From mboxrd@z Thu Jan  1 00:00:00 1970
From: bintian.wang@huawei.com (Bintian)
Date: Wed, 13 May 2015 15:30:39 +0800
Subject: [PATCH v4 5/5] arm64: dts: Add dts files for Hisilicon Hi6220 SoC
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On 2015/5/13 15:12, Bintian Wang wrote:
> Hi Mark,
>
>> Hi,
>>
>>>> I think that given that we know the UART is not quite a PL011 we should
>>>> add an additional compatible string just in case some difference crops
>>>> up later that is problematic.
>>>>
>>>> So we'd have something like:
>>>>
>>>> 	compatible = "hisilicon,hi6220-uart", "arm,pl011", "arm,primecell";
>>>>
>>>> That way we can add any optimisations or workarounds later as required.
>>> I understand and thanks for your suggestion.
>>>
>>> Can I do not do this work in this patch set? Because I got the
>>> information UART0 is PL011 compatible. Hisilicon uart engineer can do
>>> this work in the future, maybe for UART1/UART2.
>>
>> I am not asking you to do any driver work for this -- the current driver
>> should ignore the "hisilicon,hi6220-uart" string and recognise
>> "arm,pl011".
>>
>> I am only asking you to add the additional string to the DTS, and to
>> update the binding document to list the new string. That way if and when
>> we need the kernel to distinguish between a regular PL011 and the
>> hi6220-specific variant, the DTB does not need to be updated in order to
>> do so.
> How about add the following binding rule to the 2/5 patch:
> ---------------------------
> *Hisilicon Enhanced ARM AMBA Primecell PL011 serial UART
>
> Required properties:
> - compatible: must be "hisilicon,hi6220-uart", "arm,primecell", "arm,pl011"
> - reg: exactly one register range with length 0x1000
> - interrupts: exactly one interrupt specifier
>
> See also bindings/serial/pl011.txt
>
> Example:
>
> uart0: uart at f8015000 {
>          compatible = "hisilicon,hi6220-uart", "arm,pl011", "arm,primecell";
>          reg = <0x0 0xf8015000 0x0 0x1000>;
>          interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>;
>          clocks = <&ao_ctrl HI6220_UART0_PCLK>, <&ao_ctrl HI6220_UART0_PCLK>;
>          clock-names = "uartclk", "apb_pclk";
> };
> ---------------------------
>
>> Is UART 0 different from UART1 and UART2?
> Yes,  but my patch just includes UART0, we do some changements for UART1/2
> to improve performance.
>
> Thanks,
>
> Bintian
>
>>
>> Thanks,
>> Mark.
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
>
>
>
>
> .
>