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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 21807CCD19B for ; Wed, 18 Sep 2024 11:01:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=wyoz+r3z2fTtTxOXwV3PfYzr+O9ELMQOoDfKks2rgks=; b=0wplujtfOo0xrqMSHjbLKGrOcN szIzOaV3FXvkZtwNjAFLw8Ae3nUbI8c7WuO+8i8VjT6iMk+H/EO2P8lcYRhA45nAMxlrBgmErN26P 18cC/+Gu97UJyMCRUrRbHKP0jRdtgP6fPcXJekZkvirVwIwVx+HWhdfXJ9HLVMlMhei2KLKa3giHy fgkQ7Y8+FEidWAjSfDJ9JvvgRNeNqLhu3ygK7gBVlsW5dVkEYO/hVvKw+9jA2s6RVHDmodyPrt1it 7ChsiawWvBymVh4H6j/tnFo+EtEGlT+LUifOjyYvhh+H0qXy65c7JknTVxlLxPIimzILstyzmsEOH Z/6kGoig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1sqsR1-000000085MH-3fvs; Wed, 18 Sep 2024 11:01:23 +0000 Received: from mail-lj1-x22d.google.com ([2a00:1450:4864:20::22d]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1sqsPu-000000085BG-1RI0 for linux-arm-kernel@lists.infradead.org; Wed, 18 Sep 2024 11:00:15 +0000 Received: by mail-lj1-x22d.google.com with SMTP id 38308e7fff4ca-2f7529203ddso6500821fa.0 for ; Wed, 18 Sep 2024 04:00:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1726657212; x=1727262012; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to; bh=wyoz+r3z2fTtTxOXwV3PfYzr+O9ELMQOoDfKks2rgks=; b=a++Lr09soB7w993xBfFYsqEFmtkULRbpX0XU0t7QH6PsLd/3P5PRdjGKqo8EA3ZvBK KBzvHyg/hyjgsu5eaF9fe9dx02oN/57Cq+JyuYE1jrgchGzklPP0RKpOeNgUnvP7xZdV hyKbKNrwSWptZtb82NnB0lc4qy3lGkoLbZmDt3JRcevTdc81/aeXc4HFPduqt6Epxqzu k1Ej2NNTed0NiNgBmmXSJqHqY+WHoDt7IpQ0QQ3Unza5x5pXq2E2FrcaRFGd4tGSUEYW CjU+INhLeVh5TLNwsLtZ1GFqw+bpuJzwZSFQ9Zya0GUAeA32LOeSmPX6LDFlU9pntnEb b9yQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726657212; x=1727262012; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=wyoz+r3z2fTtTxOXwV3PfYzr+O9ELMQOoDfKks2rgks=; b=DFVfHx6aVczNSQKW5X4fCsF93pQKooiGDl0o/lbNQw1U4WAnbw7TIJiSnJLrgFWjFH UKzcZf8KYhrh+2DOX/7u6PfpUhZu6M8+iaK/SAsYfHAbJvmML3zTiKBccFMHxGOF33O/ UVlScWGHzj901p+5a9UU7Trnn/hDG+SvbLECdUrgKJi21xR7AYVhHVyxeqo7GKPFu2pe By/OUBIf+8CVHlFAxAjhxlD5QuEYapHww1R9/JrrUlKHIqQGKbWNZZlAZ7EF7KUhzH9G LdhD9IqHJFBiCHhoB0ax/eN/HAc2evtNscTCZFoo9WdZnXx9PQDjWSmUE8XAApTn+cn1 KOIA== X-Forwarded-Encrypted: i=1; AJvYcCUMTprOD1xJaWuvzWn0mqdFKEZGILFOPuJ9vkeWRsjtuP+PkGT8IqKqLVRkKX7h1bpgTVd+Cuc8Y0VDxj4P24Dx@lists.infradead.org X-Gm-Message-State: AOJu0YwnvMKQGRNegRih6fOjIj1hera+sB7wjYtN+HflZE9ENF+lWG/K rbbVHDCEDpN8GMosD/SZBThz54sFH35ILhBO0jk170NSklrmC9n8 X-Google-Smtp-Source: AGHT+IFlJ2O1ZZMm0urEG0PIruAPf3kfHMNdT/Jxt4BdRNZGgUDCk9cJYsWZo8HwEHhRbUhpLyeHCw== X-Received: by 2002:a05:6512:3051:b0:52f:441:bdd6 with SMTP id 2adb3069b0e04-5366b7d4cdcmr9419364e87.0.1726657211673; Wed, 18 Sep 2024 04:00:11 -0700 (PDT) Received: from localhost ([94.19.228.143]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-53687046f7bsm1482259e87.35.2024.09.18.04.00.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Sep 2024 04:00:10 -0700 (PDT) Date: Wed, 18 Sep 2024 14:00:10 +0300 From: Andrey Skvortsov To: Dragan Simic Cc: Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , =?utf-8?Q?Ond=C5=99ej?= Jirman Subject: Re: [PATCH] arm64: dts: sun50i-a64-pinephone: Add mount matrix for accelerometer Message-ID: Mail-Followup-To: Andrey Skvortsov , Dragan Simic , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , =?utf-8?Q?Ond=C5=99ej?