RE: [v3 1/4] dt-bindings: spi: Add binding file for ASPEED FMC/SPI memory controller

[Chin-Ting Kuo <chin-ting_kuo@xxxxxxxxxxxxxx>]

Hi Rob,

> -----Original Message-----
> From: Rob Herring <robh@xxxxxxxxxx>
> Sent: Friday, November 6, 2020 6:40 AM
> To: Chin-Ting Kuo <chin-ting_kuo@xxxxxxxxxxxxxx>
> Cc: broonie@xxxxxxxxxx; joel@xxxxxxxxx; andrew@xxxxxxxx; clg@xxxxxxxx;
> bbrezillon@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; linux-aspeed@xxxxxxxxxxxxxxxx;
> linux-spi@xxxxxxxxxxxxxxx; BMC-SW <BMC-SW@xxxxxxxxxxxxxx>
> Subject: Re: [v3 1/4] dt-bindings: spi: Add binding file for ASPEED FMC/SPI
> memory controller
> 
> On Thu, Nov 05, 2020 at 08:03:28PM +0800, Chin-Ting Kuo wrote:
> > Create binding file with YAML syntax for ASPEED FMC/SPI memory
> controller.
> >
> > Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@xxxxxxxxxxxxxx>
> > ---
> >  .../bindings/spi/aspeed,spi-aspeed.yaml       | 66
> +++++++++++++++++++
> >  1 file changed, 66 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/spi/aspeed,spi-aspeed.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/spi/aspeed,spi-aspeed.yaml
> > b/Documentation/devicetree/bindings/spi/aspeed,spi-aspeed.yaml
> > new file mode 100644
> > index 000000000000..41b9692c7226
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/spi/aspeed,spi-aspeed.yaml
> > @@ -0,0 +1,66 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/spi/aspeed,spi-aspeed.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: SPI memory controller for ASPEED SoCs
> > +
> > +maintainers:
> > +  - Chin-Ting Kuo <chin-ting_kuo@xxxxxxxxxxxxxx>
> > +
> > +description: |
> > +  There are three SPI memory controllers embedded in a ASPEED SoC.
> > +  They are usually connected to SPI NOR flashes. Each of them has
> > +  more than a chip select. They also support SPI single, dual and
> > +  quad IO modes for SPI NOR flash.
> > +
> > +allOf:
> > +  - $ref: /spi/spi-controller.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - items:
> 
> You can drop oneOf (there's only 1) and items.

Okay, it will be removed on the next patch version.

> > +          - enum:
> > +              - aspeed,ast2600-fmc
> > +              - aspeed,ast2600-spi
> > +
> > +  reg:
> > +    items:
> > +      - description: the control register location and length
> > +      - description: the flash memory mapping address and length
> > +
> > +  clocks:
> > +    description: AHB bus clock which will be converted to SPI bus
> > + clock
> 
> maxItems: 1

it will be added on the next patch version.

> 
> Constraints on num-cs values? Or up to 2^32 is good?
>

The maximum is 3.
The "maximum" item will be added on the next patch version

> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - clocks
> > +  - num-cs
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/ast2600-clock.h>
> > +    spi1: spi@1e630000 {
> > +      compatible = "aspeed,ast2600-spi";
> > +      reg = <0x1e630000 0xc4>, <0x30000000 0x10000000>;
> > +      reg-names = "spi_ctrl_reg", "spi_mmap";
> > +      clocks = <&syscon ASPEED_CLK_AHB>;
> > +      num-cs = <2>;
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +      flash@0 {
> > +        compatible = "jedec,spi-nor";
> > +        reg = <0>;
> > +        spi-max-frequency = <50000000>;
> > +      };
> > +      flash@1 {
> > +        compatible = "jedec,spi-nor";
> > +        reg = <1>;
> > +        spi-max-frequency = <50000000>;
> > +      };
> > +    };
> > --
> > 2.17.1
> >

Best Wishes,
Chin-Ting