From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2AF7C3F68F for ; Thu, 9 Jan 2020 16:56:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C8CE620721 for ; Thu, 9 Jan 2020 16:56:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578589004; bh=9oyg27saFaqgN0kNufIh+bWG6/4Iwy6kaQ1n0BzczVk=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=XxiVd07G+QHhurFAX2OunU1wJrekXjZOUeH8yyvRfV+BUK2Dr7v3fcyLaHFHLorad LPKQEPp1bsY9ulzDHqLjEKIC3i9zKNZ5XXeCNcpZzIs1DK16rh9UKf3L1rgXb9cBJk JLAYUIhDoUeNRMqUjffV+zmY27Gfbgw8+lMMTYio= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387930AbgAIQ4o (ORCPT ); Thu, 9 Jan 2020 11:56:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:59922 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731320AbgAIQ4n (ORCPT ); Thu, 9 Jan 2020 11:56:43 -0500 Received: from mail-qk1-f178.google.com (mail-qk1-f178.google.com [209.85.222.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8C9EA2075D; Thu, 9 Jan 2020 16:56:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578589002; bh=9oyg27saFaqgN0kNufIh+bWG6/4Iwy6kaQ1n0BzczVk=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=2CosUSQhDeszdClob89wkM5qUuLn+NGmxavbwwJtOjFrz9J9rb5rJcMgFQI1xDAQ4 fUXa0Ef1aePHujZvmpoUW/06Em/BF7VVOjDi5q5fkKIAJuUjWK6nHJS6vh0B+JXDfJ atgBkzj5WtLXXdJkwB2Qpsf8KlWlFaaxn/mc4FF0= Received: by mail-qk1-f178.google.com with SMTP id r14so6552712qke.13; Thu, 09 Jan 2020 08:56:42 -0800 (PST) X-Gm-Message-State: APjAAAWloDLS5fQEZE4v7aOsCtA5Rup0GXo5SQg8RtAKLM93Amf5aA4m vCrzxnTi1CKTJIrJyR7rKHx71dJPQ1VRecow0A== X-Google-Smtp-Source: APXvYqwejonPhLn1c6g5UIO7dw/MXR05QYRJuuZwXtZ9dn62B4O5MWFoIh0m1SoNLfPeYaTMJ9QV835I1LSeJT6q4Lo= X-Received: by 2002:a05:620a:1eb:: with SMTP id x11mr10791122qkn.254.1578589001636; Thu, 09 Jan 2020 08:56:41 -0800 (PST) MIME-Version: 1.0 References: <20200108052337.65916-1-drinkcat@chromium.org> <20200108052337.65916-5-drinkcat@chromium.org> <20200108132302.GA3817@sirena.org.uk> In-Reply-To: From: Rob Herring Date: Thu, 9 Jan 2020 10:56:29 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 4/7] drm/panfrost: Add support for a second regulator for the GPU To: Nicolas Boichat Cc: Mark Brown , David Airlie , Daniel Vetter , Mark Rutland , Matthias Brugger , Tomeu Vizoso , Steven Price , Alyssa Rosenzweig , Liam Girdwood , dri-devel , Devicetree List , lkml , linux-arm Mailing List , "moderated list:ARM/Mediatek SoC support" , Hsin-Yi Wang Content-Type: text/plain; charset="UTF-8" Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Wed, Jan 8, 2020 at 4:52 PM Nicolas Boichat wrote: > > On Wed, Jan 8, 2020 at 9:23 PM Mark Brown wrote: > > > > On Wed, Jan 08, 2020 at 01:23:34PM +0800, Nicolas Boichat wrote: > > > > > Some GPUs, namely, the bifrost/g72 part on MT8183, have a second > > > regulator for their SRAM, let's add support for that. > > > > > + pfdev->regulator_sram = devm_regulator_get_optional(pfdev->dev, "sram"); > > > + if (IS_ERR(pfdev->regulator_sram)) { > > > > This supply is required for the devices that need it so I'd therefore > > expect the driver to request the supply non-optionally based on the > > compatible string rather than just hoping that a missing regulator isn't > > important. > > That'd be a bit awkward to match, though... Currently all bifrost > share the same compatible "arm,mali-bifrost", and it'd seem > weird/wrong to match "mediatek,mt8183-mali" in this driver? I have no > idea if any other Mali implementation will require a second regulator, > but with the MT8183 we do need it, see below. The current number of supported bifrost platforms is 0. It's only a matter of time until SoC specific compatibles need to be used in the driver. This is why we require them. It could very well be that all bifrost implementations need 2 supplies. On chip RAMs are very frequently a separate thing which are synthesized differently from logic. At least within a specific IP model, I somewhat doubt there's a variable number of supplies. It could be possible to connect both to the same supply, but the correct way to handle that is both -supply properties point to the same regulator. Rob