Re: [PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660

From	zhangfei <zhangfei.gao@linaro.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660
Date	2017-05-24 04:40 +0200
Message-ID	<tKunn-4kt-3@gated-at.bofh.it> (permalink)
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Hi, Jarkko

Would you mind give some suggestion?

On 2017年05月23日 20:48, Rob Herring wrote:
>
>>>> +                       compatible = "snps,designware-i2c";
>>> These should have an SoC specific compatible.
>> We directly use drivers/i2c/busses/i2c-designware-platdrv.c,
>> do we still an soc specific compatible?
> It's fine if the driver uses the snps compatible, but the dts should
> still have an SoC specific one.
>
>> Checked arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi, and other examples,
>>
>> compatible = "snps,designware-i2c" is used.
> That was a mistake in the other platforms. We shouldn't continue repeating it.
>
> Rob

Rob suggest add something like "hisilicon,hi3660-dw-i2c" as well.
"The problem is dw-i2c does not give any clue as to what the 
configuration or version of the IP is.
Is that fully discoverable with version/capability registers? If not 
then you need a specific compatible.
Generally when we have not required them, it ends up being a problem 
later on."

While Documentation/devicetree/bindings/i2c/i2c-designware.txt
compatible : should be "snps,designware-i2c"

Besides, on Hikey960,
[    3.822353] dw_readl(dev, DW_IC_COMP_VERSION)=0x3132302a
[    3.827763] dw_readl(dev, DW_IC_COMP_TYPE)=0x44570140
Are these two registers enough to distinguish version etc?

Thanks

Thread

[PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660 Guodong Xu <guodong.xu@linaro.org> - 2017-05-17 10:40 +0200
  Re: [PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660 Rob Herring <robh@kernel.org> - 2017-05-23 02:40 +0200
    Re: [PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660 zhangfei <zhangfei.gao@linaro.org> - 2017-05-23 08:00 +0200
      Re: [PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660 zhangfei <zhangfei.gao@linaro.org> - 2017-05-23 08:40 +0200
        Re: [PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660 Rob Herring <robh@kernel.org> - 2017-05-23 14:50 +0200
      Re: [PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660 Rob Herring <robh@kernel.org> - 2017-05-23 14:50 +0200
        Re: [PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660 zhangfei <zhangfei.gao@linaro.org> - 2017-05-24 04:40 +0200
          Re: [PATCH 05/12] arm64: dts: Add I2C nodes for Hi3660 Jarkko Nikula <jarkko.nikula@linux.intel.com> - 2017-05-24 10:40 +0200

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