From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v4 2/8] arm64: dts: exynos: Add dts files for 64-bit Exynos5433 SoC Date: Tue, 24 Feb 2015 12:59:06 +0100 Message-ID: <6850624.bdB2Ab6zJx@wuerfel> References: <1424755011-15999-1-git-send-email-cw00.choi@samsung.com> <7412525.l6YnQcTxtg@wuerfel> <54EC5AB1.5090802@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <54EC5AB1.5090802@samsung.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-arm-kernel@lists.infradead.org Cc: Chanwoo Choi , mark.rutland@arm.com, jh80.chung@samsung.com, linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org, marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, a.kesavan@samsung.com, inki.dae@samsung.com, sw0312.kim@samsung.com, kgene@kernel.org, olof@lixom.net, chanho61.park@samsung.com, ideal.song@samsung.com List-Id: devicetree@vger.kernel.org On Tuesday 24 February 2015 20:04:17 Chanwoo Choi wrote: > On 02/24/2015 06:48 PM, Arnd Bergmann wrote: > > On Tuesday 24 February 2015 17:52:01 Chanwoo Choi wrote: > >> > >> But, I have a question. > >> If we put the aliases into the board dts file instaed of SoC dtsi, > >> each board dts file may use the different alias name about same phandle. > > > > Yes, that is the idea. In particular with the uarts, the intention is > > that the numbering of the device nodes in /dev is the same that is > > printed on the board (if any), which may be different from the numbering > > internal to the SoC. > > I check the uart device with Exynos5433 SoC based on Linux 4.0-rc1 > If some board use the serial_0 and serial_3 as following in board dtsi, > > &serial_0 { --> UART 0 device > status = "okay"; > }; > > &serial_3 { --> UART 3 device > status = "okay"; > }; > > The serial core driver create the follwoing /dev/ttySACx device node > by using the number of alias. It maintain the same device number of internel to the SoC. > > root@localhost:~# ls /dev/ttySAC > ttySAC1 ttySAC3 > I'm not completely following. So you have set the serial1 alias to the &serial_0 device node and serial3 to &serial_3? Why not use serial0=&serial_0 and serial1=&serial_3? Does the serial0 alias have a special meaning? Arnd