From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752203AbcADSbh (ORCPT ); Mon, 4 Jan 2016 13:31:37 -0500 Received: from mail-pa0-f68.google.com ([209.85.220.68]:35399 "EHLO mail-pa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751912AbcADSbe (ORCPT ); Mon, 4 Jan 2016 13:31:34 -0500 From: Joshua Clayton To: Alexandre Belloni , Alessandro Zummo Cc: rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org, Joshua Clayton Subject: [PATCH v2 0/8] rtc: enable adjustment of clock offset Date: Mon, 4 Jan 2016 10:31:18 -0800 Message-Id: X-Mailer: git-send-email 2.5.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexandre, this is the second version of apatch set to be able to adjust the clock on a pcf2123, but with a big addition. I am also proposing a couple of new rtc api functions and a new sysfs file. Patches 1-5 are very much v2 patches that address All of the concerns you had with v1. It is my hope to get them merged without too much more trouble. Patches 6-8 are attemping to add a new function to the rtc class to adjust the clock rate. I hope I am going about this the right way, But here goes. A number of rtc devices, such as the NXP pcf2123 include a facility to adjust the clock in order to compensate for temperature or a crystal, capacitor, etc, that results in the rtc clock not running at exactly 32.768 kHz. This patchset adds kernel and sysfs hooks to access that ability. One datasheet suggests it might be adjusted based on input from a temperature sensor. I could also potentially see it being set as part of ntp calibration. Data sheets I have seen refer to this as a clock offset, and measure it in parts per million (ppm), however they often reference ppm to 2 digits of precision, which makes integer ppm less than ideal. I use parts per billion, which more than covers the precision needed and works nicely within 32 bits The name "offset" came from the pcf-2123 datasheet and is used by at least some other data sheets. I would be happy to use a different term if someone else comes up with something more concise. Changes since v1: - Use the BIT() macro for all register bits - Remove unneeded range checks from read/write functions - Merge patch 3 (replace magic numbers with defines) into patch 2 - Add a proper commit message to patch 5, now patch 4 - Fix a function alignment bug. - Move OSC_HAS_STOPPED check into pcf2123_rtc_read_time, and get rid of pcf2123_time_valid() - Drop patches refactoring pcf2123 sysfs. - Add rtc interface and rtc sysfs file for clock offset Joshua Clayton (8): rtc-pcf2123: define registers and bit macros rtc-pcf2123: clean up reads from the chip rtc-pcf2123: clean up writes to the rtc chip rtc-pcf2123: refactor chip reset into a function rtc-pcf2123: avoid resetting the clock if possible rtc: Add functions to set and read clock offset rtc: implement a sysfs interface for clock offset rtc-pcf2123: implement read_offset and set_offset drivers/rtc/interface.c | 57 ++++++++++ drivers/rtc/rtc-pcf2123.c | 271 +++++++++++++++++++++++++++++++++------------- drivers/rtc/rtc-sysfs.c | 29 +++++ include/linux/rtc.h | 4 + 4 files changed, 284 insertions(+), 77 deletions(-) -- 2.5.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 Received: from mail-pa0-x241.google.com (mail-pa0-x241.google.com. [2607:f8b0:400e:c03::241]) by gmr-mx.google.com with ESMTPS id p88si8636075pfi.0.2016.01.04.10.31.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 04 Jan 2016 10:31:34 -0800 (PST) Received: by mail-pa0-x241.google.com with SMTP id a20so10369311pag.3 for ; Mon, 04 Jan 2016 10:31:34 -0800 (PST) From: Joshua Clayton To: Alexandre Belloni , Alessandro Zummo Cc: rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org, Joshua Clayton Subject: [rtc-linux] [PATCH v2 0/8] rtc: enable adjustment of clock offset Date: Mon, 4 Jan 2016 10:31:18 -0800 Message-Id: Reply-To: rtc-linux@googlegroups.com Content-Type: text/plain; charset=UTF-8 List-ID: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , Alexandre, this is the second version of apatch set to be able to adjust the clock on a pcf2123, but with a big addition. I am also proposing a couple of new rtc api functions and a new sysfs file. Patches 1-5 are very much v2 patches that address All of the concerns you had with v1. It is my hope to get them merged without too much more trouble. Patches 6-8 are attemping to add a new function to the rtc class to adjust the clock rate. I hope I am going about this the right way, But here goes. A number of rtc devices, such as the NXP pcf2123 include a facility to adjust the clock in order to compensate for temperature or a crystal, capacitor, etc, that results in the rtc clock not running at exactly 32.768 kHz. This patchset adds kernel and sysfs hooks to access that ability. One datasheet suggests it might be adjusted based on input from a temperature sensor. I could also potentially see it being set as part of ntp calibration. Data sheets I have seen refer to this as a clock offset, and measure it in parts per million (ppm), however they often reference ppm to 2 digits of precision, which makes integer ppm less than ideal. I use parts per billion, which more than covers the precision needed and works nicely within 32 bits The name "offset" came from the pcf-2123 datasheet and is used by at least some other data sheets. I would be happy to use a different term if someone else comes up with something more concise. Changes since v1: - Use the BIT() macro for all register bits - Remove unneeded range checks from read/write functions - Merge patch 3 (replace magic numbers with defines) into patch 2 - Add a proper commit message to patch 5, now patch 4 - Fix a function alignment bug. - Move OSC_HAS_STOPPED check into pcf2123_rtc_read_time, and get rid of pcf2123_time_valid() - Drop patches refactoring pcf2123 sysfs. - Add rtc interface and rtc sysfs file for clock offset Joshua Clayton (8): rtc-pcf2123: define registers and bit macros rtc-pcf2123: clean up reads from the chip rtc-pcf2123: clean up writes to the rtc chip rtc-pcf2123: refactor chip reset into a function rtc-pcf2123: avoid resetting the clock if possible rtc: Add functions to set and read clock offset rtc: implement a sysfs interface for clock offset rtc-pcf2123: implement read_offset and set_offset drivers/rtc/interface.c | 57 ++++++++++ drivers/rtc/rtc-pcf2123.c | 271 +++++++++++++++++++++++++++++++++------------- drivers/rtc/rtc-sysfs.c | 29 +++++ include/linux/rtc.h | 4 + 4 files changed, 284 insertions(+), 77 deletions(-) -- 2.5.0 -- -- You received this message because you are subscribed to "rtc-linux". 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