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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 5F2ADECE58C for ; Mon, 7 Oct 2019 13:47:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F1CF2173B for ; Mon, 7 Oct 2019 13:47:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728484AbfJGNrm (ORCPT ); Mon, 7 Oct 2019 09:47:42 -0400 Received: from relay10.mail.gandi.net ([217.70.178.230]:54479 "EHLO relay10.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727715AbfJGNrf (ORCPT ); Mon, 7 Oct 2019 09:47:35 -0400 Received: from localhost (aclermont-ferrand-651-1-259-53.w86-207.abo.wanadoo.fr [86.207.98.53]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay10.mail.gandi.net (Postfix) with ESMTPSA id AD66B24000E; Mon, 7 Oct 2019 13:47:33 +0000 (UTC) From: Alexandre Belloni To: linux-rtc@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Alexandre Belloni Subject: [PATCH 08/10] rtc: ds1347: properly handle oscillator failures Date: Mon, 7 Oct 2019 15:47:22 +0200 Message-Id: <20191007134724.15505-8-alexandre.belloni@bootlin.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20191007134724.15505-1-alexandre.belloni@bootlin.com> References: <20191007134724.15505-1-alexandre.belloni@bootlin.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The comment in the probe function stating that it disables oscillator stop detection and glitch filtering is incorrect as it sets bits 3 and 4 while it should be setting 5 and 6 to achieve that. Then, it is safe to assume that the oscillator failure detection is actually enabled. Properly handle oscillator failures by returning -EINVAL when the time and date are know to be incorrect and reset the flag when the time is set. Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-ds1347.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-) diff --git a/drivers/rtc/rtc-ds1347.c b/drivers/rtc/rtc-ds1347.c index 22a75b01f1ac..eeaf43586bce 100644 --- a/drivers/rtc/rtc-ds1347.c +++ b/drivers/rtc/rtc-ds1347.c @@ -29,6 +29,9 @@ #define DS1347_STATUS_REG 0x17 #define DS1347_CLOCK_BURST 0x3F +#define DS1347_NEOSC_BIT BIT(7) +#define DS1347_OSF_BIT BIT(2) + static const struct regmap_range ds1347_ranges[] = { { .range_min = DS1347_SECONDS_REG, @@ -44,9 +47,17 @@ static const struct regmap_access_table ds1347_access_table = { static int ds1347_read_time(struct device *dev, struct rtc_time *dt) { struct regmap *map = dev_get_drvdata(dev); + unsigned int status; int err; unsigned char buf[8]; + err = regmap_read(map, DS1347_STATUS_REG, &status); + if (err) + return err; + + if (status & DS1347_OSF_BIT) + return -EINVAL; + err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8); if (err) return err; @@ -66,6 +77,12 @@ static int ds1347_set_time(struct device *dev, struct rtc_time *dt) { struct regmap *map = dev_get_drvdata(dev); unsigned char buf[8]; + int err; + + err = regmap_update_bits(map, DS1347_STATUS_REG, + DS1347_NEOSC_BIT, DS1347_NEOSC_BIT); + if (err) + return err; buf[0] = bin2bcd(dt->tm_sec); buf[1] = bin2bcd(dt->tm_min); @@ -82,7 +99,12 @@ static int ds1347_set_time(struct device *dev, struct rtc_time *dt) buf[7] = bin2bcd(0x00); /* write the rtc settings */ - return regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8); + err = regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8); + if (err) + return err; + + return regmap_update_bits(map, DS1347_STATUS_REG, + DS1347_NEOSC_BIT | DS1347_OSF_BIT, 0); } static const struct rtc_class_ops ds1347_rtc_ops = { @@ -123,12 +145,6 @@ static int ds1347_probe(struct spi_device *spi) data = data & ~(1<<7); regmap_write(map, DS1347_CONTROL_REG, data); - /* Enable the oscillator , disable the oscillator stop flag, - and glitch filter to reduce current consumption */ - regmap_read(map, DS1347_STATUS_REG, &data); - data = data & 0x1B; - regmap_write(map, DS1347_STATUS_REG, data); - rtc = devm_rtc_allocate_device(&spi->dev); if (IS_ERR(rtc)) return PTR_ERR(rtc); -- 2.21.0