From: William Zhang <william.zhang@broadcom.com>
To: Florian Fainelli <f.fainelli@gmail.com>,
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
Linux SPI List <linux-spi@vger.kernel.org>,
Broadcom Kernel List <bcm-kernel-feedback-list@broadcom.com>
Cc: anand.gore@broadcom.com, tomer.yacoby@broadcom.com,
dan.beygelman@broadcom.com, joel.peshkin@broadcom.com,
jonas.gorski@gmail.com, kursad.oney@broadcom.com,
dregan@mail.com,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Mark Brown <broonie@kernel.org>, Rob Herring <robh+dt@kernel.org>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 02/16] dt-bindings: spi: Add bcmbca-hsspi controller support
Date: Tue, 10 Jan 2023 17:08:47 -0800 [thread overview]
Message-ID: <adbf1347-b81b-ee5b-f016-109d25b09f81@broadcom.com> (raw)
In-Reply-To: <32a464f8-6a4b-6777-9775-f17e990e0c6a@gmail.com>
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On 01/10/2023 02:18 PM, 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";
>
> in which case, having a fallback compatible on the SoC family that sees
> this IP being deployed is very useful for client programs of the DT
> (u-boot or kernel). As long as the fallback works, we use it, the day it
> stops and a quirk needs to be applied because SoC XYZ has a bug, match
> the SoC XYZ compatible string.
>
> FWIW, and feel free to rant at me, we have adopted this convention a
> while ago for STB chips whereby we want bindings to be defined with:
>
> <chip specific compatible>, <version of the IP>, <fallback>
>
> and the fallback may, or may not be matched, but defining in does not
> hurt at all, in fact it dramatically helps with the boot loader looking
> for specific nodes because it can search for the fallback.
>
> If the version specific compatible is not available, it does not get used.
Thanks Florian for jumping in! I was thinking to propose something with
version info:
brcm,bcmbca-hsspi-v1.0
brcm,bcmbca-hsspi-v1.1
To meet STB chip convention, then it would be:
compatible = "brcm,bcm63138-hsspi", "brcm,bcmbca-hsspi-v1.0",
"brcm,bcmbca-hsspi";
compatible = "brcm,bcm6756-hsspi", "brcm,bcmbca-hsspi-v1.1",
"brcm,bcmbca-hsspi";
Although I am not a fan of having a chip specific compatible while we
already have IP version, I am okay to have it to be consistent with
Broadcom convention. We will need to remember to update this yaml file
whenever we have a new chip.
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next prev parent reply other threads:[~2023-01-11 1:08 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-06 20:07 [PATCH 00/16] spi: bcm63xx-hsspi: driver and doc updates William Zhang
2023-01-06 20:07 ` [PATCH 01/16] dt-bindings: spi: Convert bcm63xx-hsspi bindings to json-schema William Zhang
2023-01-07 15:18 ` Rob Herring
2023-01-07 15:32 ` Krzysztof Kozlowski
2023-01-09 7:52 ` William Zhang
2023-01-09 8:48 ` Krzysztof Kozlowski
2023-01-06 20:07 ` [PATCH 02/16] dt-bindings: spi: Add bcmbca-hsspi controller support William Zhang
2023-01-08 14:51 ` Krzysztof Kozlowski
2023-01-09 8:27 ` William Zhang
2023-01-09 8:56 ` Krzysztof Kozlowski
2023-01-09 19:13 ` William Zhang
