From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932795AbcHKKBD (ORCPT ); Thu, 11 Aug 2016 06:01:03 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:34467 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752420AbcHKKBA (ORCPT ); Thu, 11 Aug 2016 06:01:00 -0400 From: Daniel Romell X-Google-Original-From: Daniel Romell To: a.zummo@towertech.it Cc: alexandre.belloni@free-electrons.com, rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org, daro@hms.se, jao@hms.se, mago@hms.se Subject: [PATCH 2/2] rtc: bq32k: Fix handling of oscillator failure flag Date: Thu, 11 Aug 2016 11:59:15 +0200 Message-Id: <1470909555-9226-3-git-send-email-daro@hms.se> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1470909555-9226-1-git-send-email-daro@hms.se> References: <1470909555-9226-1-git-send-email-daro@hms.se> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Östlund While the oscillator failure flag is set, the RTC registers should be considered invalid. bq32k_rtc_read_time() now returns an error instead of an invalid time. The failure flag is cleared the next time the clock is set. Signed-off-by: Daniel Romell --- drivers/rtc/rtc-bq32k.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/rtc/rtc-bq32k.c b/drivers/rtc/rtc-bq32k.c index 5a0c137..3fc6f7c 100644 --- a/drivers/rtc/rtc-bq32k.c +++ b/drivers/rtc/rtc-bq32k.c @@ -93,6 +93,13 @@ static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm) if (error) return error; + /* + * In case of oscillator failure, the register contents should be + * considered invalid. The flag is cleared the next time the RTC is set. + */ + if (regs.minutes & BQ32K_OF) + return -EIO; + tm->tm_sec = bcd2bin(regs.seconds & BQ32K_SECONDS_MASK); tm->tm_min = bcd2bin(regs.minutes & BQ32K_MINUTES_MASK); tm->tm_hour = bcd2bin(regs.cent_hours & BQ32K_HOURS_MASK); @@ -204,13 +211,10 @@ static int bq32k_probe(struct i2c_client *client, /* Check Oscillator Failure flag */ error = bq32k_read(dev, ®, BQ32K_MINUTES, 1); - if (!error && (reg & BQ32K_OF)) { - dev_warn(dev, "Oscillator Failure. Check RTC battery.\n"); - reg &= ~BQ32K_OF; - error = bq32k_write(dev, ®, BQ32K_MINUTES, 1); - } if (error) return error; + if (reg & BQ32K_OF) + dev_warn(dev, "Oscillator Failure. Check RTC battery.\n"); if (client->dev.of_node) trickle_charger_of_init(dev, client->dev.of_node); -- 2.7.4