ARM: dts: sun9i: Switch to the AC100 RTC clock outputs for osc32k

The 32.768 kHz clock inside the A80 SoC is fed from an external source,
typically the AC100 RTC module.

Make the osc32k placeholder a fixed-factor clock so board dts files can
specify its source.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun9i-a80-cubieboard4.dts

@@ -103,6 +103,11 @@
 	allwinner,drive = <SUN4I_PINCTRL_40_MA>;
 };
 
+&osc32k {
+	/* osc32k input is from AC100 */
+	clocks = <&ac100_rtc 0>;
+};
+
 &pio {
 	led_pins_cubieboard4: led-pins@0 {
 		allwinner,pins = "PH6", "PH17";

arch/arm/boot/dts/sun9i-a80-optimus.dts

@@ -152,6 +152,11 @@
 	status = "okay";
 };
 
+&osc32k {
+	/* osc32k input is from AC100 */
+	clocks = <&ac100_rtc 0>;
+};
+
 &pio {
 	led_pins_optimus: led-pins@0 {
 		allwinner,pins = "PH0", "PH1";

arch/arm/boot/dts/sun9i-a80.dtsi

@@ -148,15 +148,14 @@
 
 		/*
 		 * The 32k clock is from an external source, normally the
-		 * AC100 codec/RTC chip. This clock is by default enabled
-		 * and clocked at 32768 Hz, from the oscillator connected
-		 * to the AC100. It is configurable, but no such driver or
-		 * bindings exist yet.
+		 * AC100 codec/RTC chip. This serves as a placeholder for
+		 * board dts files to specify the source.
 		 */
 		osc32k: osc32k_clk {
 			#clock-cells = <0>;
-			compatible = "fixed-clock";
-			clock-frequency = <32768>;
+			compatible = "fixed-factor-clock";
+			clock-div = <1>;
+			clock-mult = <1>;
 			clock-output-names = "osc32k";
 		};