Commit 9f08c9ed authored by Phil Elwell's avatar Phil Elwell Committed by Alexandre Belloni
Browse files

rtc: pcf85063: Always clear EXT_TEST from set_time 



Power-on reset after the insertion of a battery does not always complete
successfully, leading to corrupted register content. The EXT_TEST bit
will stop the clock from running, but currently the driver will never
recover.

Safely handle the erroneous state by clearing EXT_TEST as part of the
usual set_time method.

Signed-off-by: default avatarPhil Elwell <phil@raspberrypi.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211015111208.1757110-1-phil@raspberrypi.com
parent 4c8a7b80

drivers/rtc/rtc-pcf85063.c

+2 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#define PCF85063_REG_CTRL1		0x00 /* status */

#define PCF85063_REG_CTRL1_CAP_SEL	BIT(0)

#define PCF85063_REG_CTRL1_STOP		BIT(5)

#define PCF85063_REG_CTRL1_EXT_TEST	BIT(7)



#define PCF85063_REG_CTRL2		0x01

#define PCF85063_CTRL2_AF		BIT(6)
@@ -117,6 +118,7 @@ static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm) 
	 * reset state until all time/date registers are written

	 */

	rc = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,

				PCF85063_REG_CTRL1_EXT_TEST |

				PCF85063_REG_CTRL1_STOP,

				PCF85063_REG_CTRL1_STOP);

	if (rc)