Hello, On 08/06/2023 11:04:46+0200, Andrej Picej wrote: > + ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old); > + if (ret < 0) > + return ret; > + > + /* mask out only trickle charger bits */ > + val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK); > + > /* setup trickle charger */ > - if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms", > - &ohms)) { > + if (device_property_read_u32(&client->dev, "trickle-resistor-ohms", &ohms)) { > + /* disable the trickle charger */ > + val = 0; You can't do that, this will break existing users that may set the trickle charger from their bootloader for example. > + } else { > int i; > > for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++) > @@ -947,15 +957,21 @@ static int rv3028_probe(struct i2c_client *client) > break; > > if (i < ARRAY_SIZE(rv3028_trickle_resistors)) { > - ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE | > - RV3028_BACKUP_TCR_MASK, RV3028_BACKUP_TCE | i); > - if (ret) > - return ret; > + /* enable the trickle charger and setup its resistor accordingly */ > + val = RV3028_BACKUP_TCE | i; > } else { > dev_warn(&client->dev, "invalid trickle resistor value\n"); > } > } > > + /* only update EEPROM if changes are necessary */ > + if (val_old != val) { > + ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE | > + RV3028_BACKUP_TCR_MASK, val); > + if (ret) > + return ret; > + } > + > ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group); > if (ret) > return ret; > -- > 2.25.1 > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com