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Message-ID: <b087c34f-0e2f-edd0-a738-3ffc2853a41b@linaro.org>
Date:   Fri, 20 May 2022 13:40:13 +0200
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Subject: Re: [PATCH 2/3] dt-bindings: usb: atmel: Add Microchip LAN966x
 compatible string
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To:     Herve Codina <herve.codina@bootlin.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Claudiu Beznea <claudiu.beznea@microchip.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Horatiu Vultur <horatiu.vultur@microchip.com>,
        linux-usb@vger.kernel.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-clk@vger.kernel.org,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>
References: <20220513105850.310375-1-herve.codina@bootlin.com>
 <20220513105850.310375-3-herve.codina@bootlin.com>
 <8f0d4127-7e66-cf50-21c9-99680f737e30@linaro.org>
 <20220520133426.3b4728ae@bootlin.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20220520133426.3b4728ae@bootlin.com>
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On 20/05/2022 13:34, Herve Codina wrote:
> On Fri, 13 May 2022 14:57:55 +0200
> Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:
> 
>> On 13/05/2022 12:58, Herve Codina wrote:
>>> The USB device controller available in the Microchip LAN966x SOC
>>> is the same IP as the one present in the SAMA5D3 SOC.
>>>
>>> Add the LAN966x compatible string and set the SAMA5D3 compatible
>>> string as a fallback for the LAN966x.
>>>
>>> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
>>> ---
>>>  Documentation/devicetree/bindings/usb/atmel-usb.txt | 3 +++
>>>  1 file changed, 3 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/atmel-usb.txt b/Documentation/devicetree/bindings/usb/atmel-usb.txt
>>> index f512f0290728..a6fab7d63f37 100644
>>> --- a/Documentation/devicetree/bindings/usb/atmel-usb.txt
>>> +++ b/Documentation/devicetree/bindings/usb/atmel-usb.txt
>>> @@ -87,6 +87,9 @@ Required properties:
>>>  	       "atmel,at91sam9g45-udc"
>>>  	       "atmel,sama5d3-udc"
>>>  	       "microchip,sam9x60-udc"
>>> +	       "microchip,lan996x-udc"  
>>
>> No wildcards please, especially that it closely fits previous wildcard
>> (lan996x includes lan9960 which looks a lot like sam9x60...)
>>
> 
> Well, first, I made a mistake. It should be lan966x instead of lan996x.
> 
> This family is composed of the LAN9662 and the LAN9668 SOCs.
> 
> Related to the wilcard, lan966x is used in several bindings for common
> parts used by both SOCs:
> - microchip,lan966x-gck
> - microchip,lan966x-cpu-syscon
> - microchip,lan966x-switch
> - microchip,lan966x-miim
> - microchip,lan966x-serdes
> - microchip,lan966x-pinctrl

And for new bindings I pointed that it is not preferred, so already few
other started using specific compatible.

> 
> I think it makes sense to keep 'microchip,lan966x-udc' for the USB
> device controller (same controller on LAN9662 and LAN9668) and so
> keeping the same rules as for other common parts.

Having wildcard was rather a mistake and we already started correcting
it, so keeping the "mistake" neither gives you consistency, nor
correctness...


Best regards,
Krzysztof