[v3 5/6] drm/vs: Add hdmi driver

[Andy Yan]

Hi Keith：

在 2023-12-11 18:24:35，"Keith Zhao" <keith.zhao at starfivetech.com> 写道：
>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 at 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 at 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 at 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.

I finally  make my rk3036 based kylin board bootup （use a linux 4.4 downstream bsp，I will find time to try boot
it with mainline）。 So I can help do the test for rockchip side。

It seems not that easy to buy a rk3036 based board from market now。

>
>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