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=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED autolearn=unavailable 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 A01C5C04AAD for ; Tue, 7 May 2019 14:22:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 78F71206BF for ; Tue, 7 May 2019 14:22:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726803AbfEGOWQ (ORCPT ); Tue, 7 May 2019 10:22:16 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:38798 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726454AbfEGOWQ (ORCPT ); Tue, 7 May 2019 10:22:16 -0400 X-UUID: 154115064e8a4275805302ff7213d8ff-20190507 X-UUID: 154115064e8a4275805302ff7213d8ff-20190507 Received: from mtkcas07.mediatek.inc [(172.21.101.84)] by mailgw01.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 191652116; Tue, 07 May 2019 22:22:06 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs01n1.mediatek.inc (172.21.101.68) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 7 May 2019 22:22:05 +0800 Received: from [172.21.84.99] (172.21.84.99) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Tue, 7 May 2019 22:22:05 +0800 Message-ID: <1557238925.11663.21.camel@mtksdccf07> Subject: Re: [RFC PATCH V1 1/6] dt-bindings: mt8183: Add binding for DIP shared memory From: Frederic Chen To: Rob Herring CC: , , , , , , , , , , , , , , , , , , , , Date: Tue, 7 May 2019 22:22:05 +0800 In-Reply-To: <20190430011506.GA8514@bogus> References: <20190417104511.21514-1-frederic.chen@mediatek.com> <20190417104511.21514-2-frederic.chen@mediatek.com> <20190430011506.GA8514@bogus> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Dear Rob, I appreciate your comments. On Mon, 2019-04-29 at 20:15 -0500, Rob Herring wrote: > On Wed, Apr 17, 2019 at 06:45:06PM +0800, Frederic Chen wrote: > > This patch adds the binding for describing the shared memory > > used to exchange configuration and tuning data between the > > co-processor and Digital Image Processing (DIP) unit of the > > camera ISP system on Mediatek SoCs. > > > > Signed-off-by: Frederic Chen > > --- > > .../mediatek,reserve-memory-dip_smem.txt | 45 +++++++++++++++++++ > > 1 file changed, 45 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/reserved-memory/mediatek,reserve-memory-dip_smem.txt > > > > diff --git a/Documentation/devicetree/bindings/reserved-memory/mediatek,reserve-memory-dip_smem.txt b/Documentation/devicetree/bindings/reserved-memory/mediatek,reserve-memory-dip_smem.txt > > new file mode 100644 > > index 000000000000..64c001b476b9 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/reserved-memory/mediatek,reserve-memory-dip_smem.txt > > @@ -0,0 +1,45 @@ > > +Mediatek DIP Shared Memory binding > > + > > +This binding describes the shared memory, which serves the purpose of > > +describing the shared memory region used to exchange data between Digital > > +Image Processing (DIP) and co-processor in Mediatek SoCs. > > + > > +The co-processor doesn't have the iommu so we need to use the physical > > +address to access the shared buffer in the firmware. > > + > > +The Digital Image Processing (DIP) can access memory through mt8183 IOMMU so > > +it can use dma address to access the memory region. > > +(See iommu/mediatek,iommu.txt for the detailed description of Mediatek IOMMU) > > + > > + > > +Required properties: > > + > > +- compatible: must be "mediatek,reserve-memory-dip_smem" > > Don't use '_'. I got it. I will use "mediatek,reserve-memory-dip-smem" instead in next version of the patch > > > + > > +- reg: required for static allocation (see reserved-memory.txt for > > + the detailed usage) > > + > > +- alloc-range: required for dynamic allocation. The range must > > + between 0x00000400 and 0x100000000 due to the co-processer's > > + addressing limitation > > Generally, you should pick either static or dynamic allocation for a > given binding. Static if there's some address restriction or sharing, > dynamic if not. > > Sounds like static in this case. > DIP reserved memory has address restriction so it is the static case. I would like to remove the dynamic allocation part and modify the description as following: - reg: required for DIP. The range must be between 0x00000400 and 0x100000000 due to the co-processor's addressing limitation. The size must be 26MB. Please see reserved-memory.txt for the detailed usage. > > + > > +- size: required for dynamic allocation. The unit is bytes. > > + If you want to enable the full feature of Digital Processing Unit, > > + you need 20 MB at least. > > + > > + > > +Example: > > + > > +The following example shows the DIP shared memory setup for MT8183. > > + > > + reserved-memory { > > + #address-cells = <2>; > > + #size-cells = <2>; > > + ranges; > > + reserve-memory-dip_smem { > > + compatible = "mediatek,reserve-memory-dip_smem"; > > + size = <0 0x1400000>; > > + alignment = <0 0x1000>; > > + alloc-ranges = <0 0x40000000 0 0x50000000>; > > + }; > > + }; > > -- > > 2.18.0 > > Sincerely, Frederic Chen