From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754509AbcKJDT3 (ORCPT ); Wed, 9 Nov 2016 22:19:29 -0500 Received: from mail-it0-f68.google.com ([209.85.214.68]:35876 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753338AbcKJDT1 (ORCPT ); Wed, 9 Nov 2016 22:19:27 -0500 MIME-Version: 1.0 In-Reply-To: <20161109182630.tg3puvwurgx6iinw@rob-hp-laptop> References: <1478097481-14895-1-git-send-email-andrew@aj.id.au> <1478097481-14895-3-git-send-email-andrew@aj.id.au> <20161109182630.tg3puvwurgx6iinw@rob-hp-laptop> From: Joel Stanley Date: Thu, 10 Nov 2016 13:49:05 +1030 X-Google-Sender-Auth: 5Xv7ZWb0Mg4gVBjpkZCgfbLiuVk Message-ID: Subject: Re: [PATCH v2 2/6] mfd: dt: Add bindings for the Aspeed SoC Display Controller (GFX) To: Rob Herring , Andrew Jeffery Cc: Lee Jones , Linus Walleij , Mark Rutland , linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 10, 2016 at 4:56 AM, Rob Herring wrote: > On Thu, Nov 03, 2016 at 01:07:57AM +1030, Andrew Jeffery wrote: >> The Aspeed SoC Display Controller is presented as a syscon device to >> arbitrate access by display and pinmux drivers. Video pinmux >> configuration on fifth generation SoCs depends on bits in both the >> System Control Unit and the Display Controller. >> >> Signed-off-by: Andrew Jeffery >> --- >> Documentation/devicetree/bindings/mfd/aspeed-gfx.txt | 17 +++++++++++++++++ > > The register space can't be split to 2 nodes? Do you mean splitting the GFX IP and enable register into two nodes? We can't. Pinmux needs to check bit 6 and 7 in GFX064, which is in the middle the IP block: GFX060: CRT Control Register I GFX064: CRT Control Register II GFX068: CRT Status Register GFX06C: CRT Misc Setting Register >> +The Aspeed SoC Display Controller primarily does as its name suggests, but also >> +participates in pinmux requests on the g5 SoCs. It is therefore considered a >> +syscon device. >> + >> +Required properties: >> +- compatible: "aspeed,ast2500-gfx", "syscon" > > I think perhaps we should drop the syscon here and the driver should > just register as a syscon. We want the regmap to be present whenever the GFX driver or pinmux is loaded. If we register it in pinmux but chose to not build in that driver, we lack the regmap. Same for the case where a user builds in the GFX driver and not pinmux. I think this means we want the syscon compatible string, unless my understanding is wrong? Cheers, Joel