Re: [PATCH v4 1/4] dt-bindings: phy: Add sparx5-serdes bindings

[Steen Hegelund <steen.hegelund@microchip.com>]

On 20.11.2020 17:09, Alexandre Belloni wrote:
>EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
>Hi,
>
>On 20/11/2020 16:03:56+0100, Steen Hegelund wrote:
>> Document the Sparx5 ethernet serdes phy driver bindings.
>>
>> Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
>> Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
>> ---
>>  .../bindings/phy/microchip,sparx5-serdes.yaml | 296 ++++++++++++++++++
>>  1 file changed, 296 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/phy/microchip,sparx5-serdes.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/phy/microchip,sparx5-serdes.yaml b/Documentation/devicetree/bindings/phy/microchip,sparx5-serdes.yaml
>> new file mode 100644
>> index 000000000000..0bfb752e7686
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/phy/microchip,sparx5-serdes.yaml
>> @@ -0,0 +1,296 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/phy/microchip,sparx5-serdes.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Microchip Sparx5 Serdes controller
>> +
>> +maintainers:
>> +  - Steen Hegelund <steen.hegelund@microchip.com>
>> +
>> +description: |
>> +  The Sparx5 SERDES interfaces share the same basic functionality, but
>> +  support different operating modes and line rates.
>> +
>> +  The following list lists the SERDES features:
>> +
>> +  * RX Adaptive Decision Feedback Equalizer (DFE)
>> +  * Programmable continuous time linear equalizer (CTLE)
>> +  * Rx variable gain control
>> +  * Rx built-in fault detector (loss-of-lock/loss-of-signal)
>> +  * Adjustable tx de-emphasis (FFE)
>> +  * Tx output amplitude control
>> +  * Supports rx eye monitor
>> +  * Multiple loopback modes
>> +  * Prbs generator and checker
>> +  * Polarity inversion control
>> +
>> +  SERDES6G:
>> +
>> +  The SERDES6G is a high-speed SERDES interface, which can operate at
>> +  the following data rates:
>> +
>> +  * 100 Mbps (100BASE-FX)
>> +  * 1.25 Gbps (SGMII/1000BASE-X/1000BASE-KX)
>> +  * 3.125 Gbps (2.5GBASE-X/2.5GBASE-KX)
>> +  * 5.15625 Gbps (5GBASE-KR/5G-USXGMII)
>> +
>> +  SERDES10G
>> +
>> +  The SERDES10G is a high-speed SERDES interface, which can operate at
>> +  the following data rates:
>> +
>> +  * 100 Mbps (100BASE-FX)
>> +  * 1.25 Gbps (SGMII/1000BASE-X/1000BASE-KX)
>> +  * 3.125 Gbps (2.5GBASE-X/2.5GBASE-KX)
>> +  * 5 Gbps (QSGMII/USGMII)
>> +  * 5.15625 Gbps (5GBASE-KR/5G-USXGMII)
>> +  * 10 Gbps (10G-USGMII)
>> +  * 10.3125 Gbps (10GBASE-R/10GBASE-KR/USXGMII)
>> +
>> +  SERDES25G
>> +
>> +  The SERDES25G is a high-speed SERDES interface, which can operate at
>> +  the following data rates:
>> +
>> +  * 1.25 Gbps (SGMII/1000BASE-X/1000BASE-KX)
>> +  * 3.125 Gbps (2.5GBASE-X/2.5GBASE-KX)
>> +  * 5 Gbps (QSGMII/USGMII)
>> +  * 5.15625 Gbps (5GBASE-KR/5G-USXGMII)
>> +  * 10 Gbps (10G-USGMII)
>> +  * 10.3125 Gbps (10GBASE-R/10GBASE-KR/USXGMII)
>> +  * 25.78125 Gbps (25GBASE-KR/25GBASE-CR/25GBASE-SR/25GBASE-LR/25GBASE-ER)
>> +
>> +properties:
>> +  $nodename:
>> +    pattern: "^serdes@[0-9a-f]+$"
>> +
>> +  compatible:
>> +    const: microchip,sparx5-serdes.yaml
>
>This has a spurious .yaml suffix ;)

I will remove that.
>
>> +
>> +  reg:
>> +    description: Address and length of the register set for the device
>
>You don't actually have to describe this property a sit comes from the
>generic schema. But maybe you could set maxItems

OK, I will remove the description.
Wouldn't minItems be better here, since there might be more targets in the
future, to support more modes?

>
>> +
>> +  reg-names:
>> +    description: |
>> +      Names for each of the address spaces defined in
>> +      the 'reg' property. Expects the names in the same order as the
>> +      corresponding memory region in the that property.
>> +
>
>Same comment, even better, I tink you could list the expected names in
>an enum or a const list

OK, it is a long list, but then it will be automatically checked.
>
>> +  '#phy-cells':
>> +    const: 1
>> +    description: |
>> +      - The main serdes input port
>> +
>> +  clocks:
>> +    description:
>> +      A list containing the phandle to the core clock of the Sparx5 device.
>
>You can drop the description and simply have maxItems: 1

OK
>
>
>--
>Alexandre Belloni, Bootlin
>Embedded Linux and Kernel engineering
>https://bootlin.com

BR
Steen

---------------------------------------
Steen Hegelund
steen.hegelund@microchip.com