[PATCH] rtc: pcf2127: add error checking and message when disabling POR0

From: Hugo Villeneuve
Date: Mon Jan 17 2022 - 17:57:37 EST


From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>

If PCF2127 device is absent from the I2C bus, or if there is a
communication problem, disabling POR0 may fail silently and we
still continue with probing the device. In that case, abort probe
operation and display an error message.

Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
---
drivers/rtc/rtc-pcf2127.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 81a5b1f2e68c..e6d0838ccfe3 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -690,8 +690,12 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
* The "Power-On Reset Override" facility prevents the RTC to do a reset
* after power on. For normal operation the PORO must be disabled.
*/
- regmap_clear_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
+ ret = regmap_clear_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
PCF2127_BIT_CTRL1_POR_OVRD);
+ if (ret < 0) {
+ dev_err(dev, "PORO disabling failed\n");
+ return ret;
+ }

ret = regmap_read(pcf2127->regmap, PCF2127_REG_CLKOUT, &val);
if (ret < 0)
--
2.30.2