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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY autolearn=ham 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 EBDC3C282C4 for ; Tue, 12 Feb 2019 09:37:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE287218A3 for ; Tue, 12 Feb 2019 09:37:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728087AbfBLJhi (ORCPT ); Tue, 12 Feb 2019 04:37:38 -0500 Received: from mailgw02.mediatek.com ([210.61.82.184]:42890 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726003AbfBLJhi (ORCPT ); Tue, 12 Feb 2019 04:37:38 -0500 X-UUID: d13d239f94b14bf4ac887b4b633ca697-20190212 X-UUID: d13d239f94b14bf4ac887b4b633ca697-20190212 Received: from mtkcas08.mediatek.inc [(172.21.101.126)] by mailgw02.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 2048410000; Tue, 12 Feb 2019 17:37:24 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs01n2.mediatek.inc (172.21.101.79) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 12 Feb 2019 17:37:22 +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, 12 Feb 2019 17:37:22 +0800 Message-ID: <1549964242.27207.11.camel@mtksdccf07> Subject: Re: [RFC PATCH V0 1/7] [media] dt-bindings: mt8183: Add binding for DIP shared memory From: Frederic Chen To: Laurent Pinchart , Sakari Ailus CC: , Sakari Ailus , , , , , , , , , , , , , , , , Date: Tue, 12 Feb 2019 17:37:22 +0800 In-Reply-To: <20190209181705.GB4505@pendragon.ideasonboard.com> References: <1549020091-42064-1-git-send-email-frederic.chen@mediatek.com> <1549020091-42064-2-git-send-email-frederic.chen@mediatek.com> <20190209155907.rbgwbdablndcesid@valkosipuli.retiisi.org.uk> <20190209181705.GB4505@pendragon.ideasonboard.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 X-TM-SNTS-SMTP: 15DFA9F8853A480109641174D41DD23EE4B87532B6C53798FB2B77326F4856F52000:8 X-MTK: N Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Dear Laurent and Sakari, I appreciate your messages. On Sat, 2019-02-09 at 20:17 +0200, Laurent Pinchart wrote: > On Sat, Feb 09, 2019 at 05:59:07PM +0200, Sakari Ailus wrote: > > Hi Frederic, > > > > Could you cc the devicetree list, please? > > > > On Fri, Feb 01, 2019 at 07:21:25PM +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 0000000..0ded478 > > > --- /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) > > > > What kind of purpose is the memory used for? Buffers containing video data, > > or something else? Could the buffer objects be mapped on the devices > > based on the need instead? The memory buffers contain camera 3A tuning data, which are used by the co-processor and DIP IP. About mapping the buffer based on the need instead, I’m not sure I understand this point. Do you mean that allocating and mapping the memory dynamically? > > And could CMA be used when physically contiguous memory is needed ? DIP driver does not use CMA now, because the first version will be used by CrOS but CrOS won’t enable CMA. > > > > + > > > + > > > +Required properties: > > > + > > > +- compatible: must be "mediatek,reserve-memory-dip_smem" > > > + > > > +- 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 > > > + > > > +- 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-isp_smem { > > > + compatible = "mediatek,reserve-memory-dip_smem"; > > > + size = <0 0x1400000>; > > > + alignment = <0 0x1000>; > > > + alloc-ranges = <0 0x40000000 0 0x50000000>; > > > + }; > > > + }; > Sincerely, Frederic Chen