Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1460358

[PATCH 2/2] rtc: bq32k: Fix handling of oscillator failure flag

Show all headers | View raw

From: Jan Östlund <jao@hms.se>

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 <daro@hms.se>
---
 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, &reg, BQ32K_MINUTES, 1);
-	if (!error && (reg & BQ32K_OF)) {
-		dev_warn(dev, "Oscillator Failure. Check RTC battery.\n");
-		reg &= ~BQ32K_OF;
-		error = bq32k_write(dev, &reg, 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

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 0/2] bq32000 fixes Daniel Romell <danielromell@gmail.com> - 2016-08-11 12:10 +0200
  [PATCH 2/2] rtc: bq32k: Fix handling of oscillator failure flag Daniel Romell <danielromell@gmail.com> - 2016-08-11 12:10 +0200
    Re: [PATCH 2/2] rtc: bq32k: Fix handling of oscillator failure flag Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-08-11 12:20 +0200
  [PATCH v2 0/2] bq32000 fixes Daniel Romell <danielromell@gmail.com> - 2016-08-11 13:40 +0200
    [PATCH v2 1/2] rtc: bq32k: Use correct mask name for 'minutes' register. Daniel Romell <danielromell@gmail.com> - 2016-08-11 13:40 +0200
      Re: [PATCH v2 1/2] rtc: bq32k: Use correct mask name for 'minutes'  register. Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-08-11 15:50 +0200
        Re: [rtc-linux] Re: [PATCH v2 1/2] rtc: bq32k: Use correct mask name  for 'minutes' register. Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-08-11 23:20 +0200
      RE: [PATCH v2 1/2] rtc: bq32k: Use correct mask name for 'minutes'  register. Jan Östlund <jao@hms.se> - 2016-08-15 09:50 +0200

csiph-web