From patchwork Wed Sep 27 08:18:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matti Vaittinen X-Patchwork-Id: 13400347 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 C14D9E810A2 for ; Wed, 27 Sep 2023 08:18:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230039AbjI0IS7 (ORCPT ); Wed, 27 Sep 2023 04:18:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229910AbjI0IS6 (ORCPT ); Wed, 27 Sep 2023 04:18:58 -0400 Received: from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com [IPv6:2a00:1450:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACC5095; Wed, 27 Sep 2023 01:18:55 -0700 (PDT) Received: by mail-lf1-x12e.google.com with SMTP id 2adb3069b0e04-503065c4b25so16760266e87.1; Wed, 27 Sep 2023 01:18:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1695802734; x=1696407534; darn=vger.kernel.org; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=+3x8vUXTH+hRGX3fxYyM/ow7F7EZ9k5o10DeJwSjcq4=; b=PSR5ojaGddvT2WStqShEF+rlWJXrxyKdabBR7meq6i0yuBMCkw6pz3V0aKujdV1lb6 hYd3pf5AciAZQeJMnFQCRKlG+5g1oZyue/ij+ukSOkx8Kgitq8OdQQyfbCVFJXSjT3Oh Dk1cwECTKPy1JDtzpWCo3s653UhBwXH/07A+N1lvE73qSbtre3TnsrwPe4OektrFx2Px DPt+hnW4yf4wwLWC+U5i+HD4YMH61LcHJq9lqEHJl6rcFoa+phx7XYCSqJZEGzpeDMsz DBoHVayIW+lp6zwsHpeNuO8MfbEM8AN/CSftpamwUGxx0bgVsFKO8n+ITF6N87sawlG4 0/ZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695802734; x=1696407534; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=+3x8vUXTH+hRGX3fxYyM/ow7F7EZ9k5o10DeJwSjcq4=; b=UBrLbp/tGRBmZfZuIpC6KGIc3dIJFOwtm0QPokqY/Pbb2y4n9Ax7Yyoi/EHnnW2jh1 6S9NsV4I1yIfbOl6ntafIQCF02pG/fB6R+axKKnQjov8FeTjtIldtM/55JMdmo9ZhDOj 7IrSGOi7Iqicz1MgpRoMj+QO8waNGvRR3wh+efXUupRcEa0VL6h7XjBs4JsuLD///40v r7UxD92RSmVL+9KCMGJG8Ka8WwTxtZ1U/UboAkAbEAwmfC2JL1Gkhp+xzJSBvroo+xnt akjsNO84dufIJPlCNdtcrNt5USpVdgpuTdYAy6ACcZ/jQvXqVzsSCFnQkUARVgSG4Oej em4Q== X-Gm-Message-State: AOJu0Yz3ggMhIS3JeTypI4KLrxtJsh6VNJRohlooNfRuOrvUiUwqEH3U puyqpGh1nshweILrtA70dxRm+EE/JrM= X-Google-Smtp-Source: AGHT+IEpHX0mNt6z5BMFuuLqTJ8UidjxgMkPm8uup8OdQ2EUIBGLEmKcUqWlzTaHcQnK9t5kfNyubg== X-Received: by 2002:a19:5e1c:0:b0:4fe:5860:7abf with SMTP id s28-20020a195e1c000000b004fe58607abfmr1088770lfb.13.1695802733518; Wed, 27 Sep 2023 01:18:53 -0700 (PDT) Received: from fedora ([213.255.186.46]) by smtp.gmail.com with ESMTPSA id t17-20020ac243b1000000b00502ae8db086sm2517072lfl.19.2023.09.27.01.18.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 Sep 2023 01:18:52 -0700 (PDT) Date: Wed, 27 Sep 2023 11:18:38 +0300 From: Matti Vaittinen To: Matti Vaittinen , Matti Vaittinen Cc: Jonathan Cameron , Lars-Peter Clausen , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Matti Vaittinen , Andy Shevchenko , Angel Iglesias , Andreas Klinger , Benjamin Bara , Christophe JAILLET , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 0/5] Support ROHM BM1390 pressure sensor Message-ID: MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org ROHM BM1390 Pressure sensor (BM1390GLV-Z) can measure pressures ranging from 300 hPa to 1300 hPa with configurable measurement averaging and an internal FIFO. The sensor does also provide temperature measurements although, according to the data sheet, sensor performs internal temperature compensation for the MEMS. Sensor does also contain IIR filter implemented in HW. The data-sheet says the IIR filter can be configured to be "weak", "middle" or "strong". Some RMS noise figures are provided in data sheet but no accurate maths for the filter configurations is provided. I actually asked if we can define 3db frequencies corresponding to these IIR filter settings - and I received values 0.452Hz, 0.167Hz, and 0.047Hz but I am not at all sure we understood each others with the HW colleagues... Hence, the IIR filter configuration is not supported by this driver and the filter is just configured to the "middle" setting. (at least for now) It would also be possible to not use IIR filter but just do some simple averaging. I wonder if it would make sense to implement the OVERSAMPLING value setting so that if this value is written, IIR filter is disabled and number of samples to be averaged is set to value requested by OVERSAMPLING. The data-sheet has a mention that if IIR is used, the number of averaged samples must be set to a fixed value. The FIFO measurement mode (in sensor hardware) is only measuring the pressure and not the temperature. The driver measures temperature when FIFO is flushed and simply uses the same measured temperature value to all reported temperatures. This should not be a problem when temperature is not changing very rapidly (several degrees C / second) but allows users to get the temperature measurements from sensor without any additional logic. Revision history: Major changes here, please see the head room of individual patches for more detailed list. v3 => v4: rebased back on v6.6-rc1 dropped patch implementing the exact match search for available_scan_mask tools: iio_generic_buffer: comment on aligning logic bm1390 driver: - cleanups and fixes - own info struct for case where IRQ is omitted and FIFO not supported - fix support for using other triggers. (not really tested but should work) v2 => v3: rebased on v6.6-rc2 added three IIO fixup patches so numbering of patches changed dt-bindings/MAINTAINERS: No changes bm1390 driver: - various cleanups and fixes - do not disable IRQ - fix temperature reading when FIFO is used - separate buffer and trigger initialization v1 => v2: rebased on v6.6-rc1 dt-bindings: - fix compatible in the example sensor driver: - drop unnecessary write_raw callback - plenty of small improvements and fixes MAINTAINERS: - No changes Matti Vaittinen (5): tools: iio: iio_generic_buffer ensure alignment iio: improve doc for available_scan_mask dt-bindings: Add ROHM BM1390 pressure sensor iio: pressure: Support ROHM BU1390 MAINTAINERS: Add ROHM BM1390 .../bindings/iio/pressure/rohm,bm1390.yaml | 52 + MAINTAINERS | 6 + drivers/iio/pressure/Kconfig | 9 + drivers/iio/pressure/Makefile | 1 + drivers/iio/pressure/rohm-bm1390.c | 934 ++++++++++++++++++ include/linux/iio/iio.h | 4 +- tools/iio/iio_generic_buffer.c | 18 +- 7 files changed, 1022 insertions(+), 2 deletions(-) create mode 100644 Documentation/devicetree/bindings/iio/pressure/rohm,bm1390.yaml create mode 100644 drivers/iio/pressure/rohm-bm1390.c base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d