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-rw-r--r--drivers/rtc/rtc-ds1302.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1302.c b/drivers/rtc/rtc-ds1302.c
index 7533b723082d..07e8d79b4a09 100644
--- a/drivers/rtc/rtc-ds1302.c
+++ b/drivers/rtc/rtc-ds1302.c
@@ -23,8 +23,12 @@
#define RTC_CMD_READ 0x81 /* Read command */
#define RTC_CMD_WRITE 0x80 /* Write command */
+#define RTC_CMD_WRITE_ENABLE 0x00 /* Write enable */
+#define RTC_CMD_WRITE_DISABLE 0x80 /* Write disable */
+
#define RTC_ADDR_RAM0 0x20 /* Address of RAM0 */
#define RTC_ADDR_TCR 0x08 /* Address of trickle charge register */
+#define RTC_ADDR_CTRL 0x07 /* Address of control register */
#define RTC_ADDR_YEAR 0x06 /* Address of year register */
#define RTC_ADDR_DAY 0x05 /* Address of day of week register */
#define RTC_ADDR_MON 0x04 /* Address of month register */
@@ -161,6 +165,7 @@ static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm)
static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
+ ds1302_writebyte(RTC_ADDR_CTRL, RTC_CMD_WRITE_ENABLE);
/* Stop RTC */
ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80);
@@ -175,6 +180,8 @@ static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm)
/* Start RTC */
ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);
+ ds1302_writebyte(RTC_ADDR_CTRL, RTC_CMD_WRITE_DISABLE);
+
return 0;
}