diff options
| -rw-r--r-- | src/drivers/pc80/rtc/mc146818rtc.c | 2 | ||||
| -rw-r--r-- | src/include/pc80/mc146818rtc.h | 10 |
2 files changed, 12 insertions, 0 deletions
diff --git a/src/drivers/pc80/rtc/mc146818rtc.c b/src/drivers/pc80/rtc/mc146818rtc.c index 5fb9cf695b..c3026a4dbc 100644 --- a/src/drivers/pc80/rtc/mc146818rtc.c +++ b/src/drivers/pc80/rtc/mc146818rtc.c @@ -360,6 +360,7 @@ void cmos_check_update_date(void) u8 year, century; /* Assume hardware always supports RTC_CLK_ALTCENTURY. */ + wait_uip(); century = cmos_read(RTC_CLK_ALTCENTURY); year = cmos_read(RTC_CLK_YEAR); @@ -388,6 +389,7 @@ int rtc_set(const struct rtc_time *time) int rtc_get(struct rtc_time *time) { + wait_uip(); time->sec = bcd2bin(cmos_read(RTC_CLK_SECOND)); time->min = bcd2bin(cmos_read(RTC_CLK_MINUTE)); time->hour = bcd2bin(cmos_read(RTC_CLK_HOUR)); diff --git a/src/include/pc80/mc146818rtc.h b/src/include/pc80/mc146818rtc.h index effc03d2ae..66d5edb4b9 100644 --- a/src/include/pc80/mc146818rtc.h +++ b/src/include/pc80/mc146818rtc.h @@ -112,6 +112,16 @@ static inline unsigned char cmos_read(unsigned char addr) return inb(RTC_BASE_PORT + offs + 1); } +/* Upon return the caller is guaranteed 244 microseconds to complete any + * RTC operations. wait_uip may be called a single time prior to multiple + * accesses, but sequences requiring more time should call wait_uip again. + */ +static inline void wait_uip(void) +{ + while (cmos_read(RTC_REG_A) & RTC_UIP) + ; +} + static inline void cmos_write_inner(unsigned char val, unsigned char addr) { int offs = 0; |