From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jernej =?utf-8?B?xaBrcmFiZWM=?= Subject: Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus Date: Wed, 21 Mar 2018 18:13:42 +0100 Message-ID: <2866474.lRHIcLtROC@jernej-laptop> References: <20180316175354.21437-1-icenowy@aosc.io> <20180320184646.dynqv6qubzabroe4@flea> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: linux-sunxi@googlegroups.com, icenowy@aosc.io Cc: Maxime Ripard , Rob Herring , Chen-Yu Tsai , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org List-Id: devicetree@vger.kernel.org Hi all, Dne sreda, 21. marec 2018 ob 03:18:13 CET je Icenowy Zheng napisal(a): > 于 2018年3月21日 GMT+08:00 上午2:46:46, Maxime Ripard 写到: > >On Sat, Mar 17, 2018 at 01:53:49AM +0800, Icenowy Zheng wrote: > >> All the sub-blocks of Allwinner A64 DE2 needs the SRAM C on A64 SoC > > > >to > > > >> be claimed, otherwise the whole DE2 space is inaccessible. > >> > >> Add a device tree binding of the DE2 part as a sub-bus. > > > >Where did you get the info that it was a bus? > > There's no direct evidence, just some guess. > > The DE2 is a whole part that is just allocated a memory > space at the user manual, and the SRAM controls the > access to all modules in the DE2. > > So it might be a bus. > > Implement it as a bus is a clear representation on A64. Since there is already syscon for same mmio region, we migh as well use it when loading ccu-sun8i-de2 driver on A64. Other options, like SRAM driver or bus driver, might better represent HW, but then we would have two DT nodes covering same mmio region, which I think is not really acceptable. Any suggestions? BTW, H6 has same design in this regard. Best regards, Jernej