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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6A10DC433EF for ; Tue, 1 Mar 2022 05:01:02 +0000 (UTC) Received: from localhost ([::1]:44006 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nOudB-0000et-6b for qemu-devel@archiver.kernel.org; Tue, 01 Mar 2022 00:01:01 -0500 Received: from eggs.gnu.org ([209.51.188.92]:37516) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nOsDM-0003Kd-L1; Mon, 28 Feb 2022 21:26:12 -0500 Received: from [2607:f8b0:4864:20::c35] (port=44556 helo=mail-oo1-xc35.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nOsDL-0005vT-0a; Mon, 28 Feb 2022 21:26:12 -0500 Received: by mail-oo1-xc35.google.com with SMTP id j7-20020a4ad6c7000000b0031c690e4123so21056998oot.11; Mon, 28 Feb 2022 18:26:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:mime-version:content-disposition; bh=MnNhFIgMAn/jAADic9V1Aj+2bLQDoMvnVPOMDxBpfds=; b=dKs/d67B6u9aU4yHfNlHR6Hv3HEfyLPmaiRqJ+s8TBBbW4A0r9uWlxkLpU2VvtGWvw 974yGwKZO7hADo0oVXU+XKynExo9vaFPi70L4a19oLgGm99B4BMUQtA0d5hwBbOXeYs2 7aOtjnpXjTiLqAqbenaYbXDTjpe24cat+gbypa9OuMRGtWVHY+dGuQHXtiugCOY7wYx4 w1hwLEgkJcXAG+5iviLZeSZkJcXkmEXl0KbtKQv2HfL41c/RAdpmvJSg2kbnOVaUZl/s jmkn/LISoMZd9FasKyO5GKH3AmgawhaBdfj8rkSLNwScbn7C0zKx1gyNHJ4elgQFh3fx WR+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition; bh=MnNhFIgMAn/jAADic9V1Aj+2bLQDoMvnVPOMDxBpfds=; b=VTmnZeJvClzsePmn06m0HEoFNgzb99W6MZeijSVXo56hUjYfnNrr4zrYKsQPAcan6a nsz+AEA/GexRVO5qy21gxdxNVvgErYtXTHRavQWj1+TQlT+C0PWXiJZV2tMCtLPCAq6I jCuFf6XxUgyElFgUWAh9PeoebVHiJ1hswXBYW8aPcb8Mkm7qmWpKxpVzKZn03WXr/4Pv f0zpV3ozNSoBKBqmzS3oxFITH8PzxyxzQqq/c1a8biiHkc70Fqu709UKdkBPPz7ffNyY Q8+XbdXZXaigS01J7btSJNmdjbtWwGdLqzr2RUzLM1EwUZhZ5sdxCuiaakWvX7B9K6Au BlLg== X-Gm-Message-State: AOAM533UuY67cpmRlSmcH+7uo5bIBNwziWvXDRACas3wbP1KglX5HLyz zQ9UZHnH/IjNDLaHSaSMe4NzrQSxwVY= X-Google-Smtp-Source: ABdhPJyjZSA2Ve70ITPggPJwK0Mge3hwXQLTdTKTIl0Bx5Wrkk/DeV0iHYtB8rG+Rt89fvx9SldnIg== X-Received: by 2002:a4a:2a4e:0:b0:2c6:c823:e6b4 with SMTP id x14-20020a4a2a4e000000b002c6c823e6b4mr10717886oox.29.1646101568736; Mon, 28 Feb 2022 18:26:08 -0800 (PST) Received: from marsc.168.1.7 ([2804:30c:b7a:7b00:70e:e3d5:be94:991]) by smtp.gmail.com with ESMTPSA id g7-20020a056870d20700b000d1614be328sm5310656oac.27.2022.02.28.18.26.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Feb 2022 18:26:08 -0800 (PST) Date: Mon, 28 Feb 2022 23:26:05 -0300 From: Marcelo Schmitt To: qemu-arm@nongnu.org Subject: SPI support for the virt platform Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Host-Lookup-Failed: Reverse DNS lookup failed for 2607:f8b0:4864:20::c35 (failed) Received-SPF: pass client-ip=2607:f8b0:4864:20::c35; envelope-from=marcelo.schmitt1@gmail.com; helo=mail-oo1-xc35.google.com X-Spam_score_int: -3 X-Spam_score: -0.4 X-Spam_bar: / X-Spam_report: (-0.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, PDS_HP_HELO_NORDNS=0.659, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Mon, 28 Feb 2022 23:59:18 -0500 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org, theobf@usp.br Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi, I'd like to know the opinion of the QEMU community on some topics. In 2021, a pair of patch sets for drivers of the Linux IIO subsystem was proposed based on some QEMU hacks that added virtual devices with which it was possible to test the proposed modifications to the Linux kernel [1, 2, 3]. Most Linux IIO drivers connect to the system through either SPI or I2C. So, it ends up that these buses are needed to do some tests on IIO drivers. Because of that, those QEMU changes included hacks to the virt platform to add SPI or I2C buses. The documentation says that virt is a generic virtual platform [4]. In this regard, adding more buses to virt could turn the platform into something less generic. However, if support for SPI/I2C were added, then it would reduce the effort needed to develop virtual devices to aid driver testing. Before putting effort to develop something concrete, I'd like to ask just to make sure: Would SPI/I2C support be a good addition to QEMU virt? Another possibility would be to add support for SPI and I2C buses on Raspberry Pi boards emulation [5]. Would this be a better idea? Also, the QEMU devices developed could be upstreamed. At first, I thought that developing virtual devices would be a win-win situation in which we could extend Linux's test coverage and add support for new QEMU devices. However, as these would be dummy devices, I'm not sure how QEMU would benefit from them. Anyhow, I'd appreciate it if anyone could give a word about that. Thanks, Marcelo [1] https://lore.kernel.org/linux-iio/20210314181511.531414-1-jic23@kernel.org/ [2] https://lore.kernel.org/linux-iio/20210614113507.897732-1-jic23@kernel.org/ [3] https://github.com/jic23/qemu [4] https://qemu-project.gitlab.io/qemu/system/arm/virt.html [5] https://qemu-project.gitlab.io/qemu/system/arm/raspi.html