[PATCH 07/13] arm64: dts: ti: k3-am69-aquila: fix USB clocking for compliance

[Siddharth Vadapalli]

According to section "6.5.3 Normative Spread Spectrum Clocking (SSC)" of
the USB 3.2 Specification, SSC should be enabled by default. This protects
against EMI violations. Hence, enable internal SSC for USB SuperSpeed.

Fixes: 39ac6623b1d8 ("arm64: dts: ti: Add Aquila AM69 Support")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@xxxxxx>
---
 arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi b/arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi
index 5119baf62a4c..7c98ee81ccb5 100644
--- a/arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am69-aquila.dtsi
@@ -1423,6 +1423,7 @@ serdes0_usb0_ss_link: phy@3 {
 		resets = <&serdes_wiz0 4>;
 		cdns,num-lanes = <1>;
 		cdns,phy-type = <PHY_TYPE_USB3>;
+		cdns,ssc-mode = <2>; /* 2 for internal SSC */
 	};
 };
 
@@ -1502,6 +1503,11 @@ &serdes_ln_ctrl {
 
 &serdes_wiz0 {
 	status = "okay";
+	ti,core-clk-sel = <1>;  /* Select internal reference clock */
+	ti,ssc-enable; /* Enable SSC */
+	ti,ssc-type = <1>; /* 1 for Downspread */
+	ti,ssc-frequency-hz = <33000>; /* 33 KHz */
+	ti,ssc-depth-per-mil = <5>; /* 0.5% depth */
 };
 
 &serdes_wiz1 {
-- 
2.51.1