Re: [PATCH] dt-bindings: serial: arm,sbsa-uart: Convert to json-schema

[Rob Herring <robh@kernel.org>]

On Fri, Nov 04, 2022 at 10:25:42AM -0400, Krzysztof Kozlowski wrote:
> On 04/11/2022 06:43, Thierry Reding wrote:
> > From: Thierry Reding <treding@nvidia.com>
> > 
> > Convert the ARM SBSA UART device tree bindings from the free-form text
> > format to json-schema.
> > 
> > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > ---
> >  .../bindings/serial/arm,sbsa-uart.yaml        | 37 +++++++++++++++++++
> >  .../bindings/serial/arm_sbsa_uart.txt         | 10 -----
> >  2 files changed, 37 insertions(+), 10 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/serial/arm,sbsa-uart.yaml
> >  delete mode 100644 Documentation/devicetree/bindings/serial/arm_sbsa_uart.txt

Note that NXP LS2160a has a warning with this. The warning is correct 
because both PL011 and SBSA UART is wrong IMO. The question is which one 
is it really. I would assume someone went with SBSA for some reason. The 
pl011 compatible should be ignored given 'arm,primecell' is missing.


> > diff --git a/Documentation/devicetree/bindings/serial/arm,sbsa-uart.yaml b/Documentation/devicetree/bindings/serial/arm,sbsa-uart.yaml
> > new file mode 100644
> > index 000000000000..afaa1ef7f2e6
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/serial/arm,sbsa-uart.yaml
> > @@ -0,0 +1,37 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/serial/arm,sbsa-uart.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: ARM SBSA defined generic UART
> > +
> > +maintainers:
> > +  - Rob Herring <robh@kernel.org>
> > +  - Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> This shouldn't be Greg but someone nothing the hardware. Rob might work,
> but maybe also Russell who is mentioned in maintainers entry?

I'm fine with it given I already have pl011 binding.


> Please resend with him cced.
> 
> > +
> > +description:
> > +  This UART uses a subset of the PL011 registers and consequently lives
> > +  in the PL011 driver. It's baudrate and other communication parameters
> > +  cannot be adjusted at runtime, so it lacks a clock specifier here.

Differences to PL011 are relavent, but location of the (Linux) driver is 
not.

> > +
> > +properties:
> > +  compatible:
> > +    const: arm,sbsa-uart
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +allOf:
> > +  - $ref: serial.yaml
> > +
> > +unevaluatedProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +...
> 
> Example would be nice, although it  is not a requirement.
> 
> 
> Best regards,
> Krzysztof
> 
>