From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jassi Brar Subject: Re: [PATCH v11 2/6] mailbox: qcom: Create APCS child device for clock controller Date: Fri, 29 Dec 2017 11:44:40 +0530 Message-ID: References: <20171205154701.27730-1-georgi.djakov@linaro.org> <20171205154701.27730-3-georgi.djakov@linaro.org> <20171224050625.GH12655@minitux> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20171224050625.GH12655@minitux> Sender: linux-arm-msm-owner@vger.kernel.org To: Bjorn Andersson Cc: Georgi Djakov , Stephen Boyd , Michael Turquette , Rob Herring , linux-clk@vger.kernel.org, Linux Kernel Mailing List , linux-arm-msm@vger.kernel.org, Devicetree List List-Id: devicetree@vger.kernel.org Hi Bjorn, On Sun, Dec 24, 2017 at 10:36 AM, Bjorn Andersson wrote: > On Fri 22 Dec 20:57 PST 2017, Jassi Brar wrote: > >> On Tue, Dec 5, 2017 at 9:16 PM, Georgi Djakov wrote: >> > There is a clock controller functionality provided by the APCS hardware >> > block of msm8916 devices. The device-tree would represent an APCS node >> > with both mailbox and clock provider properties. >> > >> The spec might depict a 'clock' box and 'mailbox' box inside the >> bigger APCS box. However, from the code I see in this patchset, they >> are orthogonal and can & should be represented as independent DT >> nodes. > > The APCS consists of a number of different hardware blocks, one of them > being the "APCS global" block, which is what this node and drivers > relate to. On 8916 this contains both the IPC register and clock > control. But it's still just one block according to the hardware > specification. > > As such DT should describe the one hardware block by one node IMHO. > In my even humbler opinion, DT should describe a h/w functional unit which _could_ be seen as a standalone component. For example, if this APCS had a mac controller, would we also populate a netdev from mailbox driver? And what if next revision moves/drops this clock controller out of APCS, keeping mailbox controller exactly same? Maybe some DT maintainer could enlighten either of us. Cheers!