From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bintian Subject: Re: [PATCH v4 5/5] arm64: dts: Add dts files for Hisilicon Hi6220 SoC Date: Wed, 6 May 2015 14:50:52 +0800 Message-ID: <5549B9CC.1040709@huawei.com> References: <1430827599-11560-1-git-send-email-bintian.wang@huawei.com> <1430827599-11560-6-git-send-email-bintian.wang@huawei.com> <20150505171349.GA30215@leverpostej> <5549877C.10408@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5549877C.10408@huawei.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Mark Rutland , Leo Yan , "haojian.zhuang@linaro.org" Cc: "dan.zhao@hisilicon.com" , "btw@mail.itp.ac.cn" , Catalin Marinas , "wangbinghui@hisilicon.com" , Will Deacon , "huxinwei@huawei.com" , "yanhaifeng@gmail.com" , "rob.herring@linaro.org" , "mturquette@linaro.org" , Pawel Moll , "khilman@kernel.org" , "xuwei5@hisilicon.com" , "jh80.chung@samsung.com" , "sledge.yanwei@huawei.com" , "kong.kongxinwei@hisilicon.com" , "heyunlei@huawei.com" , "w.f@huawei.com" , "zhangfei.gao@linaro.org" , "z.liuxinliang@huawei.com" List-Id: devicetree@vger.kernel.org Hello Mark, On 2015/5/6 11:16, Bintian wrote: > Hello Mark, > > On 2015/5/6 1:13, Mark Rutland wrote: [...] >>> + uart0: uart@f8015000 { /* console */ >>> + compatible = "arm,pl011", "arm,primecell"; >>> + reg = <0x0 0xf8015000 0x0 0x1000>; >>> + interrupts = ; >>> + 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. Thanks, Bintian > >> >> Thanks, >> Mark. >> >> [1] >> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/328978.html >> >> >> . >> > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > . >