From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Cochran Subject: [PATCH RFC net-next 0/1] ptp: add pseudo pps ioctl Date: Thu, 27 Sep 2012 20:12:15 +0200 Message-ID: Cc: David Miller , Jacob Keller , John Stultz , Miroslav Lichvar To: Return-path: Received: from mail-wi0-f178.google.com ([209.85.212.178]:56405 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753276Ab2I0SM2 (ORCPT ); Thu, 27 Sep 2012 14:12:28 -0400 Received: by wibhr7 with SMTP id hr7so2384082wib.1 for ; Thu, 27 Sep 2012 11:12:26 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: This patch adds a kind of "poor man's PPS" for use with those PHC drivers which do not support a true PPS. Using this ioctl, user space can estimate the system-phc offset and tune one of the clocks as desired. This patch has been tested on both the Intel igb (PCIe card) and the National Semiconductor phyter (PHY via MDIO bus), and the results seem quite promising. This patch avoids the "timecompare" code on purpose, since experiments have shown that code to be quite brittle, having been tuned to only one specific kind of hardware. Thanks, Richard Richard Cochran (1): ptp: add an ioctl to compare PHC time with system time drivers/ptp/ptp_chardev.c | 32 ++++++++++++++++++++++++++++++++ include/linux/ptp_clock.h | 14 ++++++++++++++ 2 files changed, 46 insertions(+), 0 deletions(-) -- 1.7.2.5