Re: [PATCH v8 2/5] dt-bindings: soc: sophgo: Add Sophgo system control module

[Chen Wang]

On 2024/1/16 19:37, Chen Wang wrote:
> On 2024/1/16 18:06, Krzysztof Kozlowski wrote:
> > On 16/01/2024 08:21, Chen Wang wrote:
> > > From: Chen Wang <unicorn_wang@xxxxxxxxxxx>
> > >
> > > Add documentation to describe Sophgo System Control for SG2042.
> > >
> > > Signed-off-by: Chen Wang <unicorn_wang@xxxxxxxxxxx>
> > > ---
> > >   .../soc/sophgo/sophgo,sg2042-sysctrl.yaml     | 46 
> > > +++++++++++++++++++
> > >   1 file changed, 46 insertions(+)
> > >   create mode 100644 
> > > Documentation/devicetree/bindings/soc/sophgo/sophgo,sg2042-sysctrl.yaml
> > >
> > > diff --git 
> > > a/Documentation/devicetree/bindings/soc/sophgo/sophgo,sg2042-sysctrl.yaml 
> > > b/Documentation/devicetree/bindings/soc/sophgo/sophgo,sg2042-sysctrl.yaml 
> > >
> > > new file mode 100644
> > > index 000000000000..7b50bb56b4cf
> > > --- /dev/null
> > > +++ 
> > > b/Documentation/devicetree/bindings/soc/sophgo/sophgo,sg2042-sysctrl.yaml
> > > @@ -0,0 +1,46 @@
> > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: 
> > > http://devicetree.org/schemas/soc/sophgo/sophgo,sg2042-sysctrl.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Sophgo SG2042 SoC system control
> > > +
> > > +maintainers:
> > > +  - Chen Wang <unicorn_wang@xxxxxxxxxxx>
> > > +
> > > +description:
> > > +  The Sophgo system control is a registers block (SYS_CTRL), 
> > > providing multiple
> > > +  low level platform functions like chip configuration, clock 
> > > control, etc.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: sophgo,sg2042-sysctrl
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  clock-controller:
> > > +    # Child node
> > Drop the comment, it is obvious. It cannot be anything else.
> >
> > > +    $ref: /schemas/clock/sophgo,sg2042-sysclk.yaml#
> > > +    type: object
> > Why isn't this merged here? You do not need the child node really...
> > unless the clock inputs are specific to that clock controller and you
> > will have here more devices? But where are they in such case?
> I don't see more devices will be included later. It should be ok to 
> merge them into one.

hi, Krzysztof,

After some double check, I find we will have more devices in 
system-control. For example, in the SYS_CTRL area, there is also a 
section of registers used to control the "General Purpose Interrupt". 
The pcie controller of sg2042 will use this interrupt controller which 
is defined in SYS_CTRL, we will add it in later work.

Specifically, the distribution (offset) of registers in SYS_CTRL is as 
follows:

- 0x0C0 ~ 0x0FC: for some PLL clocks :

- ......

- 0x2E0 ~ 0x30C: for General Purpose Interrupt:

- ......

- 0x368 ~ 0x3FC: For some gate clocks

So it seems that it is still necessary to keep the current child node 
method, and it will also facilitate future expansion.

What do you think, please feel free let me know.

Thanks,

Chen