diff options
Diffstat (limited to 'drivers/rtc/rtc-palmas.c')
| -rw-r--r-- | drivers/rtc/rtc-palmas.c | 44 |
1 files changed, 40 insertions, 4 deletions
diff --git a/drivers/rtc/rtc-palmas.c b/drivers/rtc/rtc-palmas.c index 7ea2c471feca..3e9663d0752b 100644 --- a/drivers/rtc/rtc-palmas.c +++ b/drivers/rtc/rtc-palmas.c @@ -45,6 +45,42 @@ struct palmas_rtc { /* Total number of RTC registers needed to set time*/ #define PALMAS_NUM_TIME_REGS (PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1) +/* + * Special bin2bcd mapping to deal with bcd storage of year. + * + * 0-69 -> 0xD0 + * 70-99 (1970 - 1999) -> 0xD0 - 0xF9 (correctly rolls to 0x00) + * 100-199 (2000 - 2099) -> 0x00 - 0x99 (does not roll to 0xA0 :-( ) + * 200-229 (2100 - 2129) -> 0xA0 - 0xC9 (really for completeness) + * 230- -> 0xC9 + * + * Confirmed: the only transition that does not work correctly for this rtc + * clock is the transition from 2099 to 2100, it proceeds to 2000. We will + * accept this issue since the clock retains and transitions the year correctly + * in all other conditions. + */ +static unsigned char year_bin2bcd(int val) +{ + if (val < 70) + return 0xD0; + if (val < 100) + return bin2bcd(val - 20) | 0x80; /* KISS leverage of bin2bcd */ + if (val >= 230) + return 0xC9; + if (val >= 200) + return bin2bcd(val - 180) | 0x80; + return bin2bcd(val - 100); +} + +static int year_bcd2bin(unsigned char val) +{ + if (val >= 0xD0) + return bcd2bin(val & 0x7F) + 20; + if (val >= 0xA0) + return bcd2bin(val & 0x7F) + 180; + return bcd2bin(val) + 100; +} + static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm) { unsigned char rtc_data[PALMAS_NUM_TIME_REGS]; @@ -71,7 +107,7 @@ static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm) tm->tm_hour = bcd2bin(rtc_data[2]); tm->tm_mday = bcd2bin(rtc_data[3]); tm->tm_mon = bcd2bin(rtc_data[4]) - 1; - tm->tm_year = bcd2bin(rtc_data[5]) + 100; + tm->tm_year = year_bcd2bin(rtc_data[5]); return ret; } @@ -87,7 +123,7 @@ static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm) rtc_data[2] = bin2bcd(tm->tm_hour); rtc_data[3] = bin2bcd(tm->tm_mday); rtc_data[4] = bin2bcd(tm->tm_mon + 1); - rtc_data[5] = bin2bcd(tm->tm_year - 100); + rtc_data[5] = year_bin2bcd(tm->tm_year); /* Stop RTC while updating the RTC time registers */ ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG, @@ -142,7 +178,7 @@ static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) alm->time.tm_hour = bcd2bin(alarm_data[2]); alm->time.tm_mday = bcd2bin(alarm_data[3]); alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1; - alm->time.tm_year = bcd2bin(alarm_data[5]) + 100; + alm->time.tm_year = year_bcd2bin(alarm_data[5]); ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG, &int_val); @@ -173,7 +209,7 @@ static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) alarm_data[2] = bin2bcd(alm->time.tm_hour); alarm_data[3] = bin2bcd(alm->time.tm_mday); alarm_data[4] = bin2bcd(alm->time.tm_mon + 1); - alarm_data[5] = bin2bcd(alm->time.tm_year - 100); + alarm_data[5] = year_bin2bcd(alm->time.tm_year); ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS); |