rtc: ds1307: add Intersil ISL12057 support

Intersil ISL12057 is a drop-in replacement for DS1337. It can be supported
by the ds1307 driver.

Acked-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 712e221..4e31036 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -186,6 +186,7 @@
 	{ "mcp7941x", mcp794xx },
 	{ "pt7c4338", ds_1307 },
 	{ "rx8025", rx_8025 },
+	{ "isl12057", ds_1337 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ds1307_id);
@@ -1333,6 +1334,11 @@
 	if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
 		ds1307_can_wakeup_device = true;
 	}
+	/* Intersil ISL12057 DT backward compatibility */
+	if (of_property_read_bool(client->dev.of_node,
+				  "isil,irq2-can-wakeup-machine")) {
+		ds1307_can_wakeup_device = true;
+	}
 #endif
 
 	switch (ds1307->type) {