Re: [PATCH v2 10/13] dt-bindings: spi: cadence-qspi: Add support for Pensando Elba SoC

[Pratyush Yadav <p.yadav@xxxxxx>]

Hi Brad,

On 28/03/21 06:59PM, Brad Larson wrote:
> Add new vendor Pensando Systems Elba SoC compatible
> string and convert to json-schema.
> 
> Signed-off-by: Brad Larson <brad@xxxxxxxxxxx>
> ---
>  .../bindings/spi/cadence-quadspi.txt          |  68 --------
>  .../bindings/spi/cadence-quadspi.yaml         | 153 ++++++++++++++++++
>  2 files changed, 153 insertions(+), 68 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/spi/cadence-quadspi.txt
>  create mode 100644 Documentation/devicetree/bindings/spi/cadence-quadspi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/spi/cadence-quadspi.txt b/Documentation/devicetree/bindings/spi/cadence-quadspi.txt
> deleted file mode 100644
> index 8ace832a2d80..000000000000
> --- a/Documentation/devicetree/bindings/spi/cadence-quadspi.txt
> +++ /dev/null
> @@ -1,68 +0,0 @@
> -* Cadence Quad SPI controller
> -
> -Required properties:
> -- compatible : should be one of the following:
> -	Generic default - "cdns,qspi-nor".
> -	For TI 66AK2G SoC - "ti,k2g-qspi", "cdns,qspi-nor".
> -	For TI AM654 SoC  - "ti,am654-ospi", "cdns,qspi-nor".
> -	For Intel LGM SoC - "intel,lgm-qspi", "cdns,qspi-nor".
> -- reg : Contains two entries, each of which is a tuple consisting of a
> -	physical address and length. The first entry is the address and
> -	length of the controller register set. The second entry is the
> -	address and length of the QSPI Controller data area.
> -- interrupts : Unit interrupt specifier for the controller interrupt.
> -- clocks : phandle to the Quad SPI clock.
> -- cdns,fifo-depth : Size of the data FIFO in words.
> -- cdns,fifo-width : Bus width of the data FIFO in bytes.
> -- cdns,trigger-address : 32-bit indirect AHB trigger address.
> -
> -Optional properties:
> -- cdns,is-decoded-cs : Flag to indicate whether decoder is used or not.
> -- cdns,rclk-en : Flag to indicate that QSPI return clock is used to latch
> -  the read data rather than the QSPI clock. Make sure that QSPI return
> -  clock is populated on the board before using this property.
> -
> -Optional subnodes:
> -Subnodes of the Cadence Quad SPI controller are spi slave nodes with additional
> -custom properties:
> -- cdns,read-delay : Delay for read capture logic, in clock cycles
> -- cdns,tshsl-ns : Delay in nanoseconds for the length that the master
> -                  mode chip select outputs are de-asserted between
> -		  transactions.
> -- cdns,tsd2d-ns : Delay in nanoseconds between one chip select being
> -                  de-activated and the activation of another.
> -- cdns,tchsh-ns : Delay in nanoseconds between last bit of current
> -                  transaction and deasserting the device chip select
> -		  (qspi_n_ss_out).
> -- cdns,tslch-ns : Delay in nanoseconds between setting qspi_n_ss_out low
> -                  and first bit transfer.
> -- resets	: Must contain an entry for each entry in reset-names.
> -		  See ../reset/reset.txt for details.
> -- reset-names	: Must include either "qspi" and/or "qspi-ocp".
> -
> -Example:
> -
> -	qspi: spi@ff705000 {
> -		compatible = "cdns,qspi-nor";
> -		#address-cells = <1>;
> -		#size-cells = <0>;
> -		reg = <0xff705000 0x1000>,
> -		      <0xffa00000 0x1000>;
> -		interrupts = <0 151 4>;
> -		clocks = <&qspi_clk>;
> -		cdns,is-decoded-cs;
> -		cdns,fifo-depth = <128>;
> -		cdns,fifo-width = <4>;
> -		cdns,trigger-address = <0x00000000>;
> -		resets = <&rst QSPI_RESET>, <&rst QSPI_OCP_RESET>;
> -		reset-names = "qspi", "qspi-ocp";
> -
> -		flash0: n25q00@0 {
> -			...
> -			cdns,read-delay = <4>;
> -			cdns,tshsl-ns = <50>;
> -			cdns,tsd2d-ns = <50>;
> -			cdns,tchsh-ns = <4>;
> -			cdns,tslch-ns = <4>;
> -		};
> -	};
> diff --git a/Documentation/devicetree/bindings/spi/cadence-quadspi.yaml b/Documentation/devicetree/bindings/spi/cadence-quadspi.yaml
> new file mode 100644
> index 000000000000..94d631045153
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/cadence-quadspi.yaml
> @@ -0,0 +1,153 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/spi/cadence-quadspi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Cadence Quad SPI controller
> +
> +maintainers:
> +  - Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
> +  - Brad Larson <brad@xxxxxxxxxxx>
> +
> +properties:
> +  compatible:
> +    contains:
> +      enum:
> +        - cdns,qspi-nor       # Generic default
> +        - ti,k2g-qspi         # TI 66AK2G SoC
> +        - ti,am654-ospi       # TI AM654 SoC
> +        - intel,lgm-qspi      # Intel LGM SoC
> +        - pensando,cdns-qspi  # Pensando Elba SoC

Wouldn't this allow any combination of all 5 strings? So for example 
this would allow "ti,am654-ospi", "pensando,cdns-qspi" which is 
obviously not correct.

I sent a patch recently [0] that does this correctly and it has gotten 
Rob's blessing. So I suggest you build your patch on top of that.

[...]

[0] https://patchwork.kernel.org/project/spi-devel-general/patch/20210326130034.15231-5-p.yadav@xxxxxx/

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.