Re: [PATCH 1/2] dt-bindings: leds: Add cznic,turris1x-leds.yaml binding

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 05/07/2022 13:42, Pali Rohár wrote:
> On Tuesday 05 July 2022 13:36:54 Krzysztof Kozlowski wrote:
>> On 05/07/2022 02:04, Pali Rohár wrote:
>>> Add device-tree bindings documentation for Turris 1.x RGB LEDs.
>>>
>>> Signed-off-by: Pali Rohár <pali@kernel.org>
>>> ---
>>>  .../bindings/leds/cznic,turris1x-leds.yaml    | 116 ++++++++++++++++++
>>>  1 file changed, 116 insertions(+)
>>>  create mode 100644 Documentation/devicetree/bindings/leds/cznic,turris1x-leds.yaml
>>>
>>> diff --git a/Documentation/devicetree/bindings/leds/cznic,turris1x-leds.yaml b/Documentation/devicetree/bindings/leds/cznic,turris1x-leds.yaml
>>> new file mode 100644
>>> index 000000000000..fd09613c8d2d
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/leds/cznic,turris1x-leds.yaml
>>> @@ -0,0 +1,116 @@
>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/leds/cznic,turris1x-leds.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: CZ.NIC's Turris 1.x LEDs driver
>>> +
>>> +maintainers:
>>> +  - Pali Rohár <pali@kernel.org>
>>> +
>>> +description:
>>> +  This module adds support for the RGB LEDs found on the front panel of the
>>> +  Turris 1.x routers. There are 8 RGB LEDs that are controlled by CZ.NIC CPLD
>>> +  firmware running on Lattice FPGA. Firmware is open source and available at
>>> +  https://gitlab.nic.cz/turris/hw/turris_cpld/-/blob/master/CZ_NIC_Router_CPLD.v
>>> +
>>> +properties:
>>> +  compatible:
>>> +    const: cznic,turris1x-leds
>>> +
>>> +  reg:
>>> +    maxItems: 2
>>
>> You need to describe the items, if it is really two items. However your
>> example has only one item, so this was not tested and won't work.
> 
> Ehm? Example has two items in the reg.

No, you have exactly one item.
<0x13 0x1d>

Two items are for example:
<0x13 0x1d>, <0x23 0x1d>

> 
>> You'll get warning from Rob's robot soon... but you should test the
>> bindings instead.
> 
> I have tested bindings on the real hardware and it is working fine
> together with the driver from patch 2/2.

Bindings cannot be tested on real hardware. Bindings are tested with
dt_binding_check, as explained in writing-schema.rst

> 
>>> +
>>> +  "#address-cells":
>>> +    const: 1
>>> +
>>> +  "#size-cells":
>>> +    const: 0
>>> +
>>> +patternProperties:
>>> +  "^multi-led@[0-7]$":
>>> +    type: object
>>> +    $ref: leds-class-multicolor.yaml#
>>
>> This looks incorrect, unless you rebased on my patchset?
> 
> So what is the correct? (I used inspiration from
> cznic,turris-omnia-leds.yaml file)

Which according to current multicolor bindings is not correct. Correct
is pwm-multicolor. However if you rebase on [1], it looks fine, except
missing unevaluatedProperties.

[1]
https://lore.kernel.org/all/20220624112106.111351-1-krzysztof.kozlowski@linaro.org/

> 
>>> +
>>> +    properties:
>>> +      reg:
>>> +        minimum: 0
>>> +        maximum: 7
>>> +
>>> +    required:
>>> +      - reg
>>> +
>>> +additionalProperties: false
>>> +
>>> +examples:
>>> +  - |
>>> +
>>
>> No blank line.
> 
> Ok.
> 
>>> +    #include <dt-bindings/leds/common.h>
>>> +
>>> +    cpld@3,0 {
>>
>> Generic node name.
> 
> Is not cpld name generic enough?

No, it means nothing to me. Just like "a", "ashjd" or "wrls".

"The name of a node should be somewhat generic, reflecting the function
of the device and not its precise programming
 model. If appropriate, the name should be one of the following choices:"

Best regards,
Krzysztof