Re: [PATCH v4 5/5] arm64: dts: Add dts files for Hisilicon Hi6220 SoC

From: Bintian <bintian.wang@huawei.com>
To: Bintian Wang <btw@mail.itp.ac.cn>, Mark Rutland <mark.rutland@arm.com>
Cc: "dan.zhao@hisilicon.com" <dan.zhao@hisilicon.com>,
	Catalin Marinas <Catalin.Marinas@arm.com>,
	"wangbinghui@hisilicon.com" <wangbinghui@hisilicon.com>,
	Will Deacon <Will.Deacon@arm.com>,
	"huxinwei@huawei.com" <huxinwei@huawei.com>,
	"haojian.zhuang@linaro.org" <haojian.zhuang@linaro.org>,
	"yanhaifeng@gmail.com" <yanhaifeng@gmail.com>,
	"rob.herring@linaro.org" <rob.herring@linaro.org>,
	"mturquette@linaro.org" <mturquette@linaro.org>,
	Pawel Moll <Pawel.Moll@arm.com>,
	"khilman@kernel.org" <khilman@kernel.org>,
	"xuwei5@hisilicon.com" <xuwei5@hisilicon.com>,
	"jh80.chung@samsung.com" <jh80.chung@samsung.com>,
	"sledge.yanwei@huawei.com" <sledge.yanwei@huawei.com>,
	"kong.kongxinwei@hisilicon.com" <kong.kongxinwei@hisilicon.com>,
	"heyunlei@huawei.com" <heyunlei@huawei.com>,
	"w.f@huawei.com" <w.f@huawei.com>,
	"zhangfei.gao@linaro.org" <zhangfei.gao@linaro.org>,
	z.liuxinliang@huaw
Subject: Re: [PATCH v4 5/5] arm64: dts: Add dts files for Hisilicon Hi6220 SoC
Date: Wed, 13 May 2015 15:30:39 +0800	[thread overview]
Message-ID: <5552FD9F.7000609@huawei.com> (raw)
In-Reply-To: <cf6ae9.68c7.14d4c1dc0f6.Coremail.btw@mail.itp.ac.cn>

Please ignore this email.

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@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@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
>
>
>
>
> .
>