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=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 92F34C433C1 for ; Tue, 23 Mar 2021 12:52:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55A73619B9 for ; Tue, 23 Mar 2021 12:52:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231162AbhCWMvv (ORCPT ); Tue, 23 Mar 2021 08:51:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230335AbhCWMvi (ORCPT ); Tue, 23 Mar 2021 08:51:38 -0400 Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50DF8C061574; Tue, 23 Mar 2021 05:51:38 -0700 (PDT) Received: by mail-pg1-x52d.google.com with SMTP id v186so11590561pgv.7; Tue, 23 Mar 2021 05:51:38 -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=W73swV/Q5he3Tzf+ydT8yObURaAc6JinvwZwIKuuRdE=; b=dZYXUHWijoTrxu0O/MxB9jXvMLnVbXkMw04Grjg2u6tC73cWCd8bN/k1W5QL2SA9TK cgk1feBNa6NS3UvdpbsMJ+DbgsNB8z8G0GstjudfCuoar/PO+v/Ww8KsqUyu6acBZFzH Ldg3koMQYMCKTWI+iaZd5e787+InPTq/NOlAIQ6PaY0tCww0/kZpSwCL4orjxRzVQF1g sNiTTiNnJMEaXQ/bK5gM04dVcwSm8uqXe+pFE2TO3BwrNCQWvq8VryHylHzqmJNJMOWd DEzimEf9EhRHfj9NNaNtIVjBHCxU9lCge5e++yYmYQc0lAOGvMRmTkPkcvmwNvpBnuE8 KYRg== 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=W73swV/Q5he3Tzf+ydT8yObURaAc6JinvwZwIKuuRdE=; b=RR5JpdlHPN3PD4VZoqpNfd/9PzFBnkwJjf+zpDOEIa4cuKHyvqTnzKdbP16wrvPsQj QwXRUI9sV2Vl/MRMMqG66cSEpBAahcc/jN6vbxBv9ThjMPLKTJuO0/MTYbuYb6UsoFka AwwrpaQQ3HvpNHKmo+1AyvnAdgwwMwcp2Y2EmAR4Ehgv5YuRXazVwBeMdCND50wJe29N Yq5XQL7yGYIO+IqVXoC573pRb1295BD0ZYpgJKxZKgCax3mgjZVwxgZlGWRGt0ECp5fo 0mxqMX4x+L/Ozm4/yA0G66pLIABb1Wsr4FPnhuyykAy+6GDwUBSyEUGbYDtzIg/HtNC6 +Mtg== X-Gm-Message-State: AOAM532DoIT99ztzWsqGeQJJYtm7QkJ5Y6DbkytrYtWtw4+X45sgIocF kxpDkj9PkJsBAAyXanfndL4= X-Google-Smtp-Source: ABdhPJxuDrAKy3Uzblr2IjLqiyBW2NhHdIddKeLQBGKEakqaTrgX3vmub48+0gOuMI8FfEBcbk/uSA== X-Received: by 2002:a17:903:3053:b029:e6:5cde:bef with SMTP id u19-20020a1709033053b02900e65cde0befmr5320783pla.81.1616503897889; Tue, 23 Mar 2021 05:51:37 -0700 (PDT) Received: from hoboy.vegasvil.org ([2601:645:c000:48:e2d5:5eff:fea5:802f]) by smtp.gmail.com with ESMTPSA id d6sm16606592pfq.109.2021.03.23.05.51.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Mar 2021 05:51:37 -0700 (PDT) Date: Tue, 23 Mar 2021 05:51:34 -0700 From: Richard Cochran To: Thierry Reding Cc: Dipen Patel , Arnd Bergmann , Linus Walleij , Kent Gibson , "linux-kernel@vger.kernel.org" , Jon Hunter , Bartosz Golaszewski , "open list:GPIO SUBSYSTEM" , linux-tegra , Thomas Gleixner , Networking Subject: Re: GTE - The hardware timestamping engine Message-ID: <20210323125134.GA29209@hoboy.vegasvil.org> References: <4c46726d-fa35-1a95-4295-bca37c8b6fe3@nvidia.com> <20210320153855.GA29456@hoboy.vegasvil.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Tue, Mar 23, 2021 at 10:03:18AM +0100, Thierry Reding wrote: > I agree. My understanding is the the TSC is basically an SoC-wide clock > that can be (and is) used by several hardware blocks. There's an > interface for software to read out the value, but it's part of a block > called TKE (time-keeping engine, if I recall correctly) that implements > various clock sources and watchdog functionality. ... > Anyway, I think given that the GTE doesn't provide that clock itself but > rather just a means of taking a snapshot of that clock and stamping > certain events with that, it makes more sense to provide that clock from > the TKE driver. It sounds like TKE + GTE together act like a PHC, and GTE doesn't need/want its own SW interface. Thanks, Richard