From 4eac3db1b97dd3b1665fec6fc6432d983701fd98 Mon Sep 17 00:00:00 2001
From: Johan Lafon <johan.lafon@syslinbit.com>
Date: Mon, 11 Sep 2023 12:18:57 +0200
Subject: [PATCH] drivers: rtc: stm32: check if tm_wday is set

tm/rtc_time structure allow for tm_wday to be set to -1 if unknown but RTC
is expecting it

Signed-off-by: Johan Lafon <johan.lafon@syslinbit.com>
---
 drivers/rtc/rtc_ll_stm32.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/rtc/rtc_ll_stm32.c b/drivers/rtc/rtc_ll_stm32.c
index f8af22d00c5..c95c331ee97 100644
--- a/drivers/rtc/rtc_ll_stm32.c
+++ b/drivers/rtc/rtc_ll_stm32.c
@@ -138,6 +138,11 @@ static int rtc_stm32_set_time(const struct device *dev, const struct rtc_time *t
 		return -EINVAL;
 	}
 
+	if (timeptr->tm_wday == -1) {
+		/* day of the week is expected */
+		return -EINVAL;
+	}
+
 	LOG_INF("Setting clock");
 	LL_RTC_DisableWriteProtection(RTC);