[2/2] dt-bindings: serial: pl011: Avoid matching device tree nodes of variant pl011 drivers

There is a variant driver of pl011, which may have a compatible string
written as: "arm,sbsa-uart", "arm,pl011". Because it contains "arm,pl011",
so the corresponding device tree nodes are also checked by this YAML file.
As a result, many flase warnings similar to the following are reported:

arch/arm64/boot/dts/freescale/fsl-lx2160a-clearfog-cx.dt.yaml:
 serial@21c0000: compatible:0: 'arm,pl011' was expected
 serial@21c0000: compatible:1: 'arm,primecell' was expected

Change to only check the device tree nodes that are matched exactly.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
 Documentation/devicetree/bindings/serial/pl011.yaml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

On 2021/5/20 19:54, Zhen Lei wrote:
> There is a variant driver of pl011, which may have a compatible string
> written as: "arm,sbsa-uart", "arm,pl011". Because it contains "arm,pl011",
> so the corresponding device tree nodes are also checked by this YAML file.
> As a result, many flase warnings similar to the following are reported:
> 
> arch/arm64/boot/dts/freescale/fsl-lx2160a-clearfog-cx.dt.yaml:
>  serial@21c0000: compatible:0: 'arm,pl011' was expected
>  serial@21c0000: compatible:1: 'arm,primecell' was expected
> 
> Change to only check the device tree nodes that are matched exactly.

Hi, all:
  This morning I rethought, and there's something wrong with this change.
The compatibles that are incorrectly written cannot be identified, for
example, only "arm,pl011". I'll think of something else.

> 
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> ---
>  Documentation/devicetree/bindings/serial/pl011.yaml | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/serial/pl011.yaml b/Documentation/devicetree/bindings/serial/pl011.yaml
> index 5ea00f8a283d..3683e4567645 100644
> --- a/Documentation/devicetree/bindings/serial/pl011.yaml
> +++ b/Documentation/devicetree/bindings/serial/pl011.yaml
> @@ -16,9 +16,9 @@ allOf:
>  select:
>    properties:
>      compatible:
> -      contains:
> -        enum:
> -          - arm,pl011
> +      items:
> +        - const: arm,pl011
> +        - const: arm,primecell
>    required:
>      - compatible
>  
>

On Thu, May 20, 2021 at 6:54 AM Zhen Lei <thunder.leizhen@huawei.com> wrote:
>

> There is a variant driver of pl011, which may have a compatible string

> written as: "arm,sbsa-uart", "arm,pl011". Because it contains "arm,pl011",

> so the corresponding device tree nodes are also checked by this YAML file.

> As a result, many flase warnings similar to the following are reported:

>

> arch/arm64/boot/dts/freescale/fsl-lx2160a-clearfog-cx.dt.yaml:

>  serial@21c0000: compatible:0: 'arm,pl011' was expected

>  serial@21c0000: compatible:1: 'arm,primecell' was expected


The DT is wrong. The h/w is either a PL011 or it isn't. If it is, then
the compatible should be '"arm,pl011", "arm,primecell"'. There is no
point in making it 'arm,sbsa-uart' as the PL011 (and OS support for
it) predate SBSA (by a lot). If it is not a PL011 and only the SBSA
subset, then it should be "arm,sbsa-uart".

Rob