rtc: ds1307: Fix wday settings for rx8130

stable inclusion
from stable-5.10.38
commit 494ade7aba117f8054f78addc5c36f1a622b17e8
bugzilla: 51875
CVE: NA

--------------------------------

[ Upstream commit 204756f0 ]

rx8130 wday specifies the bit position, not BCD.

Fixes: ee0981be ("rtc: ds1307: Add support for Epson RX8130CE")
Signed-off-by: NNobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210420023917.1949066-1-nobuhiro1.iwamatsu@toshiba.co.jpSigned-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/rtc/rtc-ds1307.c

@@ -295,7 +295,11 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 	t->tm_min = bcd2bin(regs[DS1307_REG_MIN] & 0x7f);
 	tmp = regs[DS1307_REG_HOUR] & 0x3f;
 	t->tm_hour = bcd2bin(tmp);
-	t->tm_wday = bcd2bin(regs[DS1307_REG_WDAY] & 0x07) - 1;
+	/* rx8130 is bit position, not BCD */
+	if (ds1307->type == rx_8130)
+		t->tm_wday = fls(regs[DS1307_REG_WDAY] & 0x7f);
+	else
+		t->tm_wday = bcd2bin(regs[DS1307_REG_WDAY] & 0x07) - 1;
 	t->tm_mday = bcd2bin(regs[DS1307_REG_MDAY] & 0x3f);
 	tmp = regs[DS1307_REG_MONTH] & 0x1f;
 	t->tm_mon = bcd2bin(tmp) - 1;
@@ -342,7 +346,11 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 	regs[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
 	regs[DS1307_REG_MIN] = bin2bcd(t->tm_min);
 	regs[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
-	regs[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
+	/* rx8130 is bit position, not BCD */
+	if (ds1307->type == rx_8130)
+		regs[DS1307_REG_WDAY] = 1 << t->tm_wday;
+	else
+		regs[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
 	regs[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
 	regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);