From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751702AbeBAIBw (ORCPT ); Thu, 1 Feb 2018 03:01:52 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:50678 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751272AbeBAIBs (ORCPT ); Thu, 1 Feb 2018 03:01:48 -0500 X-Google-Smtp-Source: AH8x227FLa+Qcdi6TMm+f/OsAkXEsV70QcaOKBTuBTJHwOAyNmuTFGf15ZaNqfrjsp23hJjogQMKUg== Subject: Re: [PATCH v11 2/6] mailbox: qcom: Create APCS child device for clock controller To: Jassi Brar Cc: Bjorn Andersson , Stephen Boyd , Michael Turquette , Rob Herring , linux-clk@vger.kernel.org, Linux Kernel Mailing List , linux-arm-msm@vger.kernel.org, Devicetree List References: <20171205154701.27730-1-georgi.djakov@linaro.org> <20171205154701.27730-3-georgi.djakov@linaro.org> <20171224050625.GH12655@minitux> <549f02e5-19d7-8cec-674f-247dfb2d2467@linaro.org> From: Georgi Djakov Message-ID: <384da443-a206-8db3-0a5f-90a68b7f42c2@linaro.org> Date: Thu, 1 Feb 2018 10:01:44 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/01/2018 08:57 AM, Jassi Brar wrote: > On Thu, Feb 1, 2018 at 12:10 AM, Georgi Djakov wrote: >> >> Hi Jassi, >> >> On 01/27/2018 05:44 AM, Jassi Brar wrote: >>> On Thu, Jan 4, 2018 at 10:26 PM, Georgi Djakov wrote: >>>> Hi Jassi, >>>> >>>> On 12/29/2017 08:14 AM, Jassi Brar wrote: >>>>> 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. >>>> >>>> The APCS is one separate register block related to the CPU cluster. I >>>> haven't seen any strict guidelines for such cases in the DT docs, and >>>> during the discussion got the impression that this is the preferred >>>> binding. Rob has also reviewed the binding, so we should be fine to move >>>> forward with this one. >>>> >>> Well, I can't overrule Rob. But I am really not happy with random >>> device spawning from mailbox drivers. I know there are such instances >>> already in the kernel but that doesn't make it legit... unless there >>> is some hard dependency. Is there? >> >> The dependency is that on this SoC, these functionalities are combined >> into this "CPU subsystem" block. >> > I see the register space is shared between mailbox and the clock. So I > guess, yes, simply creating a device here and passing the common > regmap is tidier. Which patches are already picked up? Patches 3, 4 and 6 are already picked into the clk tree. Still pending are patches 1, 2 and 5. Thanks, Georgi