From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH 11/14] arm64: dts: Add initial device tree support for EXYNOS7 Date: Thu, 28 Aug 2014 10:48:46 +0100 Message-ID: <20140828094846.GD14650@leverpostej> References: <1409132660-1898-1-git-send-email-ch.naveen@samsung.com> <1409132660-1898-3-git-send-email-ch.naveen@samsung.com> <20140828035639.GB4972@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20140828035639.GB4972@localhost> Sender: linux-samsung-soc-owner@vger.kernel.org To: Olof Johansson Cc: Naveen Krishna Chatradhi , Catalin Marinas , "naveenkrishna.ch@gmail.com" , "linux-arm-kernel@lists.infradead.org" , "linux-samsung-soc@vger.kernel.org" , "devicetree@vger.kernel.org" , "cpgs@samsung.com" , Thomas Abraham , Rob Herring List-Id: devicetree@vger.kernel.org Hi, > > + cpus { > > + #address-cells = <2>; > > + #size-cells = <0>; > > Why size-cells=2? Can you not fit a cpuid in 32 bits? As of commit 72aea393a2e7 (arm64: smp: honour #address-size when parsing CPU reg property) Linux can handle single-cell cpu node reg entries where /cpus/#address-cells = <1>. I can't make any guarantees about other code (e.g. bootloaders) which might try to do things with cpu nodes, YMMV. [...] > > + hsi2c_2: hsi2c@14E60000 { > > I much prefer lowercase hex in unit addresses (and reg entries) below. I > know 32-bit uses uppercase, but let's switch going forward here. My preference also; I'm happy to enforce that on new dts. [...] > > + timer { > > + compatible = "arm,armv8-timer"; > > + interrupts = <1 13 0xff01>, > > + <1 14 0xff01>, > > + <1 11 0xff01>, > > + <1 10 0xff01>; > > + clock-frequency = <24000000>; > > + use-clocksource-only; > > + use-physical-timer; > > These two properties are not standard, and I would expect any 64-bit > platform to come with PSCI such that you have a way to initialize the > virtual timers. Likewise with clock-frequency. It's not a full workaround, and it's not hard to initialise CNTFRQ on each CPU. Mark. From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Thu, 28 Aug 2014 10:48:46 +0100 Subject: [PATCH 11/14] arm64: dts: Add initial device tree support for EXYNOS7 In-Reply-To: <20140828035639.GB4972@localhost> References: <1409132660-1898-1-git-send-email-ch.naveen@samsung.com> <1409132660-1898-3-git-send-email-ch.naveen@samsung.com> <20140828035639.GB4972@localhost> Message-ID: <20140828094846.GD14650@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, > > + cpus { > > + #address-cells = <2>; > > + #size-cells = <0>; > > Why size-cells=2? Can you not fit a cpuid in 32 bits? As of commit 72aea393a2e7 (arm64: smp: honour #address-size when parsing CPU reg property) Linux can handle single-cell cpu node reg entries where /cpus/#address-cells = <1>. I can't make any guarantees about other code (e.g. bootloaders) which might try to do things with cpu nodes, YMMV. [...] > > + hsi2c_2: hsi2c at 14E60000 { > > I much prefer lowercase hex in unit addresses (and reg entries) below. I > know 32-bit uses uppercase, but let's switch going forward here. My preference also; I'm happy to enforce that on new dts. [...] > > + timer { > > + compatible = "arm,armv8-timer"; > > + interrupts = <1 13 0xff01>, > > + <1 14 0xff01>, > > + <1 11 0xff01>, > > + <1 10 0xff01>; > > + clock-frequency = <24000000>; > > + use-clocksource-only; > > + use-physical-timer; > > These two properties are not standard, and I would expect any 64-bit > platform to come with PSCI such that you have a way to initialize the > virtual timers. Likewise with clock-frequency. It's not a full workaround, and it's not hard to initialise CNTFRQ on each CPU. Mark.