= Jirman References: <20240916204521.2033218-1-andrej.skvortzov@gmail.com> <6e5d0e9978bff30559c17f30d1495b59@manjaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240918_040014_416379_71C2F7EC X-CRM114-Status: GOOD ( 34.45 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Dragan, On 24-09-18 11:27, Dragan Simic wrote: > Hello Andrey, > > > arm64: dts: allwinner: pinephone: Add mount matrix to accelerometer > > The patch description should be reworded like this, reflown into > proper line lengths, of course: > > The way InvenSense MPU-6050 accelerometer is mounted on the > user-facing side of the Pine64 PinePhone mainboard requires > the accelerometer's x- and y-axis to be swapped, and the > direction of the accelerometer's y-axis to be inverted. > > Rectify this by adding a mount-matrix to the accelerometer > definition in the PinePhone dtsi file. > > [andrey: Picked the patch description provided by dsimic] > Fixes: 91f480d40942 ("arm64: dts: allwinner: Add initial support for > Pine64 PinePhone") > Cc: stable@vger.kernel.org Thanks for the commit description, it's much better, than original one. > Please note the Fixes tag, which will submit this bugfix patch > for inclusion into the long-term/stable kernels. > > Also note that the patch description corrects the way inversion > of the axis direction is described, which should also be corrected > in the patch itself, as described further below. > > After going through the InvenSense MPU-6050 datasheet, [1] the > MPU-6050 evaluation board user guide, the PinePhone schematic, > the PinePhone mainboard component placement, [2] and the kernel > bindings documentation for mount-matrix, [3] I can conslude that > only the direction of the accelerometer's y-axis is inverted, > while the direction of the z-axis remain unchanged, according > to the right-hand rule. yes, it looks so on the first glance, but in MPU-6050 datasheet there is also following information: 7.8 Three-Axis MEMS Accelerometer with 16-bit ADCs and Signal Conditioning When the device is placed on a flat surface, it will measure 0g on the X- and Y-axes and +1g on the Z-axis. So sensors reports positive acceleration values for Z-axis, when the gravity points to Z-minus. I see the same on device. positive values are returned, when screen and IC point upwards (not the center for gravity). In device tree mount-matrix documentation [3] there is users would likely expect a value of 9.81 m/s^2 upwards along the (z) axis, i.e. out of the screen when the device is held with its screen flat on the planets surface. According to that, it looks like Z-axis here has to be inverted. It applies to other axes as well. And because of that I came from (only Y-axis is inverted) x' = -y y' = x z' = z to inverted solution (Y-axis is kept, but X and Z are inverted). x' = y y' = -x z' = -z probably should put this information into commit description. > > > > Signed-off-by: Ondrej Jirman > > > > Signed-off-by: Andrey Skvortsov > > > > --- > > > > arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > > > diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi > > > > b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi > > > > index bc6af17e9267a..1da7506c38cd0 100644 > > > > --- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi > > > > +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi > > > > @@ -229,6 +229,9 @@ accelerometer@68 { > > > > interrupts = <7 5 IRQ_TYPE_EDGE_RISING>; /* PH5 */ > > > > vdd-supply = <®_dldo1>; > > > > vddio-supply = <®_dldo1>; > > > > + mount-matrix = "0", "1", "0", > > > > + "-1", "0", "0", > > > > + "0", "0", "-1"; > > > > }; > > > > }; > > With the above-described analysis in mind, the mount-matrix > should be defined like this instead: > > mount-matrix = "0", "1", "0", > "-1", "0", "0", > "0", "0", "1"; x' = 0 * x + 1 * y + 0 * z = y y' = -1 * x + 1 * y + 0 * z = -x z' = 0 * z + 0 * y + 1 * z = z your description says, that only Y-axis is inverted, but this matrix, imho, inverts original X axis as it was in original description. > Please also note the line indentation that was changed a bit. > > [1] https://rimgo.reallyaweso.me/vrBXQPq.png > [2] https://rimgo.reallyaweso.me/uTmT1pr.png > [3] https://www.kernel.org/doc/Documentation/devicetree/bindings/iio/mount-matrix.txt -- Best regards, Andrey Skvortsov