Possible misleading information in rockchip,rk3588-cru.yaml

[Yao Zi]

On Mon, Sep 16, 2024 at 05:33:49PM +0100, Conor Dooley wrote:
> On Wed, Sep 11, 2024 at 09:20:02PM +0000, Yao Zi wrote:
> > Hi,
> > 
> > rockchip,rk3588-cru.yaml, dt-binding for RK3588 clock and reset module,
> > contains description of customized property "rockchip,grf",
> > 
> >   rockchip,grf:
> >     $ref: /schemas/types.yaml#/definitions/phandle
> >     description: >
> >       phandle to the syscon managing the "general register files". It is
> >       used for GRF muxes, if missing any muxes present in the GRF will
> >       not be available.
> > 
> > But after doing some searching, I found that clk-rk3588.c actually
> > defines no clock hardware with MUXGRF type. This is also true in in the
> > vendor code[1], it seems there is actually no GRF mux on RK3588
> > platform.
> 
> Have you been able to check the datasheet/register map for this piece of
> hardware? Does it have a grf register region?
> Wouldn't be surprised if it didn't, and the cause of it being in the
> binding was nothing more than copy-paste.

Have checked a public datasheet[1], RK3588 does have corresponding grf
region and there are only clock related bits in PHP_GRF_CLK_CON1[2].

But these gmac clocks bits are used in dwmac-rk GMAC driver[3]
internally, out of the common clock driver, rk3588-cru. So I don't think
the CRU needs access to the grf by design.

Best regards,
Yao Zi

[1]: https://github.com/FanX-Tek/rk3588-TRM-and-Datasheet/blob/master/Rockchip%20RK3588%20TRM%20V1.0-Part1-20220309.pdf
[2]: Page 836 in [1]
[3]: net/ethernet/stmicro/stmmac/dwmac-rk.c:1132