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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 026B6C3A5A4 for ; Thu, 29 Aug 2019 02:24:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF7792341B for ; Thu, 29 Aug 2019 02:24:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727069AbfH2CYZ (ORCPT ); Wed, 28 Aug 2019 22:24:25 -0400 Received: from inva021.nxp.com ([92.121.34.21]:40700 "EHLO inva021.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726245AbfH2CYZ (ORCPT ); Wed, 28 Aug 2019 22:24:25 -0400 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 1FB56200267; Thu, 29 Aug 2019 04:24:23 +0200 (CEST) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id E373E200264; Thu, 29 Aug 2019 04:24:18 +0200 (CEST) Received: from titan.ap.freescale.net (TITAN.ap.freescale.net [10.192.208.233]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 790BA402B1; Thu, 29 Aug 2019 10:24:13 +0800 (SGT) From: Biwen Li To: a.zummo@towertech.it, alexandre.belloni@bootlin.com, leoyang.li@nxp.com, broonie@kernel.org, nandor.han@vaisala.com Cc: linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, Biwen Li Subject: [v5] rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w Date: Thu, 29 Aug 2019 10:14:18 +0800 Message-Id: <20190829021418.4607-1-biwen.li@nxp.com> X-Mailer: git-send-email 2.9.5 X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Issue: - # hwclock -w hwclock: RTC_SET_TIME: Invalid argument Why: - Relative commit: 8b9f9d4dc511309918c4f6793bae7387c0c638af, this patch will always check for unwritable registers, it will compare reg with max_register in regmap_writeable. - The pcf85363/pcf85263 has the capability of address wrapping which means if you access an address outside the allowed range (0x00-0x2f) hardware actually wraps the access to a lower address. The rtc-pcf85363 driver will use this feature to configure the time and execute 2 actions in the same i2c write operation (stopping the clock and configure the time). However the driver has also configured the `regmap maxregister` protection mechanism that will block accessing addresses outside valid range (0x00-0x2f). How: - Split of writing regs to two parts, first part writes control registers about stop_enable and resets, second part writes RTC time and date registers. Signed-off-by: Biwen Li --- Change in v5: - drop robust explanation Change in v4: - use old scheme - replace link to lkml.org with commit - add proper explanation Change in v3: - replace old scheme with new scheme: increase max_register. Change in v2: - add Why and How into commit message. drivers/rtc/rtc-pcf85363.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c index a075e77617dc..3450d615974d 100644 --- a/drivers/rtc/rtc-pcf85363.c +++ b/drivers/rtc/rtc-pcf85363.c @@ -166,7 +166,12 @@ static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm) buf[DT_YEARS] = bin2bcd(tm->tm_year % 100); ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN, - tmp, sizeof(tmp)); + tmp, 2); + if (ret) + return ret; + + ret = regmap_bulk_write(pcf85363->regmap, DT_100THS, + buf, sizeof(tmp) - 2); if (ret) return ret; -- 2.17.1