From: bintian.wang@huawei•com (Bintian)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v4 5/5] arm64: dts: Add dts files for Hisilicon Hi6220 SoC
Date: Wed, 6 May 2015 18:36:07 +0800 [thread overview]
Message-ID: <5549EE97.3020801@huawei.com> (raw)
In-Reply-To: <20150506093022.GB31001@leverpostej>
Hello Mark,
On 2015/5/6 17:30, Mark Rutland wrote:
> On Wed, May 06, 2015 at 07:50:52AM +0100, Bintian wrote:
>> Hello Mark,
>>
>> On 2015/5/6 11:16, Bintian wrote:
>>> Hello Mark,
>>>
>>> On 2015/5/6 1:13, Mark Rutland wrote:
>> [...]
>>>>> + uart0: uart at f8015000 { /* console */
>>>>> + compatible = "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";
>>>>> + };
>>>>
>>>> In a previous discussion [1] the UART on HI6220 was described as not
>>>> fully PL011 compliant, with a number of differences (e.g. the FIFO
>>>> length).
>>>>
>>>> Given that, I feel somewhat uncomfortable with the current compatible
>>>> string list. What exactly are those differences? We may need a more
>>>> specific compatible string (even if in addition to those existing ones),
>>>> or perhaps other properties.
>>> The small system can be booted and the console also works well without
>>> changing any code of driver amba-pl011.c, so I think the compatible
>>> string is OK for this patch set.
>>>
>>> Hisilicon do some performance enhancements based on PL011, but the
>>> current driver "amba-pl011.c" also works on hi6220 without those
>>> enhancements driver code.
>> Checked with Hisilicon chip designer, the UART0 is used for DEBUG
>> console and compliant with PL011 fully.
>
> 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.
Thank you Mark,
BR,
Bintian
>
> Thanks,
> Mark.
>
> .
>
next prev parent reply other threads:[~2015-05-06 10:36 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-05 12:06 [PATCH v4 0/5] arm64,hi6220: Enable Hisilicon Hi6220 SoC Bintian Wang
2015-05-05 12:06 ` [PATCH v4 1/5] arm64: Enable Hisilicon ARMv8 SoC family in Kconfig and defconfig Bintian Wang
2015-05-05 12:06 ` [PATCH v4 2/5] arm64: hi6220: Document devicetree bindings for Hisilicon hi6220 SoC Bintian Wang
2015-05-15 0:27 ` Stephen Boyd
2015-05-15 1:31 ` Bintian
2015-05-05 12:06 ` [PATCH v4 3/5] clk: hi6220: Document devicetree bindings for hi6220 clock Bintian Wang
2015-05-15 0:26 ` Stephen Boyd
2015-05-05 12:06 ` [PATCH v4 4/5] clk: hi6220: Clock driver support for Hisilicon hi6220 SoC Bintian Wang
2015-05-15 0:25 ` Stephen Boyd
2015-05-15 7:42 ` Bintian
2015-05-15 19:30 ` Stephen Boyd
2015-05-16 2:54 ` Brent Wang
2015-05-19 20:35 ` Stephen Boyd
2015-05-20 0:52 ` Bintian
2015-05-05 12:06 ` [PATCH v4 5/5] arm64: dts: Add dts files for Hisilicon Hi6220 SoC Bintian Wang
2015-05-05 17:13 ` Mark Rutland
2015-05-06 3:16 ` Bintian
2015-05-06 3:51 ` Leo Yan
2015-05-06 9:20 ` Mark Rutland
2015-05-06 11:17 ` Leo Yan
2015-05-06 6:50 ` Bintian
2015-05-06 9:30 ` Mark Rutland
2015-05-06 10:36 ` Bintian [this message]
2015-05-06 10:55 ` Mark Rutland
2015-05-06 15:31 ` Brent Wang
2015-05-06 15:44 ` Mark Rutland
2015-05-06 16:03 ` Brent Wang
2015-05-06 16:23 ` Mark Rutland
2015-05-06 17:15 ` Brent Wang
2015-05-07 7:24 ` Bintian
2015-05-13 7:12 ` Bintian Wang
2015-05-13 7:30 ` Bintian
2015-05-06 10:38 ` Haojian Zhuang
2015-05-06 11:01 ` Mark Rutland
2015-05-05 13:45 ` [PATCH v4 0/5] arm64,hi6220: Enable " Haojian Zhuang
2015-05-05 23:46 ` Tyler Baker
2015-05-06 10:46 ` Bintian
2015-05-07 9:02 ` Will Deacon
2015-05-07 9:29 ` Bintian
2015-05-07 11:25 ` Will Deacon
2015-05-07 11:55 ` Leo Yan
2015-05-07 12:01 ` Bintian
2015-05-07 12:57 ` Will Deacon
2015-05-07 13:06 ` Bintian
2015-05-07 9:33 ` Haojian Zhuang
2015-05-07 10:44 ` Jorge Ramirez-Ortiz
2015-05-13 7:33 ` Bintian
2015-05-13 9:16 ` Will Deacon
2015-05-13 9:19 ` Arnd Bergmann
2015-05-13 10:17 ` Bintian
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