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

From: Rob Herring
Date: Wed Jul 11 2018 - 12:05:28 EST


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@xxxxxxxxx>
> ---
> 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
>