Re: [PATCH v2] drm: bridge: synopsys/dw-hdmi: Provide default configuration function for HDMI 2.0 PHY

[Mark yao <mark.yao@rock-chips.com>]

On 2017年07月07日 23:47, Jose Abreu wrote:
> Hi Archit,
>

Ping, Any update for this patch? Can it be landed?

This patch actually needed for rk3399 hdmi support

Best Regards
Mark

> On 23-06-2017 10:36, Jose Abreu wrote:
>> Currently HDMI 2.0 PHYs do not have a default configuration function.
>>
>> As *some* of the HDMI 2.0 PHYs have the same register layout as the 3D
>> PHYs we can provide the same default configuration function for both
>> and still let user overwrite this with custom configuration function
>> if needed.
>>
>> If, for some reason, the PHY is custom or has a register different
>> register layout then custom configuration function *must* be provided
>> in order for the system to work correctly. As we prefer the pdata
>> provided configuration function over the internal one this change
>> will not make any impact in custom platforms.
>>
>> This patch is based on today's drm-misc-next branch.
>>
>> Signed-off-by: Jose Abreu <joabreu@synopsys.com>
>> Tested-by: Mark Yao <mark.yao@rock-chips.com>
> This is needed for RK3399 support. Can you please apply it?
>
> Best regards,
> Jose Miguel Abreu
>
>> Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>> Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>> Cc: Archit Taneja <architt@codeaurora.org>
>> Cc: Andrzej Hajda <a.hajda@samsung.com>
>> Cc: Mark Yao <mark.yao@rock-chips.com>
>> Cc: Carlos Palminha <palminha@synopsys.com>
>> Cc: Heiko Stübner <heiko@sntech.de>
>>
>> Changes in v2:
>> 	- Rebased and refrased commit message
>> ---
>>
>> Hi All,
>>
>> There as been a little confusion about dw-hdmi phys so I will expand a little bit
>> here so that I can base my decision about this patch and why does it only works
>> in some platforms.
>>
>> First, if you read dw-hdmi.c code, you will see that there is an identification
>> register for the phy type being used. Unfortunatelly, this only states the phy type
>> and not the phy version.
>>
>> Second, we have many HDMI 2.0 phys (so, same phy type: 0xf3) but, as you may have guessed,
>> HW team decided to change regbank between some versions.
>>
>> Third and last, each phy in a SoC has unique characteristics, so each phy (event if
>> they are the same version) will have different PLL configuration parameters.
>>
>> Given all this I managed to conclude that Mark's phy is still an HDMI 2.0 phy but with
>> the same register layout as previous 3D PHY's. I found at least 2 phys with the same
>> register layout and only 1 phy which has a different layout, so I think majority wins
>> here and we should let the default configuration function for HDMI 2.0 phys be the same
>> one as the 3D.
>>
>> Short story: There is no way to correctly identify, at runtime, the phy version being
>> used by the controller so we can't provide a default configuration function. We can,
>> however assume that most of the HDMI 2.0 phys will have the 3D layout BUT each developer
>> must confirm that the layout in its SoC is the expected one and if not, provide a custom
>> configuration function.
>>
>> Best regards,
>> Jose Miguel Abreu
>>
>>   drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> index ead1124..10c8d8c 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> @@ -2170,6 +2170,7 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
>>   		.name = "DWC HDMI 2.0 TX PHY",
>>   		.gen = 2,
>>   		.has_svsret = true,
>> +		.configure = hdmi_phy_configure_dwc_hdmi_3d_tx,
>>   	}, {
>>   		.type = DW_HDMI_PHY_VENDOR_PHY,
>>   		.name = "Vendor PHY",
>
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