From patchwork Tue Apr 26 13:11:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Merello X-Patchwork-Id: 12827136 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB6BCC433EF for ; Tue, 26 Apr 2022 13:11:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349909AbiDZNOq (ORCPT ); Tue, 26 Apr 2022 09:14:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350742AbiDZNOe (ORCPT ); Tue, 26 Apr 2022 09:14:34 -0400 Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84A3960AB4; Tue, 26 Apr 2022 06:11:24 -0700 (PDT) Received: by mail-wm1-x336.google.com with SMTP id v64-20020a1cac43000000b0038cfd1b3a6dso1460282wme.5; Tue, 26 Apr 2022 06:11:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=VbIqYrl/j/4f2JpJRwKTfog5CMhMNsgfur6sJmAAYyM=; b=hXqzTTps2HVRXHQSYmBwN2XN1rYAupQNRApRyMp0zDmiOZ1aSMIAart17L/C3E5oUb 2cqHPJ65BoShl2+SSbrHxQTpiVHUFQVzc0G9WgtTgh6TR+8lrewvVjsOYXffalfAh1Lo AhKGn/So5VWuhfINEeZlYKEZoYJ9R8k+1xxRfPjEKnylgVGNkOgwIrY1bpfu0aCreWYG jXkW4Lq5VKZMsgThNJNyy6tLN+l+7PqVscCKFwWi+duJGWHH8ZBqMRvBsSG/fWkESXUg 5Bh68MZuWKh7nKJNXDILYPDfR7DTbYS5jfy6sbuTuExQ75Oo0EfqqYkd49X9Px5kfJ8f ny3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=VbIqYrl/j/4f2JpJRwKTfog5CMhMNsgfur6sJmAAYyM=; b=EyaQfLvim7GzkbXC4ry/d97Homs6CqkxfI2uZstGTObm36oka1eKwaF5cpDMP89V+M wICpqfHXGoysRhehlBRF2qk0IADOagS9X/OaLggHp5Ha0o9G5pdzfk76+jqs0i3wbxs5 4iqsZOYuvS/JI9I1WvJxY5QwqiaspP2okB6xVU0aG/Qe2VQfqn81gy2cdMQBTwYTTKgd sq+NxGPZfI1rvjdnrHWGjcF6Pu7nhuzRaXmLDVDndGqQxcMtE0ItngEyJbKT+DdWFHt0 LXmPXdJSYDLfJBPfmOW4AvLqNRYdbVo7uAiSHtIAn9+RZr4lnH5g8BReoPBlVXVh8hll UhQA== X-Gm-Message-State: AOAM5334OqqjHXOiA6rj27zMzxnV8+pfxPFQxT50JQu7ZcsaVABKw/es ZhkyR4YtZ5pvlsbdh301IrA= X-Google-Smtp-Source: ABdhPJyJx3p6eMl28pdya7q+rrOr3vzQaeqoVn0kIgN543h8VeoLjAyDSIjI3OLtkLU797eb8wrEHA== X-Received: by 2002:a05:600c:3b02:b0:393:e7d4:b660 with SMTP id m2-20020a05600c3b0200b00393e7d4b660mr12637839wms.183.1650978682527; Tue, 26 Apr 2022 06:11:22 -0700 (PDT) Received: from poker.lan (static.2-229-210-222.ip198.fastwebnet.it. [2.229.210.222]) by smtp.gmail.com with ESMTPSA id h9-20020a05600c350900b00393f01c8f00sm3262910wmq.47.2022.04.26.06.11.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Apr 2022 06:11:22 -0700 (PDT) From: Andrea Merello To: jic23@kernel.org, mchehab+huawei@kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Cc: lars@metafoo.de, robh+dt@kernel.org, andy.shevchenko@gmail.com, matt.ranostay@konsulko.com, ardeleanalex@gmail.com, jacopo@jmondi.org, Andrea Merello Subject: [v5 14/14] docs: iio: add documentation for BNO055 driver Date: Tue, 26 Apr 2022 15:11:02 +0200 Message-Id: <20220426131102.23966-15-andrea.merello@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220426131102.23966-1-andrea.merello@gmail.com> References: <20220426131102.23966-1-andrea.merello@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Andrea Merello The bno055 driver is rather complex and have some oddities and not-obvious things that worth to document (e.g. calibration files). Signed-off-by: Andrea Merello --- Documentation/iio/bno055.rst | 50 ++++++++++++++++++++++++++++++++++++ Documentation/iio/index.rst | 2 ++ 2 files changed, 52 insertions(+) create mode 100644 Documentation/iio/bno055.rst diff --git a/Documentation/iio/bno055.rst b/Documentation/iio/bno055.rst new file mode 100644 index 000000000000..af21376d7a25 --- /dev/null +++ b/Documentation/iio/bno055.rst @@ -0,0 +1,50 @@ +.. SPDX-License-Identifier: GPL-2.0 +============================== +BNO055 driver +============================== + +1. Overview +=========== + +This driver supports Bosch BNO055 IMUs (on both serial and I2C busses). + +Accelerometer, magnetometer and gyroscope measures are always provided. +When "fusion_enable" sysfs attribute is set to 1, orientation (both Euler +angles and quaternion), linear velocity and gravity vector are also +provided, but some sensor settings (e.g. low pass filtering and range) +became locked (the IMU firmware controls them). + +This driver supports also IIO buffers. + +2. Calibration +============== + +The IMU continuously performs an autocalibration procedure if (and only if) +operating in fusion mode. The magnetometer autocalibration can however be +disabled writing 0 in the sysfs in_magn_calibration_fast_enable attribute. + +The driver provides access to autocalibration flags (i.e. you can known if +the IMU has successfully autocalibrated) and to the calibration data blob. + +The user can save this blob in a firmware file (i.e. in /lib/firmware) that +the driver looks for at probe time. If found, then the IMU is initialized +with this calibration data. This saves the user from performing the +calibration procedure every time (which consist of moving the IMU in +various way). + +The driver looks for calibration data file using two different names: first +a file whose name is suffixed with the IMU unique ID (exposed in sysfs as +serial_number) is searched for; this is useful when there is more than one +IMU instance. If this file is not found, then a "generic" calibration file +is searched for (which can be used when only one IMU is present, without +struggling with fancy names, that change on each device). + +Valid calibration file names would be e.g. + bno055-caldata-0e7c26a33541515120204a35342b04ff.dat + bno055-caldata.dat + +In non-fusion mode the IIO 'offset' attributes provide access to the +offsets from calibration data (if any), so that the user can apply them to +the accel, angvel and magn IIO attributes. In fusion mode they are not +needed (the IMU firmware internally applies those corrections) and they +read as zero. diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst index 58b7a4ebac51..1b7292c58cd0 100644 --- a/Documentation/iio/index.rst +++ b/Documentation/iio/index.rst @@ -10,3 +10,5 @@ Industrial I/O iio_configfs ep93xx_adc + + bno055