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: Phil Elwell <phil@raspberrypi.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211015111208.1757110-1-phil@raspberrypi.com
This commit is contained in:
Phil Elwell 2021-10-15 12:12:08 +01:00 committed by Alexandre Belloni
parent 4c8a7b80d5
commit 9f08c9ed58

View File

@ -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)