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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 3D4ACC433ED for ; Thu, 29 Apr 2021 07:40:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EECC461440 for ; Thu, 29 Apr 2021 07:40:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230309AbhD2Hku (ORCPT ); Thu, 29 Apr 2021 03:40:50 -0400 Received: from first.geanix.com ([116.203.34.67]:39984 "EHLO first.geanix.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229814AbhD2Hku (ORCPT ); Thu, 29 Apr 2021 03:40:50 -0400 Received: from [192.168.64.189] (unknown [185.17.218.86]) by first.geanix.com (Postfix) with ESMTPSA id 2215446636B; Thu, 29 Apr 2021 07:40:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=geanix.com; s=first; t=1619682001; bh=56ciJXj0zEPbXvYjI8z9gZXwvKQykcQRAbA6bjkZZeA=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=hNfpozdCd3y5U+w9Dh2lPcgSHYhFC9DslnaxMfLrzv+oQfsUS8CP4hJ+fw+2pMcOM OpvEZcDrUI0QbHIY+K92bxSlajFssnBFIuUAYm7iCjPz1Ine46NIRJEEy8Kc9undQd Z+Jzyi8yV6T4HmOQ+4ceYtqrcenZchDuLvOSSI9vSb6y2iKUGHr3ehRj4WjrG23OZf LrHDgadUhJesl+JMlVNiLpXgSCPh9huEllkHfxET0VMv77ZH9xVM7wz0GdyzfvYmCT hap8bY3KR0Vq/Nkd4FYpKp50wj6+PCs/LouTnG8d/fcwIkgmyQJDUqoK1pxiPWWDAe oAhbgXtb/QCuA== Subject: Re: [RFC PATCH 3/4] iio: accel: fxls8962af: add hw buffered sampling To: Jonathan Cameron Cc: jic23@kernel.org, linux-iio@vger.kernel.org, andy.shevchenko@gmail.com, lars@metafoo.de, Nuno.Sa@analog.com, robh+dt@kernel.org, devicetree@vger.kernel.org References: <20210428082203.3587022-1-sean@geanix.com> <20210428082203.3587022-3-sean@geanix.com> <20210428173238.0000540d@Huawei.com> From: Sean Nyekjaer Message-ID: Date: Thu, 29 Apr 2021 09:40:00 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: <20210428173238.0000540d@Huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 28/04/2021 18.32, Jonathan Cameron wrote: >> When buffered sampling is enabled, the accelerometer will dump data into >> the internal fifo and interrupt at watermark. Then the driver flushes >> all data to the iio buffer. >> As the accelerometer doesn't have internal timestamps, they are aproximated >> between to interrupts. > two? > > This tends to be a noisy approach, so people often try to apply a filter. > However, no need to do that for an initial version. > > There are some things in here referring to enabling triggered modes, but I'm > not seeing code to actually do so. The fun question when dealing with fifos > and triggered mode is what the interface is to switch between the two. > One option I think we've used before is to just have 'no trigger' match > up to fifo mode and if a trigger is set, don't use the fifo. > Thanks Jonathan. Fixed the above text to: As the accelerometer doesn't have internal timestamps, they are approximated between the current and last interrupt. I don't know the correct term here, the accelerometer via the watermark, is doing interrupts. Is that called no-trigger / trigger ? /Sean