diff --git a/Documentation/devicetree/bindings/rtc/rtc-m41t80.txt b/Documentation/devicetree/bindings/rtc/rtc-m41t80.txt
index c746cb2212103c8aca59ff52f1652ce15dbc0e54..cdd196b1e9bdbe5151902f1ed80ea1a06b43a008 100644
--- a/Documentation/devicetree/bindings/rtc/rtc-m41t80.txt
+++ b/Documentation/devicetree/bindings/rtc/rtc-m41t80.txt
@@ -21,10 +21,19 @@ Optional properties:
                       clock name
 - wakeup-source: Enables wake up of host system on alarm
 
+Optional child node:
+- clock: Provide this if the square wave pin is used as boot-enabled fixed clock.
+
 Example:
 	rtc@68 {
 		compatible = "st,m41t80";
 		reg = <0x68>;
 		interrupt-parent = <&UIC0>;
 		interrupts = <0x9 0x8>;
+
+		clock {
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+			clock-frequency = <32768>;
+		};
 	};
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index 89128fc29ccce753f9bd32adbf69dea0bd19cd83..b3ece42b6f9034c83580f7607b012f5d95ec5737 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -544,10 +544,22 @@ static struct clk *m41t80_sqw_register_clk(struct m41t80_data *m41t80)
 {
 	struct i2c_client *client = m41t80->client;
 	struct device_node *node = client->dev.of_node;
+	struct device_node *fixed_clock;
 	struct clk *clk;
 	struct clk_init_data init;
 	int ret;
 
+	fixed_clock = of_get_child_by_name(node, "clock");
+	if (fixed_clock) {
+		/*
+		 * skip registering square wave clock when a fixed
+		 * clock has been registered. The fixed clock is
+		 * registered automatically when being referenced.
+		 */
+		of_node_put(fixed_clock);
+		return 0;
+	}
+
 	/* First disable the clock */
 	ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
 	if (ret < 0)