Commit fe0157ba authored by paulmn's avatar paulmn Committed by Alexandre Belloni
Browse files

rtc: pcf8523: fix for stop bit 



Bugfix for an issue detected when a goldcap capacitor gets
fully discharged due to a long absence of the power supply,
and then recharges again. The RTC failed to continue to keep
the real-time clock.

This was caused by the incorrect handling of the STOP bit in
the RTC internal register.  This fix solves the problem.

Signed-off-by: default avatarpaulmn <paulmn@axis.com>
Link: https://lore.kernel.org/r/20220829124639.10906-1-paulmn@axis.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent eec79501

drivers/rtc/rtc-pcf8523.c

+10 −10
Original line number Diff line number Diff line
@@ -99,24 +99,24 @@ static irqreturn_t pcf8523_irq(int irq, void *dev_id) 
static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);

	u8 regs[7];

	u8 regs[10];

	int err;



	err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_SECONDS, regs,

	err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_CONTROL1, regs,

			       sizeof(regs));

	if (err < 0)

		return err;



	if (regs[0] & PCF8523_SECONDS_OS)

	if ((regs[0] & PCF8523_CONTROL1_STOP) || (regs[3] & PCF8523_SECONDS_OS))

		return -EINVAL;



	tm->tm_sec = bcd2bin(regs[0] & 0x7f);

	tm->tm_min = bcd2bin(regs[1] & 0x7f);

	tm->tm_hour = bcd2bin(regs[2] & 0x3f);

	tm->tm_mday = bcd2bin(regs[3] & 0x3f);

	tm->tm_wday = regs[4] & 0x7;

	tm->tm_mon = bcd2bin(regs[5] & 0x1f) - 1;

	tm->tm_year = bcd2bin(regs[6]) + 100;

	tm->tm_sec = bcd2bin(regs[3] & 0x7f);

	tm->tm_min = bcd2bin(regs[4] & 0x7f);

	tm->tm_hour = bcd2bin(regs[5] & 0x3f);

	tm->tm_mday = bcd2bin(regs[6] & 0x3f);

	tm->tm_wday = regs[7] & 0x7;

	tm->tm_mon = bcd2bin(regs[8] & 0x1f) - 1;

	tm->tm_year = bcd2bin(regs[9]) + 100;



	return 0;

}