From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpcmd01-g.aruba.it (smtpcmd01-g.aruba.it [62.149.158.217]) (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 42DF61922D7 for ; Wed, 9 Oct 2024 08:51:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.149.158.217 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728463900; cv=none; b=S8HXpPFTixcWd9xWK2YZtlrWb5t+cNmsLsTRSENtN0LvekrzNG37tdRBLkVZLzbh+Kqy7aT0tuH0MdaZKqd0HAlgInBNFGFxM9a/1PztMDqGiFh6eMFme252DN+4ekt/LDWceutWB3aIxyfiVIZEb+1hFalA9JTvwizvOLVfmaQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728463900; c=relaxed/simple; bh=xegdOlru2FXlyYKCiCV+GnSQ4SIraYfodOdgVdYSPJE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DoPahqxJ3JCM2/1MJRYAxkzlfgrRv/fDKfF9WTqmg0N8sdLJDkSRT2Cd0NdIxHhnFV59eVWdRyE1sk4XG95y7MAG0QEATUDYh27l5ZwaR1ZsVRls+6Xo7R+/3gOmWvT/2IuxHaF2D1oOzK1H8/9HEFS8ljShhrnwqS+6T7tzMKY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enneenne.com; spf=pass smtp.mailfrom=enneenne.com; dkim=pass (2048-bit key) header.d=aruba.it header.i=@aruba.it header.b=a8uMLX+q; arc=none smtp.client-ip=62.149.158.217 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enneenne.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=enneenne.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=aruba.it header.i=@aruba.it header.b="a8uMLX+q" Received: from [192.168.1.58] ([79.0.204.227]) by Aruba Outgoing Smtp with ESMTPSA id ySN3snLGnwy3rySN3srqnd; Wed, 09 Oct 2024 10:48:38 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=aruba.it; s=a1; t=1728463718; bh=xegdOlru2FXlyYKCiCV+GnSQ4SIraYfodOdgVdYSPJE=; h=Date:MIME-Version:Subject:To:From:Content-Type; b=a8uMLX+qz1ZvjBBhgGbJv1YVCse+OAB/DWZB1QngqCy4G933h25YQpqOinevnAeVh j8p/cTUaPM1kkv7/5Z1VJWWjarxkN5inxdjd4bA56E76fbQejDIJGtj2TwFLDb0I2X kBgJeDbQLNmWvYyiwQcs+xsma0h/+SHUNHGHpPXDNEqRJbz6OnDYfKVwqtwKxS6UiL simUE8tZTCPG+l4kTz+O9MK2Cq6XOOFU8V5K2wCqfNlVWyD4nEz7/FE31KEgM82jLw g0qfg7oLp1xqwLeFHxOJfTTmmcEMoh+odtKOcl1llotn7H+UjEibIguor3djhYkpJq vtGIkRvF9rDXw== Message-ID: Date: Wed, 9 Oct 2024 10:48:37 +0200 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC 1/3] drivers pps: add PPS generators support To: "Hall, Christopher S" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" Cc: Andrew Morton , Greg KH , "corbet@lwn.net" , "Mohan, Subramanian" , "tglx@linutronix.de" , "andriy.shevchenko@linux.intel.com" , "Dong, Eddie" , "N, Pandith" , "T R, Thejesh Reddy" , "Zage, David" , "Chinnadurai, Srinivasan" References: <20241008135033.3171915-1-giometti@enneenne.com> <20241008135033.3171915-2-giometti@enneenne.com> From: Rodolfo Giometti Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfAvLGhsGccBYx9Kw36Yzyq2b9Lnlkipb/FiRx0xHUmheEVFWM4x/E3s8TIzm11//fMbnjGX5icd2tqA9B1mW+oXjLcCPdyzudN/5Ku0+jwsh1CLB6Pfp T2lvYhT7l2ExvQCW7OTkinOA8vAOGQuGL/Z8RFRYej/WrnT6NHfOm9YXrk4852cp96zDSqS1BRrI0KB6Bzx9bT3j0U4sxK1jQPKKFz1uINvIIP8Vg2z/rxEV Z1BSkKMDq0ZCECz8lkg5JfzAWbieBhzGVTntMbvNTqqQVZH09hEqrdYAhAPGJ1AUVoBebtvI3yBBe4X6H6s+WoFJCsPW2K0Pm25kQT6Ht394PPzH6/jnqzyx KeisHgHW5PpDzALlphhmRtFd7y4Ij+DSw4/cfReRI1tfldcoh5KuVLi78GIAm4iE7ds3h/KH7N+bdfpBohBviWluAKEQ32lbvYNaLX3oL44nI/BNKLfFK1BY k2gDmEBhrYvXUt5ZLcOanF7hUXTGR1O/vIKJPtQv+uzOxs36qH87q0pcnkBzdensdKhl3SamiM1z+iJao50xDfisz2yDpQwH9+oK3ETKl1Wd6CqJlMDO6oQX vRgSSOBCBMfmqv2R2Go6A3G+YSvPjirYA15+YHIluDB/sSlM9ii+qpFQiUTdUNqDiGfvXGYXrXta7JrR9NVE/o68 On 09/10/24 04:49, Hall, Christopher S wrote: > Hi Rudolfo, > >> -----Original Message----- >> From: Rodolfo Giometti >> Sent: Tuesday, October 08, 2024 6:51 AM >> To: linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org > >> Sometimes one needs to be able not only to catch PPS signals but to >> produce them also. For example, running a distributed simulation, >> which requires computers' clock to be synchronized very tightly. >> >> This patch adds PPS generators class in order to have a well-defined >> interface for these devices. >> >> Signed-off-by: Rodolfo Giometti >> --- >> drivers/pps/Makefile | 3 +- >> drivers/pps/generators/Kconfig | 19 +- >> drivers/pps/generators/Makefile | 4 + >> drivers/pps/generators/pps_gen-dummy.c | 83 ++++++++ >> drivers/pps/generators/pps_gen.c | 283 +++++++++++++++++++++++++ >> drivers/pps/generators/sysfs.c | 89 ++++++++ >> include/linux/pps_gen_kernel.h | 57 +++++ >> include/uapi/linux/pps_gen.h | 35 +++ >> 8 files changed, 571 insertions(+), 2 deletions(-) >> create mode 100644 drivers/pps/generators/pps_gen-dummy.c >> create mode 100644 drivers/pps/generators/pps_gen.c >> create mode 100644 drivers/pps/generators/sysfs.c >> create mode 100644 include/linux/pps_gen_kernel.h >> create mode 100644 include/uapi/linux/pps_gen.h > > This looks pretty good to me. I would like to see an alarm callback. We are able > to detect a missed event and rather than stopping inexplicably or writing to the > system log, it would be better to be able to notify an application directly. > > Off the top of my head, something like: > > void pps_gen_alarm(pps_gen_device *pps_gen) { > pps_gen->alarm = 1; > sysfs_notify(pps_gen->dev->kobj, NULL, "alarm"); > } > > The device is reset by disabling/enabling and this resets the alarm flag. > > Could we add something like this? Yes, of course. But it's better to provide a proper patch against my patchset V1 (I'm going to anticipate them to you shortly), since I'm not sure to understand what you need. Ciao, Rodolfo -- GNU/Linux Solutions e-mail: giometti@enneenne.com Linux Device Driver giometti@linux.it Embedded Systems phone: +39 349 2432127 UNIX programming