Hi，
在 2024-08-22 19:59:43，"Cristian Ciocaltea" <cristian.ciocal...@collabora.com>
写道：
>On 8/22/24 11:41 AM, Conor Dooley wrote:
>> On Thu, Aug 22, 2024 at 09:01:34AM +0200, Heiko Stübner wrote:
>>> @Conor: just for me, did some shift happen in our understanding of dt-
>>> best-practices in terms of syscon via phandle vs. syscon via compatible?
>>>
>>> Because Rockchip boards are referencing their GRFs via phandes forever
>>> but similar to the soc vs non-soc node thing, I'd like to stay on top of
>>> best-practices ;-)
>>
>> If IP blocks, and thus drivers, are going to be reused between devices,
>> using the phandles makes sense given that it is unlikely that syscon
>> nodes can make use of fallback compatibles due to bits within that "glue"
>> changing between devices. It also makes sense when there are multiple
>> instances of an IP on the device, which need to use different syscons.
>> My goal is to ask people why they are using these type of syscons
>> phandle properties, cos often they are not required at all - for example
>> with clocks where you effectively need a whole new driver for every
>> single soc and having a phandle property buys you nothing.
>
>That would be also the case for this HDMI controller - need to check the
>specs for the newer RK3576 SoC, but I expect the syscons would be quite
>different when compared to RK3588, hence we should keep making use of
>the phandles.
Yes，for rk3576，it shares the same HDMI IP block（hdmi controller and PHY），
of course reuse the driver of rk3588， but it has different GRF to depends on[0]:
which calls ioc_grf and vo0_grf:
I also believe that makeing use of phandle beneficial for different devices to
reuse the same code.
hdmi: hdmi@27da0000 {
compatible = "rockchip,rk3576-dw-hdmi";
reg = <0x0 0x27da0000 0x0 0x10000>, <0x0 0x27db0000 0x0
0x10000>;
interrupts = <GIC_SPI 338 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 339 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 340 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 341 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 367 IRQ_TYPE_LEVEL_HIGH>;
, rockchip,grf = <&ioc_grf>;
rockchip,vo0_grf = <&vo0_grf>;
phys = <&hdptxphy_hdmi>;
phy-names = "hdmi";
[0]https://github.com/armbian/linux-rockchip/blob/rk-6.1-rkr3/arch/arm64/boot/dts/rockchip/rk3576.dtsi#L3122C2-L3123C33
>
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