From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1487224D6; Thu, 26 Sep 2024 09:34:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727343293; cv=none; b=Y3+RMyVJtf7ZZn4P2FF/XmjmD6kbW6V8R0QCaASoAkWE4smGRSq3UE06EakNvyHahLkeUL4D62eOaXxwVSNgUNzB76gp3sQOZdTgbMAkqnHBqalU5moNIuG0WCaU5ymwl7OrLd20088ydxi/UyQFt2WAG9pJP+Ulhjx0mYz2UdY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727343293; c=relaxed/simple; bh=aBxzhfOzuC9ptbUK/5GQcxNABiudJtiN+C1y90whjiw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kV5Tgz0z69AFHY3p7Px33nfvC0p4N6uROEPULMzqWsFrfrZ2zwxEWZRgkZktX60symXMNyOdr5EVM0X6w8nhOWSyGPYKNQvLZThOicDDz5bwd17fq1uW2sb7jFB9tl2oeaboaeEvnzmfwwjddhEjYUh/OacjrR7AjPGHWMZPUJs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KBXY/dib; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KBXY/dib" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E484C4CEC5; Thu, 26 Sep 2024 09:34:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1727343292; bh=aBxzhfOzuC9ptbUK/5GQcxNABiudJtiN+C1y90whjiw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KBXY/dibcC9Nu38dW83jeRQfvs/pw+9sNqLxYhdBFoVktmsg1jlNygnF3sTxCk92e 2W0VmoJ4+ZsQwKLG4Zs/cPp6pqRMgOk7wYIXzK6JhyFH5g80Li8IAieYlkStXdy+YR oXbQCexqz9OrntpbsWX6mDjfpsVxF6n6F0NBFTTg= Date: Thu, 26 Sep 2024 11:34:38 +0200 From: Greg KH To: Rodolfo Giometti Cc: "Hall, Christopher S" , "Mohan, Subramanian" , "tglx@linutronix.de" , "corbet@lwn.net" , "linux-kernel@vger.kernel.org" , "linux-doc@vger.kernel.org" , "andriy.shevchenko@linux.intel.com" , "Dong, Eddie" , "N, Pandith" , "T R, Thejesh Reddy" , "Zage, David" , "Chinnadurai, Srinivasan" Subject: Re: [PATCH v12 2/3] Documentation: driver-api: pps: Add Intel Timed I/O PPS generator Message-ID: <2024092624-stapling-clock-5fe0@gregkh> References: <20240823070109.27815-1-subramanian.mohan@intel.com> <20240823070109.27815-3-subramanian.mohan@intel.com> <2024082456-kitchen-astride-7892@gregkh> <801c7a93-667b-4c23-9493-4cbe979847a2@enneenne.com> <2024090304-viewing-lavish-c05e@gregkh> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Sep 26, 2024 at 10:46:54AM +0200, Rodolfo Giometti wrote: > On 25/09/24 23:55, Hall, Christopher S wrote: > > Hi Rodolfo, > > Hello. > > > > From: Greg KH > > > Sent: Tuesday, September 03, 2024 3:25 AM > > > To: Rodolfo Giometti > > > > > Subject: Re: [PATCH v12 2/3] Documentation: driver-api: pps: Add Intel Timed > > > I/O PPS generator > > > > > > > > > If you are willing to stop the inclusion due this fact maybe its time to add > > > > such PPS generators interface... on the other hand, if you agree for > > > > inclusion we can do this job as soon as the code has been included, in order > > > > to fix this anomalous status. > > > > > > Please make a generic pps subsystem for this, it would make it simpler > > > for everyone. > > > > What is required to move this? We can certainly test the code and do some > > of this work, but I would look to you to define the interface. > > The problem is that a pps-generator has no related device, then no sysfs entries. > > I think the right-thing(TM) to do is adding a new class named > "pps-generator", so we will get the directory /sys/class/pps-generator with > several devices as pps-generator0, pps-generator1, etc. For each device we > should add at least these sysfs entries: > > - system : This file return "1" if the generator takes the timing from > the system clock, while it returns "0" if not (i.e. from a > peripheral device clock). > > - time : This file contains the current time stored into the generator > clock as two integers representing the current time seconds and > nanoseconds. > > - enable : This write-only file enables or disables generation of the > PPS signal. > > - period : This file defines the period for the generator signal. When > read, by default, it returns "1 0" which represent the period > second and nanoseconds (i.e. a PPS signal). When written, it > sets the period accordingly or ENOTSUPP if not supported. > > - start_time : This file defines the starting time for the the generator > signal. When read, by default, it returns "0 0" which means > "now". When written, it sets the starting time accordingly or > ENOTSUPP if not supported. This seems sane to me, thanks for writing it up! greg k-h