The default settings for RTC DS1337 keeps the OSC output, 32,768 Hz, on. This add CFG_RTC_DS1337_NOOSC to turn it off.
Signed-off-by: Joakim Tjernlund Joakim.Tjernlund@transmode.se ---
I don't want the square wave as it drains the battery needlessly so I made it configurable.
README | 1 + drivers/rtc/ds1337.c | 11 +++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/README b/README index 491397a..9a55d35 100644 --- a/README +++ b/README @@ -670,6 +670,7 @@ The following options need to be configured: CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC CONFIG_RTC_DS164x - use Dallas DS164x RTC CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC + CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
Note that if the RTC uses I2C, then the I2C interface must also be configured. See I2C Support, below. diff --git a/drivers/rtc/ds1337.c b/drivers/rtc/ds1337.c index c636ac5..56268e9 100644 --- a/drivers/rtc/ds1337.c +++ b/drivers/rtc/ds1337.c @@ -154,11 +154,18 @@ void rtc_set (struct rtc_time *tmp) * SQW/INTB* pin and program it for 32,768 Hz output. Note that * according to the datasheet, turning on the square wave output * increases the current drain on the backup battery from about - * 600 nA to 2uA. + * 600 nA to 2uA. Define CFG_RTC_DS1337_NOOSC if you wish to turn + * off the OSC output. */ +#ifdef CFG_RTC_DS1337_NOOSC + #define RTC_DS1337_RESET_VAL \ + (RTC_CTL_BIT_INTCN | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2) +#else + #define RTC_DS1337_RESET_VAL (RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2) +#endif void rtc_reset (void) { - rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2); + rtc_write (RTC_CTL_REG_ADDR, RTC_DS1337_RESET_VAL); }