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=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 ABDA3C169C4 for ; Thu, 31 Jan 2019 17:19:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72CAC20881 for ; Thu, 31 Jan 2019 17:19:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MaTIWdLC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726246AbfAaRTw (ORCPT ); Thu, 31 Jan 2019 12:19:52 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:43993 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725854AbfAaRTv (ORCPT ); Thu, 31 Jan 2019 12:19:51 -0500 Received: by mail-pg1-f195.google.com with SMTP id v28so1616848pgk.10; Thu, 31 Jan 2019 09:19:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=eOaUxd211EH6w7gop+A0WA0d4/YlWxevJ3d+4Lsu3ls=; b=MaTIWdLCfEcevThRpTE4YficCHE/0BHutYhkx1qRNwUAJFEMdxOfeA9xgqis9SadMb jHnyG9oHkcz8KZKH+TTTjCO5jtyof3wEAlL15F5WC+mTaOCfHTZbuhPx8LUV1NeQcaim 39CIJL0zyE6YQItfSpHXzgknuCIuIK73i4GI853n2x3nqd4DmcsvGONTY7n7HidjMAhY oxxktEaAhVR3fRPDGe7kMHYg7dHxfCzBRwfsguOfzfoc3Vgv4TyMHfddUfI/QZjke2Um wTcbgfvT+ERztQT04YnY81ZoOgtW+/ervxoVCoD24jyqNkmmC2dt7pKMZmCyq2McTOBF rwDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=eOaUxd211EH6w7gop+A0WA0d4/YlWxevJ3d+4Lsu3ls=; b=Qn0dq3IWGWvj4kcIIZDkpI7RJB+GxVuxCFcjTr68qBD+WibgrrY+hdgOh/LOksHPUO RflUrPsK+Wqn1HlP4l5G+dacj0/ZCf3v/aNfg5UD/41D0Bf6tTeMgei0k9Xto0uAnZa3 0U2ROZQmy3QYOW3iftp9MtKmkg9Dj8fOvBsmjeanMx8WMNLBqKjdvXwHvwGNnfskM0iX AFzVHn6GMepT9Od4w9qqJTbvhKXLR5H7JzJXWHPcc5E0JLAMACEX/UhWayw8e3qOqiaR oeMOWEsavxO1nxqNjNW2rQxD6w+QFHeMRSLqzf/0HO/fR/z91R8nm5KKhV3DbQ/mo/Qy Ir6w== X-Gm-Message-State: AJcUukfaTJFrRAZyXGwt8edsAa38x7ki8MG55wfUG5izhAGUbKEouKZd OyCJYb+aandBJpzArDNWp4w= X-Google-Smtp-Source: ALg8bN6TxvvzTiag0xUOv1o/d964EICGsrgacAIrnwaCl0+1u2prYG4qA0u5XdRJOIsaz15etOG55w== X-Received: by 2002:a62:6e07:: with SMTP id j7mr36584656pfc.135.1548955190751; Thu, 31 Jan 2019 09:19:50 -0800 (PST) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id z9sm16645598pfd.99.2019.01.31.09.19.48 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 31 Jan 2019 09:19:49 -0800 (PST) Date: Thu, 31 Jan 2019 09:19:47 -0800 From: Guenter Roeck To: Stefan Wahren Cc: Kamil Debski , Bartlomiej Zolnierkiewicz , Jean Delvare , Rob Herring , Mark Rutland , linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 1/3] dt-bindings: hwmon: Add tachometer interrupt to pwm-fan Message-ID: <20190131171947.GA14844@roeck-us.net> References: <1548860827-29796-1-git-send-email-stefan.wahren@i2se.com> <1548860827-29796-2-git-send-email-stefan.wahren@i2se.com> <20190130172815.GC14781@roeck-us.net> <625436113.118199.1548879811777@email.ionos.de> <20190130203525.GA23614@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On Thu, Jan 31, 2019 at 09:02:33AM +0100, Stefan Wahren wrote: > Hi Guenter, > > Am 30.01.19 um 21:35 schrieb Guenter Roeck: > > On Wed, Jan 30, 2019 at 09:23:31PM +0100, Stefan Wahren wrote: > >> Hi Guenter, > >> > >>> Guenter Roeck hat am 30. Januar 2019 um 18:28 geschrieben: > >>> > >>> > >>> On Wed, Jan 30, 2019 at 04:07:05PM +0100, Stefan Wahren wrote: > >>>> This adds the tachometer interrupt to the pwm-fan binding, which is > >>>> necessary for RPM support. > >>>> > >>>> Signed-off-by: Stefan Wahren > >>>> --- > >>>> Documentation/devicetree/bindings/hwmon/pwm-fan.txt | 3 +++ > >>>> 1 file changed, 3 insertions(+) > >>>> > >>>> diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt > >>>> index 49ca5d8..7f69b0b 100644 > >>>> --- a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt > >>>> +++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt > >>>> @@ -8,6 +8,9 @@ Required properties: > >>>> > >>>> Optional properties: > >>>> - fan-supply : phandle to the regulator that provides power to the fan > >>>> +- interrupts : contains a single interrupt specifier which describes the > >>>> + tachometer pin output of a 2 pulse-per-revolution fan. > >>>> + See interrupt-controller/interrupts.txt for the format. > >>> So a hypothetical {1,4} pulse-per-revolution fan would explicitly not be > >>> supported ? Why ? > >> i could add an additional property to specify the pulse per revolution and use the 2 as default (according to the Intel spec for 4 pin pwm fan) which should fit in most cases. > >> > > That would be a possibility and make sense, but that is not > > the point here. The "interrupts" property does not and should > > not care how many pulses per revolution the fan provides. > > sorry, i'm not sure what's the problem about. Do you want me to use a > GPIO instead of interrupt? > > Or is it the wording here? > You wording limits the use of interrupts with pwm fans to fans with 2 pulses per revolution. You do not explain why that restriction would be required or even make sense, or why it should be associated with the 'interrupts' property. Logically I assume that is because you expect an interrupt per pulse, but that is not explained (or what the interrupt is expected to be used for in the first place - it might, after all, be some kind of error interrupt). Guenter