Messages in this thread | | | Subject | Re: [PATCH 02/16] dt-bindings: spi: Add bcmbca-hsspi controller support | From | William Zhang <> | Date | Wed, 11 Jan 2023 10:44:22 -0800 |
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On 01/11/2023 10:12 AM, Krzysztof Kozlowski wrote: > On 11/01/2023 19:04, William Zhang wrote: >> >> >> On 01/11/2023 01:02 AM, Krzysztof Kozlowski wrote: >>> On 10/01/2023 23:18, Florian Fainelli wrote: >>>> On 1/10/23 00:40, Krzysztof Kozlowski wrote: >>>>>>> No, it is discouraged in such forms. Family or IP block compatibles >>>>>>> should be prepended with a specific compatible. There were many issues >>>>>>> when people insisted on generic or family compatibles... >>>>>>> >>>>>>>> Otherwise we will have to have a compatible string with chip model for >>>>>>>> each SoC even they share the same IP. We already have more than ten of >>>>>>>> SoCs and the list will increase. I don't see this is a good solution too. >>>>>>> >>>>>>> You will have to do it anyway even with generic fallback, so I don't get >>>>>>> what is here to gain... I also don't get why Broadcom should be here >>>>>>> special, different than others. Why it is not a good solution for >>>>>>> Broadcom SoCs but it is for others? >>>>>>> >>>>>> I saw a few other vendors like these qcom ones: >>>>>> qcom,spi-qup.yaml >>>>>> - qcom,spi-qup-v1.1.1 # for 8660, 8960 and 8064 >>>>>> - qcom,spi-qup-v2.1.1 # for 8974 and later >>>>>> - qcom,spi-qup-v2.2.1 # for 8974 v2 and later >>>>>> qcom,spi-qup.yaml >>>>>> const: qcom,geni-spi >>>>> >>>>> IP block version numbers are allowed when there is clear mapping between >>>>> version and SoCs using it. This is the case for Qualcomm because there >>>>> is such clear mapping documented and available for Qualcomm engineers >>>>> and also some of us (although not public). >>>>> >>>>>> I guess when individual who only has one particular board/chip and is >>>>>> not aware of the IP family, it is understandable to use the chip >>>>>> specific compatible string. >>>>> >>>>> Family of devices is not a versioned IP block. >>>> >>>> Would it be acceptable to define for instance: >>>> >>>> - compatible = "brcm,bcm6868-hsspi", "brcm,bcmbca-hsspi"; >>> >>> Yes, this is perfectly valid. Although it does not solve William >>> concerns because it requires defining specific compatibles for all of >>> the SoCs. >>> >>> Best regards, >>> Krzysztof >>> >> As I mentioned in another email, I would be okay to use these >> compatibles to differentiate by ip rev and to conforms to brcm convention: >> "brcm,bcmXYZ-hsspi", "brcm,bcmbca-hsspi-v1.0", "brcm,bcmbca-hsspi"; >> "brcm,bcmXYZ-hsspi", "brcm,bcmbca-hsspi-v1.1", "brcm,bcmbca-hsspi"; > > > Drop the version in such case, no benefits. I assume XYZ is the SoC > model, so for example 6868. > Yes XYZ is the SoC model >> >> In the two drivers I included in this series, it will be bound to >> brcm,bcmbca-hsspi-v1.0 (in additional to brcm,bcm6328-hsspi) and >> brcm,bcmbca-hsspi-v1.1 respectively. This way we don't need to update >> the driver with a new soc specific compatible whenever a new chips comes >> out. > > I don't understand why do you bring it now as an argument. You defined > before that your driver will bind to the generic bcmbca compatible, so > now it is not enough? > No as we are adding chip model specific info here. The existing driver spi-bcm63xx-hsspi.c only binds to brcm,bcm6328-hsspi. This driver supports all the chips with rev1.0 controller so I am using this 6328 string for other chips with v1.0 in the dts patch, which is not ideal. Now I have to add more compatible to this driver and for each new chip with 1.0 in the future if any.
With all the thoughts from you and Florian, I think it is better to use rev compatible in the driver but add on chip model compatible in the dts.
> Best regards, > Krzysztof > [unhandled content-type:application/pkcs7-signature]
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