Re: [PATCH v9 3/4] clk: meson: add DT documentation for emmc clock controller

[Liang Yang]

On 2022/1/15 6:59, Stephen Boyd wrote:
> [ EXTERNAL EMAIL ]
>
> Quoting Liang Yang (2022-01-13 19:06:07)
> > Hi Stephen,
> >
> > Thanks for your quick response.
> >
> > On 2022/1/14 5:29, Stephen Boyd wrote:
> > > [ EXTERNAL EMAIL ]
> > >
> > > Quoting Liang Yang (2022-01-13 03:57:44)
> > > > Document the MMC sub clock controller driver, the potential consumer
> > > > of this driver is MMC or NAND. Also add four clock bindings IDs which
> > > > provided by this driver.
> > > >
> > > > Signed-off-by: Liang Yang <liang.yang@xxxxxxxxxxx>
> > > > ---
> > > >    .../bindings/clock/amlogic,mmc-clkc.yaml      | 64 +++++++++++++++++++
> > > >    include/dt-bindings/clock/amlogic,mmc-clkc.h  | 14 ++++
> > > >    2 files changed, 78 insertions(+)
> > > >    create mode 100644 Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.yaml
> > > >    create mode 100644 include/dt-bindings/clock/amlogic,mmc-clkc.h
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.yaml b/Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.yaml
> > > > new file mode 100644
> > > > index 000000000000..a274c3d5fc2e
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.yaml
> > > > @@ -0,0 +1,64 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: http://devicetree.org/schemas/clock/amlogic,mmc-clkc.yaml#
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: Amlogic MMC Sub Clock Controller Driver Device Tree Bindings
> > > > +
> > > > +maintainers:
> > > > +  - jianxin.pan@xxxxxxxxxxx
> > > > +  - liang.yang@xxxxxxxxxxx
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    enum:
> > > > +      - "amlogic,axg-mmc-clkc", "syscon"
> > >
> > > Why is it a syscon?
> >
> > The register documented by reg is shared with SD/eMMC controller port C,
> > and it need to be ops on NFC driver.
>
> Is this the case where the clk is inside the SD/eMMC controller? Can the
yes.
> mmc driver register the clk controller from there and pass it an iomem
> pointer to poke clks?
we can't do that since EMMC and NAND is mutually exclusivem. both of 
them share the same data pins.
> .