2023-01-10 8:40 ` Krzysztof Kozlowski
2023-01-10 22:18 ` Florian Fainelli
2023-01-11 1:08 ` William Zhang [this message]
2023-01-11 9:02 ` Krzysztof Kozlowski
2023-01-11 18:04 ` William Zhang
2023-01-11 18:12 ` Krzysztof Kozlowski
2023-01-11 18:44 ` William Zhang
2023-01-12 8:21 ` Krzysztof Kozlowski
2023-01-12 19:50 ` William Zhang
2023-01-13 7:41 ` Krzysztof Kozlowski
2023-01-14 3:17 ` William Zhang
2023-01-15 14:31 ` Krzysztof Kozlowski
2023-01-11 0:59 ` William Zhang
2023-01-11 9:01 ` Krzysztof Kozlowski
2023-01-06 20:07 ` [PATCH 03/16] dt-bindings: spi: Add spi peripheral specific property William Zhang
2023-01-06 21:14 ` Mark Brown
2023-01-07 3:27 ` William Zhang
2023-01-07 15:38 ` Rob Herring
2023-01-09 8:06 ` William Zhang
2023-01-09 19:19 ` Mark Brown
2023-01-09 20:18 ` William Zhang
2023-01-10 22:01 ` Mark Brown
2023-01-11 19:48 ` William Zhang
2023-01-08 14:52 ` Krzysztof Kozlowski
2023-01-09 8:27 ` William Zhang
2023-01-06 20:07 ` [PATCH 04/16] ARM: dts: broadcom: bcmbca: Add spi controller node William Zhang
2023-01-06 20:07 ` [PATCH 05/16] arm64: " William Zhang
2023-01-06 20:07 ` [PATCH 06/16] spi: bcm63xx-hsspi: Endianness fix for ARM based SoC William Zhang
2023-01-07 7:44 ` kernel test robot
2023-01-07 21:21 ` kernel test robot
2023-01-07 21:52 ` kernel test robot
2023-01-07 23:23 ` kernel test robot
2023-01-11 6:33 ` kernel test robot
2023-01-06 20:07 ` [PATCH 07/16] spi: bcm63xx-hsspi: Add polling mode support William Zhang
2023-01-06 21:47 ` Mark Brown
2023-01-07 3:35 ` William Zhang
2023-01-09 19:06 ` Mark Brown
2023-01-09 20:10 ` William Zhang
2023-01-10 22:49 ` Mark Brown
2023-01-11 20:13 ` William Zhang
2023-01-11 22:41 ` Mark Brown
2023-01-11 22:57 ` William Zhang
2023-01-06 20:08 ` [PATCH 08/16] spi: bcm63xx-hsspi: Handle cs_change correctly William Zhang
2023-01-06 20:08 ` [PATCH 09/16] spi: bcm63xx-hsspi: Fix multi-bit mode setting William Zhang
2023-01-06 20:08 ` [PATCH 10/16] spi: bcm63xx-hsspi: Make dummy cs workaround as an option William Zhang
2023-01-12 18:08 ` Mark Brown
2023-01-18 23:09 ` William Zhang
2023-01-19 13:09 ` Mark Brown
2023-01-06 20:08 ` [PATCH 11/16] spi: bcm63xx-hsspi: Add prepend feature support William Zhang
2023-01-06 22:00 ` Mark Brown
2023-01-07 3:52 ` William Zhang
2023-01-09 19:31 ` Mark Brown
2023-01-09 20:43 ` William Zhang
2023-01-10 21:18 ` Mark Brown
2023-01-11 19:42 ` William Zhang
2023-01-12 16:57 ` Mark Brown
2023-01-06 20:08 ` [PATCH 12/16] spi: bcm63xx-hsspi: Add clock gate disable option support William Zhang
2023-01-06 20:08 ` [PATCH 13/16] spi: spi-mem: Allow controller supporting mem_ops without exec_op William Zhang
2023-01-06 20:08 ` [PATCH 14/16] spi: bcm63xx-hsspi: prepend: Disable spi mem dual io read op support William Zhang
2023-01-06 22:07 ` Mark Brown
2023-01-07 3:57 ` William Zhang
2023-01-06 20:08 ` [PATCH 15/16] spi: bcmbca-hsspi: Add driver for newer HSSPI controller William Zhang
2023-01-07 22:02 ` kernel test robot
2023-01-08 2:25 ` kernel test robot
2023-01-06 20:08 ` [PATCH 16/16] MAINTAINERS: Add entry for Broadcom Broadband SoC HS SPI drivers William Zhang
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