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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 45059C3279B for ; Fri, 6 Jul 2018 19:20:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC3E422B47 for ; Fri, 6 Jul 2018 19:20:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="duHivTqK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC3E422B47 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934680AbeGFTUZ (ORCPT ); Fri, 6 Jul 2018 15:20:25 -0400 Received: from mail-yw0-f194.google.com ([209.85.161.194]:44561 "EHLO mail-yw0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933150AbeGFTUX (ORCPT ); Fri, 6 Jul 2018 15:20:23 -0400 Received: by mail-yw0-f194.google.com with SMTP id k18-v6so4547496ywm.11; Fri, 06 Jul 2018 12:20:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=5IqK9fU+DCDlQ3Ffd0v+5H6Dgk5Ukd+5YRue9hkXqDI=; b=duHivTqK34UnfixvfuKQG2YDgxycY+Tqz/fe0uRRE+Q+6YbRA/IbiacUsuQGzMPeK0 uI/ivSxGNWL1qgO4CJ1+HgF7774id8g3mbiW7Sm+NC4P/CmcS/rBGrzjnt/8gFO54oHq gFTEdxxehJlqKwX2M0hcRYR6qUkFVulBXB7/zVL95+ILmfdDXHV4VMBZVY3jh5e72F6x sOIfCwdkKXiQn3IqzsC+hy8uFSP1G4BqUzWImBbPvTTjwnNbkkr6Dh/jXjHfbiEWbYJX P9rIokEtfLtVQzPDRe5j4AB5mZauCdib9BJP+XJQn5oj/jIfc3+H2hmX1mbMZR2ZCz87 LqTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=5IqK9fU+DCDlQ3Ffd0v+5H6Dgk5Ukd+5YRue9hkXqDI=; b=NZiOrddOEemC1tTOcPtvp5b1dJAPVy+Jz42L/sIMFuF4wGN7mEz7I1UfOvyG/68aFI 7kwoxFc+HSL3P0b6d2uhakhOPbM2im6YRT29LbnSBEO5FHRPeYW1+FACWd4/siH1LeEJ SWhKTbsN3gxDFULgbTT345QJm8/o62ah9a8O3oMJR1unjz7sgbLPOLxh3Z/TAmEEapBX i5Y0qUVp88pq6IFd0vuWlpZE4ZoQTypJDzJY50zVfo8VtOM1gAHsY17Dgconabro8+ct Qj4tmwFfLvqqJJUlVpmXWovr7q6v5sMmI6V3Y7Mohcg6/FmGWtdaZvPMGjnmUFPqavjw e7tA== X-Gm-Message-State: APt69E01kic/X6P2smvPYDUYr5vhjew4TgDyg7/pqtOg6j+BFYLn2smv Zc3Pj9HvSw6ETqEWKqJGflQ= X-Google-Smtp-Source: AAOMgpfIVx9dr8gWKBu96vAw9Y66edtaGhmp+n+gSX/5u7Duaw7rLBsJhN1JYRQcnhI9OCobfCEWgQ== X-Received: by 2002:a81:9f51:: with SMTP id w78-v6mr5502882ywg.334.1530904822155; Fri, 06 Jul 2018 12:20:22 -0700 (PDT) Received: from sophia ([72.188.97.40]) by smtp.gmail.com with ESMTPSA id o11-v6sm3836769ywm.107.2018.07.06.12.20.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 06 Jul 2018 12:20:21 -0700 (PDT) Date: Fri, 6 Jul 2018 15:20:13 -0400 From: William Breathitt Gray To: David Lechner Cc: Jonathan Cameron , gregkh@linuxfoundation.org, jic23@kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, fabrice.gasnier@st.com, benjamin.gaignard@st.com, robh+dt@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, mark.rutland@arm.com Subject: Re: [PATCH v7 00/10] Introduce the Counter subsystem Message-ID: <20180706192013.GA6810@sophia> References: <603b0373-f1e1-5938-fa53-8328c9a5964f@lechnology.com> <20180703024835.GA9493@sophia> <20180706182154.0000002d@huawei.com> <59b0950e-ef39-4ad4-a32b-316992e1f236@lechnology.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <59b0950e-ef39-4ad4-a32b-316992e1f236@lechnology.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 06, 2018 at 01:22:57PM -0500, David Lechner wrote: >On 07/06/2018 12:21 PM, Jonathan Cameron wrote: >> On Mon, 2 Jul 2018 22:48:35 -0400 >> William Breathitt Gray wrote: >>> Is frequency useful for other >>> applications on its own (perhaps velocity of an automobile device >>> equipped with an encoder wheel for some reason or other)? > >Since we are just dealing with counters here, I think we should call >it "rate" instead of "frequency". At least that seems to be the common >name in industrial automation. > >Another possible use case for "rate" would be flow meters. Some >flow meters generate a pulse every X gallons. Assuming that the >counter also has a rate output, then you can scale the rate (e.g. >counts/second) into flow in gallons per minute. > >>> >>> Once we figure out how this data is used, we can determine the best >>> design and place to introduce it into the Generic Counter interface, >>> then move on to integration from there. >> >> Great - as long as this fits reasonably well in ABI wise (whatever the >> details) sounds like we don't need to solve it today. I'm anxious not >> to delay merging this counter subsystem for another cycle. > >Certainly don't delay things on account of me. I'm just trying to get >a feel for where things are headed since I missed the earlier discussions. >I don't see any major problems with the current state of things. > >Once this lands, I may have a go at the eQEP and see how it looks. No worries, it looks like your application would be served well by the Generic Counter interface, and exposing a "rate" value would be a simple feature to add. However, since this patchset has been stabilizing over the past few revisions, I want to postpone the addition of new features until this interface and its current feature set is merged. David, once this introduction patchset has been merged, submit to me a patch adding the "rate" functionality feature and we'll continue discussing it there. William Breathitt Gray