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Message-ID: <2dc5ea49-9a5f-484a-98dc-1b35b79d0945@starfivetech.com>
Date:   Mon, 11 Dec 2023 18:24:35 +0800
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Subject: Re: [v3 5/6] drm/vs: Add hdmi driver
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To:     Maxime Ripard <mripard@kernel.org>, Andy Yan <andyshrk@163.com>
CC:     "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
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References: <20231204123315.28456-6-keith.zhao@starfivetech.com>
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From:   Keith Zhao <keith.zhao@starfivetech.com>
In-Reply-To: <xevxqusbizjfs4qt5rufhntd3vd656o2smocvivvulzceh3aeu@uuihphhat5wi>
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hi Maxime:
hi Andy:

On 2023/12/8 17:14, Maxime Ripard wrote:
> Hi,
> 
> On Fri, Dec 08, 2023 at 11:23:37AM +0800, Andy Yan wrote:
>> 在 2023-12-08 11:00:31，"Keith Zhao" <keith.zhao@starfivetech.com> 写道：
>> >
>> >
>> >On 2023/12/8 8:37, Andy Yan wrote:
>> >> Hi Keth：
>> >> 
>> >> 
>> >> 
>> >> 
>> >> 
>> >> 
>> >> 在 2023-12-07 18:48:13，"Keith Zhao" <keith.zhao@starfivetech.com> 写道：
>> >>>
>> >>>
>> >>>On 2023/12/7 17:02, Andy Yan wrote:
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> Hi Keith：
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> 
>> >>>> At 2023-12-06 22:11:33, "Keith Zhao" <keith.zhao@starfivetech.com> wrote:
>> >>>>>
>> >>>>>
>> >>>>>On 2023/12/6 20:56, Maxime Ripard wrote:
>> >>>>>> On Wed, Dec 06, 2023 at 08:02:55PM +0800, Keith Zhao wrote:
>> >>>>>>> >> +static const struct of_device_id starfive_hdmi_dt_ids[] = {
>> >>>>>>> >> +	{ .compatible = "starfive,jh7110-inno-hdmi",},
>> >>>>>>> > 
>> >>>>>>> > So it's inno hdmi, just like Rockchip then?
>> >>>>>>> > 
>> >>>>>>> > This should be a common driver.
>> >>>>>>>
>> >>>>>>> Rockchip has a inno hdmi IP. and Starfive has a inno hdmi IP.
>> >>>>>>> but the harewawre difference of them is big , it is not easy to use the common driver
>> >>>>>>> maybe i need the inno hdmi version here to make a distinction
>> >>>>>> 
>> >>>>>> I just had a look at the rockchip header file: all the registers but the
>> >>>>>> STARFIVE_* ones are identical.
>> >>>>>> 
>> >>>>>> There's no need to have two identical drivers then, please use the
>> >>>>>> rockchip driver instead.
>> >>>>>> 
>> >>>>>> Maxime
>> >>>>>
>> >>>>>ok, have a simple test , edid can get . i will continue 
>> >>>> 
>> >>>> Maybe you can take drivers/gpu/drm/bridge/synopsys/dw-hdmi as a reference， this
>> >>>> is also a hdmi ip used by rockchip/meson/sunxi/jz/imx。
>> >>>> We finally make it share one driver。
>> >>>>>
>> >>>hi Andy:
>> >>>
>> >>>dw_hdmi seems a good choice , it can handle inno hdmi hardware by define its dw_hdmi_plat_data.
>> >>>does it means i can write own driver files such as(dw_hdmi-starfive.c) based on dw_hdmi instead of add plat_data in inno_hdmi.c
>> >>>
>> >> 
>> >> I think the process maybe like this：
>> >> 
>> >> 1. split the inno_hdmi.c under rockchip to  inno_hdmi.c(the common part), inno_hdmi-rockchip.c(the soc specific part)
>> >> 2. move the common part inno_hdmi.c to drivers/gpu/drm/bridge/innosilicon/
>> >> 3. add startfive specific part, inno_hdmi-startfive.c
>> >> 
>> >> bellow git log from kernel three show how we convert  dw_hdmi to a common driver: 
>> >> 
>> >> 
>> >> 
>> >> 12b9f204e804 drm: bridge/dw_hdmi: add rockchip rk3288 support
>> >> 74af9e4d03b8 dt-bindings: Add documentation for rockchip dw hdmi
>> >> d346c14eeea9 drm: bridge/dw_hdmi: add function dw_hdmi_phy_enable_spare
>> >> a4d3b8b050d5 drm: bridge/dw_hdmi: clear i2cmphy_stat0 reg in hdmi_phy_wait_i2c_done
>> >> 632d035bace2 drm: bridge/dw_hdmi: add mode_valid support
>> >> 0cd9d1428322 drm: bridge/dw_hdmi: add support for multi-byte register width access
>> >> cd152393967e dt-bindings: add document for dw_hdmi
>> >> b21f4b658df8 drm: imx: imx-hdmi: move imx-hdmi to bridge/dw_hdmi
>> >> aaa757a092c2 drm: imx: imx-hdmi: split phy configuration to platform driver
>> >> 3d1b35a3d9f3 drm: imx: imx-hdmi: convert imx-hdmi to drm_bridge mode
>> >> c2c3848851a7 drm: imx: imx-hdmi: return defer if can't get ddc i2c adapter
>> >> b587833933de drm: imx: imx-hdmi: make checkpatch happy
>> >> 
>> >hi Andy:
>> >I got you means, 
>> >as I don't have a rockchip board on hand , to split the inno_hdmi.c can not be tested.
>> >
>> >how adout this idea:
>> >1、split the starfive_hdmi.c under verisilicion to  inno_hdmi.c(the common part), inno_hdmi-starfive.c(the soc specific part)
>> >2. move the common part inno_hdmi.c to drivers/gpu/drm/bridge/innosilicon/
>> >3. In the future, inno hdmi.c under rockchip will reuse the public driver.
>> 
>> I am not sure if drm maintainers are happy with this。
> 
> Not really, no.
> 
> Because we would still have two drivers for the same controller, and a
> common one that haven't really been tested on anything but a single
> platform. So arguably a worse situation than what you were suggesting in
> the first place.
> 
> The best solution would be to find someone with a Rockchip board to test
> your changes, or to get one if it's doable so you can test yourself.

ok I will also try to buy a Rockchip 3036 board for self-test.
According to the commit log idea provided by Andy before, make the inno_hdmi driver common module.

would the steps be ok? (if I tested rockchip and starifve pass)
1. split the inno_hdmi.c under rockchip to  inno_hdmi.c(the common part), inno_hdmi-rockchip.c(the soc specific part)
2. move the common part inno_hdmi.c to drivers/gpu/drm/bridge/innosilicon/
3. add startfive specific part, inno_hdmi-startfive.c

Thanks
> 
> Maxime