Re: [PATCH v4 1/5] dt-bindings: bus: Add firewall bindings

[Benjamin GAIGNARD <benjamin.gaignard@st.com>]

On 7/13/20 7:01 PM, Rob Herring wrote:
> On Wed, Jul 01, 2020 at 03:25:19PM +0200, Benjamin Gaignard wrote:
>> Add schemas for firewall consumer and provider.
>>
>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
>> ---
>>   .../bindings/bus/stm32/firewall-consumer.yaml      | 36 ++++++++++++++++++++++
>>   .../bindings/bus/stm32/firewall-provider.yaml      | 18 +++++++++++
>>   2 files changed, 54 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/bus/stm32/firewall-consumer.yaml
>>   create mode 100644 Documentation/devicetree/bindings/bus/stm32/firewall-provider.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/bus/stm32/firewall-consumer.yaml b/Documentation/devicetree/bindings/bus/stm32/firewall-consumer.yaml
>> new file mode 100644
>> index 000000000000..d3d76f99b38d
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/bus/stm32/firewall-consumer.yaml
>> @@ -0,0 +1,36 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/bus/stm32/firewall-consumer.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Common Bus Firewall consumer binding
> I'm all for common bindings, but I want to see more than 1 user before
> accepting this. There's been some other postings for similar h/w
> (AFAICT) recently.
>
>> +
>> +description: |
>> +  Firewall properties provide the possible firewall bus controller
>> +  configurations for a device.
>> +  Bus firewall controllers are typically used to control if a hardware
>> +  block can perform read or write operations on bus.
>> +  The contents of the firewall bus configuration properties are defined by
>> +  the binding for the individual firewall controller device.
>> +
>> +  The first configuration 'firewall-0' or the one named 'default' is
>> +  applied before probing the device itself.
> This is a Linux implementation detail and debatable whether the core
> should do this or drivers.
I could prefix the property with 'st,stm32' so it will dedicated to 
STM32 SoCs.
Will it sound better for you ?

 From Greg comments in the previous versions of this patch I understand that
it isn't something to be done in the core. The best I can do here is to 
keep it as
helpers for STM32 SoCs.
>
>> +
>> +maintainers:
>> +  - Benjamin Gaignard <benjamin.gaignard@st.com>
>> +
>> +# always select the core schema
>> +select: true
>> +
>> +properties:
>> +  firewall-0: true
>> +
>> +  firewall-names: true
>> +
>> +patternProperties:
>> +  "firewall-[0-9]":
>> +    $ref: "/schemas/types.yaml#/definitions/phandle-array"
> So I guess multiple properties is to encode all the modes into DT like
> pinctrl does. Is that really necessary? I don't think so as I wouldn't
> expect modes to be defined by the consumer, but by the provider in this
> case. To use pinctrl as a example, we could have pad setting per MMC
> speed. That has to be in the consumer side as the pinctrl knows nothing
> about MMC.
I expect to be able to set phandle on different firewall controllers.
I don't know if it is possible with the same structure than for pins 
controllers.
>   
> Rob