Hello, On 19/10/2022 16:39:09+0300, Ibrahim Tilki wrote: > +static int max313xx_set_time(struct device *dev, struct rtc_time *t) > +{ > + struct max313xx *rtc = dev_get_drvdata(dev); > + u8 regs[7]; > + int ret; > + > + if (t->tm_year < 100 || t->tm_year >= 300) > + return -EINVAL; This is unnecessary > + > + regs[0] = bin2bcd(t->tm_sec); > + regs[1] = bin2bcd(t->tm_min); > + regs[2] = bin2bcd(t->tm_hour); > + regs[3] = bin2bcd(t->tm_wday + 1); > + regs[4] = bin2bcd(t->tm_mday); > + regs[5] = bin2bcd(t->tm_mon + 1); > + > + if (t->tm_year >= 200) { > + regs[5] |= FIELD_PREP(MAX313XX_MONTH_CENTURY, 1); > + regs[6] = bin2bcd(t->tm_year - 200); > + } else { > + regs[6] = bin2bcd(t->tm_year - 100); > + } regs[6] = bin2bcd(t->tm_year % 100); would be simpler > +static int max313xx_set_alarm(struct device *dev, struct rtc_wkalrm *t) > +{ > + struct max313xx *rtc = dev_get_drvdata(dev); > + struct rtc_time time; > + unsigned int reg; > + u8 regs[6]; > + int ret; > + > + regs[0] = bin2bcd(t->time.tm_sec); > + regs[1] = bin2bcd(t->time.tm_min); > + regs[2] = bin2bcd(t->time.tm_hour); > + regs[3] = bin2bcd(t->time.tm_mday); > + regs[4] = bin2bcd(t->time.tm_mon + 1); > + > + if (t->time.tm_year >= 200) { > + /* > + * Century bit is shared between time and alarm registers so > + * make sure that new alarm and RTC time is in the same century. > + */ > + ret = max313xx_read_time(dev, &time); > + if (ret) > + return ret; > + > + if (time.tm_year < 200) > + return -EINVAL; > + This doesn't feel right and it seems you are losing a whole range of alarm years. The correct thing to do is to check whether the alarm is in the same 100 years range. > + /* Convert to 24Hr */ > + hour = bcd2bin(reg[MAX313XX_REG_HOUR] & 0x1f); > + if (hour == 12) > + hour = 0; I'm not sure this is worth it, you should probably instead support reading both formats and setting only 24h > + > + if (FIELD_GET(MAX313XX_HRS_F_AM_PM, reg[MAX313XX_REG_HOUR])) > + hour += 12; > + > + reg[MAX313XX_REG_HOUR] = bin2bcd(hour); > + /* > + * If minute is 59, write all registers in case hour register > + * gets updated during read-write cycle > + */ > + if (reg[MAX313XX_REG_MINUTE] == 0x59) > + return regmap_bulk_write(rtc->regmap, rtc->chip->sec_reg, reg, 7); > + > + return regmap_write(rtc->regmap, rtc->chip->sec_reg + MAX313XX_REG_HOUR, > + reg[MAX313XX_REG_HOUR]); You should probably reuse .set_time here > +/* Some devices require initialization */ > +static int max313xx_init(struct max313xx *rtc) > +{ > + switch (rtc->id) { > + case ID_MAX31341: > + case ID_MAX31342: > + return regmap_update_bits(rtc->regmap, MAX3134X_CFG_REG, > + MAX3134X_CFG_INIT_MASK, > + MAX3134X_CFG_INIT_VALUE); The comment is not really useful and now I'm intrigued and want to know what this does! -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com