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Add CFG_RTC_DS1337_NOOSC to turn off OSC output

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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>
This commit is contained in:
Joakim Tjernlund 2008-03-26 13:02:13 +01:00 committed by Wolfgang Denk
parent 438a4c1126
commit da8808df7a
2 changed files with 10 additions and 2 deletions
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1
README
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@ -689,6 +689,7 @@ The following options need to be configured:
CONFIG_RTC_DS164x - use Dallas DS164x RTC
CONFIG_RTC_ISL1208 - use Intersil ISL1208 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.

11
drivers/rtc/ds1337.c
View File

@ -158,11 +158,18 @@ 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);
}