID: <ff421d53-7308-7959-ea4a-9cf94efe63b2@canonical.com>
Date:   Fri, 25 Jun 2021 12:27:56 +0200
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On 25/06/2021 12:08, Jagan Teki wrote:
> Hi Krzysztof,
> 
> On Fri, Jun 25, 2021 at 2:51 PM Krzysztof Kozlowski
> <krzysztof.kozlowski@canonical.com> wrote:
>>
>> On Thu, 24 Jun 2021 at 14:19, Laurent Pinchart
>> <laurent.pinchart@ideasonboard.com> wrote:
>>>
>>> Hi Jagan,
>>>
>>> On Thu, Jun 24, 2021 at 05:42:43PM +0530, Jagan Teki wrote:
>>>> On Thu, Jun 24, 2021 at 8:18 AM Fabio Estevam wrote:
>>>>> On Wed, Jun 23, 2021 at 7:23 PM Laurent Pinchart wrote:
>>>>>
>>>>>> Looking at the register set, it seems to match the Exynos 5433,
>>>>>> supported by drivers/gpu/drm/exynos/exynos_drm_dsi.c. Can we leverage
>>>>>> that driver instead of adding a new one for the same IP core ?
>>>>>
>>>>> Yes. there was an attempt from Michael in this direction:
>>>>> https://patchwork.kernel.org/project/dri-devel/cover/20200911135413.3654800-1-m.tretter@pengutronix.de/
>>>>
>>>> Thanks for the reference, I will check it out and see I can send any
>>>> updated versions wrt my i.MX8MM platform.
>>>
>>> Thanks.
>>>
>>> I had a brief look at the exynos driver, and I think it should be turned
>>> into a DRM bridge as part of this rework to be used with the i.MX8MM.
>>>
>>> Is there someone from Samsung who could assist, at least to test the
>>> changes ?
>>
>> Yes, I mentioned few guys in reply to PHY. Around the DRM drivers you
>> can get in touch with:
>> Inki Dae <inki.dae@samsung.com>
>> Seung-Woo Kim <sw0312.kim@samsung.com>
>> Marek Szyprowski <m.szyprowski@samsung.com>
>> Andrzej Hajda <a.hajda@samsung.com>
> 
> Thanks for the information.
> 
>>
>> The easiest testing of the display stack would be on Hardkernel's Odroid
>> XU4 (https://www.hardkernel.com/shop/odroid-xu4-special-price/) however
>> you will not test the DSI/DSIM directly (it has only HDMI port).
> 
> Look like I found one board with Exynos5430 with DSI. Does this SoC is
> same as mainline Exynos5433?

No, Exynos5430 is ARMv7. Looks like improvement over Exynos5422.
Exynos5422 has a very good support in mainline while Exynso5430 was
never touched at all.

Exynos5433 is ARMv8, although many things are shared with 5422. About
DSI I have no clue.


Best regards,
Krzysztof