Re: [PATCH 1/4] dt-bindings: mfd: aspeed: support for AST2700

Andrew Jeffery
2024-08-20T00:46:44Z

On Mon, 2024-08-19 at 03:05 +0000, Ryan Chen wrote:
> > > Subject: Re: [PATCH 1/4] dt-bindings: mfd: aspeed: support for
> > > AST2700
> > >
> > > On Wed, 2024-08-14 at 06:35 +0000, Ryan Chen wrote:
> > > > > Subject: Re: [PATCH 1/4] dt-bindings: mfd: aspeed: support
> > > > > for
> > > > > AST2700
> > > > >
> > > > > On Fri, Aug 09, 2024 at 06:10:22AM +0000, Ryan Chen wrote:
> > > > > > > Subject: Re: [PATCH 1/4] dt-bindings: mfd: aspeed:
> > > > > > > support for
> > > > > > > AST2700
> > > > > > >
> > > > > > > On 09/08/2024 07:55, Ryan Chen wrote:
> > > > > > > > > Subject: Re: [PATCH 1/4] dt-bindings: mfd: aspeed:
> > > > > > > > > support
> > > > > > > > > for
> > > > > > > > > AST2700
> > > > > > > > >
> > > > > > > > > On 08/08/2024 09:59, Ryan Chen wrote:
> > > > > > > > > > Add compatible support for AST2700 clk, reset,
> > > > > > > > > > pinctrl,
> > > > > > > > > > silicon-id and example for AST2700 scu.
> > > > > > > > > >
> > > > > > > > > > Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> > > > > > > > > > ---
> > > > > > > > > >  .../bindings/mfd/aspeed,ast2x00-scu.yaml | 31
> > > > > > > > > +++++++++++++++++--
> > > > > > > > > >  1 file changed, 29 insertions(+), 2 deletions(-)
> > > > > > > > > >
> > > > > > > > > > diff --git
> > > > > > > > > > a/Documentation/devicetree/bindings/mfd/aspeed,ast2
> > > > > > > > > > x00-
> > > > > > > > > > scu.yaml
> > > > > > > > > > b/Documentation/devicetree/bindings/mfd/aspeed,ast2
> > > > > > > > > > x00-
> > > > > > > > > > scu.yaml
> > > > > > > > > > index 86ee69c0f45b..c0965f08ae8c 100644
> > > > > > > > > > ---
> > > > > > > > > > a/Documentation/devicetree/bindings/mfd/aspeed,ast2
> > > > > > > > > > x00-
> > > > > > > > > > scu.yaml
> > > > > > > > > > +++
> > > > > > > > > > b/Documentation/devicetree/bindings/mfd/aspeed,ast2
> > > > > > > > > > x00-
> > > > > > > > > > scu.y
> > > > > > > > > > +++ aml
> > > > > > > > > > @@ -21,6 +21,8 @@ properties:
> > > > > > > > > >            - aspeed,ast2400-scu
> > > > > > > > > >            - aspeed,ast2500-scu
> > > > > > > > > >            - aspeed,ast2600-scu
> > > > > > > > > > + - aspeed,ast2700-scu0
> > > > > > > > > > + - aspeed,ast2700-scu1
> > > > > > > > >
> > > > > > > > > What are the differences between these two?
> > > > > > > >
> > > > > > > > The next [PATCH 4/4] is scu driver that include
> > > > > > > > ast2700-scu0
> > > > > > > > and
> > > > > > > > ast2700-scu1 CLK_OF_DECLARE_DRIVER(ast2700_soc0,
> > > > > > > > "aspeed,ast2700-scu0", ast2700_soc0_clk_init);
> > > > > > > > CLK_OF_DECLARE_DRIVER(ast2700_soc1, "aspeed,ast2700-
> > > > > > > > scu1",
> > > > > > > > ast2700_soc1_clk_init);
> > > > > > >
> > > > > > > What are hardware differences? Entirely different
> > > > > > > devices?
> > > > > >
> > > > > > AST2700 have two soc die connected each other.
> > > > > > Each soc die have it own scu, so the naming is ast2700-scu0
> > > > > > for
> > > > > > soc0,
> > > > > another is ast2700-scu1 for soc1.
> > > > >
> > > > > Didn't I see in another patch one die is cpu and one is io?
> > > > > Use
> > > > > those in the compatible rather than 0 and 1 if so.
> > > > >
> > > > Sorry, I want to align with our datasheet description.
> > > > It will but scu0 and scu1 register setting.
> > >
> > > Can we document that relationship in the binding? Rob's
> > > suggestion
> > > seems more descriptive.
> > Hello,
> > Do you want me document it in yaml file or just in commit
> > message?
>
> Hello Rob, Andrew,
> I will add in yaml file in description. Like following.
>
> description:
>   The Aspeed System Control Unit manages the global behaviour of the
> SoC,
>   configuring elements such as clocks, pinmux, and reset.
> + In AST2700, it has two soc combination. Each soc include its own
> scu register control.
> + ast2700-scu0 for soc0, ast2700-scu1 for soc1.
>
> Is that will be better way ?

What Rob is suggesting is to add the compatibles "aspeed,ast2700-scu-
cpu" and "aspeed,ast2700-scu-io", and then in the description say
something like:

The AST2700 integrates both a CPU and an IO die, each with their own
SCU. The "aspeed,ast2700-scu-cpu" and "aspeed,ast2700-scu-io"
compatibles correspond to SCU0 and SCU1 respectively.

Andrew