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path: root/drivers/rtc/rtc-ds1307.c
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Diffstat (limited to 'drivers/rtc/rtc-ds1307.c')
-rw-r--r--drivers/rtc/rtc-ds1307.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 506b7d1c2397..bdb7b201a160 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -65,6 +65,7 @@ enum ds_type {
# define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
# define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
#define DS1307_REG_WDAY 0x03 /* 01-07 */
+# define MCP794XX_BIT_OSCRUN BIT(5)
# define MCP794XX_BIT_VBATEN 0x08
#define DS1307_REG_MDAY 0x04 /* 01-31 */
#define DS1307_REG_MONTH 0x05 /* 01-12 */
@@ -242,6 +243,10 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
dev_warn_once(dev, "oscillator failed, set time!\n");
return -EINVAL;
+ } else if (ds1307->type == mcp794xx &&
+ !(regs[DS1307_REG_WDAY] & MCP794XX_BIT_OSCRUN)) {
+ dev_warn_once(dev, "oscillator failed, set time!\n");
+ return -EINVAL;
}
tmp = regs[DS1307_REG_SECS];