arm64: dts: rockchip: Add 32k clk on rk3399-gru

This adds the 32k clock to the RK3399 Gru board file, which is provided
by a Silego oscillator on Gru boards.

Even though it's not directly used, muxes will end up traversing the
entire clk tree on calls to determine_rate if it doesn't exist. This
is because the 32k clk is listed as a possible parent on some clks.
Since the clk doesn't know about the 32k clk (it was never registered),
it triggers a global search for it. This can happen about 40 times per
second, which isn't great for power.

Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
[moved clock position and adapted commit message a bit]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
index ca07f60322003eadba12af80ece20ee278efa2f4..ea607a601a86516f5b9de33b24a2bd67d9c060ee 100644 (file)
--- a/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
@@ -262,6 +262,13 @@
        pp5000_usb_a_vbus: pp5000 {
        };
 
+       ap_rtc_clk: ap-rtc-clk {
+               compatible = "fixed-clock";
+               clock-frequency = <32768>;
+               clock-output-names = "xin32k";
+               #clock-cells = <0>;
+       };
+
        gpio_keys: gpio-keys {
                compatible = "gpio-keys";
                pinctrl-names = "default";