rtc: m41t80: reduce verbosity

The driver currently uses dev_err for messages that have a very low probability
of being read by the user as the error will probably never happen and the
systems with the RTC probably don't have any user able to read the message.

Moreover, the only user action after getting this message is the restart the
action so drop the level to dev_dbg.

Link: https://lore.kernel.org/r/20250525222153.1472917-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: alexandrebelloni

drivers/rtc/rtc-m41t80.c

@@ -212,7 +212,7 @@ static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	err = i2c_smbus_read_i2c_block_data(client, M41T80_REG_SSEC,
 					    sizeof(buf), buf);
 	if (err < 0) {
-		dev_err(&client->dev, "Unable to read date\n");
+		dev_dbg(&client->dev, "Unable to read date\n");
 		return err;
 	}
 
@@ -268,35 +268,35 @@ static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *in_tm)
 	err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_SSEC,
 					     sizeof(buf), buf);
 	if (err < 0) {
-		dev_err(&client->dev, "Unable to write to date registers\n");
+		dev_dbg(&client->dev, "Unable to write to date registers\n");
 		return err;
 	}
 	if (flags & M41T80_FLAGS_OF) {
 		/* OF cannot be immediately reset: oscillator has to be restarted. */
 		dev_warn(&client->dev, "OF bit is still set, kickstarting clock.\n");
 		err = i2c_smbus_write_byte_data(client, M41T80_REG_SEC, M41T80_SEC_ST);
 		if (err < 0) {
-			dev_err(&client->dev, "Can't set ST bit\n");
+			dev_dbg(&client->dev, "Can't set ST bit\n");
 			return err;
 		}
 		err = i2c_smbus_write_byte_data(client, M41T80_REG_SEC, flags & ~M41T80_SEC_ST);
 		if (err < 0) {
-			dev_err(&client->dev, "Can't clear ST bit\n");
+			dev_dbg(&client->dev, "Can't clear ST bit\n");
 			return err;
 		}
 		/* oscillator must run for 4sec before we attempt to reset OF bit */
 		msleep(4000);
 		/* Clear the OF bit of Flags Register */
 		err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS, flags & ~M41T80_FLAGS_OF);
 		if (err < 0) {
-			dev_err(&client->dev, "Unable to write flags register\n");
+			dev_dbg(&client->dev, "Unable to write flags register\n");
 			return err;
 		}
 		flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
 		if (flags < 0) {
 			return flags;
 		} else if (flags & M41T80_FLAGS_OF) {
-			dev_err(&client->dev, "Can't clear the OF bit check battery\n");
+			dev_dbg(&client->dev, "Can't clear the OF bit check battery\n");
 			return err;
 		}
 	}
@@ -336,7 +336,7 @@ static int m41t80_alarm_irq_enable(struct device *dev, unsigned int enabled)
 
 	retval = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, flags);
 	if (retval < 0) {
-		dev_err(dev, "Unable to enable alarm IRQ %d\n", retval);
+		dev_dbg(dev, "Unable to enable alarm IRQ %d\n", retval);
 		return retval;
 	}
 	return 0;
@@ -361,7 +361,7 @@ static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
 					ret & ~(M41T80_ALMON_AFE));
 	if (err < 0) {
-		dev_err(dev, "Unable to clear AFE bit\n");
+		dev_dbg(dev, "Unable to clear AFE bit\n");
 		return err;
 	}
 
@@ -375,7 +375,7 @@ static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
 					ret & ~(M41T80_FLAGS_AF));
 	if (err < 0) {
-		dev_err(dev, "Unable to clear AF bit\n");
+		dev_dbg(dev, "Unable to clear AF bit\n");
 		return err;
 	}