Re: [PATCH v2 05/12] dt-bindings: spi: Adjust the bindings for the FSL QSPI driver

[Rob Herring <robh@kernel.org>]

On Thu, Jul 05, 2018 at 01:15:01PM +0200, Frieder Schrempf wrote:
> Adjust the documentation of the new SPI memory interface based
> driver to reflect the new drivers settings.

Bindings shouldn't change (other than new properties) due to driver 
changes.

> 
> Signed-off-by: Frieder Schrempf <frieder.schrempf@exceet.de>
> ---
> Changes in v2:
> ==============
> * Split the moving and editing of the dt-bindings in two patches
> 
>  .../devicetree/bindings/spi/spi-fsl-qspi.txt    | 22 ++++++++++----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/spi/spi-fsl-qspi.txt b/Documentation/devicetree/bindings/spi/spi-fsl-qspi.txt
> index 483e9cf..8b4eed7 100644
> --- a/Documentation/devicetree/bindings/spi/spi-fsl-qspi.txt
> +++ b/Documentation/devicetree/bindings/spi/spi-fsl-qspi.txt
> @@ -3,9 +3,8 @@
>  Required properties:
>    - compatible : Should be "fsl,vf610-qspi", "fsl,imx6sx-qspi",
>  		 "fsl,imx7d-qspi", "fsl,imx6ul-qspi",
> -		 "fsl,ls1021a-qspi"
> +		 "fsl,ls1021a-qspi", "fsl,ls2080a-qspi"
>  		 or
> -		 "fsl,ls2080a-qspi" followed by "fsl,ls1021a-qspi",
>  		 "fsl,ls1043a-qspi" followed by "fsl,ls1021a-qspi"

So the 2080a h/w was compatible with the 1021a h/w, but now it is not? 
How did the h/w change?

>    - reg : the first contains the register location and length,
>            the second contains the memory mapping address and length
> @@ -15,14 +14,15 @@ Required properties:
>    - clock-names : Should contain the name of the clocks: "qspi_en" and "qspi".
>  
>  Optional properties:
> -  - fsl,qspi-has-second-chip: The controller has two buses, bus A and bus B.
> -                              Each bus can be connected with two NOR flashes.
> -			      Most of the time, each bus only has one NOR flash
> -			      connected, this is the default case.
> -			      But if there are two NOR flashes connected to the
> -			      bus, you should enable this property.
> -			      (Please check the board's schematic.)

You can't just remove properties without explanation. Why is this no 
longer needed? What about backwards compatibility with existing dtbs?

> -  - big-endian : That means the IP register is big endian
> +  - big-endian : That means the IP registers format is big endian

This is a standard property so it doesn't really need to be redefined 
here, but just reference the definition.

> +
> +Required SPI slave node properties:
> +  - reg: There are two buses (A and B) with two chip selects each.
> +	 This encodes to which bus and CS the flash is connected:
> +		<0>: Bus A, CS 0
> +		<1>: Bus A, CS 1
> +		<2>: Bus B, CS 0
> +		<3>: Bus B, CS 1
>  
>  Example:
>  
> @@ -40,7 +40,7 @@ qspi0: quadspi@40044000 {
>  	};
>  };
>  
> -Example showing the usage of two SPI NOR devices:
> +Example showing the usage of two SPI NOR devices on bus A:
>  
>  &qspi2 {
>  	pinctrl-names = "default";
> -- 
> 2.7.4
>